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Sample records for beam micro-ct system

  1. Cone Beam Micro-CT System for Small Animal Imaging and Performance Evaluation

    Directory of Open Access Journals (Sweden)

    Shouping Zhu

    2009-01-01

    Full Text Available A prototype cone-beam micro-CT system for small animal imaging has been developed by our group recently, which consists of a microfocus X-ray source, a three-dimensional programmable stage with object holder, and a flat-panel X-ray detector. It has a large field of view (FOV, which can acquire the whole body imaging of a normal-size mouse in a single scan which usually takes about several minutes or tens of minutes. FDK method is adopted for 3D reconstruction with Graphics Processing Unit (GPU acceleration. In order to reconstruct images with high spatial resolution and low artifacts, raw data preprocessing and geometry calibration are implemented before reconstruction. A method which utilizes a wire phantom to estimate the residual horizontal offset of the detector is proposed, and 1D point spread function is used to assess the performance of geometric calibration quantitatively. System spatial resolution, image uniformity and noise, and low contrast resolution have been studied. Mouse images with and without contrast agent are illuminated in this paper. Experimental results show that the system is suitable for small animal imaging and is adequate to provide high-resolution anatomic information for bioluminescence tomography to build a dual modality system.

  2. Self-calibration of a cone-beam micro-CT system

    International Nuclear Information System (INIS)

    Use of cone-beam computed tomography (CBCT) is becoming more frequent. For proper reconstruction, the geometry of the CBCT systems must be known. While the system can be designed to reduce errors in the geometry, calibration measurements must still be performed and corrections applied. Investigators have proposed techniques using calibration objects for system calibration. In this study, the authors present methods to calibrate a rotary-stage CB micro-CT (CBμCT) system using only the images acquired of the object to be reconstructed, i.e., without the use of calibration objects. Projection images are acquired using a CBμCT system constructed in the authors' laboratories. Dark- and flat-field corrections are performed. Exposure variations are detected and quantified using analysis of image regions with an unobstructed view of the x-ray source. Translations that occur during the acquisition in the horizontal direction are detected, quantified, and corrected based on sinogram analysis. The axis of rotation is determined using registration of antiposed projection images. These techniques were evaluated using data obtained with calibration objects and phantoms. The physical geometric axis of rotation is determined and aligned with the rotational axis (assumed to be the center of the detector plane) used in the reconstruction process. The parameters describing this axis agree to within 0.1 mm and 0.3 deg with those determined using other techniques. Blurring due to residual calibration errors has a point-spread function in the reconstructed planes with a full-width-at-half-maximum of less than 125 μm in a tangential direction and essentially zero in the radial direction for the rotating object. The authors have used this approach on over 100 acquisitions over the past 2 years and have regularly obtained high-quality reconstructions, i.e., without artifacts and no detectable blurring of the reconstructed objects. This self-calibrating approach not only obviates

  3. Comparative evaluation of cone-beam CT equipment with micro-CT in the visualization of root canal system

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    Bence Tamas Szabo

    2012-01-01

    Full Text Available The aim of this study was to compare three different cone-beam CT (CBCT instruments used in dental clinical practice with micro-CT as gold standard. Three female monkeys’ (Macaca fascicularis skulls were selected and scanned by the tested CBCT-s. The most apical visible root canal level on the CBCT images was used as reference level (RL. After the image acquisition by CBCT-s dental jaw sections were scanned by micro-CT at a resolution of 17 μm. Out of the left second and third molars 25 root canals were selected and analysed by three observers at RL and following cross sectional parameters were determined: area of the lumen, major and minor diameters, aspect ratio and mean thickness. Results suggest that only high resolution CBCT instruments allow dentists detecting the full length of the root canal.

  4. Simulation of mechanical misalignments in a cone-beam micro-CT system

    OpenAIRE

    Vidal-Migallón, I.; Abella, Mónica; Sisniega, Alejandro; Vaquero, Juan José; Desco, Manuel

    2008-01-01

    X-ray CT images usually show artefacts due not only to physical effects -e.g., beam hardening-, but also to misalignments that remain after mechanical calibration. These artefacts become particularly noticeable in the case of high spatial resolution systems and in hybrid systems, such as PETCT, SPECT-CT scanners, which rely on a correct registration of emission and CT data. Hence, slight mechanical misalignments affect the quality of the CT images and any attenuation correction metho...

  5. CT number variations in micro CT imaging systems

    Science.gov (United States)

    Tu, Shu-Ju; Hsieh, Hui-Ling; Chao, Tsi-Chian

    2008-03-01

    CT numbers can be directly computed from the linear attenuation coefficients in the reconstructed CT images and are correlated to the electron densities of the chemical elements with specific atomic numbers. However, the computed CT numbers can be varied when different imaging parameters are used. Phantoms composed of clinically relevant and tissue-equivalent materials (lung, bone, muscle, and adipose) were scanned with a commercial circular-scanning micro CT imager. This imaging system is composed with a micro-focused x-ray tube and charged-coupled device (CCD) camera as the detector. The mean CT numbers and the corresponding standard deviations in terms of Hounsfield units were then computed from a pre-defined region of interest located within the reconstructed volumetric images. The variations of CT number were then identified from a series of imaging parameters. Those parameters include imaging acquisition modes (e.g., the metal filter used in the x-ray tube), reconstruction methods (e.g., Feldkamp and iterative algorithm), and post-image processing techniques (e.g., ring artifact, beam-hardening artifact, and smoothing processing). These variations of CT numbers are useful and important in tissue characterization, quantitative bone structure analysis, bone marrow density evaluation, and Monte Carlo dose calculations for the pilot small animal study when micro CT imaging systems are employed. Also these variations can be used as the quantification for the performance of the micro CT imaging systems.

  6. Commissioning of a novel microCT/RT system for small animal conformal radiotherapy

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    Rodriguez, Manuel; Zhou, Hu; Keall, Paul; Graves, Edward

    2009-06-01

    The purpose of this work was to commission a 120 kVp photon beam produced by a micro-computed tomography (microCT) scanner for use in irradiating mice to therapeutic doses. A variable-aperture collimator has been integrated with a microCT scanner to allow the delivery of beams with pseudocircular profiles of arbitrary width between 0.1 and 6.0 cm. The dose rate at the isocenter of the system was measured using ion chamber and gafchromic EBT film as 1.56-2.13 Gy min-1 at the water surface for field diameters between 0.2 and 6.0 cm. The dose rate decreases approximately 10% per every 5 mm depth in water for field diameters between 0.5 and 1.0 cm. The flatness, symmetry and penumbra of the beam are 3.6%, 1.0% and 0.5 mm, respectively. These parameters are sufficient to accurately conform the radiation dose delivered to target organs on mice. The irradiated field size is affected principally by the divergence of the beam. In general, the beam has appropriate dosimetric characteristics to accurately deliver the dose to organs inside the mice's bodies. Using multiple beams delivered from a variety of angular directions, targets as small as 2 mm may be irradiated while sparing surrounding tissue. This microCT/RT system is a feasible tool to irradiate mice using treatment planning and delivery methods analogous to those applied to humans.

  7. Magnitude and effects of X-ray scatter of a cone-beam micro-CT for small animal imaging

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    Ni, Y.C. [Institute of Nuclear Energy Research, Longtan 32546, Taiwan (China); Jan, M.L. [Institute of Nuclear Energy Research, Longtan 32546, Taiwan (China); Chen, K.W. [Institute of Nuclear Energy Research, Longtan 32546, Taiwan (China); Cheng, Y.D. [Department of Nuclear Science, National Tsing-Hua University, Hsinchu 30043, Taiwan (China); Chuang, K.S. [Department of Nuclear Science, National Tsing-Hua University, Hsinchu 30043, Taiwan (China); Fu, Y.K. [Institute of Nuclear Energy Research, Longtan 32546, Taiwan (China)]. E-mail: fufrank@iner.gov.tw

    2006-12-20

    We have developed a micro-CT system to provide high-resolution and anatomic information to combine with a microPET'' (registered) R4 system. This study was to evaluate the magnitude and effects of scatter for low kVp X-ray in this cone-beam micro-CT system. Slit collimators were used to simulate fan-beam micro-CT for comparison. The magnitudes of X-ray scatter were measured using the beam-stop method and were estimated by polynomial-fitting extrapolation to 0 mm size of stoppers. The scatter-to-primary ratio at center of the cone-beam system were 45% and 20% for rat and mouse phantoms, respectively, and were reduced to 5.86% and 4.2% in fan-beam geometric setup. The effects of X-ray scatter on image uniformity and contrast ratio were evaluated also. The uniformity response was examined by the profile of the reconstructed image. The degrees of 'cupping' in the fan-beam and cone-beam conditions were 1.75% and 3.81%, respectively, in rat phantom. A contrast phantom consisting of four inserts with physical densities similar to that of acrylic was used for measuring the effect of X-ray scatter on image contrast. Contrast ratios of the inserts and acrylic in cone-beam setup degraded 36.9% in average compared with fan-beam setup. A tumor-bearing mouse was scanned by the micro-CT system. The tumor-to-background contrast ratios were measured to be 0.331 and 0.249, respectively, with fan-beam and cone-beam setups.

  8. Hybrid Spectral Micro-CT: System Design, Implementation, and Preliminary Results

    CERN Document Server

    Bennett, James R; Xu, Qiong; Yu, Hengyong; Walsh, Michael; Butler, Anthony; Butler, Phillip; Cao, Guohua; Mohs, Aaron; Wang, Ge

    2014-01-01

    Spectral CT has proven an important development in biomedical imaging, and there have been several publications in the past years demonstrating its merits in pre-clinical and clinical applications. In 2012, Xu et al. reported that near-term implementation of spectral micro-CT could be enhanced by a hybrid architecture: a narrow-beam spectral "interior" imaging chain integrated with a traditional wide-beam "global" imaging chain. This hybrid integration coupled with compressive sensing (CS)-based interior tomography demonstrated promising results for improved contrast resolution, and decreased system cost and radiation dose. The motivation for the current study is implementation and evaluation of the hybrid architecture with a first-of-its-kind hybrid spectral micro-CT system. Preliminary results confirm improvements in both contrast and spatial resolution. This technology is shown to merit further investigation and potential application in future spectral CT scanner design.

  9. Investigation of noise and contrast sensitivity of an electron multiplying charge-coupled device (EMCCD) based cone beam micro-CT system

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    Bysani Krishnakumar, Sumukh; Podgorsak, Alexander R.; Setlur Nagesh, S. V.; Jain, Amit; Rudin, Stephen; Bednarek, Daniel R.; Ionita, Ciprian N.

    2016-03-01

    A small animal micro-CT system was built using an EMCCD detectors having complex pre-digitization amplification technology, high-resolution, high-sensitivity and low-noise. Noise in CBCT reconstructed images when using predigitization amplification behaves differently than commonly used detectors and warrants a detailed investigation. In this study, noise power and contrast sensitivity were estimated for the newly built system. Noise analysis was performed by scanning a water phantom. Tube voltage was lowered to minimum delivered by the tube (20 kVp and 0.5 mA) and detector gain was varied. Contrast sensitivity was analyzed by using a phantom containing different iodine contrast solutions (20% to 70%) filled in six different tubes. First, we scanned the phantom using various x-ray exposures at 40 kVp while changing the gain to maintain the background air value of the projection images constant. Next, the exposure was varied while the detector gain was maintained constant. Radial NPS plots show that noise power level increases as gain increases. Contrast sensitivity was analyzed by calculating ratio of signal-to-noise ratios (SNR) for increased gain with those of low constant gain at each exposure. The SNR value at low constant gain was always lower than SNR of high detector gain at all x-ray settings and iodine contrast. The largest increase of SNR approached 1.3 for low contrast feature for an iodine concentration of 20%. Despite an increase in noise level as gain increases, the SNR improvement shows that signal level also increases because of the unique on-chip gain of the detector.

  10. Towards an inline reconstruction architecture for micro-CT systems

    International Nuclear Information System (INIS)

    Recent developments in micro-CT have revolutionized the ability to examine in vivo living experimental animal models such as mouse with a spatial resolution less than 50 μm. The main requirements of in vivo imaging for biological researchers are a good spatial resolution, a low dose induced to the animal during the full examination and a reduced acquisition and reconstruction time for screening purposes. We introduce inline acquisition and reconstruction architecture to obtain in real time the 3D attenuation map of the animal fulfilling the three previous requirements. The micro-CT system is based on commercially available x-ray detector and micro-focus x-ray source. The reconstruction architecture is based on a cluster of PCs where a dedicated communication scheme combining serial and parallel treatments is implemented. In order to obtain high performance transmission rate between the detector and the reconstruction architecture, a dedicated data acquisition system is also developed. With the proposed solution, the time required to filter and backproject a projection of 2048 x 2048 pixels inside a volume of 140 mega voxels using the Feldkamp algorithm is similar to 500 ms, the time needed to acquire the same projection

  11. Geometric Parameters Estimation and Calibration in Cone-Beam Micro-CT

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    Jintao Zhao

    2015-09-01

    Full Text Available The quality of Computed Tomography (CT images crucially depends on the precise knowledge of the scanner geometry. Therefore, it is necessary to estimate and calibrate the misalignments before image acquisition. In this paper, a Two-Piece-Ball (TPB phantom is used to estimate a set of parameters that describe the geometry of a cone-beam CT system. Only multiple projections of the TPB phantom at one position are required, which can avoid the rotation errors when acquiring multi-angle projections. Also, a corresponding algorithm is derived. The performance of the method is evaluated through simulation and experimental data. The results demonstrated that the proposed method is valid and easy to implement. Furthermore, the experimental results from the Micro-CT system demonstrate the ability to reduce artifacts and improve image quality through geometric parameter calibration.

  12. BIG DIPPER. The first gating-free dynamic micro-CT system design

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    Wang, Ge [Virginia Tech, Blacksburg, VA (United States). Biomedical Imaging Div.; Ritman, Erik L. [Mayo Clinic, Rochester, MN (United States). Dept. of Physiology; Yu, Hengyong [Wake Forest Univ., Winston-Salem, NC (United States). Dept. of Radiology and Biomedical Imaging Div.

    2011-07-01

    In contrast to the current 'ultrafast' micro-CT systems that scan over many cardiac and respiratory cycles aided by gating at high dose, here our biomedical imaging group (BIG) proposes the architecture and specifications for Dynamic Interior Pulsed Plural-sourcE Rotating-gantry (DIPPER) micro-CT. This patent-pending gating-free scanner targets volumetric micro-CT of a 2cm diameter ROI with 50ms scan speed and 100{mu}m voxel resolution at reduced radiation dose. In this paper, both the biological rationale and physical feasibility are presented. Numerical results are included as well, assuming a 7-source symmetric arrangement. (orig.)

  13. Iterative reconstruction optimisations for high angle cone-beam micro-CT

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    Recur, B.; Fauconneau, M.; Kingston, A.; Myers, G.; Sheppard, A.

    2014-09-01

    We address several acquisition questions that have arisen for the high cone-angle helical-scanning micro-CT facility developed at the Australian National University. These challenges are generally known in medical and industrial cone-beam scanners but can be neglected in these systems. For our large datasets, with more than 20483 voxels, minimising the number of operations (or iterations) is crucial. Large cone-angles enable high signal-to-noise ratio imaging and a large helical pitch to be used. This introduces two challenges: (i) non-uniform resolution throughout the reconstruction, (ii) over-scan beyond the region-of-interest significantly increases re- quired reconstructed volume size. Challenge (i) can be addressed by using a double-helix or lower pitch helix but both solutions slow down iterations. Challenge (ii) can also be improved by using a lower pitch helix but results in more projections slowing down iterations. This may be overcome using less projections per revolution but leads to more iterations required. Here we assume a given total time for acquisition and a given reconstruction technique (SART) and seek to identify the optimal trajectory and number of projections per revolution in order to produce the best tomogram, minimise reconstruction time required, and minimise memory requirements.

  14. Implementation and commissioning of an integrated micro-CT/RT system with computerized independent jaw collimation

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    Jensen, Michael D. [Department of Medical Biophysics, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Hrinivich, W. Thomas; Jung, Jongho A. [Department of Physics and Astronomy, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Holdsworth, David W. [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Ontario N6A 5K8 (Canada); Department of Medical Biophysics, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Department of Surgery, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Drangova, Maria [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Ontario N6A 5K8, Canada and Department of Medical Biophysics, The University of Western Ontario 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Chen, Jeff [Department of Physics and Engineering, London Regional Cancer Program, London Health Sciences Centre, 800 Commissioners Road East, London, Ontario N6A 5W9 (Canada); Department of Medical Biophysics, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Department of Oncology, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Wong, Eugene [Department of Physics and Astronomy, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Department of Medical Biophysics, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Department of Oncology, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Department of Physics and Engineering, London Regional Cancer Program, London Health Sciences Centre, 800 Commissioners Road East, London, Ontario N6A 5W9 (Canada)

    2013-08-15

    Purpose: To design, construct, and commission a set of computer-controlled motorized jaws for a micro-CT/RT system to perform conformal image-guided small animal radiotherapy.Methods: The authors designed and evaluated a system of custom-built motorized orthogonal jaws, which allows the delivery of off-axis rectangular fields on a GE eXplore CT 120 preclinical imaging system. The jaws in the x direction are independently driven, while the y-direction jaws are symmetric. All motors have backup encoders, verifying jaw positions. Mechanical performance of the jaws was characterized. Square beam profiles ranging from 2 × 2 to 60 × 60 mm{sup 2} were measured using EBT2 film in the center of a 70 × 70 × 22 mm{sup 3} solid water block. Similarly, absolute depth dose was measured in a solid water and EBT2 film stack 50 × 50 × 50 mm{sup 3}. A calibrated Farmer ion chamber in a 70 × 70 × 20 mm{sup 3} solid water block was used to measure the output of three field sizes: 50 × 50, 40 × 40, and 30 × 30 mm{sup 2}. Elliptical target plans were delivered to films to assess overall system performance. Respiratory-gated treatment was implemented on the system and initially proved using a simple sinusoidal motion phantom. All films were scanned on a flatbed scanner (Epson 1000XL) and converted to dose using a fitted calibration curve. A Monte Carlo beam model of the micro-CT with the jaws has been created using BEAMnrc for comparison with the measurements. An example image-guided partial lung irradiation in a rat is demonstrated.Results: The averaged random error of positioning each jaw is less than 0.1 mm. Relative output factors measured with the ion chamber agree with Monte Carlo simulations within 2%. Beam profiles and absolute depth dose curves measured from the films agree with simulations within measurement uncertainty. Respiratory-gated treatments applied to a phantom moving with a peak-to-peak amplitude of 5 mm showed improved beam penumbra (80%–20%) from 3.9 to

  15. Implementation and commissioning of an integrated micro-CT/RT system with computerized independent jaw collimation

    International Nuclear Information System (INIS)

    Purpose: To design, construct, and commission a set of computer-controlled motorized jaws for a micro-CT/RT system to perform conformal image-guided small animal radiotherapy.Methods: The authors designed and evaluated a system of custom-built motorized orthogonal jaws, which allows the delivery of off-axis rectangular fields on a GE eXplore CT 120 preclinical imaging system. The jaws in the x direction are independently driven, while the y-direction jaws are symmetric. All motors have backup encoders, verifying jaw positions. Mechanical performance of the jaws was characterized. Square beam profiles ranging from 2 × 2 to 60 × 60 mm2 were measured using EBT2 film in the center of a 70 × 70 × 22 mm3 solid water block. Similarly, absolute depth dose was measured in a solid water and EBT2 film stack 50 × 50 × 50 mm3. A calibrated Farmer ion chamber in a 70 × 70 × 20 mm3 solid water block was used to measure the output of three field sizes: 50 × 50, 40 × 40, and 30 × 30 mm2. Elliptical target plans were delivered to films to assess overall system performance. Respiratory-gated treatment was implemented on the system and initially proved using a simple sinusoidal motion phantom. All films were scanned on a flatbed scanner (Epson 1000XL) and converted to dose using a fitted calibration curve. A Monte Carlo beam model of the micro-CT with the jaws has been created using BEAMnrc for comparison with the measurements. An example image-guided partial lung irradiation in a rat is demonstrated.Results: The averaged random error of positioning each jaw is less than 0.1 mm. Relative output factors measured with the ion chamber agree with Monte Carlo simulations within 2%. Beam profiles and absolute depth dose curves measured from the films agree with simulations within measurement uncertainty. Respiratory-gated treatments applied to a phantom moving with a peak-to-peak amplitude of 5 mm showed improved beam penumbra (80%–20%) from 3.9 to 0.8 mm.Conclusions: A set of

  16. Comparison of fan-beam, cone-beam, and spiral scan reconstruction in x-ray micro-CT

    Science.gov (United States)

    Sasov, Alexander

    2001-06-01

    We developed and tested reconstruction software packages for different algorithms: fan-beam, cone-beam (Feldkamp) and spiral (helical) scans. All algorithms were applied to different simulations as well as to the real datasets from the commercial micro-CT instruments. From the results of testing a number of strong and weak points at different approaches was found. Several examples from the different application areas (bone microstructure, industrial applications) show typical reconstruction artifacts with different algorithms.

  17. Accurate Resolution Measurement for X-Ray Micro-CT Systems

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    Sharma, K. Sen; Seshadri, S.; Feser, M.; Wang, G.

    2011-09-01

    Accurate measurement of modulation transfer function (MTF), or alternatively point spread function, of an x-ray micro-CT system is essential for various purposes—to determine scanner resolution, to retrieve further information about a scanned object by image-processing, etc. In this paper, a new method for MTF measurement is proposed that can be used with any resolution pattern and is more adept at studying MTF spatial variation than the traditional method of using bar pattern analysis. A resolution target used to determine micro-CT resolution was scanned in a lab-based nano-CT system—the image from the nano-CT gave the `ground truth'. The ground truth was quantitavely compared with the micro-CT projection of same target to determine the point spread function of the system. Results matched well with bar pattern analysis, but the new method was able to study spatial variations while the bar pattern analysis failed.

  18. MicroCT Bone Densitometry: Context Sensitivity, Beam Hardening Correction and the Effect of Surrounding Media

    Directory of Open Access Journals (Sweden)

    Philip L. Salmon

    2014-12-01

    Full Text Available The context-sensitivity of microCT bone densitometry due to beam hardening artefacts was assessed. Bones and teeth are scanned with varying thickness of surrounding media (water, alcohol, biological tissue and it is important to understand how this affects reconstructed attenuation (“density” of the mineralized tissue. Aluminium tubes and rods with thickness 0.127mm–5mm were scanned both in air or surrounded by up to 2cm of water. Scans were performed with different energy filters and degrees of software beam hardening correction (BHC. Also tested were the effects of signal-to-noise ratio, magnification and truncation. The thickness of an aluminium tube significantly affected its mean reconstructed attenuation. This effect of thickness could be reduced substantially by BHC for scans in air, but not for scans in water. Varying thickness of surrounding water also changed the mean attenuation of an aluminium tube. This artefact could be almost eliminated by an optimal BHC value. The “cupping” artefact of heterogeneous attenuation (elevated at outer surfaces could be corrected if aluminium was scanned in air, but in water BHC was much less effective. Scan truncation, changes to magnification and signal-to-noise ratio also caused artificial changes to measured attenuation. Measurement of bone mineral density by microCT is highly context sensitive. A surrounding layer of liquid or biological tissue reduces the ability of software BHC to remove bone density artefacts. Sample thickness, truncation, magnification and signal to noise ratio also affect reconstructed attenuation. Thus it is important for densitometry that sample and calibration phantom dimensions and mounting materials are standardised.

  19. Method for correction of rotation errors in Micro-CT System

    Science.gov (United States)

    Zhao, Jintao; Hu, Xiaodong; Zou, Jing; Zhao, Gengyan; Lv, Hanyu; Xu, Linyan; Xu, Ying; Hu, Xiaotang

    2016-04-01

    In Micro-CT (Computed Tomography) system, a series of projection data of sample are collected by the detector as the precision stage rotates step by step. However, the accuracy of projection images is limited by rotation errors during the acquisition process. Therefore, evaluating the performance of precision rotary stage and developing corresponding compensation method are necessary in Micro-CT system. In this paper, a metered system is designed which is composed of four precision capacitive sensors, a precision machined steel cylinder and four flexible hinges. Based on the metered system, a method to calibrate and correct the errors when the precision stage turns is proposed. Firstly, the theoretical analysis is proposed and the imperfect situations are considered. And then, the method has been applied to correct experimental data taken from a microscope type of Micro-CT system. Successful results are shown through evaluating MTF (Modulation Transfer Function) of Micro-CT system. Lastly, a sample of tungsten wire is scanned and the reconstructed images are compared before and after using the calibrated method.

  20. Processing of microCT implant-bone systems images using Fuzzy Mathematical Morphology

    Science.gov (United States)

    Bouchet, A.; Colabella, L.; Omar, S.; Ballarre, J.; Pastore, J.

    2016-04-01

    The relationship between a metallic implant and the existing bone in a surgical permanent prosthesis is of great importance since the fixation and osseointegration of the system leads to the failure or success of the surgery. Micro Computed Tomography is a technique that helps to visualize the structure of the bone. In this study, the microCT is used to analyze implant-bone systems images. However, one of the problems presented in the reconstruction of these images is the effect of the iron based implants, with a halo or fluorescence scattering distorting the micro CT image and leading to bad 3D reconstructions. In this work we introduce an automatic method for eliminate the effect of AISI 316L iron materials in the implant-bone system based on the application of Compensatory Fuzzy Mathematical Morphology for future investigate about the structural and mechanical properties of bone and cancellous materials.

  1. Design and characterization of a multi-beam micro-CT scanner based on carbon nanotube field emission x-ray technology

    Science.gov (United States)

    Peng, Rui

    In this dissertation, I will present the results for my Ph.D. research for the past five years. My project mainly focuses on advanced imaging applications with a multi-beam x-ray source array based on carbon nanotube field emission technology. In the past few years, research in carbon nanotubes gradually changed from the raw material science to its application. Field emission x-ray application is one of the hottest research areas for carbon nanotube. Compared to traditional thermionic x-ray sources, the carbon nanotube field emission x-ray source has some natural advantages over traditional thermionic x-ray sources such as instantaneous x-ray generation, programmability and miniaturization. For the past few years, the research and development of carbon nanotube field emission x-ray has shifted from single x-ray beam applications to spatially distributed multi-beam x-ray sources. Previously in Zhou group, we have already built a gated micro-CT system with single beam micro-focus x-ray tube for higher spatial and temporal resolution as required in live animal imaging and a multi-beam tomosynthesis system targeting for faster and more stable breast imaging. Now my project mainly focused on the design, characterization and optimization of a multi-beam micro-CT imaging system. With the increase of gantry rotation speed approaching the mechanical limit, it is getting more and more difficult to further speed up the CT scanning. My new system promises a potential solution for the problem, and it serves as a great test platform for truly stationary micro-CT geometry. The potential capabilities it showed during the characterization and imaging measurements was promising. The dissertation is composed of five chapters. In Chapter 1, I will generally review the physics principles of x-ray generation and interaction with matter. Then the discovery of carbon nanotube and its great potential to serve as an excellent field emission electron source will be introduced in the second

  2. Characterization of operating parameters of an in vivo micro CT system

    Science.gov (United States)

    Ghani, Muhammad U.; Ren, Liqiang; Yang, Kai; Chen, Wei R.; Wu, Xizeng; Liu, Hong

    2016-03-01

    The objective of this study was to characterize the operating parameters of an in-vivo micro CT system. In-plane spatial resolution, noise, geometric accuracy, CT number uniformity and linearity, and phase effects were evaluated using various phantoms. The system employs a flat panel detector with a 127 μm pixel pitch, and a micro focus x-ray tube with a focal spot size ranging from 5-30 μm. The system accommodates three magnification sets of 1.72, 2.54 and 5.10. The in-plane cutoff frequencies (10% MTF) ranged from 2.31 lp/mm (60 mm FOV, M=1.72, 2×2 binning) to 13 lp/mm (10 mm FOV, M=5.10, 1×1 binning). The results were qualitatively validated by a resolution bar pattern phantom and the smallest visible lines were in 30-40 μm range. Noise power spectrum (NPS) curves revealed that the noise peaks exponentially increased as the geometric magnification (M) increased. True in-plane pixel spacing and slice thickness were within 2% of the system's specifications. The CT numbers in cone beam modality are greatly affected by scattering and thus they do not remain the same in the three magnifications. A high linear relationship (R2 > 0.999) was found between the measured CT numbers and Hydroxyapatite (HA) loadings of the rods of a water filled mouse phantom. Projection images of a laser cut acrylic edge acquired at a small focal spot size of 5 μm with 1.5 fps revealed that noticeable phase effects occur at M=5.10 in the form of overshooting at the boundary of air and acrylic. In order to make the CT numbers consistent across all the scan settings, scatter correction methods may be a valuable improvement for this system.

  3. Investigation of signal thresholding to reduce the effects of instrument noise of an EMCCD based micro-CT system

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    Podgorsak, Alexander R.; Bysani Krishnakumar, Sumukh; Setlur Nagesh, S. V.; Bednarek, Daniel R.; Rudin, Stephen; Ionita, Ciprian N.

    2016-03-01

    This project investigated the signal thresholding effectiveness at reducing the instrument noise of an electron multiplying charged coupled device (EMCCD) based micro-CT system at low x-ray exposure levels. Scans of a mouse spine and an iodine phantom were taken using an EMCCD detector coupled with a micro-CT system. An iodine filter of 4 mg/cm2 area density was placed in the beam. The output signal was thresholded using some multiple of the inherent background noise. For each threshold, 100, 200, and 300 frames were summed for each projection to evaluate the effect on the reconstructed image. The projection images from the scans were compared using line profiles and their SNR. Our results indicate that, as the threshold was increased, the line profiles of the projection images showed less statistical variation, but also lower signal levels, so that the SNR of the projection images decreased as the threshold increased. When the line profile of a projection image obtained using a signal threshold is compared with one obtained using energy integrating mode, the profile obtained using thresholding had less variation than that obtained using energy integration, which indicates less instrument noise. The SNR at the edges of the scan object is higher in the thresholded images when compared with the energy integrated projection images. We conclude that thresholding the output signal from an EMCCD detector at low x-ray exposure levels is an effective method to reduce the instrument noise of an EMCCD detector.

  4. Quantitative micro-CT

    Science.gov (United States)

    Prevrhal, Sven

    2005-09-01

    Micro-CT for bone structural analysis has progressed from an in-vitro laboratory technique to devices for in-vivo assessment of small animals and the peripheral human skeleton. Currently, topological parameters of bone architecture are the primary goals of analysis. Additional measurement of the density or degree of mineralization (DMB) of trabecular and cortical bone at the microscopic level is desirable to study effects of disease and treatment progress. This information is not commonly extracted because of the challenges of accurate measurement and calibration at the tissue level. To assess the accuracy of micro-CT DMB measurements in a realistic but controlled situation, we prepared bone-mimicking watery solutions at concentrations of 100 to 600 mg/cm3 K2PO4H and scanned them with micro-CT, both in glass vials and microcapillary tubes with inner diameters of 50, 100 and 150 μm to simulate trabecular thickness. Values of the linear attenuation coefficients μ in the reconstructed image are commonly affected by beam hardening effects for larger samples and by partial volume effects for small volumes. We implemented an iterative reconstruction technique to reduce beam hardening. Partial voluming was sought to be reduced by excluding voxels near the tube wall. With these two measures, improvement on the constancy of the reconstructed voxel values and linearity with solution concentration could be observed to over 90% accuracy. However, since the expected change in real bone is small more measurements are needed to confirm that micro-CT can indeed be adapted to assess bone mineralization at the tissue level.

  5. A faster ordered-subset convex algorithm for iterative reconstruction in a rotation-free micro-CT system

    International Nuclear Information System (INIS)

    We present a faster iterative reconstruction algorithm based on the ordered-subset convex (OSC) algorithm for transmission CT. The OSC algorithm was modified such that it calculates the normalization term before the iterative process in order to save computational cost. The modified version requires only one backprojection per iteration as compared to two required for the original OSC. We applied the modified OSC (MOSC) algorithm to a rotation-free micro-CT system that we proposed previously, observed its performance, and compared with the OSC algorithm for 3D cone-beam reconstruction. Measurements on the reconstructed images as well as the point spread functions show that MOSC is quite similar to OSC; in noise-resolution trade-off, MOSC is comparable with OSC in a regular-noise situation and it is slightly worse than OSC in an extremely high-noise situation. The timing record shows that MOSC saves 25-30% CPU time, depending on the number of iterations used. We conclude that the MOSC algorithm is more efficient than OSC and provides comparable images.

  6. A flat-panel detector based micro-CT system: performance evaluation for small-animal imaging.

    Science.gov (United States)

    Lee, Sang Chul; Kim, Ho Kyung; Chun, In Kon; Cho, Myung Hye; Lee, Soo Yeol; Cho, Min Hyoung

    2003-12-21

    A dedicated small-animal x-ray micro computed tomography (micro-CT) system has been developed to screen laboratory small animals such as mice and rats. The micro-CT system consists of an indirect-detection flat-panel x-ray detector with a field-of-view of 120 x 120 mm2, a microfocus x-ray source, a rotational subject holder and a parallel data processing system. The flat-panel detector is based on a matrix-addressed photodiode array fabricated by a CMOS (complementary metal-oxide semiconductor) process coupled to a CsI:T1 (thallium-doped caesium iodide) scintillator as an x-ray-to-light converter. Principal imaging performances of the micro-CT system have been evaluated in terms of image uniformity, voxel noise and spatial resolution. It has been found that the image non-uniformity mainly comes from the structural non-uniform sensitivity pattern of the flat-panel detector and the voxel noise is about 48 CT numbers at the voxel size of 100 x 100 x 200 microm3 and the air kerma of 286 mGy. When the magnification ratio is 2, the spatial resolution of the micro-CT system is about 14 1p/mm (line pairs per millimetre) that is almost determined by the flat-panel detector showing about 7 1p/mm resolving power. Through low-contrast phantom imaging studies, the minimum resolvable contrast has been found to be less than 36 CT numbers at the air kerma of 95 mGy. Some laboratory rat imaging results are presented. PMID:14727760

  7. A flat-panel detector based micro-CT system: performance evaluation for small-animal imaging

    International Nuclear Information System (INIS)

    A dedicated small-animal x-ray micro computed tomography (micro-CT) system has been developed to screen laboratory small animals such as mice and rats. The micro-CT system consists of an indirect-detection flat-panel x-ray detector with a field-of-view of 120 x 120 mm2, a microfocus x-ray source, a rotational subject holder and a parallel data processing system. The flat-panel detector is based on a matrix-addressed photodiode array fabricated by a CMOS (complementary metal-oxide semiconductor) process coupled to a CsI:Tl (thallium-doped caesium iodide) scintillator as an x-ray-to-light converter. Principal imaging performances of the micro-CT system have been evaluated in terms of image uniformity, voxel noise and spatial resolution. It has been found that the image non-uniformity mainly comes from the structural non-uniform sensitivity pattern of the flat-panel detector and the voxel noise is about 48 CT numbers at the voxel size of 100 x 100 x 200 μm3 and the air kerma of 286 mGy. When the magnification ratio is 2, the spatial resolution of the micro-CT system is about 14 lp/mm (line pairs per millimetre) that is almost determined by the flat-panel detector showing about 7 lp/mm resolving power. Through low-contrast phantom imaging studies, the minimum resolvable contrast has been found to be less than 36 CT numbers at the air kerma of 95 mGy. Some laboratory rat imaging results are presented

  8. An adaptive genetic algorithm for misalignment estimation (AGAME) in circular, sequential and spiral cone-beam micro-CT

    International Nuclear Information System (INIS)

    The reconstruction of volumetric datasets based on micro-CT scans is a common task in every small animal imaging lab. The used reconstruction algorithms thereby rely on the exact knowledge of the scanner geometry. If this geometry is misaligned or not known accurately severe artifacts in terms of edge blurring and a loss in spatial resolution appear in the reconstructed images as long as no geometry calibration is performed. We propose a novel method for misalignment estimation of micro-CT scanners using an adaptive genetic algorithm (AGAME) that does not rely on dedicated calibration phantoms. Furthermore not only the misaligned scanner geometry is estimated but also the direction vector of table movement as well as the displacement between different imaging chains within a scanner. The algorithm is validated using simulations of a micro-CT scanner indicating that the misalignment can be estimated up to a relative error of less than 1 % compared to the simulated geometry which is sufficient to reconstruct volumes without misalignment artifacts. To assess the quality of the algorithm in a real world scenario the calibration of a micro-CT scanner is performed and several reconstructions with and without misalignment estimation are carried out proving that the AGAME algorithm is able to succesfully estimate all geometry parameters. (orig.)

  9. Investigation of the effect of tube voltage and imaging geometry on phase contrast imaging for a micro-CT system

    International Nuclear Information System (INIS)

    Based upon a bench-top micro-CT system, propagation-based phase-contrast imaging has been investigated using insects and a thin plastic sheet. The system mainly includes a micro-focus source with focal spot size of 13-20 μm and a cooled X-ray CCD detector with pixel size of 24 μm. The edge-enhancement effect can be found clearly in the acquired images. With a 0.5 mm thickness plastic edge phantom, the effects of X-ray tube voltage and imaging geometry on the phase-contrast imaging were investigated, and quantitative index, edge-enhancement index (EEI), were also calculated. In our study, an interesting phenomenon was observed that the phase-contrast effect becomes more pronounced as the tube voltage increases from 20 kVp to 90 kVp. Further investigation indicates that smaller focal spot size resulting from the reduction of tube current at higher tube voltage, has caused the unexpected phenomenon. Inferred from our results, phase-contrast effect is insensitive to the tube voltage in the range of 20-90 kVp (widely used in medical diagnosis); however, it is sensitive to the focal spot size. In addition, for the investigation of the effect of imaging geometry, an optimal geometric magnification range of 2.5-4.5 is suggested to get a good phase-contrast imaging for a micro-CT system with source-to-detector distance of 720 mm.

  10. Three-dimensional imaging properties of rotation-free square and hexagonal micro-CT systems

    Science.gov (United States)

    Quan, Enzhuo; Lalush, David S.

    2009-02-01

    We perform simulation studies of proposed square and hexagonal geometries of a multi-source X-ray micro-computed tomography (CT) system. The system uses linear arrays of the carbon nano-tube (CNT)-based X-ray sources which are individually addressable. In the square geometry, two linear source arrays and two area detectors form a square; whereas in the hexagonal geometry, three linear source arrays and three area detectors form a hexagon. The tomographic angular sampling for both geometries requires no motion of the sources or subject. Based on the sinogram maps, the hexagonal geometry has improved angular coverage than the square geometry. The ordered-subset convex iterative algorithm is implemented in both geometries for reconstructions from cone-beam projection data. The reconstructed images from both geometries are generally consistent with the phantom, although some streaking artifacts due to the limited-angle nature of the geometries are observed. The two geometries show similar performance in resolution-noise tradeoff. The gap-free hexagonal geometry produces lower mean squared error in the reconstructed images; when gaps between the source arrays and detectors are introduced, the angular coverage of the hexagonal geometry degrades faster and becomes worse than the square geometry. The impact of gaps on the imaging properties must be studied further.

  11. Comparison of microCT and an inverse finite element approach for biomechanical analysis: Results in a MSC therapeutic system for fracture healing

    OpenAIRE

    Weis, Jared A.; Granero-Moltó, Froilán; MYERS, TIMOTHY J.; Longobardi, Lara; Spagnoli, Anna; Miga, Michael I.

    2012-01-01

    An important concern in the study of fracture healing is the ability to assess mechanical integrity in response to candidate therapeutics in small-animal systems. In recent reports, it has been proposed that microCT image-derived densitometric parameters could be used as a surrogate for mechanical property assessment. Recently, we have proposed an inverse methodology that iteratively reconstructs the modulus of elasticity of the lumped soft callus/hard callus region by integrating both intrin...

  12. Beam hardening and smoothing correction effects on performance of micro-ct SkyScan 1173 for imaging low contrast density materials

    International Nuclear Information System (INIS)

    We have designed and fabricated phantom mimicking breast cancer composition known as a region that has low contrast density. The used compositions are a microcalcifications, fatty tissues and tumor mass by using Al2O3, C27H46O, and hard nylon materials. Besides, phantom also has a part to calculate low cost criteria /CNR (Contrast to Noise Ratio). Uniformity will be measured at water distillation medium located in a part of phantom scale contrast. Phantom will be imaged by using micro ct-sky scan 1173 high energy type, and then also can be quantified CT number to examine SkyScan 1173 performance in imaging low contrast density materials. Evaluation of CT number is done at technique configuration parameter using voltage of 30 kV, exposure 0.160 mAs, and camera resolution 560x560 pixel, the effect of image quality to reconstruction process is evaluated by varying image processing parameters in the form of beam hardening corrections with amount of 25%, 66% and100% with each smoothing level S10,S2 and S7. To obtain the better high quality image, the adjustment of beam hardening correction should be 66% and smoothing level reach maximal value at level 10

  13. Imaging of pore networks and related interfaces in soil systems by using high resolution X-ray micro-CT

    Science.gov (United States)

    Zacher, Gerhard; Eickhorst, Thilo; Schmidt, Hannes; Halisch, Matthias

    2016-04-01

    Today's high-resolution X-ray CT with its powerful tubes and great detail detectability lends itself naturally to geological and pedological applications. Those include the non-destructive interior examination and textural analysis of rock and soil samples and their permeability and porosity - to name only a few. Especially spatial distribution and geometry of pores, mineral phases and fractures are important for the evaluation of hydrologic and aeration properties in soils as well as for root development in the soil matrix. The possibility to visualize a whole soil aggregate or root tissue in a non-destructive way is undoubtedly the most valuable feature of this type of analysis and is a new area for routine application of high resolution X-ray micro-CT. The paper outlines recent developments in hard- and software requirements for high resolution CT. It highlights several pedological applications which were performed with the phoenix nanotom m, the first 180 kV nanofocus CT system tailored specifically for extremely high-resolution scans of variable sized samples with voxel-resolutions down to micro-scale representing the space of microbial habitats. Therefore, soils were impregnated with resin and scanned via X-ray CT. Scans at higher resolution were obtained from sub-volumes cut from the entire resin impregnated block and from crop roots surrounded by rhizosphere soil. Within the scanned structures we will highlight interfaces i.e. pore-solid interface and soil-root interface. The latter will be linked to examples of fluorescent microscopy and scanning electron microscopy obtained from 2D sections revealing additional biological and chemical information in the respective microenvironment. Based on the combination of all 3D and 2D imaging data habitat features of soils can be characterized and combined with studies analyzing microbial rhizosphere colonization.

  14. Morphologic analysis of peripheral airway and lung by micro-CT

    International Nuclear Information System (INIS)

    The purpose of this study is to determine capability of the newly developed micro-computed tomography (micro-CT) system for imaging of the micro structures of normal preexisting lung, the fundamental elements of broncho-pulmonary physiology. The basic components of the micro-CT system consist of a microfocus X-ray source, a specimen manipulator, and an image intensifier detector coupled to charge-coupled device (CCD) camera. Three-dimensional (3D) image reconstruction was performed slice by slice. A standard fan-beam convolution and backprojection algorithm was used to reconstruct the center plane intersecting the X-ray source. The preprocessing of the 3-D image reconstruction included the correction of the geometrical distortions and the shading artifact introduced by the image intensifier. The main advances of the system is to obtain a high resolution minimal 5 μm. In this work we report on preliminary studies carried out with the micro CT for imaging surgically resected, inflated and fixed lung specimens of a normal lung. We compared the CT images with soft X-ray images and stereomicroscopic findings of the specimens. Experimental results reveal ultra fine structures of lung tissues, such as alveolar walls, interlobular septa, and bronchioles. From the results, the micro CT system is expected to have interesting potentials for experimental and clinical investigations. (author)

  15. A method of determining bending properties of poultry long bones using beam analysis and micro-CT data.

    Science.gov (United States)

    Vaughan, Patrick E; Orth, Michael W; Haut, Roger C; Karcher, Darrin M

    2016-01-01

    While conventional mechanical testing has been regarded as a gold standard for the evaluation of bone heath in numerous studies, with recent advances in medical imaging, virtual methods of biomechanics are rapidly evolving in the human literature. The objective of the current study was to evaluate the feasibility of determining the elastic and failure properties of poultry long bones using established methods of analysis from the human literature. In order to incorporate a large range of bone sizes and densities, a small number of specimens were utilized from an ongoing study of Regmi et al. (2016) that involved humeri and tibiae from 3 groups of animals (10 from each) including aviary, enriched, and conventional housing systems. Half the animals from each group were used for 'training' that involved the development of a regression equation relating bone density and geometry to bending properties from conventional mechanical tests. The remaining specimens from each group were used for 'testing' in which the mechanical properties from conventional tests were compared to those predicted by the regression equations. Based on the regression equations, the coefficients of determination for the 'test' set of data were 0.798 for bending bone stiffness and 0.901 for the yield (or failure) moment of the bones. All regression slopes and intercepts values for the tests versus predicted plots were not significantly different from 1 and 0, respectively. The study showed the feasibility of developing future methods of virtual biomechanics for the evaluation of poultry long bones. With further development, virtual biomechanics may have utility in future in vivo studies to assess laying hen bone health over time without the need to sacrifice large groups of animals at each time point. PMID:26794840

  16. A Correlative Method for Imaging Identical Regions of Samples by Micro-CT, Light Microscopy, and Electron Microscopy: Imaging Adipose Tissue in a Model System

    OpenAIRE

    Sengle, Gerhard; Tufa, Sara F.; Sakai, Lynn Y.; Zulliger, Martin A.; Keene, Douglas R

    2013-01-01

    We present a method in which a precise region of interest within an intact organism is spatially mapped in three dimensions by non-invasive micro-computed X-ray tomography (micro-CT), then further evaluated by light microscopy (LM) and transmission electron microscopy (TEM). Tissues are prepared as if for TEM including osmium fixation, which imparts soft tissue contrast in the micro-CT due to its strong X-ray attenuation. This method may therefore be applied to embedded, archived TEM samples....

  17. Interior micro-CT with an offset detector

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Kriti Sen [Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States); Gong, Hao [VT-WFU School of Biomedical Engingeering and Sciences, Virginia Tech, Blacksburg, Virginia 24061 (United States); Ghasemalizadeh, Omid [Department of Mechanical Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States); Yu, Hengyong [VT-WFU School of Biomedical Engineering and Sciences, Wake Forest University Health Sciences, Winston-Salem, North Carolina 27157 (United States); Wang, Ge [Biomedical Imaging Center/Cluster CBIS/BME, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Cao, Guohua, E-mail: ghcao@vt.edu [VT-WFU School of Biomedical Engineering and Sciences, Virginia Tech, Blacksburg, Virginia 24061 (United States)

    2014-06-15

    Purpose: The size of field-of-view (FOV) of a microcomputed tomography (CT) system can be increased by offsetting the detector. The increased FOV is beneficial in many applications. All prior investigations, however, have been focused to the case in which the increased FOV after offset-detector acquisition can cover the transaxial extent of an object fully. Here, the authors studied a new problem where the FOV of a micro-CT system, although increased after offset-detector acquisition, still covers an interior region-of-interest (ROI) within the object. Methods: An interior-ROI-oriented micro-CT scan with an offset detector poses a difficult reconstruction problem, which is caused by both detector offset and projection truncation. Using the projection completion techniques, the authors first extended three previous reconstruction methods from offset-detector micro-CT to offset-detector interior micro-CT. The authors then proposed a novel method which combines two of the extended methods using a frequency split technique. The authors tested the four methods with phantom simulations at 9.4%, 18.8%, 28.2%, and 37.6% detector offset. The authors also applied these methods to physical phantom datasets acquired at the same amounts of detector offset from a customized micro-CT system. Results: When the detector offset was small, all reconstruction methods showed good image quality. At large detector offset, the three extended methods gave either visible shading artifacts or high deviation of pixel value, while the authors’ proposed method demonstrated no visible artifacts and minimal deviation of pixel value in both the numerical simulations and physical experiments. Conclusions: For an interior micro-CT with an offset detector, the three extended reconstruction methods can perform well at a small detector offset but show strong artifacts at a large detector offset. When the detector offset is large, the authors’ proposed reconstruction method can outperform the three

  18. Interior micro-CT with an offset detector

    International Nuclear Information System (INIS)

    Purpose: The size of field-of-view (FOV) of a microcomputed tomography (CT) system can be increased by offsetting the detector. The increased FOV is beneficial in many applications. All prior investigations, however, have been focused to the case in which the increased FOV after offset-detector acquisition can cover the transaxial extent of an object fully. Here, the authors studied a new problem where the FOV of a micro-CT system, although increased after offset-detector acquisition, still covers an interior region-of-interest (ROI) within the object. Methods: An interior-ROI-oriented micro-CT scan with an offset detector poses a difficult reconstruction problem, which is caused by both detector offset and projection truncation. Using the projection completion techniques, the authors first extended three previous reconstruction methods from offset-detector micro-CT to offset-detector interior micro-CT. The authors then proposed a novel method which combines two of the extended methods using a frequency split technique. The authors tested the four methods with phantom simulations at 9.4%, 18.8%, 28.2%, and 37.6% detector offset. The authors also applied these methods to physical phantom datasets acquired at the same amounts of detector offset from a customized micro-CT system. Results: When the detector offset was small, all reconstruction methods showed good image quality. At large detector offset, the three extended methods gave either visible shading artifacts or high deviation of pixel value, while the authors’ proposed method demonstrated no visible artifacts and minimal deviation of pixel value in both the numerical simulations and physical experiments. Conclusions: For an interior micro-CT with an offset detector, the three extended reconstruction methods can perform well at a small detector offset but show strong artifacts at a large detector offset. When the detector offset is large, the authors’ proposed reconstruction method can outperform the three

  19. Recent micro-CT scanner developments at UGCT

    Science.gov (United States)

    Dierick, Manuel; Van Loo, Denis; Masschaele, Bert; Van den Bulcke, Jan; Van Acker, Joris; Cnudde, Veerle; Van Hoorebeke, Luc

    2014-04-01

    This paper describes two X-ray micro-CT scanners which were recently developed to extend the experimental possibilities of microtomography research at the Centre for X-ray Tomography (www.ugct.ugent.be) of the Ghent University (Belgium). The first scanner, called Nanowood, is a wide-range CT scanner with two X-ray sources (160 kVmax) and two detectors, resolving features down to 0.4 μm in small samples, but allowing samples up to 35 cm to be scanned. This is a sample size range of 3 orders of magnitude, making this scanner well suited for imaging multi-scale materials such as wood, stone, etc. Besides the traditional cone-beam acquisition, Nanowood supports helical acquisition, and it can generate images with significant phase-contrast contributions. The second scanner, known as the Environmental micro-CT scanner (EMCT), is a gantry based micro-CT scanner with variable magnification for scanning objects which are not easy to rotate in a standard micro-CT scanner, for example because they are physically connected to external experimental hardware such as sensor wiring, tubing or others. This scanner resolves 5 μm features, covers a field-of-view of about 12 cm wide with an 80 cm vertical travel range. Both scanners will be extensively described and characterized, and their potential will be demonstrated with some key application results.

  20. Recent micro-CT scanner developments at UGCT

    Energy Technology Data Exchange (ETDEWEB)

    Dierick, Manuel, E-mail: Manuel.Dierick@UGent.be [UGCT-Department of Physics and Astronomy, Faculty of Sciences, Ghent University, Proeftuinstraat 86, 9000 Ghent (Belgium); XRE, X-Ray Engineering bvba, De Pintelaan 111, 9000 Ghent (Belgium); Van Loo, Denis, E-mail: info@XRE.be [XRE, X-Ray Engineering bvba, De Pintelaan 111, 9000 Ghent (Belgium); Masschaele, Bert [UGCT-Department of Physics and Astronomy, Faculty of Sciences, Ghent University, Proeftuinstraat 86, 9000 Ghent (Belgium); XRE, X-Ray Engineering bvba, De Pintelaan 111, 9000 Ghent (Belgium); Van den Bulcke, Jan [UGCT-Woodlab-UGent, Department of Forest and Water Management, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent (Belgium); Van Acker, Joris, E-mail: Joris.VanAcker@UGent.be [UGCT-Woodlab-UGent, Department of Forest and Water Management, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent (Belgium); Cnudde, Veerle, E-mail: Veerle.Cnudde@UGent.be [UGCT-SGIG, Department of Geology and Soil Science, Faculty of Sciences, Ghent University, Krijgslaan 281, S8, 9000 Ghent (Belgium); Van Hoorebeke, Luc, E-mail: Luc.VanHoorebeke@UGent.be [UGCT-Department of Physics and Astronomy, Faculty of Sciences, Ghent University, Proeftuinstraat 86, 9000 Ghent (Belgium)

    2014-04-01

    This paper describes two X-ray micro-CT scanners which were recently developed to extend the experimental possibilities of microtomography research at the Centre for X-ray Tomography ( (www.ugct.ugent.be)) of the Ghent University (Belgium). The first scanner, called Nanowood, is a wide-range CT scanner with two X-ray sources (160 kV{sub max}) and two detectors, resolving features down to 0.4 μm in small samples, but allowing samples up to 35 cm to be scanned. This is a sample size range of 3 orders of magnitude, making this scanner well suited for imaging multi-scale materials such as wood, stone, etc. Besides the traditional cone-beam acquisition, Nanowood supports helical acquisition, and it can generate images with significant phase-contrast contributions. The second scanner, known as the Environmental micro-CT scanner (EMCT), is a gantry based micro-CT scanner with variable magnification for scanning objects which are not easy to rotate in a standard micro-CT scanner, for example because they are physically connected to external experimental hardware such as sensor wiring, tubing or others. This scanner resolves 5 μm features, covers a field-of-view of about 12 cm wide with an 80 cm vertical travel range. Both scanners will be extensively described and characterized, and their potential will be demonstrated with some key application results.

  1. Recent micro-CT scanner developments at UGCT

    International Nuclear Information System (INIS)

    This paper describes two X-ray micro-CT scanners which were recently developed to extend the experimental possibilities of microtomography research at the Centre for X-ray Tomography ( (www.ugct.ugent.be)) of the Ghent University (Belgium). The first scanner, called Nanowood, is a wide-range CT scanner with two X-ray sources (160 kVmax) and two detectors, resolving features down to 0.4 μm in small samples, but allowing samples up to 35 cm to be scanned. This is a sample size range of 3 orders of magnitude, making this scanner well suited for imaging multi-scale materials such as wood, stone, etc. Besides the traditional cone-beam acquisition, Nanowood supports helical acquisition, and it can generate images with significant phase-contrast contributions. The second scanner, known as the Environmental micro-CT scanner (EMCT), is a gantry based micro-CT scanner with variable magnification for scanning objects which are not easy to rotate in a standard micro-CT scanner, for example because they are physically connected to external experimental hardware such as sensor wiring, tubing or others. This scanner resolves 5 μm features, covers a field-of-view of about 12 cm wide with an 80 cm vertical travel range. Both scanners will be extensively described and characterized, and their potential will be demonstrated with some key application results

  2. 4D micro-CT using fast prospective gating

    Science.gov (United States)

    Guo, Xiaolian; Johnston, Samuel M.; Qi, Yi; Johnson, G. Allan; Badea, Cristian T.

    2012-01-01

    Micro-CT is currently used in preclinical studies to provide anatomical information. But, there is also significant interest in using this technology to obtain functional information. We report here a new sampling strategy for 4D micro-CT for functional cardiac and pulmonary imaging. Rapid scanning of free-breathing mice is achieved with fast prospective gating (FPG) implemented on a field programmable gate array. The method entails on-the-fly computation of delays from the R peaks of the ECG signals or the peaks of the respiratory signals for the triggering pulses. Projection images are acquired for all cardiac or respiratory phases at each angle before rotating to the next angle. FPG can deliver the faster scan time of retrospective gating (RG) with the regular angular distribution of conventional prospective gating for cardiac or respiratory gating. Simultaneous cardio-respiratory gating is also possible with FPG in a hybrid retrospective/prospective approach. We have performed phantom experiments to validate the new sampling protocol and compared the results from FPG and RG in cardiac imaging of a mouse. Additionally, we have evaluated the utility of incorporating respiratory information in 4D cardiac micro-CT studies with FPG. A dual-source micro-CT system was used for image acquisition with pulsed x-ray exposures (80 kVp, 100 mA, 10 ms). The cardiac micro-CT protocol involves the use of a liposomal blood pool contrast agent containing 123 mg I ml-1 delivered via a tail vein catheter in a dose of 0.01 ml g-1 body weight. The phantom experiment demonstrates that FPG can distinguish the successive phases of phantom motion with minimal motion blur, and the animal study demonstrates that respiratory FPG can distinguish inspiration and expiration. 4D cardiac micro-CT imaging with FPG provides image quality superior to RG at an isotropic voxel size of 88 µm and 10 ms temporal resolution. The acquisition time for either sampling approach is less than 5 min. The

  3. Key components for artifact-free micro-CT and nano-CT instruments

    Science.gov (United States)

    Sasov, Alexander; Pauwels, Bart; Liu, Xuan; Bruyndonckx, Peter

    2010-09-01

    Proper selection of modern key components allows eliminating most artifacts in micro-CT and nano-CT systems already during data acquisition. X-ray cameras with direct photon detection allow avoiding ring artifacts. Newly developed fully depleted CCD sensors show an energy response similar to traditional cameras with a thin scintillator, but without any geometrical distortions and flashes from x-ray photons penetrating through the fiber optics. Air-bearing rotation stages and piezo-positioning minimizes mechanical inaccuracies in acquiring angular projections. Beam hardening can be eliminated by energy-selective photon counting imaging.

  4. Reconstruction algorithm improving the spatial resolution of Micro-CT

    Science.gov (United States)

    Fu, Jian; Wei, Dongbo; Li, Bing; Zhang, Lei

    2008-03-01

    X-ray Micro computed tomography (Micro-CT) enables nondestructive visualization of the internal structure of objects with high-resolution images and plays an important role for industrial nondestructive testing, material evaluation and medical researches. Because the micro focus is much smaller than the ordinary focus, the geometry un-sharpness of Micro-CT projection is several decuples less than that of ordinary CT systems. So the scan conditions with high geometry magnification can be adopted to acquire the projection data with high sampling frequency. Based on this feature, a new filter back projection reconstruction algorithm is researched to improve the spatial resolution of Micro-CT. This algorithm permits the reconstruction center at any point on the line connecting the focus and the rotation center. It can reconstruct CT images with different geometry magnification by adjusting the position of the reconstruction center. So it can make the best of the above feature to improve the spatial resolution of Micro-CT. The computer simulation and the CT experiment of a special spatial resolution phantom are executed to check the validity of this method. The results demonstrate the effect of the new algorithm. Analysis shows that the spatial resolution can be improved 50%.

  5. Understanding the micro structure of Berea Sandstone by the simultaneous use of micro-computed tomography (micro-CT) and focused ion beam-scanning electron microscopy (FIB-SEM).

    Science.gov (United States)

    Bera, Bijoyendra; Mitra, Sushanta K; Vick, Douglas

    2011-07-01

    Berea sandstone is the building block for reservoirs containing precious hydrocarbon fuel. In this study, we comprehensively reveal the microstructure of Berea sandstone, which is often treated as a porous material with interconnected micro-pores of 2-5 μm. This has been possible due to the combined application of micro-computed tomography (CT) and focused ion beam (FIB)-scanning electron microscopy (SEM) on a Berea sample. While the use of micro-CT images are common for geological materials, the clubbing and comparison of tomography on Berea with state-of-the-art microstructure imaging techniques like FIB-SEM reveals some unforeseen features of Berea microstructure. In particular, for the first time FIB-SEM has been used to understand the micro-structure of reservoir rock material like Berea sandstone. By using these characterization tools, we are able to show that the micro-pores (less than 30 μm) are absent below the solid material matrix, and that it has small interconnected pores (30-40 μm) and large crater-like voids (100-250 μm) throughout the bulk material. Three-dimensional pore space reconstructions have been prepared from the CT images. Accordingly, characterization of Berea sandstone specimen is performed by calculation of pore-structure volumes and determination of porosity values. PMID:21208806

  6. Simulation of trabecular mineralization measurements in micro-CT

    Science.gov (United States)

    Prevrhal, Sven

    2006-08-01

    Micro-CT for bone structural analysis has progressed from an in-vitro laboratory technique to devices for in-vivo assessment of small animals and the peripheral human skeleton. Currently, topological parameters of bone architecture are the primary goals of analysis. Additional measurement of the density or degree of mineralization (DMB) of trabecular and cortical bone at the microscopic level is desirable to study effects of disease and treatment progress. This information is not commonly extracted because of the challenges of accurate measurement and calibration at the tissue level. To assess the accuracy of micro-CT DMB measurements in a realistic but controlled situation, we prepared bone-mimicking watery solutions at concentrations of 100 to 600 mg/cm3 K2PO4H and scanned them with micro-CT, both in glass vials and microcapillary tubes with inner diameters of 50, 100 and 150 mm to simulate trabecular thickness. Values of the linear attenuation coefficients m in the reconstructed image are commonly affected by beam hardening effects for larger samples and by partial volume effects for small volumes. We implemented an iterative reconstruction technique to reduce beam hardening. Partial voluming was sought to be reduced by excluding voxels near the tube wall. With these two measures, improvement on the constancy of the reconstructed voxel values and linearity with solution concentration could be observed to over 90% accuracy. However, since the expected change in real bone is small more measurements are needed to confirm that micro-CT can indeed be adapted to assess bone mineralization at the tissue level.

  7. Angular dispersive diffraction microCT of small breast tissue samples

    International Nuclear Information System (INIS)

    A diffraction microCT system was used at a synchrotron radiation source to create images of small breast tissue samples which highlight the fatty regions within the samples. Transmission microCT images of the samples were also obtained for correlation with, and attenuation correction of, the diffraction images. The results show that diffraction techniques have the ability to increase contrast between tissue types and also that an attenuation correction has no significant effect when imaging small tissue samples at mammographic energies

  8. Micro CT settings for caries detection: how to optimize.

    OpenAIRE

    Chaiben CL

    2015-01-01

    Some important items that can influence micro CT image were reviewed in this study. Different settings were optimized for the assessment of early caries lesions. There are several researches on bone using micro CT but not too much on dental hard tissues when assessing mineral loss. Different kinds of micro CT devices and technologies are taking place today, each requiring unique settings, and this consists one of the greatest obstacles for the use of micro CT on dental hard tissue...

  9. MicroCT: Automated Analysis of CT Reconstructed Data of Home Made Explosive Materials Using the Matlab MicroCT Analysis GUI

    Energy Technology Data Exchange (ETDEWEB)

    Seetho, I M; Brown, W D; Kallman, J S; Martz, H E; White, W T

    2011-09-22

    This Standard Operating Procedure (SOP) provides the specific procedural steps for analyzing reconstructed CT images obtained under the IDD Standard Operating Procedures for data acquisition [1] and MicroCT image reconstruction [2], per the IDD Quality Assurance Plan for MicroCT Scanning [3]. Although intended to apply primarily to MicroCT data acquired in the HEAFCAT Facility at LLNL, these procedures may also be applied to data acquired at Tyndall from the YXLON cabinet and at TSL from the HEXCAT system. This SOP also provides the procedural steps for preparing the tables and graphs to be used in the reporting of analytical results. This SOP applies to production work - for R and D there are two other semi-automated methods as given in [4, 5].

  10. MicroCT: Semi-Automated Analysis of CT Reconstructed Data of Home Made Explosive Materials Using the Matlab MicroCT Analysis GUI

    Energy Technology Data Exchange (ETDEWEB)

    Seetho, I M; Brown, W D; Kallman, J S; Martz, H E; White, W T

    2011-09-22

    This Standard Operating Procedure (SOP) provides the specific procedural steps for analyzing reconstructed CT images obtained under the IDD Standard Operating Procedures for data acquisition [1] and MicroCT image reconstruction [2], per the IDD Quality Assurance Plan for MicroCT Scanning [3]. Although intended to apply primarily to MicroCT data acquired in the HEAFCAT Facility at LLNL, these procedures may also be applied to data acquired at Tyndall from the YXLON cabinet and at TSL from the HEXCAT system. This SOP also provides the procedural steps for preparing the tables and graphs to be used in the reporting of analytical results. This SOP applies to R and D work - for production applications, use [4].

  11. Pathological calcifications studied with micro-CT

    Science.gov (United States)

    Stock, Stuart R.; Rajamannan, Nalini M.; Brooks, Ellen R.; Langman, Craig B.; Pachman, Lauren M.

    2004-10-01

    The microstructure of pathological biomineral deposits has received relatively little attention, perhaps, in part because of the difficulty preparing samples for microscopy. MicroCT avoids these difficulties, and laboratory microCT results are reviewed for aortic valve calcification (human as well as a rabbit model), for human renal calculi (stones) and for calcinoses formed in juvenile dermatomyositis (JDM). In calcified aortic valves of rabbits, numerical analysis of the data shows statistically significant correlation with diet. In a large kidney stone the pattern of mineralization is clearly revealed and may provide a temporal blueprint for stone growth. In JDM calcified deposits, very different microstructures are observed and may be related to processes unique to this disease.

  12. SU-E-I-85: Absorbed Dose Estimation for a Commercially Available MicroCT Scanner

    International Nuclear Information System (INIS)

    Purpose: To quantify the simulated absorbed dose delivered for a typical scan from a commercially available microCT scanner in order to aid in the dose estimation. Methods: The simulations were conducted using the Geant4 Monte Carlo Toolkit (version 10) with the standard electromagnetic classes. The Quantum FX microCT scanner (PerkinElmer, Waltham, MA) was modeled incorporating the energy fluence and angular distributions of generated photons, spatial dimensions of nominal source-to-object and source-to-detector distances. The energy distribution was measured using a spectrometer (X-123CdTe, Amptek Inc., Bedford, USA) with a 300 angular spread from the source for the 90 kVp X-ray beams with no additional filtration. The nominal distances from the source to object consisted of three setups: 154.0 mm, 104.0 mm, and 51.96 mm. Our simulations recorded the dose absorbed in a cylindrical phantom of PMMA with a fixed length of 2 cm and varying radii (10, 20, 30 and 40 mm) using 100 million incident photons. The averaged absorbed dose in the object was then quantified for all setups. An exposure measurement of 417 mR was taken using a Radcal 9095 system utilizing 10×9–180 ion chamber with the given technique of 90 kVp, 63 μA, and 12 s. The exposure rate was also simulated with same setup to calculate the conversion factor of the beam current and the number of incident photons. Results: For a typical cone-beam scan with non-filtered 90kVp, the dose coefficients (the absorbed dose per mAs) were 2.614, 2.549 and 2.467 μGy/mAs under source to object distance of 104 mm for the object diameters of 10 mm, 20 mm and 30 mm, respectively. Conclusion: A look-up table was developed where an investigator can estimate the delivered dose using this particular microCT given the scanning protocol (kVp and mAs) as well as the size of the scanned object

  13. In vivo microCT imaging of rodent cerebral vasculature

    International Nuclear Information System (INIS)

    Computed tomography (CT) remains a critical diagnostic tool for evaluating patients with cerebrovascular disease, and the advent of specialized systems for imaging rodents has extended these techniques to small animal models of these diseases. We therefore have evaluated in vivo methods of imaging rat models of hemorrhagic stroke using a high resolution compact computed tomography ('microCT') system (FLEX(tm) X-O(tm), Gamma Medica-Ideas, Northridge, CA). For all in vivo studies, the head of the anesthetized rat was secured in a custom immobilization device for microCT imaging with 512 projections over 2 min at 60 kVp and 0.530 mA (Itube x t/rotation = 63.6 mAs). First, imaging without iodinated contrast was performed (a) to differentiate the effect of contrast agent in contrast-enhanced CT and (b) to examine the effectiveness of the immobilization device between two time points of CT acquisitions. Then, contrast-enhanced CT was performed with continuous administration of iopromide (300 mgI ml-1 at 1.2 ml min-1) to visualize aneurysms and other vascular formations in the carotid and cerebral arteries that may precede subarachnoid hemorrhage. The accuracy of registration between the noncontrast and contrast-enhanced CT images with the immobilization device was compared against the images aligned with normalized mutual information using FMRIB's linear image registration tool (FLIRT). Translations and rotations were examined between the FLIRT-aligned noncontrast CT image and the nonaligned noncontrast CT image. These two data sets demonstrated translational and rotational differences of less than 0.5 voxel (∼85 μm) and 0.5 deg., respectively. Noncontrast CT demonstrated a very small volume (0.1 ml) of femoral arterial blood introduced surgically into the rodent brain. Continuous administration of iopromide during the CT acquisition produced consistent vascular contrast in the reconstructed CT images. As a result, carotid arteries and major cerebral blood vessels

  14. In vivo microCT imaging of rodent cerebral vasculature

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Youngho; Hasegawa, Bruce H [Center for Molecular and Functional Imaging, Department of Radiology, University of California, San Francisco, CA 94143 (United States); Hashimoto, Tomoki; Nuki, Yoshitsugu [Center for Cerebrovascular Research, Department of Anesthesia and Perioperative Care, University of California, San Francisco, CA 94143 (United States)], E-mail: youngho.seo@radiology.ucsf.edu

    2008-04-07

    Computed tomography (CT) remains a critical diagnostic tool for evaluating patients with cerebrovascular disease, and the advent of specialized systems for imaging rodents has extended these techniques to small animal models of these diseases. We therefore have evaluated in vivo methods of imaging rat models of hemorrhagic stroke using a high resolution compact computed tomography ('microCT') system (FLEX(tm) X-O(tm), Gamma Medica-Ideas, Northridge, CA). For all in vivo studies, the head of the anesthetized rat was secured in a custom immobilization device for microCT imaging with 512 projections over 2 min at 60 kVp and 0.530 mA (I{sub tube} x t/rotation = 63.6 mAs). First, imaging without iodinated contrast was performed (a) to differentiate the effect of contrast agent in contrast-enhanced CT and (b) to examine the effectiveness of the immobilization device between two time points of CT acquisitions. Then, contrast-enhanced CT was performed with continuous administration of iopromide (300 mgI ml{sup -1} at 1.2 ml min{sup -1}) to visualize aneurysms and other vascular formations in the carotid and cerebral arteries that may precede subarachnoid hemorrhage. The accuracy of registration between the noncontrast and contrast-enhanced CT images with the immobilization device was compared against the images aligned with normalized mutual information using FMRIB's linear image registration tool (FLIRT). Translations and rotations were examined between the FLIRT-aligned noncontrast CT image and the nonaligned noncontrast CT image. These two data sets demonstrated translational and rotational differences of less than 0.5 voxel ({approx}85 {mu}m) and 0.5 deg., respectively. Noncontrast CT demonstrated a very small volume (0.1 ml) of femoral arterial blood introduced surgically into the rodent brain. Continuous administration of iopromide during the CT acquisition produced consistent vascular contrast in the reconstructed CT images. As a result, carotid

  15. The effect of spatial micro-CT image resolution and surface complexity on the morphological 3D analysis of open porous structures

    Energy Technology Data Exchange (ETDEWEB)

    Pyka, Grzegorz, E-mail: gregory.pyka@mtm.kuleuven.be [Department of Metallurgy and Materials Engineering, KU Leuven, Kasteelpark Arenberg 44 – PB2450, B-3001 Leuven (Belgium); Kerckhofs, Greet [Department of Metallurgy and Materials Engineering, KU Leuven, Kasteelpark Arenberg 44 – PB2450, B-3001 Leuven (Belgium); Biomechanics Research Unit, Université de Liege, Chemin des Chevreuils 1 - BAT 52/3, B-4000 Liège (Belgium); Schrooten, Jan; Wevers, Martine [Department of Metallurgy and Materials Engineering, KU Leuven, Kasteelpark Arenberg 44 – PB2450, B-3001 Leuven (Belgium)

    2014-01-15

    In material science microfocus X-ray computed tomography (micro-CT) is one of the most popular non-destructive techniques to visualise and quantify the internal structure of materials in 3D. Despite constant system improvements, state-of-the-art micro-CT images can still hold several artefacts typical for X-ray CT imaging that hinder further image-based processing, structural and quantitative analysis. For example spatial resolution is crucial for an appropriate characterisation as the voxel size essentially influences the partial volume effect. However, defining the adequate image resolution is not a trivial aspect and understanding the correlation between scan parameters like voxel size and the structural properties is crucial for comprehensive material characterisation using micro-CT. Therefore, the objective of this study was to evaluate the influence of the spatial image resolution on the micro-CT based morphological analysis of three-dimensional (3D) open porous structures with a high surface complexity. In particular the correlation between the local surface properties and the accuracy of the micro-CT-based macro-morphology of 3D open porous Ti6Al4V structures produced by selective laser melting (SLM) was targeted and revealed for rough surfaces a strong dependence of the resulting structure characteristics on the scan resolution. Reducing the surface complexity by chemical etching decreased the sensitivity of the overall morphological analysis to the spatial image resolution and increased the detection limit. This study showed that scan settings and image processing parameters need to be customized to the material properties, morphological parameters under investigation and the desired final characteristics (in relation to the intended functional use). Customization of the scan resolution can increase the reliability of the micro-CT based analysis and at the same time reduce its operating costs. - Highlights: • We examine influence of the image resolution

  16. MicroCT with energy-resolved photon-counting detectors

    OpenAIRE

    Wang, X.; Meier, D.; Mikkelsen, S.; Maehlum, G E; Wagenaar, D J; Tsui, BMW; Patt, B E; Frey, E. C.

    2011-01-01

    The goal of this paper was to investigate the benefits that could be realistically achieved on a microCT imaging system with an energy-resolved photon-counting x-ray detector. To this end, we built and evaluated a prototype microCT system based on such a detector. The detector is based on cadmium telluride (CdTe) radiation sensors and application-specific integrated circuit (ASIC) readouts. Each detector pixel can simultaneously count x-ray photons above six energy thresholds, providing the c...

  17. Cryostatic micro-CT imaging of transient processes

    Science.gov (United States)

    Jorgensen, Steven M.; Blank, Basil; Ritman, Erik L.

    2002-01-01

    A double walled copper vessel, 32 cc in volume, was fabricated for micro-CT scanning tissue specimens maintained at cryogenic temperature. The space between the two nested vessels was evacuated and in two opposing sides of the vessel the copper has been replaced by beryllium foil. Nitrogen gas, boiling off liquid nitrogen, is injected continuously into the top of the chamber during the scanning process. Just prior to venting from the vessel the gas is heated and directed through a narrow gap over the outside of the beryllium windows so as to maintain the beryllium windows frost free. A temperature detector within the chamber is used to control the rate of inflow of the nitrogen gas. The frozen specimen is attached to a small horizontal platform on top of a vertical stainless steel pin which exits the base of the vessel through a closely fitting hole and is attached to the computer-controlled rotating stage under the vessel. The vessel and rotation-stage assembly is mounted on a computer-controlled horizontal translation stage which can move the specimen out of the x- ray beam, from time to time, for x-ray beam calibration purposes. The purpose of this arrangement is to permit scanning of specimens that: 1) either cannot be fixed (e.g., with formalin) because of biomolecular analyses which are incompatible with prior fixation, or 2) are snap-frozen during a transient process, such as the accumulation and/or washout of radiopaque indicators distributed in microvascular or extravascular compartments, which lasts only seconds and hence is too fast for normal micro-CT methods to capture.

  18. Performance evaluation of a micro-CT x-ray scanner using Kanpur theorems

    OpenAIRE

    Manish Bajpai, Prabhat Munshi, Phalguni Gupta, Valeriy Titarenko, Philip J Withers

    2011-01-01

    The present work focuses on the performance evaluation of the new Micro-CT scanner installed at University of Manchester. A graphite core object has been scanned through MicroCT scanner. The system has 2k x 2k size detector array. An experiment has been carried out with this scanner to scan the object cross section for 3796 data rays and 3600 views. The projection data obtained has been used for the reconstruction using CBP algorithm for the central plane of the object. Hamming class of filte...

  19. Current status of developments and applications of micro-CT.

    Science.gov (United States)

    Ritman, Erik L

    2011-08-15

    Use of microscopic computed-tomography (micro-CT) scanning continues to grow in biomedical research. Laboratory-based micro-CT scanners, laboratory-based nano-CT scanners, and integrated micro-CT/SPECT and micro-CT/PET scanners are now manufactured for "turn-key" operation by a number of commercial vendors. In recent years a number of technical developments in X-ray sources and X-ray imaging arrays have broadened the utility of micro-CT. Of particular interest are photon-counting and energy-resolving detector arrays. These are being explored to maximize micro-CT image grayscale dynamic range and to further increase image contrast by utilizing the unique spectral attenuation characteristics of individual chemical elements. X-ray phase-shift images may increase contrast resolution and reduce radiation exposure. Although radiation exposure is becoming a concern with the drive for increased spatial and temporal resolution, especially for longitudinal studies, gated scans and limited scan-data-set reconstruction algorithms show great potential for keeping radiation exposure to a minimum. PMID:21756145

  20. Micro CT settings for caries detection: how to optimize.

    Directory of Open Access Journals (Sweden)

    Chaiben CL

    2015-11-01

    Full Text Available Some important items that can influence micro CT image were reviewed in this study. Different settings were optimized for the assessment of early caries lesions. There are several researches on bone using micro CT but not too much on dental hard tissues when assessing mineral loss. Different kinds of micro CT devices and technologies are taking place today, each requiring unique settings, and this consists one of the greatest obstacles for the use of micro CT on dental hard tissues. Achieving the settings for an ideal dental image is therefore a challenge. The purpose of this study was to evaluate different micro CT settings to optimize the assessment of early caries lesions aiming the integrity of the dental specimen thus, making possible to reuse it for further studies. Three teeth with early caries lesions were submitted to different micro CT settings and different reconstruction settings, aiming a better image. The final image was compared visually through different densities and attenuation coefficients. The best setting for teeth tissues was achieved regarding contrast, definition, noise reduction and the larger difference between sound enamel and early lesions attenuation coefficient.

  1. Establishing a process of irradiating small animal brain using a CyberKnife and a microCT scanner

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Haksoo; Welford, Scott [Department of Radiation Oncology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106 (United States); Fabien, Jeffrey; Zheng, Yiran; Yuan, Jake; Brindle, James; Yao, Min; Lo, Simon; Wessels, Barry; Machtay, Mitchell; Sohn, Jason W., E-mail: jason.sohn@case.edu [Department of Radiation Oncology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106 and University Hospitals of Cleveland, 11100 Euclid Avenue, Cleveland, Ohio 44106 (United States); Sloan, Andrew [Department of Neurosurgery, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106 (United States)

    2014-02-15

    Purpose: Establish and validate a process of accurately irradiating small animals using the CyberKnife G4 System (version 8.5) with treatment plans designed to irradiate a hemisphere of a mouse brain based on microCT scanner images. Methods: These experiments consisted of four parts: (1) building a mouse phantom for intensity modulated radiotherapy (IMRT) quality assurance (QA), (2) proving usability of a microCT for treatment planning, (3) fabricating a small animal positioning system for use with the CyberKnife's image guided radiotherapy (IGRT) system, and (4)in vivo verification of targeting accuracy. A set of solid water mouse phantoms was designed and fabricated, with radiochromic films (RCF) positioned in selected planes to measure delivered doses. After down-sampling for treatment planning compatibility, a CT image set of a phantom was imported into the CyberKnife treatment planning system—MultiPlan (ver. 3.5.2). A 0.5 cm diameter sphere was contoured within the phantom to represent a hemispherical section of a mouse brain. A nude mouse was scanned in an alpha cradle using a microCT scanner (cone-beam, 157 × 149 pixels slices, 0.2 mm longitudinal slice thickness). Based on the results of our positional accuracy study, a planning treatment volume (PTV) was created. A stereotactic body mold of the mouse was “printed” using a 3D printer laying UV curable acrylic plastic. Printer instructions were based on exported contours of the mouse's skin. Positional reproducibility in the mold was checked by measuring ten CT scans. To verify accurate dose delivery in vivo, six mice were irradiated in the mold with a 4 mm target contour and a 2 mm PTV margin to 3 Gy and sacrificed within 20 min to avoid DNA repair. The brain was sliced and stained for analysis. Results: For the IMRT QA using a set of phantoms, the planned dose (6 Gy to the calculation point) was compared to the delivered dose measured via film and analyzed using Gamma analysis (3% and 3 mm

  2. Establishing a process of irradiating small animal brain using a CyberKnife and a microCT scanner

    International Nuclear Information System (INIS)

    Purpose: Establish and validate a process of accurately irradiating small animals using the CyberKnife G4 System (version 8.5) with treatment plans designed to irradiate a hemisphere of a mouse brain based on microCT scanner images. Methods: These experiments consisted of four parts: (1) building a mouse phantom for intensity modulated radiotherapy (IMRT) quality assurance (QA), (2) proving usability of a microCT for treatment planning, (3) fabricating a small animal positioning system for use with the CyberKnife's image guided radiotherapy (IGRT) system, and (4)in vivo verification of targeting accuracy. A set of solid water mouse phantoms was designed and fabricated, with radiochromic films (RCF) positioned in selected planes to measure delivered doses. After down-sampling for treatment planning compatibility, a CT image set of a phantom was imported into the CyberKnife treatment planning system—MultiPlan (ver. 3.5.2). A 0.5 cm diameter sphere was contoured within the phantom to represent a hemispherical section of a mouse brain. A nude mouse was scanned in an alpha cradle using a microCT scanner (cone-beam, 157 × 149 pixels slices, 0.2 mm longitudinal slice thickness). Based on the results of our positional accuracy study, a planning treatment volume (PTV) was created. A stereotactic body mold of the mouse was “printed” using a 3D printer laying UV curable acrylic plastic. Printer instructions were based on exported contours of the mouse's skin. Positional reproducibility in the mold was checked by measuring ten CT scans. To verify accurate dose delivery in vivo, six mice were irradiated in the mold with a 4 mm target contour and a 2 mm PTV margin to 3 Gy and sacrificed within 20 min to avoid DNA repair. The brain was sliced and stained for analysis. Results: For the IMRT QA using a set of phantoms, the planned dose (6 Gy to the calculation point) was compared to the delivered dose measured via film and analyzed using Gamma analysis (3% and 3 mm). A

  3. Correlating Micro-CT Imaging with Quantitative Histology

    Czech Academy of Sciences Publication Activity Database

    Gregor, T.; Kochová, P.; Eberlová, L.; Nedorost, L.; Prosecká, Eva; Liška, V.; Mírka, H.; Kachlík, D.; Pirner, I.; Zimmermann, P.; Králíčková, A.; Králíčková, M.; Tonar, Z.

    Rijeka: InTech Open Access Publisher, 2012 - (Goswami, T.), s. 173-196 ISBN 978-953-51-0690-6 R&D Projects: GA ČR GAP304/10/1307 Grant ostatní: GA ČR(CZ) GA106/09/0740; GA UK(CZ) GAUK 96610; GA MZd(CZ) NT13326 Institutional research plan: CEZ:AV0Z50390512; CEZ:AV0Z50390703 Keywords : micro CT * quantitative Histology * biomechanical models Subject RIV: FP - Other Medical Disciplines http://www.intechopen.com/books/injury-and-skeletal-biomechanics/correlating-micro-ct-imaging-with-quantitative-histology

  4. From the sample preparation to the volume rendering images of small animals: A step by step example of a procedure to carry out the micro-CT study of the leafhopper insect Homalodisca vitripennis (Hemiptera: Cicadellidae)

    Science.gov (United States)

    Advances in micro-CT, digital computed tomography (CT) scan uses X-rays to make detailed pictures of structures inside of the body. Combining micro-CT with Digital Video Library systems, and linking this to Big Data, will change the way researchers, entomologist, and the public search and use anato...

  5. MicroCT Scan in paleobiology: application to the study of dental tissues

    International Nuclear Information System (INIS)

    State of the art in paleoanthropological and paleoprimatological research foresees the use of advanced non-destructive investigative approaches. Microcomputed tomography (microCT) is a fundamental tool, since it offers the opportunity to get high quality morphological information with high spatial resolution. We carried out the set-up of an experimental microCT system able to examine paleobiological samples. The equipment can operate on small objects (size up to 3 cm) with a nominal spatial resolution of 30 μm, allowing their 3D volume reconstruction and morphometric analysis. This approach represents a forefront technique in paleobiological studies, successfully employed only in a limited number of advanced research centers. A specific program of microCT analysis has been planned on a sample of human and non-human fossil primate dentitions, in order to assess the specific nature of a number of tooth lesions (e.g. caries versus abrasion). This currently in progress experimental activity represents the first step for the set-up of a research center specifically devoted to the realization of advanced studies in the field of archaeo-paleobiology

  6. Scout-view assisted interior micro-CT

    Science.gov (United States)

    Sharma, Kriti Sen; Holzner, Christian; Vasilescu, Dragoş M.; Jin, Xin; Narayanan, Shree; Agah, Masoud; Hoffman, Eric A.; Yu, Hengyong; Wang, Ge

    2013-06-01

    Micro computed tomography (micro-CT) is a widely-used imaging technique. A challenge of micro-CT is to quantitatively reconstruct a sample larger than the field-of-view (FOV) of the detector. This scenario is characterized by truncated projections and associated image artifacts. However, for such truncated scans, a low resolution scout scan with an increased FOV is frequently acquired so as to position the sample properly. This study shows that the otherwise discarded scout scans can provide sufficient additional information to uniquely and stably reconstruct the interior region of interest. Two interior reconstruction methods are designed to utilize the multi-resolution data without significant computational overhead. While most previous studies used numerically truncated global projections as interior data, this study uses truly hybrid scans where global and interior scans were carried out at different resolutions. Additionally, owing to the lack of standard interior micro-CT phantoms, we designed and fabricated novel interior micro-CT phantoms for this study to provide means of validation for our algorithms. Finally, two characteristic samples from separate studies were scanned to show the effect of our reconstructions. The presented methods show significant improvements over existing reconstruction algorithms.

  7. Scout-view assisted interior micro-CT

    International Nuclear Information System (INIS)

    Micro computed tomography (micro-CT) is a widely-used imaging technique. A challenge of micro-CT is to quantitatively reconstruct a sample larger than the field-of-view (FOV) of the detector. This scenario is characterized by truncated projections and associated image artifacts. However, for such truncated scans, a low resolution scout scan with an increased FOV is frequently acquired so as to position the sample properly. This study shows that the otherwise discarded scout scans can provide sufficient additional information to uniquely and stably reconstruct the interior region of interest. Two interior reconstruction methods are designed to utilize the multi-resolution data without significant computational overhead. While most previous studies used numerically truncated global projections as interior data, this study uses truly hybrid scans where global and interior scans were carried out at different resolutions. Additionally, owing to the lack of standard interior micro-CT phantoms, we designed and fabricated novel interior micro-CT phantoms for this study to provide means of validation for our algorithms. Finally, two characteristic samples from separate studies were scanned to show the effect of our reconstructions. The presented methods show significant improvements over existing reconstruction algorithms. (paper)

  8. Application of the optically stimulated luminescence (OSL) technique for mouse dosimetry in micro-CT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Vrigneaud, Jean-Marc; Courteau, Alan; Oudot, Alexandra; Collin, Bertrand [Department of Nuclear Medicine, Centre Georges-François Leclerc, 1 rue Professeur Marion, Dijon 21079 Cedex (France); Ranouil, Julien [Landauer Europe, 33 avenue du Général Leclerc, Fontenay-aux-Roses 92266 Cedex (France); Morgand, Loïc; Raguin, Olivier [Oncodesign, 20 rue Jean Mazen, Dijon 21076 Cedex (France); Walker, Paul [LE2i CNRS UMR 5158, Faculty of Medicine, BP 87900, 21079 Dijon Cedex (France); Brunotte, François [Department of Nuclear Medicine, Centre Georges-François Leclerc, 1 rue Professeur Marion, Dijon 21079 Cedex, France and LE2i CNRS UMR 5158, Faculty of Medicine, BP 87900, 21079 Dijon Cedex (France)

    2013-12-15

    -like phantom. OSLDs exhibited a reproducibility of 2.4% and good linearity was found between 60 and 450 mGy. The energy scaling factor was calculated to be between 1.80 ± 0.16 and 1.86 ± 0.16, depending on protocol used. In phantoms, mean doses to tissue over a whole-body CT examination were ranging from 186.4 ± 7.6 to 234.9 ± 7.1 mGy. In mice, mean doses to tissue in the mouse trunk (thorax, abdomen, pelvis, and flanks) were between 213.0 ± 17.0 and 251.2 ± 13.4 mGy. Skin doses (3 OSLDs) were much higher with average doses between 350.6 ± 25.3 and 432.5 ± 34.1 mGy. The dose delivered during a topogram was found to be below 10 mGy. Use of the multimouse bed of the system gave a significantly 20%–40% lower dose per animal (p < 0.05).Conclusions: Absorbed doses in micro-CT were found to be relatively high. In micro-SPECT/CT imaging, the micro-CT unit is mainly used to produce a localization frame. As a result, users should pay attention to adjustable CT parameters so as to minimize the radiation dose and avoid any adverse radiation effects which may interfere with biological parameters studied.

  9. Monte Carlo dosimetry of iodine contrast objects in a small animal microCT

    International Nuclear Information System (INIS)

    Small animal microcomputed tomography (microCT) studies with iodine-based contrast media are commonly used in preclinical research. While the use of contrast media improves the quality of the images, it can also result in an increase in the absorbed dose to organs with high concentration of the contrast agent, which might cause radiation damage to the animal. In this work we present the results of a Monte Carlo investigation of a microCT dosimetry study using mouse-sized cylindrical water phantoms with iodine contrast insets for different X-ray spectra (Mo and W targets, 30-80 kVp), iodine concentrations (0, 5, 10 and 15 mg mL-1) and contrast object sizes (3 and 10 mm diameter). Our results indicate an absorbed dose increase in the contrast-inset regions with respect to the absorbed dose distribution within a reference uniform water phantom. The calculated spatial absorbed dose distributions show large gradients due to beam hardening effects, and large absorbed dose enhancement as the mean energy of the beam and iodine concentration increase. We have found that absorbed doses in iodine contrast objects can increase by a factor of up to 12 for a realistic 80 kVp X-ray spectra and an iodine concentration of 15 mg mL-1.

  10. Identification of New Lithic Clasts in Lunar Breccia 14305 by Micro-CT and Micro-XRF Analysis

    Science.gov (United States)

    Zeigler, Ryan A.; Carpenter, Paul K.; Jolliff, Bradley L.

    2014-01-01

    From 1969 to 1972, Apollo astronauts collected 382 kg of rocks, soils, and core samples from six locations on the surface of the Moon. The samples were initially characterized, largely by binocular examination, in a custom-built facility at Johnson Space Center (JSC), and the samples have been curated at JSC ever since. Despite over 40 years of study, demand for samples remains high (500 subsamples per year are allocated to scientists around the world), particularly for plutonic (e.g., anorthosites, norites, etc.) and evolved (e.g., granites, KREEP basalts) lithologies. The reason for the prolonged interest is that as new scientists and new techniques examine the samples, our understanding of how the Moon, Earth, and other inner Solar System bodies formed and evolved continues to grow. Scientists continually clamor for new samples to test their emerging hypotheses. Although all of the large Apollo samples that are igneous rocks have been classified, many Apollo samples are complex polymict breccias that have previously yielded large (cm-sized) igneous clasts. In this work we present the initial efforts to use the non-destructive techniques of micro-computed tomography (micro-CT) and micro x-ray fluorescence (micro-XRF) to identify large lithic clasts in Apollo 14 polymict breccia sample 14305. The sample in this study is 14305,483, a 150 g slab of regolith breccia 14305 measuring 10x6x2 cm (Figure 1a). The sample was scanned at the University of Texas High-Resolution X-ray CT Facility on an Xradia MicroXCT scanner. Two adjacent overlapping volumes were acquired at 49.2 micrometer resolution and stitched together, resulting in 1766 slices. Each volume was acquired at 100 kV accelerating voltage and 98 mA beam current with a 1 mm CaF2 filter, with 2161 views gathered over 360deg at 3 seconds acquisition time per view. Micro-XRF analyses were done at Washington University in St. Louis, Missouri on an EDAX Orbis PC micro-XRF instrument. Multiple scans were made at 40 k

  11. Thermoluminescent Dosimetry: A Preliminary Study for microCT Applications

    International Nuclear Information System (INIS)

    Preliminary measurements for microCT dosimetry are reported in this work, using TLD-100 crystals (1x1x1 mm3) within a solid water phantom specially designed with approximate dimensions of a mouse. A dose dependence as a function of radial distance and position along the axis of the phantom was found. Because of the smaller doses used in this work we can say that it is feasible to perform dosimetry measurements with high accuracy using TLD-100 microcubes

  12. HECTOR: a 240kV micro-CT setup optimized for research

    OpenAIRE

    Masschaele, Bert; Dierick, Manuel; Van Loo, Denis; Boone, Matthieu; Brabant, Loes; Pauwels, Elin; Cnudde, Veerle; Van Hoorebeke, Luc

    2013-01-01

    X-ray micro-CT has become a very powerful and common tool for non-destructive three-dimensional (3D) visualization and analysis of objects. Many systems are commercially available, but they are typically limited in terms of operational freedom both from a mechanical point of view as well as for acquisition routines. HECTOR is the latest system developed by the Ghent University Centre for X-ray Tomography (http://www.ugct.ugent.be) in collaboration with X-Ray Engineering (XRE bvba, Ghent, Belg...

  13. Evaluation of the adaptation of zirconia-based fixed partial dentures using micro-CT technology

    OpenAIRE

    Marcia Borba; Walter Gomes Miranda Jr.; Paulo Francisco Cesar; Jason Allan Griggs; Alvaro Della Bona

    2013-01-01

    The objective of the study was to measure the marginal and internal fit of zirconia-based all-ceramic three-unit fixed partial dentures (FPDs) (Y-TZP - LAVA, 3M-ESPE), using a novel methodology based on micro-computed tomography (micro-CT) technology. Stainless steel models of prepared abutments were fabricated to design FPDs. Ten frameworks were produced with 9 mm2 connector cross-sections using a LAVATM CAD-CAM system. All FPDs were veneered with a compatible porcelain. Each FPD was seated ...

  14. Evaluation of the adaptation of zirconia-based fixed partial dentures using micro-CT technology.

    Science.gov (United States)

    Borba, Márcia; Miranda, Walter Gomes; Cesar, Paulo Francisco; Griggs, Jason Allan; Bona, Alvaro Della

    2013-01-01

    The objective of the study was to measure the marginal and internal fit of zirconia-based all-ceramic three-unit fixed partial dentures (FPDs) (Y-TZP - LAVA, 3M-ESPE), using a novel methodology based on micro-computed tomography (micro-CT) technology. Stainless steel models of prepared abutments were fabricated to design FPDs. Ten frameworks were produced with 9 mm2 connector cross-sections using a LAVATM CAD-CAM system. All FPDs were veneered with a compatible porcelain. Each FPD was seated on the original model and scanned using micro-CT. Files were processed using NRecon and CTAn software. Adobe Photoshop and Image J software were used to analyze the cross-sectional images. Five measuring points were selected, as follows: MG - marginal gap; CA - chamfer area; AW - axial wall; AOT - axio-occlusal transition area; OA - occlusal area. Results were statistically analyzed by Kruskall-Wallis and Tukey's post hoc test (α= 0.05). There were significant differences for the gap width between the measurement points evaluated. MG showed the smallest median gap width (42 µm). OA had the highest median gap dimension (125 µm), followed by the AOT point (105 µm). CA and AW gap width values were statistically similar, 66 and 65 µm respectively. Thus, it was possible to conclude that different levels of adaptation were observed within the FPD, at the different measuring points. In addition, the micro-CT technology seems to be a reliable tool to evaluate the fit of dental restorations. PMID:24036977

  15. Evaluation of the adaptation of zirconia-based fixed partial dentures using micro-CT technology

    International Nuclear Information System (INIS)

    The objective of the study was to measure the marginal and internal fit of zirconia-based all-ceramic three-unit fixed partial dentures (FPDs) (Y-TZP - LAVA, 3M-ESPE), using a novel methodology based on micro-computed tomography (micro-CT) technology. Stainless steel models of prepared abutments were fabricated to design FPDs. Ten frameworks were produced with 9 mm² connector cross-sections using a LAVA® CAD-CAM system. All FPDs were veneered with a compatible porcelain. Each FPD was seated on the original model and scanned using micro-CT. Files were processed using NRecon and CTAn software. Adobe Photoshop and Image J software were used to analyze the cross sectional images. Five measuring points were selected, as follows: MG- marginal gap; CA - chamfer area; AW - axial wall; AOT - axio-occlusal transition area; OA - occlusal area. Results were statistically analyzed by Kruskall-Wallis and Tukey's post hoc test (α = 0.05). There were significant differences for the gap width between the measurement points evaluated. MG showed the smallest median gap width (42 μm). OA had the highest median gap dimension (125 μm), followed by the AOT point (105 μm). CA and AW gap width values were statistically similar, 66 and 65 μm respectively. Thus, it was possible to conclude that different levels of adaptation were observed within the FPD, at the different measuring points. In addition, the micro-CT technology seems to be a reliable tool to evaluate the fit of dental restorations. (author)

  16. Evaluation of the adaptation of zirconia-based fixed partial dentures using micro-CT technology

    Directory of Open Access Journals (Sweden)

    Marcia Borba

    2013-09-01

    Full Text Available The objective of the study was to measure the marginal and internal fit of zirconia-based all-ceramic three-unit fixed partial dentures (FPDs (Y-TZP - LAVA, 3M-ESPE, using a novel methodology based on micro-computed tomography (micro-CT technology. Stainless steel models of prepared abutments were fabricated to design FPDs. Ten frameworks were produced with 9 mm2 connector cross-sections using a LAVATM CAD-CAM system. All FPDs were veneered with a compatible porcelain. Each FPD was seated on the original model and scanned using micro-CT. Files were processed using NRecon and CTAn software. Adobe Photoshop and Image J software were used to analyze the cross-sectional images. Five measuring points were selected, as follows: MG - marginal gap; CA - chamfer area; AW - axial wall; AOT - axio-occlusal transition area; OA - occlusal area. Results were statistically analyzed by Kruskall-Wallis and Tukey's post hoc test (α= 0.05. There were significant differences for the gap width between the measurement points evaluated. MG showed the smallest median gap width (42 µm. OA had the highest median gap dimension (125 µm, followed by the AOT point (105 µm. CA and AW gap width values were statistically similar, 66 and 65 µm respectively. Thus, it was possible to conclude that different levels of adaptation were observed within the FPD, at the different measuring points. In addition, the micro-CT technology seems to be a reliable tool to evaluate the fit of dental restorations.

  17. Evaluation of the adaptation of zirconia-based fixed partial dentures using micro-CT technology

    Energy Technology Data Exchange (ETDEWEB)

    Borba, Marcia; Bona, Alvaro Della, E-mail: marcia_borb@hotmail.com [Universidade de Passo Fundo (UPF), RS (Brazil). Fac. de Odontologia; Miranda Junior, Walter Gomes; Cesar, Paulo Francisco [Universidade de Sao Paulo (USP), SP (Brazil). Fac. de Odontologia. Dept. de Biomateriais e Bioquimica Oral; Griggs, Jason Allan [Department of Biomedical Materials Science, Dental School, University of Mississippi Medical Center - UMMC, Jackson, MS (United States)

    2013-09-15

    The objective of the study was to measure the marginal and internal fit of zirconia-based all-ceramic three-unit fixed partial dentures (FPDs) (Y-TZP - LAVA, 3M-ESPE), using a novel methodology based on micro-computed tomography (micro-CT) technology. Stainless steel models of prepared abutments were fabricated to design FPDs. Ten frameworks were produced with 9 mm² connector cross-sections using a LAVA® CAD-CAM system. All FPDs were veneered with a compatible porcelain. Each FPD was seated on the original model and scanned using micro-CT. Files were processed using NRecon and CTAn software. Adobe Photoshop and Image J software were used to analyze the cross sectional images. Five measuring points were selected, as follows: MG- marginal gap; CA - chamfer area; AW - axial wall; AOT - axio-occlusal transition area; OA - occlusal area. Results were statistically analyzed by Kruskall-Wallis and Tukey's post hoc test (α = 0.05). There were significant differences for the gap width between the measurement points evaluated. MG showed the smallest median gap width (42 μm). OA had the highest median gap dimension (125 μm), followed by the AOT point (105 μm). CA and AW gap width values were statistically similar, 66 and 65 μm respectively. Thus, it was possible to conclude that different levels of adaptation were observed within the FPD, at the different measuring points. In addition, the micro-CT technology seems to be a reliable tool to evaluate the fit of dental restorations. (author)

  18. Electron beam focusing system

    Energy Technology Data Exchange (ETDEWEB)

    Dikansky, N.; Nagaitsev, S.; Parkhomchuk, V.

    1997-09-01

    The high energy electron cooling requires a very cold electron beam. Thus, the electron beam focusing system is very important for the performance of electron cooling. A system with and without longitudinal magnetic field is presented for discussion. Interaction of electron beam with the vacuum chamber as well as with the background ions and stored antiprotons can cause the coherent electron beam instabilities. Focusing system requirements needed to suppress these instabilities are presented.

  19. Parameterization of X-ray spectra appropriate for microCT scanners

    International Nuclear Information System (INIS)

    Non-filtered X-ray spectra from three tubes (Oxford Instruments Ultrabright microfocus W anode, Apogee Series 5000 with W and Mo anodes) appropriate for microCT scanners have been measured using a CdTe solid-state detector. The normalized and efficiency-corrected spectra have been parameterized using Boone et al. third-order polynomial expression, obtaining good agreement with the data (typical mean ratio between parameterization and measurement equals 1.02, with standard deviation 0.10). Attenuation of the computed spectra by external filters was analytically simulated, obtaining results that agree well with direct measurements. The air kerma angular distribution of the X-ray beams was measured and the magnitude of the heel effect was evaluated. Tungsten collimators provided by the detector manufacturer had to be used to reduce dead time and it was found that their apertures do not necessarily agree with the nominal values.

  20. Phase-selective image reconstruction of the lungs in small animals using micro-CT

    Science.gov (United States)

    Johnston, S. M.; Perez, B. A.; Kirsch, D. G.; Badea, C. T.

    2010-04-01

    Gating in small animal imaging can compensate for artifacts due to physiological motion. This paper presents a strategy for sampling and image reconstruction in the rodent lung using micro-CT. The approach involves rapid sampling of freebreathing mice without any additional hardware to detect respiratory motion. The projection images are analyzed postacquisition to derive a respiratory signal, which is used to provide weighting factors for each projection that favor a selected phase of the respiration (e.g. end-inspiration or end-expiration) for the reconstruction. Since the sampling cycle and the respiratory cycle are uncorrelated, the sets of projections corresponding to any of the selected respiratory phases do not have a regular angular distribution. This drastically affects the image quality of reconstructions based on simple filtered backprojection. To address this problem, we use an iterative reconstruction algorithm that combines the Simultaneous Algebraic Reconstruction Technique with Total Variation minimization (SART-TV). At each SART-TV iteration, backprojection is performed with a set of weighting factors that favor the desired respiratory phase. To reduce reconstruction time, the algorithm is implemented on a graphics processing unit. The performance of the proposed approach was investigated in simulations and in vivo scans of mice with primary lung cancers imaged with our in-house developed dual tube/detector micro-CT system. We note that if the ECG signal is acquired during sampling, the same approach could be used for phase-selective cardiac imaging.

  1. Exploring miniature insect brains using micro-CT scanning techniques.

    Science.gov (United States)

    Smith, Dylan B; Bernhardt, Galina; Raine, Nigel E; Abel, Richard L; Sykes, Dan; Ahmed, Farah; Pedroso, Inti; Gill, Richard J

    2016-01-01

    The capacity to explore soft tissue structures in detail is important in understanding animal physiology and how this determines features such as movement, behaviour and the impact of trauma on regular function. Here we use advances in micro-computed tomography (micro-CT) technology to explore the brain of an important insect pollinator and model organism, the bumblebee (Bombus terrestris). Here we present a method for accurate imaging and exploration of insect brains that keeps brain tissue free from trauma and in its natural stereo-geometry, and showcase our 3D reconstructions and analyses of 19 individual brains at high resolution. Development of this protocol allows relatively rapid and cost effective brain reconstructions, making it an accessible methodology to the wider scientific community. The protocol describes the necessary steps for sample preparation, tissue staining, micro-CT scanning and 3D reconstruction, followed by a method for image analysis using the freeware SPIERS. These image analysis methods describe how to virtually extract key composite structures from the insect brain, and we demonstrate the application and precision of this method by calculating structural volumes and investigating the allometric relationships between bumblebee brain structures. PMID:26908205

  2. Prospective respiratory-gated micro-CT of free breathing rodents

    International Nuclear Information System (INIS)

    Microcomputed tomography (Micro-CT) has the potential to noninvasively image the structure of organs in rodent models with high spatial resolution and relatively short image acquisition times. However, motion artifacts associated with the normal respiratory motion of the animal may arise when imaging the abdomen or thorax. To reduce these artifacts and the accompanying loss of spatial resolution, we propose a prospective respiratory gating technique for use with anaesthetized, free-breathing rodents. A custom-made bed with an embedded pressure chamber was connected to a pressure transducer. Anaesthetized animals were placed in the prone position on the bed with their abdomens located over the chamber. During inspiration, the motion of the diaphragm caused an increase in the chamber pressure, which was converted into a voltage signal by the transducer. An output voltage was used to trigger image acquisition at any desired time point in the respiratory cycle. Digital radiographic images were acquired of anaesthetized, free-breathing rats with a digital radiographic system to correlate the respiratory wave form with respiration-induced organ motion. The respiratory wave form was monitored and recorded simultaneously with the x-ray radiation pulses, and an imaging window was defined, beginning at end expiration. Phantom experiments were performed to verify that the respiratory gating apparatus was triggering the micro-CT system. Attached to the distensible phantom were 100 μm diameter copper wires and the measured full width at half maximum was used to assess differences in image quality between respiratory-gated and ungated imaging protocols. This experiment allowed us to quantify the improvement in the spatial resolution, and the reduction of motion artifacts caused by moving structures, in the images resulting from respiratory-gated image acquisitions. The measured wire diameters were 0.135 mm for the stationary phantom image, 0.137 mm for the image gated at end

  3. Pilot study for compact microbeam radiation therapy using a carbon nanotube field emission micro-CT scanner

    Energy Technology Data Exchange (ETDEWEB)

    Hadsell, Mike, E-mail: mhadsell@stanford.edu; Cao, Guohua; Zhang, Jian; Burk, Laurel; Schreiber, Torsten; Lu, Jianping; Zhou, Otto [Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Schreiber, Eric; Chang, Sha [Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina 27599 (United States)

    2014-06-15

    Purpose: Microbeam radiation therapy (MRT) is defined as the use of parallel, microplanar x-ray beams with an energy spectrum between 50 and 300 keV for cancer treatment and brain radiosurgery. Up until now, the possibilities of MRT have mainly been studied using synchrotron sources due to their high flux (100s Gy/s) and approximately parallel x-ray paths. The authors have proposed a compact x-ray based MRT system capable of delivering MRT dose distributions at a high dose rate. This system would employ carbon nanotube (CNT) field emission technology to create an x-ray source array that surrounds the target of irradiation. Using such a geometry, multiple collimators would shape the irradiation from this array into multiple microbeams that would then overlap or interlace in the target region. This pilot study demonstrates the feasibility of attaining a high dose rate and parallel microbeam beams using such a system. Methods: The microbeam dose distribution was generated by our CNT micro-CT scanner (100μm focal spot) and a custom-made microbeam collimator. An alignment assembly was fabricated and attached to the scanner in order to collimate and superimpose beams coming from different gantry positions. The MRT dose distribution was measured using two orthogonal radiochromic films embedded inside a cylindrical phantom. This target was irradiated with microbeams incident from 44 different gantry angles to simulate an array of x-ray sources as in the proposed compact CNT-based MRT system. Finally, phantom translation in a direction perpendicular to the microplanar beams was used to simulate the use of multiple parallel microbeams. Results: Microbeams delivered from 44 gantry angles were superimposed to form a single microbeam dose distribution in the phantom with a FWHM of 300μm (calculated value was 290 μm). Also, during the multiple beam simulation, a peak to valley dose ratio of ∼10 was found when the phantom translation distance was roughly 4x the beam width

  4. Beam alignment system

    International Nuclear Information System (INIS)

    A patent is claimed for the invention of a beam alignment system. The aim of the invention is the obtention of an accurate monitoring of the beam position and direction. It is of great interest in the nuclear industry. The invention can be applied in an infrared laser beam for welding operations. An auxiliar radiation source is incorporated to the device. The system's configuration allows a simultaneous and separated utilisation of two beams. The description and the design of the proposed system are provided

  5. High Resolution X-Ray Micro-CT of Ultra-Thin Wall Space Components

    Science.gov (United States)

    Roth, Don J.; Rauser, R. W.; Bowman, Randy R.; Bonacuse, Peter; Martin, Richard E.; Locci, I. E.; Kelley, M.

    2012-01-01

    A high resolution micro-CT system has been assembled and is being used to provide optimal characterization for ultra-thin wall space components. The Glenn Research Center NDE Sciences Team, using this CT system, has assumed the role of inspection vendor for the Advanced Stirling Convertor (ASC) project at NASA. This article will discuss many aspects of the development of the CT scanning for this type of component, including CT system overview; inspection requirements; process development, software utilized and developed to visualize, process, and analyze results; calibration sample development; results on actual samples; correlation with optical/SEM characterization; CT modeling; and development of automatic flaw recognition software. Keywords: Nondestructive Evaluation, NDE, Computed Tomography, Imaging, X-ray, Metallic Components, Thin Wall Inspection

  6. MicroCT with energy-resolved photon-counting detectors

    Energy Technology Data Exchange (ETDEWEB)

    Wang, X; Tsui, B M W; Frey, E C [Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD (United States); Meier, D; Mikkelsen, S; Maehlum, G E [Gamma Medica-Ideas (AS), Oslo (Norway); Wagenaar, D J; Patt, B E, E-mail: efrey1@jhmi.edu [Gamma Medica-Ideas, Northridge, CA (United States)

    2011-05-07

    The goal of this paper was to investigate the benefits that could be realistically achieved on a microCT imaging system with an energy-resolved photon-counting x-ray detector. To this end, we built and evaluated a prototype microCT system based on such a detector. The detector is based on cadmium telluride (CdTe) radiation sensors and application-specific integrated circuit (ASIC) readouts. Each detector pixel can simultaneously count x-ray photons above six energy thresholds, providing the capability for energy-selective x-ray imaging. We tested the spectroscopic performance of the system using polychromatic x-ray radiation and various filtering materials with K-absorption edges. Tomographic images were then acquired of a cylindrical PMMA phantom containing holes filled with various materials. Results were also compared with those acquired using an intensity-integrating x-ray detector and single-energy (i.e. non-energy-selective) CT. This paper describes the functionality and performance of the system, and presents preliminary spectroscopic and tomographic results. The spectroscopic experiments showed that the energy-resolved photon-counting detector was capable of measuring energy spectra from polychromatic sources like a standard x-ray tube, and resolving absorption edges present in the energy range used for imaging. However, the spectral quality was degraded by spectral distortions resulting from degrading factors, including finite energy resolution and charge sharing. We developed a simple charge-sharing model to reproduce these distortions. The tomographic experiments showed that the availability of multiple energy thresholds in the photon-counting detector allowed us to simultaneously measure target-to-background contrasts in different energy ranges. Compared with single-energy CT with an integrating detector, this feature was especially useful to improve differentiation of materials with different attenuation coefficient energy dependences.

  7. Monte Carlo simulations of the dose from imaging with GE eXplore 120 micro-CT using GATE

    Energy Technology Data Exchange (ETDEWEB)

    Bretin, Florian; Bahri, Mohamed Ali; Luxen, André; Phillips, Christophe; Plenevaux, Alain; Seret, Alain, E-mail: aseret@ulg.ac.be [Cyclotron Research Centre, University of Liège, Sart Tilman B30, Liège 4000 (Belgium)

    2015-10-15

    Purpose: Small animals are increasingly used as translational models in preclinical imaging studies involving microCT, during which the subjects can be exposed to large amounts of radiation. While the radiation levels are generally sublethal, studies have shown that low-level radiation can change physiological parameters in mice. In order to rule out any influence of radiation on the outcome of such experiments, or resulting deterministic effects in the subjects, the levels of radiation involved need to be addressed. The aim of this study was to investigate the radiation dose delivered by the GE eXplore 120 microCT non-invasively using Monte Carlo simulations in GATE and to compare results to previously obtained experimental values. Methods: Tungsten X-ray spectra were simulated at 70, 80, and 97 kVp using an analytical tool and their half-value layers were simulated for spectra validation against experimentally measured values of the physical X-ray tube. A Monte Carlo model of the microCT system was set up and four protocols that are regularly applied to live animal scanning were implemented. The computed tomography dose index (CTDI) inside a PMMA phantom was derived and multiple field of view acquisitions were simulated using the PMMA phantom, a representative mouse and rat. Results: Simulated half-value layers agreed with experimentally obtained results within a 7% error window. The CTDI ranged from 20 to 56 mGy and closely matched experimental values. Derived organ doses in mice reached 459 mGy in bones and up to 200 mGy in soft tissue organs using the highest energy protocol. Dose levels in rats were lower due to the increased mass of the animal compared to mice. The uncertainty of all dose simulations was below 14%. Conclusions: Monte Carlo simulations proved a valuable tool to investigate the 3D dose distribution in animals from microCT. Small animals, especially mice (due to their small volume), receive large amounts of radiation from the GE eXplore 120

  8. Monte Carlo simulations of the dose from imaging with GE eXplore 120 micro-CT using GATE

    International Nuclear Information System (INIS)

    Purpose: Small animals are increasingly used as translational models in preclinical imaging studies involving microCT, during which the subjects can be exposed to large amounts of radiation. While the radiation levels are generally sublethal, studies have shown that low-level radiation can change physiological parameters in mice. In order to rule out any influence of radiation on the outcome of such experiments, or resulting deterministic effects in the subjects, the levels of radiation involved need to be addressed. The aim of this study was to investigate the radiation dose delivered by the GE eXplore 120 microCT non-invasively using Monte Carlo simulations in GATE and to compare results to previously obtained experimental values. Methods: Tungsten X-ray spectra were simulated at 70, 80, and 97 kVp using an analytical tool and their half-value layers were simulated for spectra validation against experimentally measured values of the physical X-ray tube. A Monte Carlo model of the microCT system was set up and four protocols that are regularly applied to live animal scanning were implemented. The computed tomography dose index (CTDI) inside a PMMA phantom was derived and multiple field of view acquisitions were simulated using the PMMA phantom, a representative mouse and rat. Results: Simulated half-value layers agreed with experimentally obtained results within a 7% error window. The CTDI ranged from 20 to 56 mGy and closely matched experimental values. Derived organ doses in mice reached 459 mGy in bones and up to 200 mGy in soft tissue organs using the highest energy protocol. Dose levels in rats were lower due to the increased mass of the animal compared to mice. The uncertainty of all dose simulations was below 14%. Conclusions: Monte Carlo simulations proved a valuable tool to investigate the 3D dose distribution in animals from microCT. Small animals, especially mice (due to their small volume), receive large amounts of radiation from the GE eXplore 120

  9. Analysis on correlation between bone strength by FEA, micro-CT parameters and bone mineral density

    International Nuclear Information System (INIS)

    Bone mineral density (BMD) and bone micro architecture and important determinants for bone strength. Recently micro-CT have provided possibilities for measuring a variety of structural indices to characterize bone micro architecture. The objective of this study was to compare the BMD and micro-CT parameters with Young's modulus calculated by finite element analysis (FEA) for the evaluation of bone strength. Bone specimens were obtained from the 18 female rabbits aged 16 weeks. Of those, 36 samples (right and left femur) were selected for 3D micro-CT analysis(ANT 'TM, SKYSCAN, Belgium) and BMD by PIXImus 2 (GE Lunar Co. USA). Five microstructural parameters of micro-CT, such as trabecular thickness(Tb. Th), bone specific surface (BS/BV), percent bone volume (BV/TV), structure model index (SMI) and degree of anisotropy (DOA) were studied. Young's modulus was obtained by software program (ANSYS 9.0, ANSYS Inc, Canonsburg, PA) based on micro-CT three dimensional images. Young's modults assessed by FEA correlated significantly with Tb.Th, BV/TV. BS/BV and SMI respectively. Young's modulus showed higher correlation with these microstructural parameters of micro-CT than BMD. Microstructural parameters except DOA showed significant correlations within the examined group. The micro architectural parameters of micro-CT and BMD represented some information in the evaluation of bone strength assessed by FEA

  10. Assessing Cardiac Injury in Mice With Dual Energy-MicroCT, 4D-MicroCT, and MicroSPECT Imaging After Partial Heart Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chang-Lung; Min, Hooney [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Befera, Nicholas; Clark, Darin; Qi, Yi [Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, North Carolina (United States); Das, Shiva [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Johnson, G. Allan; Badea, Cristian T. [Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, North Carolina (United States); Kirsch, David G., E-mail: david.kirsch@duke.edu [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina (United States)

    2014-03-01

    Purpose: To develop a mouse model of cardiac injury after partial heart irradiation (PHI) and to test whether dual energy (DE)-microCT and 4-dimensional (4D)-microCT can be used to assess cardiac injury after PHI to complement myocardial perfusion imaging using micro-single photon emission computed tomography (SPECT). Methods and Materials: To study cardiac injury from tangent field irradiation in mice, we used a small-field biological irradiator to deliver a single dose of 12 Gy x-rays to approximately one-third of the left ventricle (LV) of Tie2Cre; p53{sup FL/+} and Tie2Cre; p53{sup FL/−} mice, where 1 or both alleles of p53 are deleted in endothelial cells. Four and 8 weeks after irradiation, mice were injected with gold and iodinated nanoparticle-based contrast agents, and imaged with DE-microCT and 4D-microCT to evaluate myocardial vascular permeability and cardiac function, respectively. Additionally, the same mice were imaged with microSPECT to assess myocardial perfusion. Results: After PHI with tangent fields, DE-microCT scans showed a time-dependent increase in accumulation of gold nanoparticles (AuNp) in the myocardium of Tie2Cre; p53{sup FL/−} mice. In Tie2Cre; p53{sup FL/−} mice, extravasation of AuNp was observed within the irradiated LV, whereas in the myocardium of Tie2Cre; p53{sup FL/+} mice, AuNp were restricted to blood vessels. In addition, data from DE-microCT and microSPECT showed a linear correlation (R{sup 2} = 0.97) between the fraction of the LV that accumulated AuNp and the fraction of LV with a perfusion defect. Furthermore, 4D-microCT scans demonstrated that PHI caused a markedly decreased ejection fraction, and higher end-diastolic and end-systolic volumes, to develop in Tie2Cre; p53{sup FL/−} mice, which were associated with compensatory cardiac hypertrophy of the heart that was not irradiated. Conclusions: Our results show that DE-microCT and 4D-microCT with nanoparticle-based contrast agents are novel imaging approaches

  11. Assessing Cardiac Injury in Mice With Dual Energy-MicroCT, 4D-MicroCT, and MicroSPECT Imaging After Partial Heart Irradiation

    International Nuclear Information System (INIS)

    Purpose: To develop a mouse model of cardiac injury after partial heart irradiation (PHI) and to test whether dual energy (DE)-microCT and 4-dimensional (4D)-microCT can be used to assess cardiac injury after PHI to complement myocardial perfusion imaging using micro-single photon emission computed tomography (SPECT). Methods and Materials: To study cardiac injury from tangent field irradiation in mice, we used a small-field biological irradiator to deliver a single dose of 12 Gy x-rays to approximately one-third of the left ventricle (LV) of Tie2Cre; p53FL/+ and Tie2Cre; p53FL/− mice, where 1 or both alleles of p53 are deleted in endothelial cells. Four and 8 weeks after irradiation, mice were injected with gold and iodinated nanoparticle-based contrast agents, and imaged with DE-microCT and 4D-microCT to evaluate myocardial vascular permeability and cardiac function, respectively. Additionally, the same mice were imaged with microSPECT to assess myocardial perfusion. Results: After PHI with tangent fields, DE-microCT scans showed a time-dependent increase in accumulation of gold nanoparticles (AuNp) in the myocardium of Tie2Cre; p53FL/− mice. In Tie2Cre; p53FL/− mice, extravasation of AuNp was observed within the irradiated LV, whereas in the myocardium of Tie2Cre; p53FL/+ mice, AuNp were restricted to blood vessels. In addition, data from DE-microCT and microSPECT showed a linear correlation (R2 = 0.97) between the fraction of the LV that accumulated AuNp and the fraction of LV with a perfusion defect. Furthermore, 4D-microCT scans demonstrated that PHI caused a markedly decreased ejection fraction, and higher end-diastolic and end-systolic volumes, to develop in Tie2Cre; p53FL/− mice, which were associated with compensatory cardiac hypertrophy of the heart that was not irradiated. Conclusions: Our results show that DE-microCT and 4D-microCT with nanoparticle-based contrast agents are novel imaging approaches complementary to microSPECT for

  12. Accuracy of cancellous bone volume fraction measured by micro-CT scanning

    DEFF Research Database (Denmark)

    Ding, Ming; Odgaard, A; Hvid, I

    1999-01-01

    which covered a large range of volume fraction (9.8-39.8%) were produced. The specimens were micro-CT scanned, and the volume fraction based on Archimedes' principle was determined as a reference. After scanning, all micro-CT data were segmented using individual thresholds determined by the scanner......Volume fraction, the single most important parameter in describing trabecular microstructure, can easily be calculated from three-dimensional reconstructions of micro-CT images. This study sought to quantify the accuracy of this measurement. One hundred and sixty human cancellous bone specimens...

  13. Comparison of photon counting versus charge integration micro-CT within the irradiation setup PIXSCAN

    International Nuclear Information System (INIS)

    The pathway that has been followed by the imXgam team at CPPM was to adapt the hybrid pixel technology XPAD to biomedical imaging. It is in this context that the micro-CT PIXSCAN II based on the new generation of hybrid pixel detectors called XPAD3 has been developed. This thesis describes the process undertaken to assess the contribution of the hybrid pixel technology in X-ray computed tomography in terms of contrast and dose and to explore new opportunities for biomedical imaging at low doses. Performance evaluation as well as the validation of the results obtained with data acquired with the detector XPAD3 were compared to results obtained with the CCD camera DALSA XR-4 similar to detectors used in most conventional micro-CT systems. The detector XPAD3 allows to obtain reconstructed images of satisfactory quality close to that of images from the DALSA XR-4 camera, but with a better spatial resolution. At low doses, the images from the detector XPAD3 have a better quality that is those from CCD camera. From an instrumentation point of view, this project demonstrated the proper operations of the device PIXSCAN II for mouse imaging. We were able to reproduce an image quality similar to that obtained with a charge integration detector such as a CCD camera. To improve the performance of the detector XPAD3, we will have to optimize the stability of the thresholds and in order to obtain more homogeneous response curves of the pixels as a function as energy by using a denser sensor such as CdTe. (author)

  14. State of the Art of Micro-CT Applications in Dental Research

    OpenAIRE

    Swain, Michael V.; Xue, Jing

    2009-01-01

    This review highlights the recent advances in X-ray microcomputed tomography (Micro-CT) applied in dental research. It summarizes Micro-CT applications in measurement of enamel thickness, root canal morphology, evaluation of root canal preparation, craniofacial skeletal structure, micro finite element modeling, dental tissue engineering, mineral density of dental hard tissues and about dental implants. Details of studies in each of these areas are highlighted along with the advantages of Micr...

  15. Dual-energy micro-CT imaging of pulmonary airway obstruction: correlation with micro-SPECT

    Science.gov (United States)

    Badea, C. T.; Befera, N.; Clark, D.; Qi, Y.; Johnson, G. A.

    2014-03-01

    To match recent clinical dual energy (DE) CT studies focusing on the lung, similar developments for DE micro-CT of the rodent lung are required. Our group has been actively engaged in designing pulmonary gating techniques for micro- CT, and has also introduced the first DE micro-CT imaging method of the rodent lung. The aim of this study was to assess the feasibility of DE micro-CT imaging for the evaluation of airway obstruction in mice, and to compare the method with micro single photon emission computed tomography (micro-SPECT) using technetium-99m labeled macroaggregated albumin (99mTc-MAA). The results suggest that the induced pulmonary airway obstruction causes either atelectasis, or air-trapping similar to asthma or chronic bronchitis. Atelectasis could only be detected at early time points in DE micro-CT images, and is associated with a large increase in blood fraction and decrease in air fraction. Air trapping had an opposite effect with larger air fraction and decreased blood fraction shown by DE micro-CT. The decrease in perfusion to the hypoventilated lung (hypoxic vasoconstriction) is also seen in micro-SPECT. The proposed DE micro-CT technique for imaging localized airway obstruction performed well in our evaluation, and provides a higher resolution compared to micro-SPECT. Both DE micro-CT and micro-SPECT provide critical, quantitative lung biomarkers for image-based anatomical and functional information in the small animal. The methods are readily linked to clinical methods allowing direct comparison of preclinical and clinical results.

  16. Fault-related structural permeability: Qualitative insights of the damage-zone from micro-CT analysis.

    Science.gov (United States)

    Gomila, Rodrigo; Arancibia, Gloria; Nehler, Mathias; Bracke, Rolf; Stöckhert, Ferdinand

    2016-04-01

    Fault zones and their related structural permeability play a leading role in the migration of fluids through the continental crust. A first approximation to understanding the structural permeability conditions, and the estimation of its hydraulic properties (i.e. palaeopermeability and fracture porosity conditions) of the fault-related fracture mesh is the 2D analysis of its veinlets, usually made in thin-section. Those estimations are based in the geometrical parameters of the veinlets, such as average fracture density, length and aperture, which can be statistically modelled assuming penny-shaped fractures of constant radius and aperture within an anisotropic fracture system. Thus, this model is related to fracture connectivity, its length and to the cube of the fracture apertures. In this way, the estimated values presents their own inaccuracies owing to the method used. Therefore, the study of the real spatial distribution of the veinlets of the fault-related fracture mesh (3D), feasible with the use of micro-CT analyses, is a first order factor to unravel both, the real structural permeability conditions of a fault-zone, together with the validation of previous estimations made in 2D analyses in thin-sections. This early contribution shows the preliminary results of a fault-related fracture mesh and its 3D spatial distribution in the damage zone of the Jorgillo Fault (JF), an ancient subvertical left-lateral strike-slip fault exposed in the Atacama Fault System in northern Chile. The JF is a ca. 20 km long NNW-striking strike-slip fault with sinistral displacement of ca. 4 km. The methodology consisted of the drilling of vertically oriented plugs of 5 mm in diameter located at different distances from the JF core - damage zone boundary. Each specimen was, then, scanned with an x-ray micro-CT scanner (ProCon X-Ray CTalpha) in order to assess the fracture mesh. X-rays were generated in a transmission target x-ray tube with acceleration voltages ranging from 90

  17. Checking collagen preservation in archaeological bone by non-destructive studies (Micro-CT and IBA)

    International Nuclear Information System (INIS)

    The material to be studied is a piece of human skull discovered (1999) in Pleistocene sediments from the Orsang river (Gujarat state, India). From anatomical view point, this skull is highly composite: modern Homo sapiens characters are associated to undoubtedly more ancient features. Absolute dating by 14C is critical to understand this discovery. Prior to dating measurements, non-destructive studies have been carried out. Micro-CT reconstruction (X-ray microtomography) and Ion Beam Analysis (IBA) have been undertaken to check the structural preservation of the fossil and the collagen preservation. PIXE elemental map was used to select well-preserved bone area. RBS/EBS and NRA were used for light element quantification, in particular C, N and O contents. We also demonstrate that the PIXE-RBS/EBS combination is a effective tool for the whole characterization of archaeological and recent bones by analysing in one experiment both mineral and organic fractions. We have shown that the archaeological bone, a fragment of the potentially oldest modern Indian, is enough preserved for radiocarbon dating. We propose that Elastic Backscattering Spectrometry (EBS) using 3 MeV protons could be a good non destructive alternative to conventional CHN method using Carbon–Hydrogen–Nitrogen analyzer for measuring C and N before 14C dating.

  18. Ultrafast micro-CT for in vivo small animal imaging and industrial applications

    Science.gov (United States)

    Sasov, Alexander

    2004-10-01

    A new, ultra-fast microCT instrument with scanning+reconstruction cycle under 50 seconds for full 3D-volume has been created. The scanner based on the scanning geometry with static object and rotation of source-camera pair(s), which allows using it for industrial applications as well as for low-dose in-vivo imaging of small laboratory animals where rotation of the object is not acceptable. Acquisition part contains two pairs of x-ray sources and cameras for data collection from complementary directions simultaneously. Reconstruction engine (cone-beam reconstruction by modified Feldkamp algotithm) includes 1, 2 or 4 dual Intel-Xeon computers working in parallel under control of the host PC through local network. The instrument specifications are following: voxel size is 48 or 96 um for corresponding 1024x1024x1024 or 512x512x512 reconstruction array; scanning time with parallel reconstruction is 50 seconds for 96um resolution. X-ray sources peak energy can be adjusted in the range of 20-65kV. Typical scanning dose is 0.4Gy. The scanner itself is a compact desktop instrument, which contains all x-ray parts and necessary shielding for safe operations in the normal laboratory environments.

  19. Checking collagen preservation in archaeological bone by non-destructive studies (Micro-CT and IBA)

    Energy Technology Data Exchange (ETDEWEB)

    Beck, L., E-mail: lucile.beck@cea.fr [C2RMF - UMR171 CNRS, Centre de Recherche et de Restauration des Musees de France, Palais du Louvre, Porte des Lions, 14 quai Francois Mitterrand, 75001 Paris (France); CEA, DEN, Service de Recherches de Metallurgie Physique, Laboratoire JANNUS, 91191 Gif-sur-Yvette (France); Cuif, J.-P. [UMR IDES 8148, Universite Paris XI-Orsay, 91405 Orsay cedex (France); Pichon, L. [C2RMF - UMR171 CNRS, Centre de Recherche et de Restauration des Musees de France, Palais du Louvre, Porte des Lions, 14 quai Francois Mitterrand, 75001 Paris (France); Vaubaillon, S. [CEA, INSTN, Laboratoire JANNUS, 91191 Gif-sur-Yvette (France); Dambricourt Malasse, A. [Departement de Prehistoire, Museum national d' Histoire naturelle, UMR 7194 - CNRS, Institut de Paleontologie Humaine, 1, rue Rene Panhard, 75013 Paris (France); Abel, R.L. [The Natural History Museum, London (United Kingdom)

    2012-02-15

    The material to be studied is a piece of human skull discovered (1999) in Pleistocene sediments from the Orsang river (Gujarat state, India). From anatomical view point, this skull is highly composite: modern Homo sapiens characters are associated to undoubtedly more ancient features. Absolute dating by {sup 14}C is critical to understand this discovery. Prior to dating measurements, non-destructive studies have been carried out. Micro-CT reconstruction (X-ray microtomography) and Ion Beam Analysis (IBA) have been undertaken to check the structural preservation of the fossil and the collagen preservation. PIXE elemental map was used to select well-preserved bone area. RBS/EBS and NRA were used for light element quantification, in particular C, N and O contents. We also demonstrate that the PIXE-RBS/EBS combination is a effective tool for the whole characterization of archaeological and recent bones by analysing in one experiment both mineral and organic fractions. We have shown that the archaeological bone, a fragment of the potentially oldest modern Indian, is enough preserved for radiocarbon dating. We propose that Elastic Backscattering Spectrometry (EBS) using 3 MeV protons could be a good non destructive alternative to conventional CHN method using Carbon-Hydrogen-Nitrogen analyzer for measuring C and N before {sup 14}C dating.

  20. ITER neutral beam system

    International Nuclear Information System (INIS)

    The Neutral Beam (NB) system for the International Thermonuclear Experimental Reactor (ITER) has reached a high degree of integration with the tokamak and with the rest of the plant. Operational requirements and maintainability have been considered in the design. The paper considers the integration with the tokamak, discusses design improvements which appear necessary and finally notes R and D progress in key areas. (author)

  1. Electron beam processing system

    International Nuclear Information System (INIS)

    Electron beam Processing Systems (EPS) are used as useful and powerful tools in many industrial application fields such as the production of cross-linked wire, rubber tire, heat shrinkable film and tubing, curing, degradation of polymers, sterilization and environmental application. In this paper, the feature and application fields, the selection of machine ratings and safety measures of EPS will be described. (author)

  2. 基于Medipix的谱微CT(英文)%Medipix-based Spectral Micro-CT

    Institute of Scientific and Technical Information of China (English)

    James Bennett; Raja Amir; Bruce Dobbs; 牟轩沁; 魏彪; Anthony Butler; Phillip Butler

    2012-01-01

    自从几十年前豪斯菲尔德因其突破性工作而赢得诺贝尔奖以来,X线CT已经被广泛的应用到了临床前以及临床应用,并产生了海量的灰度断层图像。由于其固有的光子计数问题涉及到较高的辐射剂量,这些灰度断层图像的软组织对比度差,经常难以提供一些关键性的细节而满足诊断的需要。从物理的角度来看,X线的谱是多能的,获得多能CT(亦被称为谱CT,真彩色CT)图像是可行的。这种谱图像提供了强有力的新诊断信息。近年来,新兴的Medipix技术提供了一种准确而快速的高分辨率能量选择的X线检测技术。本文将以我们小组的研究结果为重点来综述基于Medipix的谱微CT的研究进展。主要内容包括:先进的MediPix检测器,商业化MARS谱微CT的系统与方法,以及混合谱微CT的设计以及彩色扩散现象。%Since Hounsfield’s Nobel Prize winning breakthrough decades ago, X-ray CT has been widely applied in the clinical and preclinical applications-producing a huge number of tomographic gray-scale images. However, these images are often insufficient to distinguish crucial differences needed for diagnosis. They have poor soft tissue contrast due to inherent photon-count issues, involving high radiation dose. By physics, the X-ray spectrum is polychromatic, and it is now feasible to obtain multi-energy, spectral, or true-color, CT images. Such spectral images promise powerful new diagnostic information. The emerging Medipix technology promises energy-sensitive, high-resolution, accurate and rapid X-ray detection. In this paper, we will review the recent progress of Medipix-based spectral micro-CT with the emphasis on the results obtained by our team. It includes the state-of-the-art Medipix detector, the system and method of a commercial MARS (Medipix All Resolution System) spectral micro-CT, and the design and color diffusion of a hybrid spectral micro-CT.

  3. Performance evaluation of the General Electric eXplore CT 120 micro-CT using the vmCT phantom

    Energy Technology Data Exchange (ETDEWEB)

    Bahri, M.A., E-mail: M.Bahri@ulg.ac.be [ULg-Liege University, Cyclotron Research Centre, Liege, Bat. 30, Allee du 6 aout, 8 (Belgium); Warnock, G.; Plenevaux, A. [ULg-Liege University, Cyclotron Research Centre, Liege, Bat. 30, Allee du 6 aout, 8 (Belgium); Choquet, P.; Constantinesco, A. [Biophysique et Medecine Nucleaire, Hopitaux universitaires de Strasbourg, Strasbourg (France); Salmon, E.; Luxen, A. [ULg-Liege University, Cyclotron Research Centre, Liege, Bat. 30, Allee du 6 aout, 8 (Belgium); Seret, A. [ULg-Liege University, Cyclotron Research Centre, Liege, Bat. 30, Allee du 6 aout, 8 (Belgium); ULg-Liege University, Experimental Medical Imaging, Liege (Belgium)

    2011-08-21

    The eXplore CT 120 is the latest generation micro-CT from General Electric. It is equipped with a high-power tube and a flat-panel detector. It allows high resolution and high contrast fast CT scanning of small animals. The aim of this study was to compare the performance of the eXplore CT 120 with that of the eXplore Ultra, its predecessor for which the methodology using the vmCT phantom has already been described . The phantom was imaged using typical a rat (fast scan or F) or mouse (in vivo bone scan or H) scanning protocols. With the slanted edge method, a 10% modulation transfer function (MTF) was observed at 4.4 (F) and 3.9-4.4 (H) mm{sup -1} corresponding to 114 {mu}m resolution. A fairly larger MTF was obtained by the coil method with the MTF for the thinnest coil (3.3 mm{sup -1}) equal to 0.32 (F) and 0.34 (H). The geometric accuracy was better than 0.3%. There was a highly linear (R{sup 2}>0.999) relationship between measured and expected CT numbers for both the CT number accuracy and linearity sections of the phantom. A cupping effect was clearly seen on the uniform slices and the uniformity-to-noise ratio ranged from 0.52 (F) to 0.89 (H). The air CT number depended on the amount of polycarbonate surrounding the area where it was measured; a difference as high as approximately 200 HU was observed. This hindered the calibration of this scanner in HU. This is likely due to the absence of corrections for beam hardening and scatter in the reconstruction software. However in view of the high linearity of the system, the implementation of these corrections would allow a good quality calibration of the scanner in HU. In conclusion, the eXplore CT 120 achieved a better spatial resolution than the eXplore Ultra (based on previously reported specifications) and future software developments will include beam hardening and scatter corrections that will make the new generation CT scanner even more promising.

  4. Correlation of energy dispersive diffraction signatures and microCT of small breast tissue samples with pathological analysis

    International Nuclear Information System (INIS)

    Identification of specific tissue types in conventional mammographic examinations is extremely limited. However, the use of x-ray diffraction effects during imaging has the potential to characterize the tissue types present due to the fact that each tissue type produces its own unique diffraction signature. Nevertheless, the analysis and categorization of these diffraction signatures by tissue type can be hampered by the inhomogeneous nature of breast tissue, leading to categorization errors where several types are present. This work aims to reduce sample categorization errors by combining spectral diffraction signature collection with sample imaging, giving more detailed data on the composition of each sample. Diffraction microCT was carried out on 19 unfixed breast tissue samples using an energy resolving translate-rotate CT system. High-resolution transmission microCT images were also recorded for comparison and sample composition analysis. Following imaging, the samples were subjected to histopathological analysis. Reconstructing on various momentum transfer regions allows different tissue types to be identified in the diffraction images. Results show a correlation between measured x-ray diffraction images and stained histopathological tissue sections. X-ray diffraction signatures generated from the measured data were categorized and analysed, with a t-test indicating that they have the potential for use in tissue type identification

  5. Micro-CT examination of human bone: from biopsies towards the entire organ

    Directory of Open Access Journals (Sweden)

    Egon Perilli

    2012-01-01

    Full Text Available Micro-CT systems are available that facilitate ex vivo examinations of human specimens as big as entire vertebrae, with spatial resolutions in the 10-micrometer range. This opens a new way for looking at entire bones in 3D. Accurate description of the internal microarchitecture of the entire organ can be obtained, at spatial resolutions previously achievable only on excised biopsies. These high resolution scans produce large datasets and come with costs and benefits, which have to be considered in the successful planning of an experiment. The aim of this paper is to present examples of human vertebrae scanned at high resolution (17 μm/pixel, allowing the visualization and quantification of the microarchitecture, and to discuss some aspects of using high resolution scans of such large specimens. The datasets were down-sampled to 34 μm and 68 μm pixel size, and their morphometric parameters compared to those obtained at 17 μm pixel size, in relation to data size and calculation time.

  6. Simulation of PIXSCAN, a photon counting micro-CT for small animal imaging

    International Nuclear Information System (INIS)

    A main challenge in the development of new detectors is the achievement of a satisfactory comprehension of the instrument behaviour. We present the simulation work developed to understand and characterize an innovative micro-CT scanner. The PIXSCAN scanner is a photon counting device based on hybrid pixel detectors. Its working principle is expected to improve the contrast for soft tissues and to reduce both the scan duration and the dose absorbed by the animal. A prototype of the scanner, PIXSCAN-XPAD2, has been assembled and studied in order to achieve a proof of principle of the system. Simulations by analytical and Monte Carlo methods of the prototype and of the evaluation phantoms have been developed to ensure a satisfactory comprehension of the data. The Monte Carlo simulation was based on the GATE package. It included the complete simulation of photon propagation in matter, together with the modelling of the source spectrum, the scanner geometry and the sensor response. The analytical simulation is much more approximate, but its merit is the rapidity which permits fast preliminary results. Several figures of merit are studied and show good agreement with real data. Hence, the developed simulations can be used as a valid tool for the estimation of the ultimate PIXSCAN performances, in terms of spatial resolution, contrast measurement and dose reduction.

  7. Noninvasive monitoring of mouse renal allograft rejection using micro-CT

    OpenAIRE

    Hou, Jiangang; Fujino, Masayuki; Cai, Songjie; Ding, Qiang; Li, Xiao-Kang

    2015-01-01

    Purpose Acute renal graft rejection can only be definitively diagnosed by renal biopsy. However, biopsies carry a risk of renal transplant injury and loss. Micro-CT is widely used in preclinical studies of small animals. Here, we propose micro-CT could noninvasively monitor and evaluate renal location and function in a mouse kidney transplant model. Methods Orthotopic kidney transplantation was performed in a BALB/c -to- C57BL/6j or C57BL/6j-to- C57BL/6j mouse model. After optimizing imaging ...

  8. Value of Micro-CT for Monitoring Spinal Microvascular Changes after Chronic Spinal Cord Compression

    Directory of Open Access Journals (Sweden)

    Hou-Qing Long

    2014-07-01

    Full Text Available Neurological degeneration can occur after compression of the spinal cord. It is widely accepted that spinal cord compression leads to ischemic lesions and ultimately neurological dysfunction due to a narrowed spinal canal. Therefore, an in-depth understanding of the pathogenesis of spinal cord compression injury is required to help develop effective clinical interventions. In the present study, we propose a new method of quantitative 3D micro-CT to observe microvascular events in a chronic spinal cord compression rat model. A total of 36 rats were divided into two groups: sham control group (n = 12 and compressive spinal cord injury group (n = 24. Rats were scarified at four weeks after surgery. In each group, CD34 micro-vessel immunohistochemical staining was performed in half of the animals, while micro-CT scanning was performed in the other half. Microvessel density (MVD was measured after immunohistochemical staining, while the vascular index (VI was measured in 3D micro-CT. In comparison with sham control, abnormal somatosensory evoked potentials (SEP can be seen in all 24 cases of the compression group, and VI shows the amount of microvessels reduced consistently and significantly (p < 0.01. A significant correlation is also found between MVD and VI (r = 0.95, p < 0.01. These data suggest that quantitative 3D micro-CT is a sensitive and promising tool for investigating microvascular changes during chronic compressive spinal cord injury.

  9. Quantifying lung morphology with respiratory-gated micro-CT in a murine model of emphysema

    Energy Technology Data Exchange (ETDEWEB)

    Ford, N L [Department of Physics, Ryerson University, 350 Victoria Street, Toronto, Ontario M5B 2K3 (Canada); Martin, E L; Lewis, J F; Veldhuizen, R A W [Lawson Health Research Institute, 268 Grosvenor Street, London, Ontario N6A 4V2 (Canada); Holdsworth, D W; Drangova, M [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, PO Box 5015, London, Ontario N6A 5K8 (Canada)], E-mail: nlford@ryerson.ca

    2009-04-07

    Non-invasive micro-CT imaging techniques have been developed to investigate lung structure in free-breathing rodents. In this study, we investigate the utility of retrospectively respiratory-gated micro-CT imaging in an emphysema model to determine if anatomical changes could be observed in the image-derived quantitative analysis at two respiratory phases. The emphysema model chosen was a well-characterized, genetically altered model (TIMP-3 knockout mice) that exhibits a homogeneous phenotype. Micro-CT scans of the free-breathing, anaesthetized mice were obtained in 50 s and retrospectively respiratory sorted and reconstructed, providing 3D images representing peak inspiration and end expiration with 0.15 mm isotropic voxel spacing. Anatomical measurements included the volume and CT density of the lungs and the volume of the major airways, along with the diameters of the trachea, left bronchus and right bronchus. From these measurements, functional parameters such as functional residual capacity and tidal volume were calculated. Significant differences between the wild-type and TIMP-3 knockout groups were observed for measurements of CT density over the entire lung, indicating increased air content in the lungs of TIMP-3 knockout mice. These results demonstrate retrospective respiratory-gated micro-CT, providing images at multiple respiratory phases that can be analyzed quantitatively to investigate anatomical changes in murine models of emphysema.

  10. Integrated visualization of multi-angle bioluminescence imaging and micro CT

    NARCIS (Netherlands)

    Kok, P.; Dijkstra, J.; Botha, C.P.; Post, F.H.; Kaijzel, E.; Que, I.; Löwik, C.W.G.M.; Reiber, J.H.C.; Lelieveldt, B.P.F.

    2007-01-01

    This paper explores new methods to visualize and fuse multi-2D bioluminescence imaging (BLI) data with structural imaging modalities such as micro CT and MR. A geometric, back-projection-based 3D reconstruction for superficial lesions from multi-2D BLI data is presented, enabling a coarse estimate o

  11. Micro-CT molecular imaging of tumor angiogenesis using a magnetite nano-cluster probe.

    Science.gov (United States)

    Liu, Ping; Li, Jing; Zhang, Chunfu; Xu, Lisa X

    2013-06-01

    Due to its high resolution, micro-CT is desirable for molecular imaging of tumor angiogenesis. However, the sensitivity of micro-CT to contrast agents is relatively low. Therefore, the purpose of this study is to develop high micro-CT sensitive molecular imaging probes for direct visualization and dynamic monitoring of tumor angiogenesis. To this end, Arg-Gly-Asp (RGD) peptides conjugated magnetite nano clusters (RGD-MNCs) were developed by assembling individual magnetite nano particles into clusters with amphiphilic (maleimide) methoxypoly(ethylene glycol)-b-poly(lactic acid) ((Mal)mPEG-PLA) copolymer and subsequently encoding RGD peptides onto the clusters for specific targeting alpha(v)beta3 integrin. The hydrodynamic size of RGD-MNCs was about 85 nm. To test its specificity, alpha(v)beta3 positive cells (H1299) were incubated with magnetite nano clusters (MNCs), RGD-MNCs or RGD-MNCs competition with free RGD peptides. Prussian Blue staining and inductively coupled plasma optical emission spectrometer (ICP-OES) measurements indicated that the cell uptake of RGD-MNCs was significantly more than that of MNCs, which could be inhibited by free RGD peptides. For detection of tumor angiogenesis, mice bearing H1299 tumors were injected intravenously with RGD-MNCs at the dose of 400 micro mol Fe/kg. Tumor angiogenic hot spots as well as individual angiogenic vessels could be clearly manifested by micro-CT imaging 12 h post injection, which was dynamically monitored with the extension of probe circulation time. Subsequent histological studies of tumor tissues verified that RGD-MNCs registered tumor angiogenic vessels. Our study demonstrated that RGD-MNC probes fabricated in this study could be used to effectively target alpha(v)beta3 integrin. Using high resolution micro-CT in combination with the probes, tumor angiogenesis could be studied dynamically. PMID:23858968

  12. HECTOR: A 240kV micro-CT setup optimized for research

    Science.gov (United States)

    Masschaele, Bert; Dierick, Manuel; Van Loo, Denis; Boone, Matthieu N.; Brabant, Loes; Pauwels, Elin; Cnudde, Veerle; Van Hoorebeke, Luc

    2013-10-01

    X-ray micro-CT has become a very powerful and common tool for non-destructive three-dimensional (3D) visualization and analysis of objects. Many systems are commercially available, but they are typically limited in terms of operational freedom both from a mechanical point of view as well as for acquisition routines. HECTOR is the latest system developed by the Ghent University Centre for X-ray Tomography (http://www.ugct.ugent.be) in collaboration with X-Ray Engineering (XRE bvba, Ghent, Belgium). It consists of a mechanical setup with nine motorized axes and a modular acquisition software package and combines a microfocus directional target X-ray source up to 240 kV with a large flat-panel detector. Provisions are made to install a line-detector for a maximal operational range. The system can accommodate samples up to 80 kg, 1 m long and 80 cm in diameter while it is also suited for high resolution (down to 4 μm) tomography. The bi-directional detector tiling is suited for large samples while the variable source-detector distance optimizes the signal to noise ratio (SNR) for every type of sample, even with peripheral equipment such as compression stages or climate chambers. The large vertical travel of 1 m can be used for helical scanning and a vertical detector rotation axis allows laminography experiments. The setup is installed in a large concrete bunker to allow accommodation of peripheral equipment such as pumps, chillers, etc., which can be integrated in the modular acquisition software to obtain a maximal correlation between the environmental control and the CT data taken. The acquisition software does not only allow good coupling with the peripheral equipment but its scripting feature is also particularly interesting for testing new and exotic acquisition routines.

  13. HECTOR: A 240kV micro-CT setup optimized for research

    International Nuclear Information System (INIS)

    X-ray micro-CT has become a very powerful and common tool for non-destructive three-dimensional (3D) visualization and analysis of objects. Many systems are commercially available, but they are typically limited in terms of operational freedom both from a mechanical point of view as well as for acquisition routines. HECTOR is the latest system developed by the Ghent University Centre for X-ray Tomography (http://www.ugct.ugent.be) in collaboration with X-Ray Engineering (XRE bvba, Ghent, Belgium). It consists of a mechanical setup with nine motorized axes and a modular acquisition software package and combines a microfocus directional target X-ray source up to 240 kV with a large flat-panel detector. Provisions are made to install a line-detector for a maximal operational range. The system can accommodate samples up to 80 kg, 1 m long and 80 cm in diameter while it is also suited for high resolution (down to 4 μm) tomography. The bi-directional detector tiling is suited for large samples while the variable source-detector distance optimizes the signal to noise ratio (SNR) for every type of sample, even with peripheral equipment such as compression stages or climate chambers. The large vertical travel of 1 m can be used for helical scanning and a vertical detector rotation axis allows laminography experiments. The setup is installed in a large concrete bunker to allow accommodation of peripheral equipment such as pumps, chillers, etc., which can be integrated in the modular acquisition software to obtain a maximal correlation between the environmental control and the CT data taken. The acquisition software does not only allow good coupling with the peripheral equipment but its scripting feature is also particularly interesting for testing new and exotic acquisition routines

  14. Micro CT imaging assessment for spatial distribution of magnetic nanoparticles in an ex vivo thrombolysis model

    Science.gov (United States)

    Wang, Fu-Sheng; Chao, Tsi-Chian; Tu, Shu-Ju

    2012-03-01

    In recent nanotechnology development, iron-based magnetic nanoparticles (MNPs) have been used in several investigations on biomedical research for small animal experiments. Their important applications include targeted drug delivery for therapeutic purpose, contrast agent for magnetic resonance imaging, and hyperthermia treatment for tumors. These MNPs can be guided by an external magnetic field due to their physical characteristics of superparamagnetism. In a recent report, authors indicated that covalently bound recombinant tissue plasminogen activator (rtPA) to MNP (MNPrtPA) with preserved enzyme activity may be guided by a bar magnet and induce target thrombolysis in an embolic model in rats. Delivery of rtPA by binding the thrombolytic drug to MNPs will improve the possibility of the drug to be delivered under magnetic guidance and retained in a local targeted area in the circulation system. In this work, an ex vivo intravascular thrombolysis model was developed to study the impact of external magnetic field on the penetration of MNP-rtPA in the blood clot samples. The samples were then scanned by a micro CT system for quantification. Images of MNPs show strong contrast with their surrounding blood clot materials. The optimum drug loading was found when 0.5 mg/ml rtPA is conjugated with 10 mg SiO2-MNP where 98% drug was attached to the carrier with full retention of its thrombolytic activity. Effective thrombolysis with tPA bound to SiO2-MNP under magnetic guidance was demonstrated in our ex vivo model where substantial reduction in time for blood clot lysis was observed compared with control groups without magnetic field application.

  15. Longitudinal study of a mouse model of chronic pulmonary inflammation using breath hold gated micro-CT

    International Nuclear Information System (INIS)

    To evaluate the feasibility of using automatic quantitative analysis of breath hold gated micro-CT images to detect and monitor disease in a mouse model of chronic pulmonary inflammation, and to compare image-based measurements with pulmonary function tests and histomorphometry. Forty-nine A/J mice were used, divided into control and inflammation groups. Chronic inflammation was induced by silica aspiration. Fourteen animals were imaged at baseline, and 4, 14, and 34 weeks after silica aspiration, using micro-CT synchronized with ventilator-induced breath holds. Lung input impedance was measured as well using forced oscillation techniques. Five additional animals from each group were killed after micro-CT for comparison with histomorphometry. At all time points, micro-CT measurements show statistically significant differences between the two groups, while first differences in functional test parameters appear at 14 weeks. Micro-CT measurements correlate well with histomorphometry and discriminate diseased and healthy groups better than functional tests. Longitudinal studies using breath hold gated micro-CT are feasible on the silica-induced model of chronic pulmonary inflammation, and automatic measurements from micro-CT images correlate well with histomorphometry, being more sensitive than functional tests to detect lung damage in this model. (orig.)

  16. Beam alignment system for laser welding system

    International Nuclear Information System (INIS)

    The patent describes a beam alignment system for laser welding work pieces, such as fuel rod grids for nuclear fuel assemblies. The apparatus for performing various laser-machining comprises a beam alignment system including alignment target means, as well as means for emitting, directing and focusing the laser beam. (U.K.)

  17. X-ray micro-CT scanner for small animal imaging based on Timepix detector technology

    Energy Technology Data Exchange (ETDEWEB)

    Dudak, Jan, E-mail: jan.dudak@utef.cvut.cz [Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, 128 00 Prague 2 (Czech Republic); Faculty of Biomedical Engineering, Czech Technical University in Prague, Nam. Sitna 3105, 272 00 Kladno (Czech Republic); Zemlicka, Jan; Krejci, Frantisek; Polansky, Stepan; Jakubek, Jan [Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, 128 00 Prague 2 (Czech Republic); Mrzilkova, Jana; Patzelt, Matej; Trnka, Jan [Third Faculty of Medicine, Charles University in Prague, Ruska 87, 100 00 Prague (Czech Republic)

    2015-02-11

    We describe a newly developed compact micro-CT scanner with rotating gantry equipped with a Timepix Quad hybrid pixel semiconductor detector and a micro-focus X-ray tube providing spatial resolution down to 30 µm. The resolving power of the device in relation to soft tissue sensitivity is demonstrated using a tissue-equivalent phantom and different types of biological samples. The results demonstrate that the use of noiseless particle counting detectors is a promising way to achieve sufficient soft tissue contrast even without any contrast agents. - Highlights: • We developed a new micro-CT scanner for small animal imaging. • Application of Timepix technology to obtain enhanced soft tissue contrast. • Spatial resolution below 30 µm achieved. • Performance demonstrated using a tissue equivalent phantom and biological samples.

  18. X-ray micro-CT scanner for small animal imaging based on Timepix detector technology

    International Nuclear Information System (INIS)

    We describe a newly developed compact micro-CT scanner with rotating gantry equipped with a Timepix Quad hybrid pixel semiconductor detector and a micro-focus X-ray tube providing spatial resolution down to 30 µm. The resolving power of the device in relation to soft tissue sensitivity is demonstrated using a tissue-equivalent phantom and different types of biological samples. The results demonstrate that the use of noiseless particle counting detectors is a promising way to achieve sufficient soft tissue contrast even without any contrast agents. - Highlights: • We developed a new micro-CT scanner for small animal imaging. • Application of Timepix technology to obtain enhanced soft tissue contrast. • Spatial resolution below 30 µm achieved. • Performance demonstrated using a tissue equivalent phantom and biological samples

  19. Automated segmentation of murine lung tumors in x-ray micro-CT images

    Science.gov (United States)

    Swee, Joshua K. Y.; Sheridan, Clare; de Bruin, Elza; Downward, Julian; Lassailly, Francois; Pizarro, Luis

    2014-03-01

    Recent years have seen micro-CT emerge as a means of providing imaging analysis in pre-clinical study, with in-vivo micro-CT having been shown to be particularly applicable to the examination of murine lung tumors. Despite this, existing studies have involved substantial human intervention during the image analysis process, with the use of fully-automated aids found to be almost non-existent. We present a new approach to automate the segmentation of murine lung tumors designed specifically for in-vivo micro-CT-based pre-clinical lung cancer studies that addresses the specific requirements of such study, as well as the limitations human-centric segmentation approaches experience when applied to such micro-CT data. Our approach consists of three distinct stages, and begins by utilizing edge enhancing and vessel enhancing non-linear anisotropic diffusion filters to extract anatomy masks (lung/vessel structure) in a pre-processing stage. Initial candidate detection is then performed through ROI reduction utilizing obtained masks and a two-step automated segmentation approach that aims to extract all disconnected objects within the ROI, and consists of Otsu thresholding, mathematical morphology and marker-driven watershed. False positive reduction is finally performed on initial candidates through random-forest-driven classification using the shape, intensity, and spatial features of candidates. We provide validation of our approach using data from an associated lung cancer study, showing favorable results both in terms of detection (sensitivity=86%, specificity=89%) and structural recovery (Dice Similarity=0.88) when compared against manual specialist annotation.

  20. High resolution micro-CT of low attenuating material utilizing large area photon counting detector

    Czech Academy of Sciences Publication Activity Database

    Kumpová, Ivana; Vavřík, Daniel; Kytýř, Daniel; Fíla, Tomáš; Gantar, A.

    Brno : Central European Institute of Technology, 2015. s. 104-104 ISBN N. [Creating life in 3D. Conference on frontiers in materials and life sciences. 02.09.2015-04.09.2015, Brno] R&D Projects: GA MŠk(CZ) LO1219 Keywords : micro-CT * gellan gum * WidePIX Subject RIV: AL - Art, Architecture, Cultural Heritage http://www.ceitec.eu/a5-abstracts-book-3d/f33102

  1. Recent Progress Validating the HADES Model of LLNL's HEAF MicroCT Measurements

    Energy Technology Data Exchange (ETDEWEB)

    White, W. T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bond, K. C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lennox, K. P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Aufderheide, M. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Seetho, I. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Roberson, G. P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-07-17

    This report compares recent HADES calculations of x-ray linear attenuation coefficients to previous MicroCT measurements made at Lawrence Livermore National Laboratory’s High Energy Applications Facility (HEAF). The chief objective is to investigate what impact recent changes in HADES modeling have on validation results. We find that these changes have no obvious effect on the overall accuracy of the model. Detailed comparisons between recent and previous results are presented.

  2. Microstructural Properties of Acetabular Region of Human Pelvic Bone Revealed Using micro-CT

    Czech Academy of Sciences Publication Activity Database

    Kytýř, Daniel; Jiroušek, Ondřej; Vavřík, Daniel

    Praha : ÚTAM, 2009 - (Náprstek,, J.; Fischer, C.), s. 166-167 ISBN 978-80-86246-35-2. [Engineering mechanics 2009. Svratka (CZ), 11.05.2009-14.05.2009] R&D Projects: GA ČR(CZ) GP103/07/P483 Institutional research plan: CEZ:AV0Z20710524 Keywords : micro-CT * acetabulum * microstructure Subject RIV: FI - Traumatology, Orthopedics

  3. The extensor carpi ulnaris pseudolesion: evaluation with microCT, histology, and MRI

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Sayed; Cunningham, Ryan; Mohamed, Feroze [Temple University Hospital, Department of Radiology, Philadelphia, PA (United States); Amin, Mamta; Popoff, Steven N.; Barbe, Mary F. [Temple University School of Medicine, Department of Anatomy, Philadelphia, PA (United States)

    2015-12-15

    To determine if magic angle plays a role in apparent central increased signal intensity of the distal extensor carpi ulnaris tendon (ECU) on MRI, to see if histologic findings of tendon degeneration are associated with increased T1 or T2 tendon signal on MR imaging, and to determine the prevalence of the ECU ''pseudolesion''. A standard 3 Tesla protocol was utilized to scan ten cadaveric wrists. A 40 mm length of 10 ECU and four extensor carpi radialis brevis (ECRB) tendons were immersion fixed before microCT scanning. Staining with Alcian blue, Masson's trichrome and Safranin O was performed before light microscopy. Fifty clinical wrist MRIs were also reviewed for the presence of increased T1 and/or T2 signal. Central increased T1 and/or T2 signal was observed in 9 of 10 cadaveric ECU tendons, but not in ECRB tendons. MicroCT and histology showed inter-tendinous matrix between the two distal heads of the ECU. Increased mucoid degeneration correlated with increased MRI signal intensity. The tendon fibers were at a maximum of 8.39 to the longitudinal axis on microCT. Clinical MRIs showed increased T1 signal in 6 %, increased T2 signal in 8 %, increased T1 and T2 signal in 80 %, and 6 % showing no increased signal. Central increased T1 and/or T2 signal in the ECU tendon indicates the presence of normal inter-tendinous ground substance, with increased proteoglycan content (mucoid degeneration) responsible for increased signal intensity. None of the fibers were shown on microCT to approach the magic angle. (orig.)

  4. The extensor carpi ulnaris pseudolesion: evaluation with microCT, histology, and MRI

    International Nuclear Information System (INIS)

    To determine if magic angle plays a role in apparent central increased signal intensity of the distal extensor carpi ulnaris tendon (ECU) on MRI, to see if histologic findings of tendon degeneration are associated with increased T1 or T2 tendon signal on MR imaging, and to determine the prevalence of the ECU ''pseudolesion''. A standard 3 Tesla protocol was utilized to scan ten cadaveric wrists. A 40 mm length of 10 ECU and four extensor carpi radialis brevis (ECRB) tendons were immersion fixed before microCT scanning. Staining with Alcian blue, Masson's trichrome and Safranin O was performed before light microscopy. Fifty clinical wrist MRIs were also reviewed for the presence of increased T1 and/or T2 signal. Central increased T1 and/or T2 signal was observed in 9 of 10 cadaveric ECU tendons, but not in ECRB tendons. MicroCT and histology showed inter-tendinous matrix between the two distal heads of the ECU. Increased mucoid degeneration correlated with increased MRI signal intensity. The tendon fibers were at a maximum of 8.39 to the longitudinal axis on microCT. Clinical MRIs showed increased T1 signal in 6 %, increased T2 signal in 8 %, increased T1 and T2 signal in 80 %, and 6 % showing no increased signal. Central increased T1 and/or T2 signal in the ECU tendon indicates the presence of normal inter-tendinous ground substance, with increased proteoglycan content (mucoid degeneration) responsible for increased signal intensity. None of the fibers were shown on microCT to approach the magic angle. (orig.)

  5. MR spectroscopy and micro-CT in evaluation of osteoporosis model in rabbits: comparison with histopathology

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guan-wu; Tang, Guang-yu; Liu, Yong; Tang, Rong-biao; Peng, Yi-feng; Li, Wei [People' s Hospital of Tongji University, Department of Radiology, Shanghai (China)

    2012-04-15

    To explore the evidence of regular alteration of bone quality in osteoporosis dynamically examined by MRS and micro-CT, comparing with histopathology. Forty rabbits were allocated into two groups. Group A were used as sham. Group B underwent bilateral ovariectomy (OVX) combined with daily intramuscular methylprednisolone, underwent MR spectroscopy, micro-CT, and histopathology of L5 at 2, 4, 8, and 10 weeks after operation. Fat fraction as shown by MRS in Group B was significantly increased over the time course of osteoporosis development with significant difference between two groups at 4, 8, and 10 weeks after OVX. Continuous deterioration of cancellous bone architecture in Group B, was first detected at week4. FF value in group B correlated with micro-CT parameters. Marrow fat as measured by MR and CT was positively correlated with both the mean density and diameter of adipocytes (both of which increased over time). Marrow adipogenesis occurs in synchrony with deterioration of trabecular microarchitecture.MRS may be valuable to assess the pathophysiological changes of bone marrow in osteoporosis in early stage. (orig.)

  6. MR spectroscopy and micro-CT in evaluation of osteoporosis model in rabbits: comparison with histopathology

    International Nuclear Information System (INIS)

    To explore the evidence of regular alteration of bone quality in osteoporosis dynamically examined by MRS and micro-CT, comparing with histopathology. Forty rabbits were allocated into two groups. Group A were used as sham. Group B underwent bilateral ovariectomy (OVX) combined with daily intramuscular methylprednisolone, underwent MR spectroscopy, micro-CT, and histopathology of L5 at 2, 4, 8, and 10 weeks after operation. Fat fraction as shown by MRS in Group B was significantly increased over the time course of osteoporosis development with significant difference between two groups at 4, 8, and 10 weeks after OVX. Continuous deterioration of cancellous bone architecture in Group B, was first detected at week4. FF value in group B correlated with micro-CT parameters. Marrow fat as measured by MR and CT was positively correlated with both the mean density and diameter of adipocytes (both of which increased over time). Marrow adipogenesis occurs in synchrony with deterioration of trabecular microarchitecture.MRS may be valuable to assess the pathophysiological changes of bone marrow in osteoporosis in early stage. (orig.)

  7. Adaptive region of interest method for analytical micro-CT reconstruction.

    Science.gov (United States)

    Yang, Wanneng; Xu, Xiaochun; Bi, Kun; Zeng, Shaoqun; Liu, Qian; Chen, Shangbin

    2011-01-01

    The real-time imaging is important in automatic successive inspection with micro-computerized tomography (micro-CT). Generally, the size of the detector is chosen according to the most probable size of the measured object to acquire all the projection data. Given enough imaging area and imaging resolution of X-ray detector, the detector is larger than specimen projection area, which results in redundant data in the Sinogram. The process of real-time micro-CT is computation-intensive because of the large amounts of source and destination data. The speed of the reconstruction algorithm can't always meet the requirements of real-time applications. A preprocessing method called adaptive region of interest (AROI), which detects the object's boundaries automatically to focus the active Sinogram regions, is introduced into the analytical reconstruction algorithm in this paper. The AROI method reduces the volume of the reconstructing data and thus directly accelerates the reconstruction process. It has been further shown that image quality is not compromised when applying AROI, while the reconstruction speed is increased as the square of the ratio of the sizes of the detector and the specimen slice. In practice, the conch reconstruction experiment indicated that the process is accelerated by 5.2 times with AROI and the imaging quality is not degraded. Therefore, the AROI method improves the speed of analytical micro-CT reconstruction significantly. PMID:21422587

  8. A MicroCT-Based Method for the Measurement of Pulmonary Compliance in Healthy and Bleomycin-Exposed Mice

    OpenAIRE

    Shofer, Scott; Badea, Cristian; Auerbach, Scott; Schwartz, David A.; Johnson, G. Allan

    2007-01-01

    Micro-computed tomography (microCT) is being increasingly used to examine small animal models of pulmonary injury. We have developed a microCT technique suitable for the determination of pulmonary compliance in injured mice. Lung volumes in normal mice were radiographically determined at end-inspiration and end-expiration and pulmonary compliance was calculated at two timepoints 2 weeks apart, while a second group of mice were given bleomycin and imaged 3 weeks following drug administration. ...

  9. Local variations in bone mineral density: a comparison of OCT versus x-ray micro-CT

    Science.gov (United States)

    Ugryumova, Nadya; Stevens-Smith, Jenna; Scutt, Andrew; Matcher, Stephen J.

    2008-02-01

    We describe variations in the degree of mineralisation within the subchondral bone plate of the equine metacarpophalangeal joint. A comparison of Optical Coherence Tomography, Micro CT, and SEM techniques was performed. These data are compared between sites on a healthy sample and at points on an osteoarthritically degenerated sample. No significant correlation was found between the optical scattering coefficient and the micro-CT derived BMD for comparisons between different sites on the bone surface. Also OCT demonstrated a larger regional variation in scattering coefficient than did micro CT for bone mineral density. This suggests that the optical scattering coefficient of bone is not related solely to the volume-density of calcium-phosphate. Patches of lower optical scattering coefficient were found in the bone structure that was related to the osteoarthritic lesion area on the overlying cartilage. Areas of microcracking, as revealed by both SEM and micro CT produced distinctive granularity in the OCT images. In further experiments, OCT was compared with micro CT and mechanical strength testing (3-point bending) in a small animal model of cardiovascular disease (cholesterol overload in mice). In the cardiovascular diseased mice, micro-CT of the trabecular bone did not demonstrate a significant change in trabecular bone mineral density before and after administration of the high cholesterol diet. However mechanical testing demonstrated a decrease in mechanical strength and OCT demonstrated a corresponding statistically significant decrease in optical scattering of the bone.

  10. Beam Cleaning and Collimation Systems

    CERN Document Server

    Redaelli, S

    2016-01-01

    Collimation systems in particle accelerators are designed to dispose of unavoidable losses safely and efficiently during beam operation. Different roles are required for different types of accelerator. The present state of the art in beam collimation is exemplified in high-intensity, high-energy superconducting hadron colliders, like the CERN Large Hadron Collider (LHC), where stored beam energies reach levels up to several orders of magnitude higher than the tiny energies required to quench cold magnets. Collimation systems are essential systems for the daily operation of these modern machines. In this document, the design of a multistage collimation system is reviewed, taking the LHC as an example case study. In this case, unprecedented cleaning performance has been achieved, together with a system complexity comparable to no other accelerator. Aspects related to collimator design and operational challenges of large collimation systems are also addressed.

  11. Beam steering system

    Science.gov (United States)

    Bowhill, S. A.; Merewether, K. O.

    1986-01-01

    A simple technique for steering the beam of a multimodule phased array MST (mesosphere, stratosphere, troposphere) radar antenna is described. It is desirable to be able to point the antenna in multiple directions, so as to derive all components of the horizontal velocity. This was done on an experimental basis by adding parallel wire line to the feed and achieving a southward tilt of the antenna. It is proved possible to steer the beam through most of the available range without adversely affecting the VSWR seen from the transmitter. Calibrating the antenna direction can be accomplished by observing radio sources, though there are an inadequate number to cover all directions. For various assumed values of the aspect sensitivity in dB/deg, and the calculated antenna pattern, it is possible to calculate the effective pointing angle of the antenna, defined as that angle which would give an identical location for the centroid of the power spectrum if aspect sensitivity were absent. Using averaged apparent steering directions, eastward and northward winds were calculated for special radar runs simultaneous with 14 balloon launches at Peoria and results are presented.

  12. Combined micro-PET/micro-CT imaging of lung tumours in SPC-raf and SPC-myc transgenic mice.

    Directory of Open Access Journals (Sweden)

    Thomas Rodt

    Full Text Available INTRODUCTION: SPC-raf and SPC-myc transgenic mice develop disseminated and circumscribed lung adenocarcinoma respectively, allowing for assessment of carcinogenesis and treatment strategies. The purpose of this study was to investigate the technical feasibility, the correlation of initial findings to histology and the administered radiation dose of combined micro-PET/micro-CT in these animal models. MATERIAL AND METHODS: 14 C57BL/6 mice (4 nontransgenic, 4 SPC-raf transgenic, 6 SPC-myc transgenic were examined using micro-CT and (18F-Fluoro-deoxyglucose micro-PET in-vivo. Micro-PET data was corrected for random events and scatter prior to reconstruction with a 3D-FORE/2D-OSEM iterative algorithm. Rigid micro-PET/micro-CT registration was performed. Tumour-to-non-tumour ratios were calculated for different lung regions and focal lesions. Diffuse tumour growth was quantified using a semiautomated micro-CT segmentation routine reported earlier. Regional histologic tumour load was assessed using a 4-point rating scale. Gamma radiation dose was determined using thermoluminescence dosimeters. RESULTS: Micro-CT allowed visualisation of diffuse and circumscribed tumours in SPC-raf and SPC-myc transgenic animals along with morphology, while micro-PET provided information on metabolism, but lacked morphologic detail. Mean tumour-to-non-tumour ratio was 2.47 for circumscribed lesions. No significant correlation could be shown between histological tumour load and tumour-to-nontumour ratio for diffuse tumours in SPC-raf transgenic animals. Calculation of the expected dose based on gamma dosimetry yielded approximately 140 mGy/micro-PET examination additional to approximately 200 mGy due to micro-CT. CONCLUSIONS: Combined micro-PET/micro-CT imaging allows for in-vivo assessment of lung tumours in SPC-raf and SPC-myc transgenic mice. The technique has potential for the evaluation of carcinogenesis and treatment strategies in circumscribed lung tumours.

  13. Combined Micro-PET/Micro-CT Imaging of Lung Tumours in SPC-raf and SPC-myc Transgenic Mice

    Science.gov (United States)

    Rodt, Thomas; Luepke, Matthias; Boehm, Claudia; Hueper, Katja; Halter, Roman; Glage, Silke; Hoy, Ludwig; Wacker, Frank; Borlak, Juergen; von Falck, Christian

    2012-01-01

    Introduction SPC-raf and SPC-myc transgenic mice develop disseminated and circumscribed lung adenocarcinoma respectively, allowing for assessment of carcinogenesis and treatment strategies. The purpose of this study was to investigate the technical feasibility, the correlation of initial findings to histology and the administered radiation dose of combined micro-PET/micro-CT in these animal models. Material and Methods 14 C57BL/6 mice (4 nontransgenic, 4 SPC-raf transgenic, 6 SPC-myc transgenic) were examined using micro-CT and 18F-Fluoro-deoxyglucose micro-PET in-vivo. Micro-PET data was corrected for random events and scatter prior to reconstruction with a 3D-FORE/2D-OSEM iterative algorithm. Rigid micro-PET/micro-CT registration was performed. Tumour-to-non-tumour ratios were calculated for different lung regions and focal lesions. Diffuse tumour growth was quantified using a semiautomated micro-CT segmentation routine reported earlier. Regional histologic tumour load was assessed using a 4-point rating scale. Gamma radiation dose was determined using thermoluminescence dosimeters. Results Micro-CT allowed visualisation of diffuse and circumscribed tumours in SPC-raf and SPC-myc transgenic animals along with morphology, while micro-PET provided information on metabolism, but lacked morphologic detail. Mean tumour-to-non-tumour ratio was 2.47 for circumscribed lesions. No significant correlation could be shown between histological tumour load and tumour-to-nontumour ratio for diffuse tumours in SPC-raf transgenic animals. Calculation of the expected dose based on gamma dosimetry yielded approximately 140 mGy/micro-PET examination additional to approximately 200 mGy due to micro-CT. Conclusions Combined micro-PET/micro-CT imaging allows for in-vivo assessment of lung tumours in SPC-raf and SPC-myc transgenic mice. The technique has potential for the evaluation of carcinogenesis and treatment strategies in circumscribed lung tumours. PMID:23028537

  14. ITER Neutral Beam Injection System

    International Nuclear Information System (INIS)

    A Japanese design proposal of the ITER Neutral Beam Injection System (NBS) which is consistent with the ITER common design requirements is described. The injection system is required to deliver a neutral deuterium beam of 75MW at 1.3MeV to the reactor plasma and utilized not only for plasma heating but also for current drive and current profile control. The injection system is composed of 9 modules, each of which is designed so as to inject a 1.3MeV, 10MW neutral beam. The most important point in the design is that the injection system is based on the utilization of a cesium-seeded volume negative ion source which can produce an intense negative ion beam with high current density at a low source operating pressure. The design value of the source is based on the experimental values achieved at JAERI. The utilization of the cesium-seeded volume source is essential to the design of an efficient and compact neutral beam injection system which satisfies the ITER common design requirements. The critical components to realize this design are the 1.3MeV, 17A electrostatic accelerator and the high voltage DC acceleration power supply, whose performances must be demonstrated prior to the construction of ITER NBI system. (author)

  15. The SSC beam scraper system

    Energy Technology Data Exchange (ETDEWEB)

    Maslov, M.A.; Mokhov, N.V.; Yazynin (Superconducting Super Collider Lab., Dallas, TX (United States) Institut Fiziki Vysokikh Ehnergij, Protvino (USSR))

    1991-06-01

    In this paper we present the results of a full-scale study of a beam scraping system that is designed to guarantee reliable operation of the SSC throughout the whole cycle and for minimum background for experiments at the interaction regions. The machine aperture limits and beam loss formation are analyzed. Simulation programs and a calculational model are described. The physics of beam scraping is explored, and measures to increase significantly the system efficiency are determined. A tolerable scraping rate, taking into account scraper material integrity, quench limits in downstream superconducting magnets, radiation shielding requirements, and minimal beam halo levels at the IPs are also determined. Finally, a complete multi-component scraper system in the SSC East Cluster is proposed. Throughout the paper we define a scraper as a primary absorber consisting of precise movable jaws that have a flat inner edge along the circulation beam and which may be forced to touch the beam halo in horizontal or vertical planes. Secondary absorbers -- collimators -- are destined to intercept outscattered protons and other particles produced in scraper material. All these are surrounded with a radiation shielding. 15 refs., 50 figs., 13 tabs.

  16. Micro-CT features of intermediate gunshot wounds covered by textiles.

    Science.gov (United States)

    Giraudo, Chiara; Fais, Paolo; Pelletti, Guido; Viero, Alessia; Miotto, Diego; Boscolo-Berto, Rafael; Viel, Guido; Montisci, Massimo; Cecchetto, Giovanni; Ferrara, Santo Davide

    2016-09-01

    The analysis of gunshot residue (GSR) on the clothing and the underlying skin of the victim may play an important role in the reconstruction of the shooting incident. The aim of the present study was to test micro-computed tomography (micro-CT) for the analysis of firearm wounds experimentally produced on human skin covered by textiles. Firing trials were performed on 60 sections of human calves enveloped by a single layer of fabric (cotton or jeans or leather or nylon) and 15 controls consisting of bare calves. Experimental firings were conducted in a ballistic laboratory at three different muzzle-to-target distances (5, 15, and 30 cm), using a .32 ACP pistol (Beretta Mod. 81) loaded with full-jacketed bullets coming from the same production lot (7.65 × 17 mm, Browning SR). The visual inspection revealed the classic pattern of GSR distribution on the fabrics and the skin of control samples, while only a dark ring around the entrance lesion was identified on the skin beneath the fabrics. Micro-CT analysis showed the presence of radiopaque material on all entrance wounds, with a statistically significant difference between cases and controls. No differences were found among specimens covered by fabrics, with regard to the firing distance and the type of clothing. No GSR-like deposits were detected in exit wounds. Our results suggest that micro-CT analysis may be a useful screening tool for differentiating entry from exit gunshot wounds when the covering textiles are contaminated, damaged, or missing. PMID:27325255

  17. High-resolution 3D micro-CT imaging of breast microcalcifications: a preliminary analysis

    International Nuclear Information System (INIS)

    Detection of microcalcifications on mammograms indicates the presence of breast lesion, and the shapes of the microcalcifications as seen by conventional mammography correlates with the probability of malignancy. This preliminary study evaluated the 3D shape of breast microcalcifications using micro-computed tomography (micro-CT) and compared the findings with those obtained using anatomopathological analysis. The study analyzed breast biopsy samples from 11 women with findings of suspicious microcalcifications on routine mammograms. The samples were imaged using a micro-CT (SkyScan 1076) at a resolution of 35 μm. Images were reconstructed using filtered back-projection and analyzed in 3D using surface rendering. The samples were subsequently analyzed by the pathology service. Reconstructed 3D images were compared with the corresponding histological slices. Anatomopathological analysis showed that 5 of 11 patients had ductal breast carcinoma in situ. One patient was diagnosed with invasive ductal carcinoma. Individual object analysis was performed on 597 microcalcifications. Malignant microcalcifications tended to be thinner and to have a smaller volume and surface area, while their surface area-to-volume ratio was greater than that of benign microcalcifications. The structure model index values were the same for malignant and benign microcalcifications. This is the first study to use micro-CT for quantitative 3D analysis of microcalcifications. This high-resolution imaging technique will be valuable for gaining a greater understanding of the morphologic characteristics of malignant and benign microcalcifications. The presence of many small microcalcifications can be an indication of malignancy. For the larger microcalcifications, 3D parameters confirmed the more irregular shape of malignant microcalcifications

  18. Calculation of intertial properties of the malleus-incus complex from micro CT-imaging

    OpenAIRE

    Sim, J H; Puria, S; Steele, C. R.

    2007-01-01

    The middle ear bones are the smallest bones in the human body and are among the most complicated functionally. These bones are located within the temporal bone making them difficult to access and study. We use the micro-CT imaging modality to obtain quantitative inertial properties of the MIC (malleus-incus complex), which is a subcomponent of the middle ear. The principal moment of inertia of the malleus along the superior-inferior axis (17.3 ± 2.3 mg/mm3) is lower by about a factor of six i...

  19. Combination of laboratory micro-CT and micro-XRF on geological objects

    OpenAIRE

    Boone, Matthieu; Dewanckele, Jan; Cnudde, Veerle; Silversmit, Geert; Van Hoorebeke, Luc; Vincze, Laszlo; Jacobs, Patric

    2010-01-01

    Laboratory micro-CT scanning is a very useful tool in the characterization of geological samples. Due to its ability to visualize different phases and structures in 3D, many characteristics can be derived from the data. However, very limited chemical information on the different phases can be derived by CT. Micro-XRF (µXRF) images this compositional information for a wide range of samples. In µXRF, a two-dimensional grid of fluorescence spectra is collected from the surface of the sample, ge...

  20. Tumor volume in subcutaneous mouse xenografts measured by microCT is more accurate and reproducible than determined by 18F-FDG-microPET or external caliper

    DEFF Research Database (Denmark)

    Jensen, Mette Munk; Jørgensen, Jesper Tranekjaer; Binderup, Tina;

    2008-01-01

    BACKGROUND: In animal studies tumor size is used to assess responses to anticancer therapy. Current standard for volumetric measurement of xenografted tumors is by external caliper, a method often affected by error. The aim of the present study was to evaluate if microCT gives more accurate...... systematic bias compared to reference volume. Coefficients of variation for intra-observer variation were 7% and 14% for microCT and caliper measurements, respectively. Regression coefficients between observers were 0.97 for microCT and 0.91 for caliper measurements. CONCLUSION: MicroCT was more accurate...

  1. Serial micro-CT assessment of the therapeutic effects of rosiglitazone in a bleomycin-induced lung fibrosis mouse model

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Eun Jung; Jin, Gong Yong; Bok, Se Mi; Han, Young Min; Lee, Young Sun; Jung, Myung Ja; Kwon, Keun Sang [Research Institute of Clinical Medicine of Chonbuk National University, Biomedical Research Institute of Chonbuk National University Hospital, Institute for Medical Sciences, Jeonju (Korea, Republic of)

    2014-08-15

    The aim of this study was to assess the therapeutic effects of rosiglitazone with serial micro-CT findings before and after rosiglitazone administration in a lung fibrosis mouse model induced with bleomycin. We instilled the bleomycin solution directly into the trachea in twenty mice (female, C57BL/6 mice). After the instillation with bleomycin, mice were closely observed for 3 weeks and then all mice were scanned using micro-CT without sacrifice. At 3 weeks, the mice were treated with rosiglitazone on days 21 to 27 if they had abnormal CT findings (n = 9, 45%). For the mice treated with rosiglitazone, we performed micro-CT with mouse sacrifice 2 weeks after the rosiglitazone treatment completion. We assessed the abnormal CT findings (ground glass attenuation, consolidation, bronchiectasis, reticular opacity, and honeycombing) using a five-point scale at 3 and 6 weeks using Wilcoxon-signed ranked test. The micro-CT findings were correlated with the histopathologic results. One out of nine (11.1%) mice improved completely. In terms of consolidation, all mice (100%) showed marked decrease from 3.1 ± 1.4 at 3 weeks to 0.9 ± 0.9 at 6 weeks (p = 0.006). At 6 weeks, mild bronchiectasis (n = 6, 66.7%), mild reticular opacity (n 7, 77.8%) and mild honeycomb patterns (n = 3, 33.3%) appeared. A serial micro-CT enables the evaluation of drug effects in a lung fibrosis mouse model.

  2. In vivo micro-CT assessment of airway remodeling in a flexible OVA-sensitized murine model of asthma.

    Directory of Open Access Journals (Sweden)

    Mathieu Lederlin

    Full Text Available Airway remodeling is a major pathological feature of asthma. Up to now, its quantification still requires invasive methods. In this study, we aimed at determining whether in vivo micro-computed tomography (micro-CT is able to demonstrate allergen-induced airway remodeling in a flexible mouse model of asthma. Sixty Balb/c mice were challenged intranasally with ovalbumin or saline at 3 different endpoints (Days 35, 75, and 110. All mice underwent plethysmography at baseline and just prior to respiratory-gated micro-CT. Mice were then sacrificed to assess bronchoalveolar lavage and lung histology. From micro-CT images (voxel size = 46×46×46 µm, the numerical values of total lung attenuation, peribronchial attenuation (PBA, and PBA normalized by total lung attenuation were extracted. Each parameter was compared between OVA and control mice and correlation coefficients were calculated between micro-CT and histological data. As compared to control animals, ovalbumin-sensitized mice exhibited inflammation alone (Day 35, remodeling alone (Day 110 or both inflammation and remodeling (Day 75. Normalized PBA was significantly greater in mice exhibiting bronchial remodeling either alone or in combination with inflammation. Normalized PBA correlated with various remodeling markers such as bronchial smooth muscle size or peribronchial fibrosis. These findings suggest that micro-CT may help monitor remodeling non-invasively in asthmatic mice when testing new drugs targeting airway remodeling in pre-clinical studies.

  3. Antiproton source beam position system

    International Nuclear Information System (INIS)

    The TeV I Beam Position Monitor (BPM) system is designed to provide a useful diagnostic tool during the commissioning and operational phases of the antiproton source. Simply stated the design goal is to provide single turn position information for intensities of > 1x109 particles, and multi-turn (clocked orbit) information for beam intensities of > 1x107 particles, both with sub-millimeter resolution. It is anticipated that the system will be used during commissioning for establishing the first turn through the Debuncher and Accumulator, for aligning injection orbits, for providing information necessary to correct closed orbits, and for measuring various machine parameters (e.g. tunes, dispersion, aperture, chromaticity). During normal antiproton operation the system will be used to monitor the beam position throughout the accumulation process

  4. MicroCT angiography detects vascular formation and regression in skin wound healing.

    Science.gov (United States)

    Urao, Norifumi; Okonkwo, Uzoagu A; Fang, Milie M; Zhuang, Zhen W; Koh, Timothy J; DiPietro, Luisa A

    2016-07-01

    Properly regulated angiogenesis and arteriogenesis are essential for effective wound healing. Tissue injury induces robust new vessel formation and subsequent vessel maturation, which involves vessel regression and remodeling. Although formation of functional vasculature is essential for healing, alterations in vascular structure over the time course of skin wound healing are not well understood. Here, using high-resolution ex vivo X-ray micro-computed tomography (microCT), we describe the vascular network during healing of skin excisional wounds with highly detailed three-dimensional (3D) reconstructed images and associated quantitative analysis. We found that relative vessel volume, surface area and branching number are significantly decreased in wounds from day 7 to days 14 and 21. Segmentation and skeletonization analysis of selected branches from high-resolution images as small as 2.5μm voxel size show that branching orders are decreased in the wound vessels during healing. In histological analysis, we found that the contrast agent fills mainly arterioles, but not small capillaries nor large veins. In summary, high-resolution microCT revealed dynamic alterations of vessel structures during wound healing. This technique may be useful as a key tool in the study of the formation and regression of wound vessels. PMID:27009591

  5. Influence of metal artifacts on in vivo micro-CT for orthodontic mini-implants

    International Nuclear Information System (INIS)

    This study aimed to show the effects of metal artifacts on the in vivo micro-CT of mini-implants by measuring bone volume. We drilled a hole in the cortical bone of a rat tibia and embedded a titanium orthodontic mini-implant (diameter, 1.5 mm) in the hole. Twelve individually weighed hydroxyapatite grains (HA grains) were placed around the implant either by one dentist (method 1) or separately by 12 dentists (method 2). In vivo micro-CT was used to scan the model after placement of each grain to measure increases and decreases in bone volume voxel number. The subtracted bone voxel volume increased with HA weight in both methods. Simple linear regression analysis showed a significant correlation between weight and volume in both methods (method 1: regression coefficient: 516.502, P<0.05; method 2: regression coefficient: 4837.432, P<0.05). Metal artifacts did not appear to influence measurements of bone volume, although further studies are required to determine the effect of thicker implants. (author)

  6. Stress distribution in maxillary alveolar ridge according to finite element analysis using micro-CT

    International Nuclear Information System (INIS)

    The purpose of the present study was to evaluate stress distribution by finite element analysis in an accurate model simulating trabecular bone using micro-CT. Dentulous and edentulous maxillary jaws of Japanese adult cadavers were used (5 sides each; total, 10 sides). Imaging was performed using a micro-CT, followed by reconstruction with 3-D images. Finite element analysis models were developed using the maxilla with average bone morphometry. A load corresponding to occlusal force was applied in different loading conditions, followed by evaluation of stress distribution. In dentulous maxillas, a load was applied in the dental axis direction to the first molar crown (LD). In edentulous maxillas, a load was applied directly to a circular area 4 mm in diameter (LER0) to a cylinder 4 mm in diameter and 10 mm in height (LER10) corresponding to the first molar area. Stress was concentrated in cortical bone around the first molar, trabecular bone and cortical bone at the maxillary sinus base in LD, cortical bone of the alveolar ridge in LER0, and trabecular bone around the cylinder and cortical bone at the maxillary sinus base in LER10. LER0 showed a stress distribution markedly different from that in LD. Compared with LER0, LER10 showed a stress distribution close to that in LD. A model simulating trabecular bone allows a more accurate evaluation of stress distribution. (author)

  7. Performance characterization of large-area CMOS FPD for micro-CT applications

    Energy Technology Data Exchange (ETDEWEB)

    Kam, Soohwa; Kim, Hokyung; Jeon, Hosang [Pusan National Univ., Busan (Korea, Republic of)

    2013-10-15

    Recent advanced echnologies in a Si wafer growth and buttable detector module have overcomes the imaging detector size limitation to develop a large area digital radiography (DR) detector. With these advantages, the usage of the CMOS FPD for large-area x-ray detector applications (small-animal imaging, fluoroscopy, angiography, etc.) has been recently spotlighted. Although a-Si FPDs have many advantages such as a large imaging area, thin structure, and veiling glares, there are still some technical difficulties including relatively large pixel size and image lag to apply for a dynamic imaging applications such as a micro-CT for small-animal imaging. However, CMOS technology can be a solution for these technical limitations. Therefore, it is necessary to characterize the quantitative performance of CMOS FPD for small animal micro-CT application. In this study, we have investigated an imaging performance of CMOS FPD. As an imaging performance metrics, sensitivity, modulation-transfer function (MTF), noise-power spectrum (NPS), and detective quantum efficiency (DQE) have been investigated.

  8. An Indirect Method to Measure Abutment Screw Preload: A Pilot Study Based on Micro-CT Scanning.

    Science.gov (United States)

    Rezende, Carlos Eduardo E; Griggs, Jason Alan; Duan, Yuanyuan; Mushashe, Amanda M; Nolasco, Gisele Maria Correr; Borges, Ana Flávia Sanches; Rubo, José Henrique

    2015-12-01

    This study aimed to measure the preload in different implant platform geometries based on micro-CT images. External hexagon (EH) implants and Morse Tapered (MT) implants (n=5) were used for the preload measurement. The abutment screws were scanned in micro-CT to obtain their virtual models, which were used to record their initial length. The abutments were screwed on the implant with a 20 Ncm torque and the set composed by implant, abutment screw and abutment were taken to the micro-CT scanner to obtain virtual slices of the specimens. These slices allowed the measurement of screw lengths after torque application and based on the screw elongation. Preload values were calculated using the Hooke's Law. The preloads of both groups were compared by independent t-test. Removal torque of each specimen was recorded. To evaluate the accuracy of the micro-CT technique, three rods with known lengths were scanned and the length of their virtual model was measured and compared with the original length. One rod was scanned four times to evaluate the measuring method variation. There was no difference between groups for preload (EH = 461.6 N and MT = 477.4 N), but the EH group showed higher removal torque values (13.8±4.7 against 8.2±3.6 Ncm for MT group). The micro-CT technique showed a variability of 0.053% and repeatability showed an error of 0.23 to 0.28%. Within the limitations of this study, there was no difference between external hexagon and Morse taper for preload. The method using micro-CT may be considered for preload calculation. PMID:26963202

  9. Micro-CT evaluation of murine fetal skeletal development yields greater morphometric precision over traditional clear-staining methods.

    Science.gov (United States)

    Oest, Megan E; Jones, Jeryl C; Hatfield, Cindy; Prater, M Renee

    2008-12-01

    Traditional techniques for quantification of murine fetal skeletal development (gross measurements, clear-staining) are severely limited by specimen processing, soft tissue presence, diffuse staining, and unclear landmarks between which to make measurements. Nondestructive microcomputed tomography (micro-CT) imaging is a versatile, well-documented tool traditionally used to generate high-resolution 3-D images and quantify microarchitectural parameters of trabecular bone. Although previously described as a tool for phenotyping fetal murine specimens, micro-CT has not previously been used to directly measure individual fetal skeletal structures. Imaging murine fetal skeletons using micro-CT enables the researcher to nondestructively quantify fetal skeletal development parameters including limb length, total bone volume, and average bone mineral density, as well as identify skeletal malformations. Micro-CT measurement of fetal limb lengths correlates well with traditional clear-staining methods (83.98% agreement), decreases variability in measurements (average standard errors: 6.28% for micro-CT and 10.82% for clear-staining), decreases data acquisition time by eliminating the need for tissue processing, and preserves the intact fixed fetus for further analysis. Use of the rigorous micro-CT technique to generate 3-D images for digital measurement enables isolation of skeletal structures based on degree of mineralization (local radiodensity), eliminating the complications of blurred stain boundaries and soft tissue inclusion that accompany clear-staining and gross measurement techniques. Microcomputed tomography provides a facile, accurate, and nondestructive method for determining the developmental state of the fetal skeleton using not only limb lengths and identification of malformations, but total skeletal bone volume and average skeletal mineral density as well. PMID:19048632

  10. ATF neutral beam injection system

    International Nuclear Information System (INIS)

    The Advanced Toroidal Facility is a stellarator torsatron being built at Oak Ridge National Laboratory to investigate improved plasma confinement schemes. Plasmas heating will be carried out predominantly by means of neutral beam injection. This paper describes the basic parameters of the injection system. Numerical calculations were done to optimize the aiming of the injectors. The results of these calculations and their implications on the neutral power to the machine are elaborated. The effects of improving the beam optics and altering the focal length on the power transmitted to the plasma are discussed

  11. Proton beam therapy control system

    Science.gov (United States)

    Baumann, Michael A.; Beloussov, Alexandre V.; Bakir, Julide; Armon, Deganit; Olsen, Howard B.; Salem, Dana

    2008-07-08

    A tiered communications architecture for managing network traffic in a distributed system. Communication between client or control computers and a plurality of hardware devices is administered by agent and monitor devices whose activities are coordinated to reduce the number of open channels or sockets. The communications architecture also improves the transparency and scalability of the distributed system by reducing network mapping dependence. The architecture is desirably implemented in a proton beam therapy system to provide flexible security policies which improve patent safety and facilitate system maintenance and development.

  12. Analysis of X-ray micro-CT images observed with compacted bentonite

    International Nuclear Information System (INIS)

    In this study, a method of statistical analyses was developed and applied to the data sets of images observed with a micro focus X-ray computed tomograph for compacted bentonite, which is a candidate of buffer material for geological disposal of high-level radioactive waste. The bentonite sample used in this study has the grain size around 100 microns under dry state, but less than the size under water-saturated state due to the gel formation of the sample. Statistical information of bentonite grains (i.e. the sizes and the shapes of the grains) before and after water-saturation was analyzed with a boundary determination algorithm developed in this study. Since the images obtained with micro CT apparatus contain ring-shaped artifacts and noise with higher intensity than that of signal, a radial averaging technique and a Gaussian filter were applied to the images before the analysis. (author)

  13. KTeV beam systems design report

    Energy Technology Data Exchange (ETDEWEB)

    Bocean, V.; Childress, S.; Coleman, R. [and others

    1997-09-01

    The primary and secondary beams for the KTeV experiments E799-II and E832 are discussed. The specifications are presented and justified. The technical details of the implementation of the primary beam transport and stability are detailed. The target, beam dump, and radiation safety issues are discussed. The details of the collimation system for the pair of secondary beams are presented.

  14. KTeV beam systems design report

    International Nuclear Information System (INIS)

    The primary and secondary beams for the KTeV experiments E799-II and E832 are discussed. The specifications are presented and justified. The technical details of the implementation of the primary beam transport and stability are detailed. The target, beam dump, and radiation safety issues are discussed. The details of the collimation system for the pair of secondary beams are presented

  15. Optimization of a retrospective technique for respiratory-gated high speed micro-CT of free-breathing rodents

    Energy Technology Data Exchange (ETDEWEB)

    Ford, Nancy L [Department of Physics, Ryerson University, 350 Victoria Street, Toronto, Ontario M5B 2K3 (Canada); Wheatley, Andrew R [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, PO Box 5015, London, Ontario N6A 5K8 (Canada); Holdsworth, David W [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, PO Box 5015, London, Ontario N6A 5K8 (Canada); Drangova, Maria [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, PO Box 5015, London, Ontario N6A 5K8 (Canada)

    2007-09-21

    The objective of this study was to develop a technique for dynamic respiratory imaging using retrospectively gated high-speed micro-CT imaging of free-breathing mice. Free-breathing C57Bl6 mice were scanned using a dynamic micro-CT scanner, comprising a flat-panel detector mounted on a slip-ring gantry. Projection images were acquired over ten complete gantry rotations in 50 s, while monitoring the respiratory motion in synchrony with projection-image acquisition. Projection images belonging to a selected respiratory phase were retrospectively identified and used for 3D reconstruction. The effect of using fewer gantry rotations-which influences both image quality and the ability to quantify respiratory function-was evaluated. Images reconstructed using unique projections from six or more gantry rotations produced acceptable images for quantitative analysis of lung volume, CT density, functional residual capacity and tidal volume. The functional residual capacity (0.15 {+-} 0.03 mL) and tidal volumes (0.08 {+-} 0.03 mL) measured in this study agree with previously reported measurements made using prospectively gated micro-CT and at higher resolution (150 {mu}m versus 90 {mu}m voxel spacing). Retrospectively gated micro-CT imaging of free-breathing mice enables quantitative dynamic measurement of morphological and functional parameters in the mouse models of respiratory disease, with scan times as short as 30 s, based on the acquisition of projection images over six gantry rotations.

  16. Assessment of scatter for the micro-CT subsystem of the trimodality FLEX Triumph (TM) preclinical scanner

    NARCIS (Netherlands)

    Gutierrez, Daniel; Zaidi, Habib

    2011-01-01

    Purpose: This work aims at assessing, through experimental measurements and Monte Carlo calculations, the scatter to primary ratio (SPR) for the micro-CT subsystem of the FLEX Triumph (TM) preclinical PET-CT scanner to improve its quantitative capabilities. Methods: Experimental measurements were ca

  17. Optimization of a retrospective technique for respiratory-gated high speed micro-CT of free-breathing rodents

    International Nuclear Information System (INIS)

    The objective of this study was to develop a technique for dynamic respiratory imaging using retrospectively gated high-speed micro-CT imaging of free-breathing mice. Free-breathing C57Bl6 mice were scanned using a dynamic micro-CT scanner, comprising a flat-panel detector mounted on a slip-ring gantry. Projection images were acquired over ten complete gantry rotations in 50 s, while monitoring the respiratory motion in synchrony with projection-image acquisition. Projection images belonging to a selected respiratory phase were retrospectively identified and used for 3D reconstruction. The effect of using fewer gantry rotations-which influences both image quality and the ability to quantify respiratory function-was evaluated. Images reconstructed using unique projections from six or more gantry rotations produced acceptable images for quantitative analysis of lung volume, CT density, functional residual capacity and tidal volume. The functional residual capacity (0.15 ± 0.03 mL) and tidal volumes (0.08 ± 0.03 mL) measured in this study agree with previously reported measurements made using prospectively gated micro-CT and at higher resolution (150 μm versus 90 μm voxel spacing). Retrospectively gated micro-CT imaging of free-breathing mice enables quantitative dynamic measurement of morphological and functional parameters in the mouse models of respiratory disease, with scan times as short as 30 s, based on the acquisition of projection images over six gantry rotations

  18. High power neutral beam systems

    International Nuclear Information System (INIS)

    Spurred by the requirement to supply megawatts of power to heat magnetically confined plasmas to temperatures of interest for fusion research, a new class of low energy, high power accelerators termed neutral beam injectors has been developed. Industry has played an important role in building upon technology advances at the national laboratories to engineer neutral beam injectors to meet the needs of specific users. A brief retrospective of the field is presented, with emphasis upon one particular application, that of DIII-D, a large tokamak at General Atomics. In this instance, the role of industry has been especially extensive because the user/system integrator is itself an industrial concern. 4 refs., 7 figs., 2 tabs

  19. Requirements of CLIC Beam Loss Monitoring System

    CERN Document Server

    Sapinski, M; Holzer, EB; Jonker, M; Mallows, S; Otto, T; Welsch, C

    2010-01-01

    The Compact Linear Collider (CLIC) [1] is a proposed multi-TeV linear electron-positron collider being designed by a world-wide collaboration. It is based on a novel twobeam acceleration scheme in which two beams (drive and main beam) are placed in parallel to each other and energy is transferred from the drive beam to the main one. Beam losses on either of them can have catastrophic consequences for the machine, because of high intensity (drive beam) or high energy and small emittance (main beam). In the framework of machine protection, a Beam Loss Monitoring (BLM) system has to be put in place. This paper discusses the requirements for the beam loss system in terms of detector sensitivity, resolution, dynamic range and ability to distinguish losses originating from various sources. The two-beam module where the protection from beam losses is particularly challenging and important, is studied.

  20. Using Micro-CT Derived Bone Microarchitecture to Analyze Bone Stiffness - A Case Study on Osteoporosis Rat Bone.

    Science.gov (United States)

    Wu, Yuchin; Adeeb, Samer; Doschak, Michael R

    2015-01-01

    Micro-computed tomography (Micro-CT) images can be used to quantitatively represent bone geometry through a range of computed attenuation-based parameters. Nonetheless, those parameters remain indirect indices of bone microarchitectural strength and require further computational tools to interpret bone structural stiffness and potential for mechanical failure. Finite element analysis (FEA) can be applied to measure trabecular bone stiffness and potentially predict the location of structural failure in preclinical animal models of osteoporosis, although that procedure from image segmentation of Micro-CT derived bone geometry to FEA is often challenging and computationally expensive, resulting in failure of the model to build. Notably, the selection of resolution and threshold for bone segmentation are key steps that greatly affect computational complexity and validity. In the following study, we evaluated an approach whereby Micro-CT derived grayscale attenuation and segmentation data guided the selection of trabecular bone for analysis by FEA. We further correlated those FEA results to both two- and three-dimensional bone microarchitecture from sham and ovariectomized (OVX) rats (n = 10/group). A virtual cylinder of vertebral trabecular bone 40% in length from the caudal side was selected for FEA, because Micro-CT based image analysis indicated the largest differences in microarchitecture between the two groups resided there. Bone stiffness was calculated using FEA and statistically correlated with the three-dimensional values of bone volume/tissue volume, bone mineral density, fractal dimension, trabecular separation, and trabecular bone pattern factor. Our method simplified the process for the assessment of trabecular bone stiffness by FEA from Micro-CT images and highlighted the importance of bone microarchitecture in conferring significantly increased bone quality capable of resisting failure due to increased mechanical loading. PMID:26042089

  1. A Combined Micro-CT Imaging/Microfluidic Approach for Understating Methane Recovery in Coal Seam Gas Reservoirs

    Science.gov (United States)

    Mostaghimi, P.; Armstrong, R. T.; Gerami, A.; Lamei Ramandi, H.; Ebrahimi Warkiani, M.

    2015-12-01

    Coal seam methane is a form of natural gas stored in coal beds and is one of the most important unconventional resources of energy. The flow and transport in coal beds occur in a well-developed system of natural fractures that are also known as cleats. We use micro-Computed Tomography (CT) imaging at both dry and wet conditions to resolve the cleats below the resolution of the image. Scanning Electron Microscopy (SEM) is used for calibration of micro-CT data. Using soft lithography technique, the cleat system is duplicated on a silicon mould. We fabricate a microfluidic chip using Polydimethylsiloxane (PDMS) to study both imbibition and drainage in generated coal structures for understating gas and water transport in coal seam reservoirs. First, we use simple patterns observed on coal images to analyse the effects of wettability, cleat size and distribution on flow behaviour. Then, we study transport in a coal by injecting both distilled water and decane with a rate of 1 microliter/ min into the fabricated cleat structure (Figure 1), initially saturated with air. We repeat the experiment for different contact angles by plasma treating the microfluidic chip, and results show significant effects of wettability on the displacement efficiency. The breakthrough time in the imbibition setup is significantly longer than in the drainage. Using rapid video capturing, and high resolution microscopy, we measure the saturation of displacing fluid with respect to time. By measuring gas and liquid recovery in the outlet at different saturation, we predict relative permeability of coal. This work has important applications for optimising gas recovery and our results can serve as a benchmark in the verification of multiphase numerical models used in coal seam gas industry.

  2. LHC beam instrumentation detectors and acquisition systems

    International Nuclear Information System (INIS)

    An overview of some of the detectors and acquisition systems being developed for measuring and controlling beam parameters in the LHC. The two largest systems concern the measurement of beam position, with over 1000 monitors, and beam loss, with over 3000 monitors. For the beam position system a novel wide band time normaliser has been developed to allow bunch-by-bunch 40MHz acquisitions with a dynamic range greater than 30dB and an overall linearity of better than 1%. Also mentioned will be the acquisition system for the fast beam current transformers and the development of CdTe detectors for luminosity monitoring. [author

  3. Dynamic Micro-CT Study of Fracture-Matrix Flow During Capillary Imbibition in Layered Berea Sandstone

    Science.gov (United States)

    Karpyn, Z. T.; Halleck, P. M.; Grader, A. S.; Elsworth, D.

    2004-12-01

    Studies concerning flow in fractured rocks have important applications in hydrocarbon recovery, hydrogeology, and environmental remediation of subsurface spills, such as DNAPLs. To properly design immiscible flow processes in those systems, it is crucial to understand fracture-matrix transfer mechanisms. The goal of this work is to provide a mechanistic description of capillary-driven imbibition in fractured media and the effects of fluid occupancy in the fracture and of matrix heterogeneity on saturation distribution. Capillary imbibition experiments where performed in a layered Berea sample, 4.75 cm long and 2.54 cm in diameter, with a single longitudinal fracture. The artificially created fracture was oriented perpendicular to the natural bedding of the rock. The sample was initially vacuum saturated with non-wetting phase. Small amounts of a wetting phase were introduced into the bottom of the fracture, allowing it to imbibe and exchange places with the resident non-wetting phase through the fracture-matrix interface. Progress of the imbibition process was monitored after each injection using high-resolution Micro Computed Tomography (CT). Micro-CT also provided non-destructive means to characterize the fracture structure and rock properties. A series of simulation scenarios were also tested using a commercially available package developed by the Computer Modeling Group (CMG). Experimental observations combined with simulation results indicate that the fracture itself exhibits a strong capillary behavior. Its rough-walled nature, leads to a two-phase flow similar to that in porous media. Experimental observations also show a strong correspondence between fluid invasion in the matrix and variations in porosity in the rock's bedding planes. Our results suggest that different porosities correspond to different permeabilities and capillary pressure curves. Fluid accessibility in the fracture space is also an important factor governing imbibition in fractured media

  4. Nondestructive Analysis of Astromaterials by Micro-CT and Micro-XRF Analysis for PET Examination

    Science.gov (United States)

    Zeigler, R. A.; Righter, K.; Allen, C. C.

    2013-01-01

    An integral part of any sample return mission is the initial description and classification of returned samples by the preliminary examination team (PET). The goal of the PET is to characterize and classify returned samples and make this information available to the larger research community who then conduct more in-depth studies on the samples. The PET tries to minimize the impact their work has on the sample suite, which has in the past limited the PET work to largely visual, nonquantitative measurements (e.g., optical microscopy). More modern techniques can also be utilized by a PET to nondestructively characterize astromaterials in much more rigorous way. Here we discuss our recent investigations into the applications of micro-CT and micro-XRF analyses with Apollo samples and ANSMET meteorites and assess the usefulness of these techniques in future PET. Results: The application of micro computerized tomography (micro-CT) to astromaterials is not a new concept. The technique involves scanning samples with high-energy x-rays and constructing 3-dimensional images of the density of materials within the sample. The technique can routinely measure large samples (up to approx. 2700 cu cm) with a small individual voxel size (approx. 30 cu m), and has the sensitivity to distinguish the major rock forming minerals and identify clast populations within brecciated samples. We have recently run a test sample of a terrestrial breccia with a carbonate matrix and multiple igneous clast lithologies. The test results are promising and we will soon analyze a approx. 600 g piece of Apollo sample 14321 to map out the clast population within the sample. Benchtop micro x-ray fluorescence (micro-XRF) instruments can rapidly scan large areas (approx. 100 sq cm) with a small pixel size (approx. 25 microns) and measure the (semi) quantitative composition of largely unprepared surfaces for all elements between Be and U, often with sensitivity on the order of a approx. 100 ppm. Our recent

  5. In vivo micro-CT imaging of the murine lung via a computer controlled intermittent iso-pressure breath hold (IIBH) technique

    Science.gov (United States)

    Namati, Eman; Chon, Deokiee; Thiesse, Jacqueline; McLennan, Geoffrey; Sieren, Jered; Ross, Alan; Hoffman, Eric A.

    2006-03-01

    Micro-CT, a technique for imaging small objects at high resolution using micro focused x-rays, is becoming widely available for small animal imaging. With the growing number of mouse models of pulmonary pathology, there is great interest in following disease progression and evaluating the alteration in longitudinal studies. Along with the high resolution associated with micro CT comes increased scanning times, and hence minimization of motion artifacts is required. We propose a new technique for imaging mouse lungs in vivo by inducing an intermittent iso-pressure breath hold (IIBH) with a fixed level of positive airway pressure during image acquisition, to decrease motion artifacts and increase image resolution and quality. Mechanical ventilation of the respiratory system for such a setup consists of three phases, 1) tidal breathing (hyperventilated), 2) a breath hold during a fixed level of applied positive airway pressure, 3) periodic deep sighs. Image acquisition is triggered over the stable segment of the IIBH period. Comparison of images acquired from the same mouse lung using three imaging techniques (normal breathing / no gating, normal breathing with gating at End Inspiration (EI) and finally the IIBH technique) demonstrated substantial improvements in resolution and quality when using the IIBH gating. Using IIBH triggering the total image acquisition time increased from 15 minutes to 35 minutes, although total x-ray exposure time and hence animal dosage remains the same. This technique is an important step in providing high quality lung imaging of the mouse in vivo, and will provide a good foundation for future longitudinal studies.

  6. Morphological changes of the internal structure of maxillae with tooth loss. Three-dimensional and mechanical analysis using micro-CT and finite element method

    International Nuclear Information System (INIS)

    The purpose of this study was to analyze the morphological and mechanical properties of the internal structures of maxillae at the molar region using a micro-CT system. Ten dentulous and edentulous maxillae were employed in this study. Images and angle information from all materials were taken by a micro-CT and 100 x 100 x 100 voxels were extracted from the fixed buccal and palatal molar regions in each material for three-dimensional morphological analysis of the internal structure. The bone volume fraction, trabecular thickness, trabecular separation and trabecular number were calculated. To analyze mechanical properties all voxels were converted to micro finite element models with element size of 33 x 33 x 33 μm3 and maximal stiffness, axial stiffness and angle between the stiffest direction of trabecular and the axial loading direction (angleα) were determined using micro finite element method. In the result, the morphological changes including decrease of bone volume fraction, trabecular thickness and increase of trabecular separation were evident with tooth loss, although trabecular number was not changed. Mechanically, maximal stiffness was decreased with tooth loss at buccal region. However, the axial stiffness at buccal region was larger and the angleα was distributed widely in each edentulous maxilla, comparing to the same region of dentulous maxilla. These findings suggest that trabecular bone become thinner in both buccal and palatal regions, consequently maximal stiffness at buccal region become smaller with tooth loss. On the other hand, axial stiffness at the buccal region in edentulous was larger than one in dentulous. It seems to be caused by the change of the angleα. (author)

  7. Spiral kicker for the beam abort system

    Energy Technology Data Exchange (ETDEWEB)

    Martin, R.L.

    1983-01-01

    A brief study was carried out to determine the feasibility of a special kicker to produce a damped spiral beam at the beam dump for the beam abort system. There appears to be no problem with realizing this concept at a reasonably low cost.

  8. Taxonomy and nomenclature of some mainland SE-Asian Coeliccia species (Odonata, Platycnemididae) using micro-CT analysis.

    Science.gov (United States)

    Steinhoff, Philip O M; Uhl, Gabriele

    2015-01-01

    The taxonomic status of some mainland Southeast Asian Coeliccia species is evaluated. The following synonymies are presented: C. acco is a junior synonym of C. pyriformis; C. tomokunii that of C. scutellum; C.onoi that of C. cyanomelas. C. scutellum hainanense is promoted to species level, C. hainanense. Redescriptions of the holotype of C. pyriformis and of the lectotypes of C. scutellum and C. hainanense are presented with illustrations. The male genital ligulae were examined by means of non-destructive X-ray micro-computed tomography (micro-CT) and subsequent 3D-reconstruction. The advantage of virtual types generated by micro-CT analysis, particularly for the examination of internal structures, is discussed. PMID:26701563

  9. When a 520 million-year-old Chengjiang fossil meets a modern micro-CT--a case study.

    Science.gov (United States)

    Liu, Yu; Scholtz, Gerhard; Hou, Xianguang

    2015-01-01

    The 520 million-year-old Chengjiang biota of China (UNESCO World Heritage) presents the earliest known evidence of the so-called Cambrian Explosion. Studies, however, have mainly been limited to the information exposed on the surface of the slabs. Thus far, structures preserved inside the slabs were accessed by careful removal of the matrix, in many cases with the unfortunate sacrifice of some "less important" structures, which destroys elements of exceptionally preserved specimens. Here, we show for the first time that microtomography (micro-CT) can reveal structures situated inside a Chengjiang fossil slab without causing any damage. In the present study a trilobitomorph arthropod (Xandarella spectaculum) can be reliably identified only with the application of micro-CT. We propose that this technique is an important tool for studying three-dimensionally preserved Chengjiang fossils and, most likely, also those from other biota with a comparable type of preservation, specifically similar iron concentrations. PMID:26238773

  10. When a 520 million-year-old Chengjiang fossil meets a modern micro-CT - a case study

    Science.gov (United States)

    Liu, Yu; Scholtz, Gerhard; Hou, Xianguang

    2015-08-01

    The 520 million-year-old Chengjiang biota of China (UNESCO World Heritage) presents the earliest known evidence of the so-called Cambrian Explosion. Studies, however, have mainly been limited to the information exposed on the surface of the slabs. Thus far, structures preserved inside the slabs were accessed by careful removal of the matrix, in many cases with the unfortunate sacrifice of some “less important” structures, which destroys elements of exceptionally preserved specimens. Here, we show for the first time that microtomography (micro-CT) can reveal structures situated inside a Chengjiang fossil slab without causing any damage. In the present study a trilobitomorph arthropod (Xandarella spectaculum) can be reliably identified only with the application of micro-CT. We propose that this technique is an important tool for studying three-dimensionally preserved Chengjiang fossils and, most likely, also those from other biota with a comparable type of preservation, specifically similar iron concentrations.

  11. Micro-CT evaluation of the marginal fit of CAD/CAM all ceramic crowns

    Science.gov (United States)

    Brenes, Christian

    Objectives: Evaluate the marginal fit of CAD/CAM all ceramic crowns made from lithium disilicate and zirconia using two different fabrication protocols (model and model-less). METHODS: Forty anterior all ceramic restorations (20 lithium disilicate, 20 zirconia) were fabricated using a CEREC Bluecam scanner. Two different fabrication methods were used: a full digital approach and a printed model. Completed crowns were cemented and marginal gap was evaluated using Micro-CT. Each specimen was analyzed in sagittal and trans-axial orientations, allowing a 360° evaluation of the vertical and horizontal fit. RESULTS: Vertical measurements in the lingual, distal and mesial views had and estimated marginal gap from 101.9 to 133.9 microns for E-max crowns and 126.4 to 165.4 microns for zirconia. No significant differences were found between model and model-less techniques. CONCLUSION: Lithium disilicate restorations exhibited a more accurate and consistent marginal adaptation when compared to zirconia crowns. No statistically significant differences were observed when comparing model or model-less approaches.

  12. On estimating the directionality distribution in pedicle trabecular bone from micro-CT images

    International Nuclear Information System (INIS)

    Our interest in the trabecular alignment within bone stems from the need to better understand the manner in which it can affect ultrasound propagation, particularly in pedicles. Within long bones it is well established that trabecular structures are aligned in an organized manner associated with the direction of load distribution; however, for smaller bones there are limited alignment studies. To investigate the directionality distribution in a quantitative manner we used a micro-CT to obtain three-dimensional (3D) structural data and developed analytical methods based on the special properties of Gabor filters. Implementation of these techniques has been developed and tested on a variety of simulated images as well as on 3D structures whose geometry is well-defined. To test the use of this technique we compared the results obtained on vertebral body trabecular bone with visual directionality and previous measurements by others. The method has been applied to six human pedicle samples in two orthogonal planes with results that provide reasonable proof-of-principle evidence that the method is well suited for estimating the directionality distribution within pedicle bones. (paper)

  13. Compensation of mechanical inaccuracies in micro-CT and nano-CT

    Science.gov (United States)

    Sasov, Alexander; Liu, Xuan; Salmon, Phil L.

    2008-08-01

    Micro-CT and especially nano-CT scanning requires very high mechanical precision and stability of object manipulator, which is difficult to reach. Several other problems, such as drift of emission point inside an X-ray source, thermal expansion in different parts of the scanner, mechanical vibrations, and object movement or shrinkage during long scans, can also contribute to geometrical inaccuracies. All these inaccuracies result in artifacts which reduce achievable spatial resolution. Linear distortions can be partially compensated by rigid X/Y shifts in projection images. More complicated object movement and shrinkage will require non-linear transforms. This paper investigates techniques to compensate geometrical inaccuracies by linear transformation only. We have developed two methods to estimate individual X/Y shifts in each measured projection. The first method aligns measured projections with forward-projected projections iteratively to reach an optimal X/Y shift estimation. It is more suitable for mechanical inaccuracies caused by random and jittery movement. The second method uses a very short reference scan acquired immediately after a main scan to obtain estimates of X/Y shifts. This method is rather effective for mechanical inaccuracies caused by slow and coherent mechanical drifts. Both methods have been implemented and evaluated on multiple scanners. Significant improvements in image quality have been observed.

  14. Reconstruction of Cochlea Based on Micro-CT and Histological Images of the Human Inner Ear

    Directory of Open Access Journals (Sweden)

    Christos Bellos

    2014-01-01

    Full Text Available The study of the normal function and pathology of the inner ear has unique difficulties as it is inaccessible during life and, so, conventional techniques of pathologic studies such as biopsy and surgical excision are not feasible, without further impairing function. Mathematical modelling is therefore particularly attractive as a tool in researching the cochlea and its pathology. The first step towards efficient mathematical modelling is the reconstruction of an accurate three dimensional (3D model of the cochlea that will be presented in this paper. The high quality of the histological images is being exploited in order to extract several sections of the cochlea that are not visible on the micro-CT (mCT images (i.e., scala media, spiral ligament, and organ of Corti as well as other important sections (i.e., basilar membrane, Reissner membrane, scala vestibule, and scala tympani. The reconstructed model is being projected in the centerline of the coiled cochlea, extracted from mCT images, and represented in the 3D space. The reconstruction activities are part of the SIFEM project, which will result in the delivery of an infrastructure, semantically interlinking various tools and libraries (i.e., segmentation, reconstruction, and visualization tools with the clinical knowledge, which is represented by existing data, towards the delivery of a robust multiscale model of the inner ear.

  15. A simple electron-beam lithography system

    DEFF Research Database (Denmark)

    Mølhave, Kristian; Madsen, Dorte Nørgaard; Bøggild, Peter

    2005-01-01

    A large number of applications of electron-beam lithography (EBL) systems in nanotechnology have been demonstrated in recent years. In this paper we present a simple and general-purpose EBL system constructed by insertion of an electrostatic deflector plate system at the electron-beam exit of the...... be used to write three-dimensional nanostructures by electron-beam deposition. (C) 2004 Elsevier B.V. All rights reserved....

  16. A correlative approach for combining microCT, light and transmission electron microscopy in a single 3D scenario

    OpenAIRE

    Handschuh, Stephan; Baeumler, Natalie; Schwaha, Thomas; Ruthensteiner, Bernhard

    2013-01-01

    Background In biomedical research, a huge variety of different techniques is currently available for the structural examination of small specimens, including conventional light microscopy (LM), transmission electron microscopy (TEM), confocal laser scanning microscopy (CLSM), microscopic X-ray computed tomography (microCT), and many others. Since every imaging method is physically limited by certain parameters, a correlative use of complementary methods often yields a significant broader rang...

  17. The application of micro-CT in monitoring bone alterations in tail-suspended rats in vivo

    Science.gov (United States)

    Luan, Hui-Qin; Sun, Lian-Wen; Huang, Yun-Fei; Wang, Ying; McClean, Colin J.; Fan, Yu-Bo

    2014-06-01

    Osteopenia is a pathological process that affects human skeletal health not only on earth but also in long-time spaceflight. Micro-computed tomography (micro-CT) is a nondestructive method for assessing both bone quantity and bone quality. To investigate the characteristics of micro-CT on evaluating the microgravity-induced osteopenia (e.g. early detection time and the sensitive parameters), the bone loss process of tail-suspended rats was monitored by micro-CT in this study. 8-Week-old female Sprague Dawley rats were divided into two groups: tail suspension (TS) and control (CON). Volumetric bone mineral density (vBMD) and microstructure of the femur and tibia were evaluated in vivo by micro-CT at 0, 7, 14, 22 days. Biomechanical properties of the femur and tibia were determined by three-point bending test. The ash weight of bone was also investigated. The results showed that (1) bone loss in the proximal tibia appeared earlier than in the distal femur. (2) On day 7, the percent bone volume (BV/TV) of the tibia 15.44% decreased significantly, and the trabecular separation (Tb.Sp) 30.29% increased significantly in TS group, both of which were detected earlier than other parameters. (3) Biomechanical properties (e.g. femur, -22.4% maximum load and -23.75% Young’s modulus vs. CON) and ash weight of the femur and tibia decreased significantly in the TS group in comparison to CON group. (4) vBMD of the femur and tibia were clearly related to bone ash and dry weight (r = 0.75-0.87, p reliable and sensitive method for predicting unloading-induced bone loss in small animals.

  18. In Vivo Micro-CT Assessment of Airway Remodeling in a Flexible OVA-Sensitized Murine Model of Asthma

    OpenAIRE

    Lederlin, Mathieu; Ozier, Annaïg; Dournes, Gaël; Ousova, Olga; Girodet, Pierre-Olivier; Begueret, Hugues; Marthan, Roger; Montaudon, Michel; Laurent, François; Berger, Patrick

    2012-01-01

    Airway remodeling is a major pathological feature of asthma. Up to now, its quantification still requires invasive methods. In this study, we aimed at determining whether in vivo micro-computed tomography (micro-CT) is able to demonstrate allergen-induced airway remodeling in a flexible mouse model of asthma. Sixty Balb/c mice were challenged intranasally with ovalbumin or saline at 3 different endpoints (Days 35, 75, and 110). All mice underwent plethysmography at baseline and just prior to ...

  19. Combined Micro-PET/Micro-CT Imaging of Lung Tumours in SPC-raf and SPC-myc Transgenic Mice

    OpenAIRE

    Thomas Rodt; Matthias Luepke; Claudia Boehm; Katja Hueper; Roman Halter; Silke Glage; Ludwig Hoy; Frank Wacker; Juergen Borlak; Christian von Falck

    2012-01-01

    INTRODUCTION: SPC-raf and SPC-myc transgenic mice develop disseminated and circumscribed lung adenocarcinoma respectively, allowing for assessment of carcinogenesis and treatment strategies. The purpose of this study was to investigate the technical feasibility, the correlation of initial findings to histology and the administered radiation dose of combined micro-PET/micro-CT in these animal models. MATERIAL AND METHODS: 14 C57BL/6 mice (4 nontransgenic, 4 SPC-raf transgenic, 6 SPC-myc transg...

  20. Micro-CT Based Experimental Liver Imaging Using a Nanoparticulate Contrast Agent: A Longitudinal Study in Mice

    OpenAIRE

    Boll, Hanne; Nittka, Stefanie; Doyon, Fabian; Neumaier, Michael; Marx, Alexander; Kramer, Martin; Groden, Christoph; Brockmann, Marc A.

    2011-01-01

    Background Micro-CT imaging of liver disease in mice relies on high soft tissue contrast to detect small lesions like liver metastases. Purpose of this study was to characterize the localization and time course of contrast enhancement of a nanoparticular alkaline earth metal-based contrast agent (VISCOVER ExiTron nano) developed for small animal liver CT imaging. Methodology ExiTron nano 6000 and ExiTron nano 12000, formulated for liver/spleen imaging and angiography, respectively, were intra...

  1. Using Micro-CT Derived Bone Microarchitecture to Analyze Bone Stiffness - A Case Study on Osteoporosis Rat Bone

    Directory of Open Access Journals (Sweden)

    Yuchin eWu

    2015-05-01

    Full Text Available Micro-computed tomography images can be used to quantitatively represent bone geometry through a range of computed attenuation-based parameters. Nonetheless, those parameters remain indirect indices of bone micro-architectural strength and require further computational tools to interpret bone structural stiffness and potential for mechanical failure. Finite element analysis (FEA can be applied to measure trabecular bone stiffness and potentially predict the location of structural failure in preclinical animal models of osteoporosis, although that procedure from image segmentation of micro-CT derived bone geometry to FEA is often challenging and computationally expensive, resulting in failure of the model to build. Notably, the selection of resolution and threshold for bone segmentation are key steps that greatly affect computational complexity and validity. In the following study, we evaluated an approach whereby Micro-CT derived greyscale attenuation and segmentation data guided the selection of trabecular bone for analysis by FEA. We further correlated those FEA results to both two and three dimensional bone microarchitecture from sham and ovariectomized (OVX rats (n=10/group. A virtual cylinder of vertebral trabecular bone 40% in length from the caudal side was selected for FEA because micro-CT based image analysis indicated the largest differences in microarchitecture between the two groups resided there. Bone stiffness was calculated using FEA and statistically correlated with the three dimensional values of bone volume/tissue volume, bone mineral density, fractal dimension, trabecular separation and trabecular bone pattern factor. Our method simplified the process for the assessment of trabecular bone stiffness by FEA from Micro-CT images and highlighted the importance of bone microarchitecture in conferring significantly increased bone quality capable of resisting failure due to increased mechanical loading.

  2. Technique for bone volume measurement from human femur head samples by classification of micro-CT image histograms

    OpenAIRE

    Franco Marinozzi; Fabiano Bini; Andrea Marinozzi; Francesca Zuppante; Annalisa De Paolis; Raffaella Pecci; Rossella Bedini

    2013-01-01

    INTRODUCTION: Micro-CT analysis is a powerful technique for a non-invasive evaluation of the morphometric parameters of trabecular bone samples. This elaboration requires a previous binarization of the images. A problem which arises from the binarization process is the partial volume artifact. Voxels at the external surface of the sample can contain both bone and air so thresholding operates an incorrect estimation of volume occupied by the two materials. AIM: The aim of this study is the ext...

  3. BEAM CONTAINMENT SYSTEM FOR NSLS-II

    International Nuclear Information System (INIS)

    The shielding design for the NSLS-II will provide adequate protection for the full injected beam loss in two periods of the ring around the injection point, but the remainder of the ring is shielded for lower losses of (le) 10% full beam. This will require a system to insure that beam losses don't exceed these levels for a period of time that could cause excessive radiation levels outside the shield walls. This beam containment system will measure, provide a level of control and alarm indication of the beam power losses along the beam path from the source (e-gun, linac) thru the injection system and the storage ring. This system will consist of collimators that will provide limits to (and potentially to measure) the beam miss-steering and control the loss points of the charge and monitors that will measure the average beam current losses along the beam path and alarm when this beam power loss exceeds the level set by the shielding specifications. This will require some new ideas in beam loss detection capability and collimation. The initial planning and R and D program will be presented.

  4. Micro-CT image-derived metrics quantify arterial wall distensibility reduction in a rat model of pulmonary hypertension

    Science.gov (United States)

    Johnson, Roger H.; Karau, Kelly L.; Molthen, Robert C.; Haworth, Steven T.; Dawson, Christopher A.

    2000-04-01

    We developed methods to quantify arterial structural and mechanical properties in excised rat lungs and applied them to investigate the distensibility decrease accompanying chronic hypoxia-induced pulmonary hypertension. Lungs of control and hypertensive (three weeks 11% O2) animals were excised and a contrast agent introduced before micro-CT imaging with a special purpose scanner. For each lung, four 3D image data sets were obtained, each at a different intra-arterial contrast agent pressure. Vessel segment diameters and lengths were measured at all levels in the arterial tree hierarchy, and these data used to generate features sensitive to distensibility changes. Results indicate that measurements obtained from 3D micro-CT images can be used to quantify vessel biomechanical properties in this rat model of pulmonary hypertension and that distensibility is reduced by exposure to chronic hypoxia. Mechanical properties can be assessed in a localized fashion and quantified in a spatially-resolved way or as a single parameter describing the tree as a whole. Micro-CT is a nondestructive way to rapidly assess structural and mechanical properties of arteries in small animal organs maintained in a physiological state. Quantitative features measured by this method may provide valuable insights into the mechanisms causing the elevated pressures in pulmonary hypertension of differing etiologies and should become increasingly valuable tools in the study of complex phenotypes in small-animal models of important diseases such as hypertension.

  5. A registration-based segmentation method with application to adiposity analysis of mice microCT images

    Science.gov (United States)

    Bai, Bing; Joshi, Anand; Brandhorst, Sebastian; Longo, Valter D.; Conti, Peter S.; Leahy, Richard M.

    2014-04-01

    Obesity is a global health problem, particularly in the U.S. where one third of adults are obese. A reliable and accurate method of quantifying obesity is necessary. Visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) are two measures of obesity that reflect different associated health risks, but accurate measurements in humans or rodent models are difficult. In this paper we present an automatic, registration-based segmentation method for mouse adiposity studies using microCT images. We co-register the subject CT image and a mouse CT atlas. Our method is based on surface matching of the microCT image and an atlas. Surface-based elastic volume warping is used to match the internal anatomy. We acquired a whole body scan of a C57BL6/J mouse injected with contrast agent using microCT and created a whole body mouse atlas by manually delineate the boundaries of the mouse and major organs. For method verification we scanned a C57BL6/J mouse from the base of the skull to the distal tibia. We registered the obtained mouse CT image to our atlas. Preliminary results show that we can warp the atlas image to match the posture and shape of the subject CT image, which has significant differences from the atlas. We plan to use this software tool in longitudinal obesity studies using mouse models.

  6. Comparison of high-resolution X-ray and micro-CT for experimental evaluation of intracranial stent prototypes: quality evaluation beyond CE mark

    Energy Technology Data Exchange (ETDEWEB)

    Keuler, Andreas; Taschner, Christian; Schumacher, Martin [University Medical Center Freiburg, Department of Neuroradiology, Freiburg (Germany); Brockmann, Marc Alexander [University Hospital of RWTH Aachen, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); University of Heidelberg, Department of Neuroradiology, University Medical Center Mannheim, Mannheim (Germany); Boll, Hanne [University of Heidelberg, Department of Neuroradiology, University Medical Center Mannheim, Mannheim (Germany); Foerster, Katharina [University Medical Center Freiburg, Department of Cardiovascular Surgery, Freiburg (Germany); Lutz, Lisa [University Medical Center Freiburg, Department of Pathology, Freiburg (Germany); Herrmann-Frank, Annegret; Lelgemann, Monika [Medical Advisory Service of Social Health Insurance, Department of Evidence-Based Medicine, Essen (Germany)

    2014-04-15

    As digital mammography and micro-computed tomography (CT) have been used for evaluation of stents deployed in experimental animal models, we compared the two methods regarding their sensitivity to detect abnormalities in three prototypes of intracranial stents. Three different prototypes of intracranial stents (n = 84) were implanted in various animal models. Explanted stents were examined using digital mammography and micro-CT. The images were compared with respect to maintenance of material and form and the stents were compared to one another. Histological analysis was performed as well. In the open-cell stents, expansion of the stent cells was detected in the majority of cases (57.1 %) using micro-CT and less frequently using mammography (42.3 %). The closed-cell stent revealed kink stenoses in mammography as well as in micro-CT (3/7, 42.9 %). Detailed reconstructions of micro-CT images showed high-grade kink stenoses of the flow-diverter stent in two extremely curved vessels. Strut breaks were observed more frequently using micro-CT (6/84, 7.1 %) than by mammography (4/84, 4.8 %). Histology confirmed all changes of stent architecture. Significant changes of stent architecture can be observed and assessed even in the two-dimensional mammographic images. The use of micro-CT is recommended to detect subtle changes like single strut breaks and for three-dimensional information. (orig.)

  7. Phenotypic characterization of skeletal abnormalities of osteopotentia mutant mice by micro-CT: a descriptive approach with emphasis on reconstruction techniques

    Energy Technology Data Exchange (ETDEWEB)

    Roemer, Frank W. [Department of Radiology, Klinikum Augsburg, Augsburg (Germany); Boston University School of Medicine, Quantitative Imaging Center, Boston, MA (United States); University of California, San Francisco, Osteoporosis and Arthritis Research Group, San Francisco, CA (United States); Boston University Medical Center, Department of Radiology, Boston, MA (United States); Mohr, Andreas [University of California, San Francisco, Osteoporosis and Arthritis Research Group, San Francisco, CA (United States); Sligo General Hospital, Department of Radiology, Sligo (Ireland); Guermazi, Ali [Boston University School of Medicine, Quantitative Imaging Center, Boston, MA (United States); University of California, San Francisco, Osteoporosis and Arthritis Research Group, San Francisco, CA (United States); Jiang, Yebin [University of California, San Francisco, Osteoporosis and Arthritis Research Group, San Francisco, CA (United States); University of Michigan Medical School, Osteoporosis and Arthritis Laboratory, Musculoskeletal Division, Department of Radiology, Ann Arbor, MI (United States); Schlechtweg, Philipp [University of Erlangen, Department of Radiology, Erlangen (Germany); Genant, Harry K. [University of California, San Francisco, Osteoporosis and Arthritis Research Group, San Francisco, CA (United States); CCBR-SYNARC, Inc., San Francisco, CA (United States); Sohaskey, Michael L. [University of California, Berkeley, Department of Molecular and Cell Biology and Center for Integrative Genomics, Berkeley, CA (United States)

    2011-08-15

    The novel protein osteopotentia (Opt) has recently been described as an essential regulator of postnatal osteoblast maturation and might possibly be responsible for some of the rarer types of osteogenesis imperfecta. Our aim was the evaluation of micro CT for the qualitative morphological assessment of skeletal abnormalities of Osteopotentia-mutant mice in comparison to radiography and histology. Four homozygous mice with insertional mutations in the Opt gene and three wild-type controls were examined ex vivo using radiography and micro-CT. Two of the homozygous animals were evaluated histologically (trichrome reagent). For the micro-CT evaluation three-dimensional (3D) surface reconstructions and two-dimensional (2D) multiplanar reformations (MPRs) were applied. The Opt-homozygous mice exhibited severe growth. The radiographic examinations showed osteopenia and fractures with hypertrophic callus formation and pseudarthroses of the forelimbs and ribs. Micro-CT confirmed these findings and was able to demonstrate additional fractures especially at smaller bones such as the metacarpals and phalanges. Additional characterization and superior delineation of cortices and fracture fragments was achieved by 2D MPRs. Histological correlation verified several of these imaging findings. Micro-CT is able to screen Opt-mutant mice for osseous pathologies and furthermore characterize these anomalies. The modality seems superior to conventional radiography, but is not able to demonstrate cellular pathology. However, histology is destructive and more time- and material-consuming than micro-CT. Additional information may be gathered by 2D MPRs. (orig.)

  8. Phenotypic characterization of skeletal abnormalities of osteopotentia mutant mice by micro-CT: a descriptive approach with emphasis on reconstruction techniques

    International Nuclear Information System (INIS)

    The novel protein osteopotentia (Opt) has recently been described as an essential regulator of postnatal osteoblast maturation and might possibly be responsible for some of the rarer types of osteogenesis imperfecta. Our aim was the evaluation of micro CT for the qualitative morphological assessment of skeletal abnormalities of Osteopotentia-mutant mice in comparison to radiography and histology. Four homozygous mice with insertional mutations in the Opt gene and three wild-type controls were examined ex vivo using radiography and micro-CT. Two of the homozygous animals were evaluated histologically (trichrome reagent). For the micro-CT evaluation three-dimensional (3D) surface reconstructions and two-dimensional (2D) multiplanar reformations (MPRs) were applied. The Opt-homozygous mice exhibited severe growth. The radiographic examinations showed osteopenia and fractures with hypertrophic callus formation and pseudarthroses of the forelimbs and ribs. Micro-CT confirmed these findings and was able to demonstrate additional fractures especially at smaller bones such as the metacarpals and phalanges. Additional characterization and superior delineation of cortices and fracture fragments was achieved by 2D MPRs. Histological correlation verified several of these imaging findings. Micro-CT is able to screen Opt-mutant mice for osseous pathologies and furthermore characterize these anomalies. The modality seems superior to conventional radiography, but is not able to demonstrate cellular pathology. However, histology is destructive and more time- and material-consuming than micro-CT. Additional information may be gathered by 2D MPRs. (orig.)

  9. Comparison of high-resolution X-ray and micro-CT for experimental evaluation of intracranial stent prototypes: quality evaluation beyond CE mark

    International Nuclear Information System (INIS)

    As digital mammography and micro-computed tomography (CT) have been used for evaluation of stents deployed in experimental animal models, we compared the two methods regarding their sensitivity to detect abnormalities in three prototypes of intracranial stents. Three different prototypes of intracranial stents (n = 84) were implanted in various animal models. Explanted stents were examined using digital mammography and micro-CT. The images were compared with respect to maintenance of material and form and the stents were compared to one another. Histological analysis was performed as well. In the open-cell stents, expansion of the stent cells was detected in the majority of cases (57.1 %) using micro-CT and less frequently using mammography (42.3 %). The closed-cell stent revealed kink stenoses in mammography as well as in micro-CT (3/7, 42.9 %). Detailed reconstructions of micro-CT images showed high-grade kink stenoses of the flow-diverter stent in two extremely curved vessels. Strut breaks were observed more frequently using micro-CT (6/84, 7.1 %) than by mammography (4/84, 4.8 %). Histology confirmed all changes of stent architecture. Significant changes of stent architecture can be observed and assessed even in the two-dimensional mammographic images. The use of micro-CT is recommended to detect subtle changes like single strut breaks and for three-dimensional information. (orig.)

  10. Neutral beam data systems at ORNL

    International Nuclear Information System (INIS)

    A control system for neutral injection beam lines has been designed, implemented, and used with much success. Despite the problems with very high power levels this system is very successful in relieving the operators burdens of slow conditioning, data recording, and mode switching. The use of computer control with multiple beam lines now appears very promising

  11. Airway and pulmonary vascular measurements using contrast-enhanced micro-CT in rodents.

    Science.gov (United States)

    Counter, W B; Wang, I Q; Farncombe, T H; Labiris, N R

    2013-06-15

    Preclinical imaging allows pulmonary researchers to study lung disease and pulmonary drug delivery noninvasively and longitudinally in small animals. However, anatomically localizing a pathology or drug deposition to a particular lung region is not easily done. Thus, a detailed knowledge of the anatomical structure of small animal lungs is necessary for understanding disease progression and in addition would facilitate the analysis of the imaging data, mapping drug deposition and relating function to structure. In this study, contrast-enhanced micro-computed tomography (CT) of the lung produced high-resolution images that allowed for the characterization of the rodent airway and pulmonary vasculature. Contrast-enhanced micro-CT was used to visualize the airways and pulmonary vasculature in Sprague-Dawley rats (200-225 g) and BALB/c mice (20-25 g) postmortem. Segmented volumes from these images were processed to yield automated measurements of the airways and pulmonary vasculature. The diameters, lengths, and branching angles of the airway, arterial, and venous trees were measured and analyzed as a function of generation number and vessel diameter to establish rules that could be applied at all levels of tree hierarchy. In the rat, airway, arterial, and venous tress were measured down to the 20th, 16th, and 14th generation, respectively. In the mouse, airway, arterial, and venous trees were measured down to the 16th, 8th, and 7th generation, respectively. This structural information, catalogued in a rodent database, will increase our understanding of lung structure and will aid in future studies of the relationship between structure and function in animal models of disease. PMID:23564512

  12. Contrast agent comparison for three-dimensional micro-CT angiography: A cadaveric study.

    Science.gov (United States)

    Kingston, Mitchell J; Perriman, Diana M; Neeman, Teresa; Smith, Paul N; Webb, Alexandra L

    2016-07-01

    Barium sulfate and lead oxide contrast media are frequently used for cadaver-based angiography studies. These contrast media have not previously been compared to determine which is optimal for the visualisation and measurement of blood vessels. In this study, the lower limb vessels of 16 embalmed Wistar rats, and four sets of cannulae of known diameter, were injected with one of three different contrast agents (barium sulfate and resin, barium sulfate and gelatin, and lead oxide combined with milk powder). All were then scanned using micro-computed tomography (CT) angiography and 3-D reconstructions generated. The number of branching generations of the rat lower limb vessels were counted and compared between the contrast agents using ANOVA. The diameter of the contrast-filled cannulae, were measured and used to calculate the accuracy of the measurements by comparing the bias and variance of the estimates. Intra- and inter-observer reliability were calculated using intra-class correlation coefficients. There was no significant difference (mean difference [MD] 0.05; MD 95% confidence interval [CI] -0.83 to 0.93) between the number of branching generations for barium sulfate-resin and lead oxide-milk powder. Barium sulfate-resin demonstrated less bias and less variance of the estimates (MD 0.03; standard deviation [SD] 1.96 mm) compared to lead oxide-milk powder (MD 0.11; SD 1.96 mm) for measurements of contrast-filled cannulae scanned at high resolution. Barium sulfate-resin proved to be more accurate than lead oxide-milk powder for high resolution micro-CT scans and is preferred due to its non-toxicity. This technique could be applied to any embalmed specimen model. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27075920

  13. Micro-CT imaging of denatured chitin by silver to explore honey bee and insect pathologies.

    Directory of Open Access Journals (Sweden)

    Peter R Butzloff

    Full Text Available BACKGROUND: Chitin and cuticle coatings are important to the environmental and immune defense of honey bees and insect pollinators. Pesticides or environmental effects may target the biochemistry of insect chitin and cuticle coating. Denaturing of chitin involves a combination of deacetylation, intercalation, oxidation, Schweiger-peeling, and the formation of amine hydrochloride salt. The term "denatured chitin" calls attention to structural and property changes to the internal membranes and external carapace of organisms so that some properties affecting biological activities are diminished. METHODOLOGY/PRINCIPAL FINDINGS: A case study was performed on honey bees using silver staining and microscopic computer-tomographic x-ray radiography (micro-CT. Silver nitrate formed counter-ion complexes with labile ammonium cations and reacted with amine hydrochloride. Silver was concentrated in the peritrophic membrane, on the abdomen, in the glossa, at intersegmental joints (tarsi, at wing attachments, and in tracheal air sacs. Imaged mono-esters and fatty acids from cuticle coating on external surfaces were apparently reduced by an alcohol pretreatment. CONCLUSIONS/SIGNIFICANCE: The technique provides 3-dimensional and sectional images of individual honey bees consistent with the chemistries of silver reaction and complex formation with denatured chitin. Environmental exposures and influences such as gaseous nitric oxide intercalant, trace oxidants such as ozone gas, oligosachharide salt conversion, exposure to acid rain, and chemical or biochemical denaturing by pesticides may be studied using this technique. Peritrophic membranes, which protect against food abrasion, microorganisms, and permit efficient digestion, were imaged. Apparent surface damage to the corneal lenses of compound eyes by dilute acid exposure consistent with chitin amine hydrochloride formation was imaged. The technique can contribute to existing insect pathology research, and may

  14. Pore-scale simulation of carbonate dissolution in micro-CT images

    Science.gov (United States)

    Pereira Nunes, J. P.; Blunt, M. J.; Bijeljic, B.

    2016-02-01

    We present a particle-based method to simulate carbonate dissolution at the pore scale directly on the voxels of three-dimensional micro-CT images. The flow field is computed on the images by solving the incompressible Navier-Stokes equations. Rock-fluid interaction is modeled using a three-step approach: solute advection, diffusion, and reaction. Advection is simulated with a semianalytical pore-scale streamline tracing algorithm, diffusion by random walk is superimposed, while the reaction rate is defined by the flux of particles through the pore-solid interface. We derive a relationship between the local particle flux and the independently measured batch calcite dissolution rate. We validate our method against a dynamic imaging experiment where a Ketton oolite is imaged during CO2-saturated brine injection at reservoir conditions. The image-calculated increases in porosity and permeability are predicted accurately, and the spatial distribution of the dissolution front is correctly replicated. The experiments and simulations are performed at a high flow rate, in the uniform dissolution regime - Pe ≫ 1 and PeDa ≪ 1—thus extending the reaction throughout the sample. Transport is advection dominated, and dissolution is limited to regions with significant inflow of solute. We show that the sample-averaged reaction rate is 1 order of magnitude lower than that measured in batch reactors. This decrease is the result of restrictions imposed on the flux of solute to the solid surface by the heterogeneous flow field, at the millimeter scale.

  15. Simulation studies for ion beam extraction systems

    Energy Technology Data Exchange (ETDEWEB)

    Abdelrahman, M.M.; Zakhary, S.G. [Atomic Energy, Cairo (Egypt). Nuclear Research Center. Accelerators and Ion Sources Dept.], e-mail: moustafa82003@yahoo.com

    2009-06-15

    The characteristics of the ion beam extracted from an ion sources were investigated using computer code SIMION 3 D Version 7.0. It has been used to evaluate the extraction system in order to produce an ion beam with high current and low beam emittance. The results show that the shape of the extraction electrode plays an important role in ion beam formation. Comparison has been made between two extraction systems, Pierce extraction electrode and spherical extraction electrode. The results show that the spherical extraction system yields ion extraction beam with lower emittance and radius than that the Pierce system. The simulation can provide the basis for optimizing the extraction system and the acceleration gap for ion source. (author)

  16. Low energy beam transport system developments

    International Nuclear Information System (INIS)

    For high brightness beam production it is important to preserve the brightness in the low energy beam transport system (LEBT) used to transport and match the ion beams to the next stage of acceleration, usually an RFQ. While electrostatic focusing can be problematic for high current beam transport, reliable electrostatic LEBT operation has been demonstrated with H− beams up to 60 mA. Now, however, it is commonly accepted that an optimal LEBT for high current accelerator applications consists of focusing solenoids with space charge compensation. Two-solenoid LEBTs are successfully used for high current (>100 mA) proton beam transport. Preservation of low emittances (~0.15 π mm-mrad) requires the addition of a heavy gas (Xe, Kr), which causes ~5% of proton loss in a 1 m long LEBT. Similar Xe densities would be required to preserve low emittances of H− beams, but such gas densities cause unacceptably high H− beam losses. A short LEBT with only one short solenoid, movable for RFQ matching, can be used for reduced negative ion stripping. A strong electrostatic-focusing LEBT has been successfully adopted for transport of high current H− beams in the SNS Front End. Some modifications of such electrostatic LEBTs are expected to improve the reliable transport of intense positive and negative ion beams without greatly degrading their low emittances. We concentrate on processes that determine the beam brightness degradation and on their prevention. Proposed improvements to the SNS electrostatic LEBT are discussed

  17. Low energy beam transport system developments

    Science.gov (United States)

    Dudnikov, V.; Han, B.; Stockli, M.; Welton, R.; Dudnikova, G.

    2015-04-01

    For high brightness beam production it is important to preserve the brightness in the low energy beam transport system (LEBT) used to transport and match the ion beams to the next stage of acceleration, usually an RFQ. While electrostatic focusing can be problematic for high current beam transport, reliable electrostatic LEBT operation has been demonstrated with H- beams up to 60 mA. Now, however, it is commonly accepted that an optimal LEBT for high current accelerator applications consists of focusing solenoids with space charge compensation. Two-solenoid LEBTs are successfully used for high current (>100 mA) proton beam transport. Preservation of low emittances (~0.15 π mm-mrad) requires the addition of a heavy gas (Xe, Kr), which causes ~5% of proton loss in a 1 m long LEBT. Similar Xe densities would be required to preserve low emittances of H- beams, but such gas densities cause unacceptably high H- beam losses. A short LEBT with only one short solenoid, movable for RFQ matching, can be used for reduced negative ion stripping. A strong electrostatic-focusing LEBT has been successfully adopted for transport of high current H- beams in the SNS Front End. Some modifications of such electrostatic LEBTs are expected to improve the reliable transport of intense positive and negative ion beams without greatly degrading their low emittances. We concentrate on processes that determine the beam brightness degradation and on their prevention. Proposed improvements to the SNS electrostatic LEBT are discussed.

  18. Gamma beam system at ELI-NP

    Energy Technology Data Exchange (ETDEWEB)

    Ur, Calin Alexandru, E-mail: calin.ur@eli-np.ro [Extreme Light Infrastructure, IFIN-HH, Magurele-Bucharest (Romania)

    2015-02-24

    The Gamma Beam System of ELI-NP will produce brilliant, quasi-monochromatic gamma-ray beams via Inverse Compton Scattering of short laser pulses on relativistic electron beam pulses. The scattered radiation is Doppler upshifted by more than 1,000,000 times and is forward focused in a narrow, polarized, tunable, laser-like beam. The gamma-ray beam at ELI-NP will be characterized by large spectral density of about 10{sup 4} photons/s/eV, narrow bandwidth (< 0.5%) and tunable energy from 200 keV up to about 20 MeV. The Gamma Beam System is a state-of-the-art equipment employing techniques and technologies at the limits of the present-day's knowledge.

  19. Progress of beam diagnosis system for EAST neutral beam injector

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Y. J., E-mail: yjxu@ipp.ac.cn; Hu, C. D.; Yu, L.; Liang, L. Z.; Zhang, W. T.; Chen, Y.; Li, X. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2016-02-15

    Neutral beam injection has been recognized as one of the most effective means for plasma heating. According to the research plan of the EAST physics experiment, two sets of neutral beam injector (NBI) were built and operational in 2014. The paper presents the development of beam diagnosis system for EAST NBI and the latest experiment results obtained on the test-stand and EAST-NBI-1 and 2. The results show that the optimal divergence angle is (0.62°, 1.57°) and the full energy particle is up to 77%. They indicate that EAST NBI work properly and all targets reach or almost reach the design targets. All these lay a solid foundation for the achievement of high quality plasma heating for EAST.

  20. Advanced Light Source beam diagnostics systems

    International Nuclear Information System (INIS)

    The Advanced Light Source (ALS), a third-generation synchrotron light source, has been recently commissioned. Beam diagnostics were very important to the success of the operation. Each diagnostic system is described in this paper along with detailed discussion of its performance. Some of the systems have been in operation for two years. Others, in the storage ring, have not yet been fully commissioned. These systems were, however, working well enough to provide the essential information needed to store beam. The devices described in this paper include wall current monitors, a beam charge monitor, a 50 ohm Faraday cup, DC current transformers, broad-hand striplines, fluorescence screens, beam collimators and scrapers, and beam position monitors. Also, the means by which waveforms are digitized and displayed in the control room is discussed

  1. Vibrations and stability of complex beam systems

    CERN Document Server

    Stojanović, Vladimir

    2015-01-01

     This book reports on solved problems concerning vibrations and stability of complex beam systems. The complexity of a system is considered from two points of view: the complexity originating from the nature of the structure, in the case of two or more elastically connected beams; and the complexity derived from the dynamic behavior of the system, in the case of a damaged single beam, resulting from the harm done to its simple structure. Furthermore, the book describes the analytical derivation of equations of two or more elastically connected beams, using four different theories (Euler, Rayleigh, Timoshenko and Reddy-Bickford). It also reports on a new, improved p-version of the finite element method for geometrically nonlinear vibrations. The new method provides more accurate approximations of solutions, while also allowing us to analyze geometrically nonlinear vibrations. The book describes the appearance of longitudinal vibrations of damaged clamped-clamped beams as a result of discontinuity (damage). It...

  2. Osteoarthitis of Leptin-Deficient ob/ob Mice in Response to Biomechanical Loading in Micro-CT

    Directory of Open Access Journals (Sweden)

    Hansjoerg Heep, Gero Hilken, Sebastian Hofmeister, Christian Wedemeyer

    2009-01-01

    Full Text Available Objective: Mechanotransduction is the mechanism that due to reacting chondrocytes on biomechanical loading of body mass. Higher biomechanical loading lead to increased degeneration of chondrocytes, whereas moderate loading is protecting. This suggests that body fat regulates bone metabolism first by means of hormonal factors and second that the effects of muscle and loading are signaling factors in mechanotransduction. Leptin, a peptide hormone produced predominantly by white fat cells, is one of these hormonal factors. The aim of this study was to investigate and measure the different effects of weight-bearing on trabecular bone formation in mice without the stimulation of leptin and with or without osteoarthritis. Materials and methods: 40 C57BL/ 6J ob/ob-mice in the age of 20 weeks have been devided into two groups with an ad-libitum-diet and with reduced diet. The hip- and knee-joints have been examinated in micro-CT-scan and histomorphologically. Results: Animals with an ad-libitum-diet were found to increase body weight significantly at the age of six weeks in comparison with lean mice. At the age of twenty weeks the obese mice were almost twice as heavy as the lean mice. Significant statistical differences are shown between the two groups for body weight and bone mineral density. Examination of trabecular bone in micro-CT revealed that the only statistically significant difference between the two groups was the trabecular number for the proximal femur. High weight-bearing insignificantly improved all trabecular bone parameters in the obese mice. Correlation was found between trabecular number and bone mineral density on the one hand and body weight on the other hand. The correlation between body weight and osteoarthritis shows a significant increase in grade of osteoarthritis as body weight increases in hip-joint and knee-joint but not in osteoarthritis-positive (OP versus osteoarthritis-negative (ON mices. The correlation of the hip

  3. Dynamic contrast-enhanced micro-CT on mice with mammary carcinoma for the assessment of antiangiogenic therapy response

    Energy Technology Data Exchange (ETDEWEB)

    Eisa, Fabian [University of Erlangen-Nuremberg, Institute of Medical Physics, Erlangen (Germany); University of Erlangen-Nuremberg, Graduate School in Advanced Optical Technologies (SAOT), Erlangen (Germany); Brauweiler, Robert; Hupfer, Martin; Nowak, Tristan; Kalender, Willi A. [University of Erlangen-Nuremberg, Institute of Medical Physics, Erlangen (Germany); Lotz, Laura; Hoffmann, Inge; Dittrich, Ralf; Beckmann, Matthias W. [University of Erlangen-Nuremberg, OB/GYN, University Hospital Erlangen, Erlangen (Germany); Wachter, David [University Hospital Erlangen, Institute of Pathology, Erlangen (Germany); Jost, Gregor; Pietsch, Hubertus [Bayer Pharma AG, Berlin (Germany)

    2012-04-15

    To evaluate the potential of in vivo dynamic contrast-enhanced micro-computed tomography (DCE micro-CT) for the assessment of antiangiogenic drug therapy response of mice with mammary carcinoma. 20 female mice with implanted MCF7 tumours were split into control group and therapy group treated with a known effective antiangiogenic drug. All mice underwent DCE micro-CT for the 3D analysis of functional parameters (relative blood volume [rBV], vascular permeability [K], area under the time-enhancement curve [AUC]) and morphology. All parameters were determined for total, peripheral and central tumour volumes of interest (VOIs). Immunohistochemistry was performed to characterise tumour vascularisation. 3D dose distributions were determined. The mean AUCs were significantly lower in therapy with P values of 0.012, 0.007 and 0.023 for total, peripheral and central tumour VOIs. K and rBV showed significant differences for the peripheral (P{sub per}{sup K} = 0.032, P{sub per}{sup rBV} = 0.029), but not for the total and central tumour VOIs (P{sub total}{sup K} = 0.108, P{sub central}{sup K} = 0.246, P{sub total}{sup rBV} = 0.093, P{sub central}{sup rBV} = 0.136). Mean tumour volume was significantly smaller in therapy (P{sub in} {sub vivo} = 0.001, P{sub ex} {sub vivo} = 0.005). Histology revealed greater vascularisation in the controls and central tumour necrosis. Doses ranged from 150 to 300 mGy. This study indicates the great potential of DCE micro-CT for early in vivo assessment of antiangiogenic drug therapy response. (orig.)

  4. MicroCT evaluation of bone mineral density loss in human bones

    International Nuclear Information System (INIS)

    Bone is a connective tissue largely composed of an organic protein, collagen and the inorganic mineral hydroxyapatite [Ca10(PO4)6OH2], which combine to provide a mechanical and supportive role in the body. Depending on the orientation of collagen fibers, two types of bone can be distinguished: trabecular and cortical bone. Degree of mineralization is considered an important feature of bone quality. Changes in the degree of mineralization is generally due to osteoporosis, but many recent studies have already shown that alterations in degree of mineralization can occur due to a large variety of factors. The transmission X-ray microtomography is one of the most popular methods, which provides the spatial distribution of the total absorption coefficient inside the sample. The aim of this study was to investigate the suitability of using microCT as a supplementary tool for the diagnosis of the health status of human bones. Eleven samples were constructed simulating the physiological range of bone mineral density (BMD) found in cortical human bone. The samples represent healthy mixtures of swine compact bone dried at room temperature, powdered and mixed with fat (0 - 100 % by mass). The samples were imaged by a microfocus tube (Fein-Focus) with focal size of about 60 μm (±5%), and a CCD camera (0.143 mm pixel size) coupled with an intensifier tube with fluoroscope screen at the Nuclear Instrumentation Laboratory (COPPE/UFRJ), Brazil. The images were reconstructed and treated with suitable software developed at the Nuclear Instrumentation Laboratory. The mineral content in cortical bone is defined by the volume of dry, fat-free bone per unit bulk volume of the bone. The volumes were calculated from the bone density using the relationship between volume and density. The densities of fat and bone were taken to be 0.95 g.cm-3 and 1.92 g.cm-3 respectively. The correlation of the measured absorption coefficient with the mineral content in the samples was then investigated

  5. Establishing the Nude Mice Bone Metastasis Model of Lung Adenocarcinoma and Applying MicroCT into the Observation

    OpenAIRE

    Yongqi CUI; Geng, Qin; Gu, Aiqin; Miaoxin ZHU; Hanwei KONG; Sun, Lei; Liu, Lei; Yan, Mingxia; Yao, Ming

    2013-01-01

    Background and objective 50%-70% of patients with advanced lung cancer will develop bone metastases. The aim of this study is to establish the nude mice bone metastasis model of lung adenocarcinoma using A549, H1299, SPC-A-1 and XL-2, all of which own different invasion and migration abilities in vitro and supervise the bone metastases by MicroCT. Methods fifty BALB/C-nu/nu nude mice were grouped into five groups on average randomly. Cells of the four cell lines were injected into the left ca...

  6. Detection systems for radioactive ion beams

    International Nuclear Information System (INIS)

    Two main methods are used to produce radioactive ion beams: -) the ISOL method (isotope separation on-line) in which the stable beam interacts with a thick target, the reaction products diffuse outside the target and are transferred to a source where they are ionized, a mass separator and a post-accelerator drive the selected radioactive ions to the right energy; -) the in-flight fragmentation method in which the stable beam interacts with a thin target, the reaction products are emitted from the target with a restricted angular distribution and a velocity close to that of the incident beam, the experimenter has to take advantage from the reaction kinetics to get the right particle beam. Characteristic time is far longer with the ISOL method but the beam intensity is much better because of the use of a post-accelerator. In both cases, the beam intensity is lower by several orders of magnitude than in the case of a stable beam. This article presents all the constraints imposed by radioactive beams to the detection systems of the reaction products and gives new technical solutions according to the type of nuclear reaction studied. (A.C.)

  7. Walking beam pumping unit system efficiency measurements

    International Nuclear Information System (INIS)

    The cost of electricity used by walking beam pumping units is a major expense in producing crude oil. However, only very limited information is available on the efficiency of beam pumping systems and less is known about the efficiency of the various components of the pumping units. This paper presents and discusses measurements that have been made on wells at several Shell locations and on a specially designed walking beam pump test stand at Lufkin Industries. These measurements were made in order to determine the overall system efficiency and efficiency of individual components. The results of this work show that the overall beam pumping system efficiency is normally between 48 and 58 percent. This is primarily dependent on the motor size, motor type, gearbox size, system's age, production, pump size, tubing size, and rod sizes

  8. Low energy beam transport system developments

    Energy Technology Data Exchange (ETDEWEB)

    Dudnikov, V., E-mail: vadim@muonsinc.com [Muons, Inc., Batavia, IL 60510 (United States); Han, B.; Stockli, M.; Welton, R. [ORNL, Oak Ridge, TN 37831 (United States); Dudnikova, G. [University of Maryland, College Park, MD 3261 (United States); Institute of Computational Technologies SBRAS, Novosibirsk (Russian Federation)

    2015-04-08

    For high brightness beam production it is important to preserve the brightness in the low energy beam transport system (LEBT) used to transport and match the ion beams to the next stage of acceleration, usually an RFQ. While electrostatic focusing can be problematic for high current beam transport, reliable electrostatic LEBT operation has been demonstrated with H{sup −} beams up to 60 mA. Now, however, it is commonly accepted that an optimal LEBT for high current accelerator applications consists of focusing solenoids with space charge compensation. Two-solenoid LEBTs are successfully used for high current (>100 mA) proton beam transport. Preservation of low emittances (~0.15 π mm-mrad) requires the addition of a heavy gas (Xe, Kr), which causes ~5% of proton loss in a 1 m long LEBT. Similar Xe densities would be required to preserve low emittances of H{sup −} beams, but such gas densities cause unacceptably high H{sup −} beam losses. A short LEBT with only one short solenoid, movable for RFQ matching, can be used for reduced negative ion stripping. A strong electrostatic-focusing LEBT has been successfully adopted for transport of high current H{sup −} beams in the SNS Front End. Some modifications of such electrostatic LEBTs are expected to improve the reliable transport of intense positive and negative ion beams without greatly degrading their low emittances. We concentrate on processes that determine the beam brightness degradation and on their prevention. Proposed improvements to the SNS electrostatic LEBT are discussed.

  9. Beam position monitoring electronics system for LEHIPA

    International Nuclear Information System (INIS)

    The primary function of beam position monitoring system (BPM) is to determine the position of the beam with respect to the centre of beam pipe. The present system is VME based and mainly consists of two VME boards one Analog and one Digital. The system has been developed for 352.21 MHz Low Energy High Intensity Proton Accelerator (LEHIPA). The electronic system processes the signals coming from the sensor which incorporates four button pick-ups placed orthogonally around the beam pipe. The fundamental component of the beam signal is extracted from the signals from the sensor and amplified with gain stabilized amplifiers on the analog board. Offset tone based technique has been used for the stabilization of the gain of the amplifiers against changes in temperature, power supply, etc. The filtered and amplified signals are given to the digital board for digitization and further processing. The signal processing consists of demodulation in I-Q domain followed by CORDIC which gives the signal information in the form of amplitude and phase. The stabilization of the gain is also carried out in the digital domain. The phase information can be utilized for energy gain measurements. The amplitudes give the position of the beam which is calculated online in FPGA using difference over sum method. The EPICS system has been chosen as the basic framework for command control. The hardware architecture is as per standard VME crate. (author)

  10. A simple electron-beam lithography system

    DEFF Research Database (Denmark)

    Mølhave, Kristian; Madsen, Dorte Nørgaard; Bøggild, Peter

    2005-01-01

    A large number of applications of electron-beam lithography (EBL) systems in nanotechnology have been demonstrated in recent years. In this paper we present a simple and general-purpose EBL system constructed by insertion of an electrostatic deflector plate system at the electron-beam exit of the...... column of a scanning electron microscope (SEM). The system can easily be mounted on most standard SEM systems. The tested setup allows an area of up to about 50 x 50 pm to be scanned, if the upper limit for acceptable reduction of the SEM resolution is set to 10 run. We demonstrate how the EBL system can...... be used to write three-dimensional nanostructures by electron-beam deposition. (C) 2004 Elsevier B.V. All rights reserved....

  11. Antares beam-alignment-system performance

    International Nuclear Information System (INIS)

    The beam alignment system for the 24-beam-sector Antares CO2 fusion laser automatically aligns more than 200 optical elements. A visible-wavelength alignment technique is employed which uses a telescope/TV system to view point-light sources appropriately located down the beamline. The centroids of the light spots are determined by a video tracker, which generates error signals used by the computer control system to move appropriate mirrors in a closed-loop system. Final touch-up alignment is accomplished by projecting a CO2 alignment laser beam through the system and sensing its position at the target location. The techniques and control algorithms employed have resulted in alignment accuracies exceeding design requirements. By employing video processing to determine the centroids of diffraction images and by averaging over multiple TV frames, we achieve alignment accuracies better than 0.1 times system diffraction limits in the presence of air turbulence

  12. Volume of sealer in the apical region of teeth filled by different techniques: a micro-CT analysis

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Vanessa Lessa; Souza-Gabriel, Aline Evangelista; Cruz Filho, Antonio Miranda da; Pecora, Jesus Djalma; Silva, Ricardo Gariba, E-mail: vanessalessa@usp.br [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Escola de Odontologia. Departamento de Odontologia Restauradora

    2016-05-01

    The volume of sealer in the apical 1 mm of teeth filled using different techniques was evaluated by micro-commuted tomography (micro-CT). Sixty-four maxillary central incisors were prepared using NiTi rotary instruments. Teeth were randomly distributed into four groups according to root canal sealers (AH Plus, Endofill, Sealapex, and Sealer 26) and subdivided into two subgroups according to the filling techniques (active and passive lateral condensation; n = 8 each). Subsequently, teeth were examined using the 1174 SkyScan micro-CT device. Images were reconstructed using the NRecon software, and the sealer volume (mm{sup 3}) in the apical region was analyzed using the two-way ANOVA and post-hoc Student-Newman-Keuls test (α = 0.05). The lowest volume of sealer was observed in teeth filled with Sealapex (0.100 ± 0.009) and Endofill (0.103 ± 0.010). The highest volume was observed in teeth filled with AH Plus (0.112 ± 0.008) and Sealer 26 (0.109 ± 0.018) (p > 0.05). Regarding the filling technique, a lower sealer volume was observed using the active lateral condensation technique compared with that using the passive lateral condensation technique (0.100 ± 0.010 vs. 0.111 ± 0.012) (p < 0.05). Therefore, the lowest volume of sealer was observed in teeth filled with Sealapex and Endofill using the active lateral condensation technique. (author)

  13. Volume of sealer in the apical region of teeth filled by different techniques: a micro-CT analysis

    International Nuclear Information System (INIS)

    The volume of sealer in the apical 1 mm of teeth filled using different techniques was evaluated by micro-commuted tomography (micro-CT). Sixty-four maxillary central incisors were prepared using NiTi rotary instruments. Teeth were randomly distributed into four groups according to root canal sealers (AH Plus, Endofill, Sealapex, and Sealer 26) and subdivided into two subgroups according to the filling techniques (active and passive lateral condensation; n = 8 each). Subsequently, teeth were examined using the 1174 SkyScan micro-CT device. Images were reconstructed using the NRecon software, and the sealer volume (mm3) in the apical region was analyzed using the two-way ANOVA and post-hoc Student-Newman-Keuls test (α = 0.05). The lowest volume of sealer was observed in teeth filled with Sealapex (0.100 ± 0.009) and Endofill (0.103 ± 0.010). The highest volume was observed in teeth filled with AH Plus (0.112 ± 0.008) and Sealer 26 (0.109 ± 0.018) (p > 0.05). Regarding the filling technique, a lower sealer volume was observed using the active lateral condensation technique compared with that using the passive lateral condensation technique (0.100 ± 0.010 vs. 0.111 ± 0.012) (p < 0.05). Therefore, the lowest volume of sealer was observed in teeth filled with Sealapex and Endofill using the active lateral condensation technique. (author)

  14. Technique for bone volume measurement from human femur head samples by classification of micro-CT image histograms

    Directory of Open Access Journals (Sweden)

    Franco Marinozzi

    2013-09-01

    Full Text Available INTRODUCTION: Micro-CT analysis is a powerful technique for a non-invasive evaluation of the morphometric parameters of trabecular bone samples. This elaboration requires a previous binarization of the images. A problem which arises from the binarization process is the partial volume artifact. Voxels at the external surface of the sample can contain both bone and air so thresholding operates an incorrect estimation of volume occupied by the two materials. AIM: The aim of this study is the extraction of bone volumetric information directly from the image histograms, by fitting them with a suitable set of functions. METHODS: Nineteen trabecular bone samples were extracted from femoral heads of eight patients subject to a hip arthroplasty surgery. Trabecular bone samples were acquired using micro-CT Scanner. Hystograms of the acquired images were computed and fitted by Gaussian-like functions accounting for: a gray levels produced by the bone x-ray absorption, b the portions of the image occupied by air and c voxels that contain a mixture of bone and air. This latter contribution can be considered such as an estimation of the partial volume effect. RESULTS: The comparison of the proposed technique to the bone volumes measured by a reference instrument such as by a helium pycnometer show the method as a good way for an accurate bone volume calculation of trabecular bone samples.

  15. TFTR neutral beam injection system conceptual design

    International Nuclear Information System (INIS)

    Three subsystems are described in the following chapters: (1) Neutral Beam Injection Line; (2) Power Supplies; and (3) Controls. Each chapter contains two sections: (1) Functions and Design Requirements; this is a brief listing of the requirements of components of the subsystem. (2) Design Description; this section describes the design and cost estimates. The overall performance requirements of the neutral beam injection system are summarized. (MOW)

  16. Construction of ion beam pulse radiolysis system

    Energy Technology Data Exchange (ETDEWEB)

    Chitose, Norihisa; Katsumura, Yosuke; Domae, Masafumi; Ishigure, Kenkichi; Murakami, Takeshi [Tokyo Univ. (Japan)

    1996-10-01

    An ion beam pulse radiolysis system has been constructed at HIMAC facility. Ion beam of 24 MeV He{sup 2+} with the duration longer than 1 {mu}s is available for irradiation. Three kinds of aqueous solutions, (C{sub 6}H{sub 5}){sub 2}CO, NaHCO{sub 3} and KSCN, were irradiated and the absorption signals were observed. (author)

  17. The AGS Booster Beam Position Monitor system

    International Nuclear Information System (INIS)

    To accelerate both protons and heavy ions, the AGS Booster requires a broadband (multi-octave) beam position monitoring system with a dynamic range spanning several orders of magnitude (2 x 1010 to 1.5 x 1013 particles per pulse). System requirements include the ability to acquire single turn trajectory and average orbit information with ± 0.1 mm resolution. The design goal of ± 0.5 mm corrected accuracy requires that the detectors have repeatable linear performance after periodic bakeout at 300 degree C. The system design and capabilities of the Booster Beam Position Monitor will be described, and initial results presented. 7 refs., 5 figs

  18. The elettra beam line control system

    International Nuclear Information System (INIS)

    Elettra is a third generation Synchrotron Light Source located in Trieste (Italy). It consists of a full energy linac injector and a storage ring with beam energies between 1.5 and 2 GeV. The facility is scheduled to be operational by end 1993. For the whole project 22 beam lines from insertion devices are foreseen, each of them is composed of a large number of measurement and controls instruments, most of them embedded in intelligent devices; in addition each beam line can be considered unique compared to the others, having been designed to provide a different kind of synchrotron radiation. This results in a large not homogenous environment where more than 200,000 physical points have to be controlled. A joint team composed of Softeco Sismat and Digital Equipment has developed a fully automated beam line control system able to give full remote controls, with different kind of access rights, to beam line users and beam line specialists as well as a full integration with experiment control systems. ((orig.))

  19. Upgrading of the beam diagnostic system of U-70 beam transfer lines

    CERN Document Server

    Kovaltsov, V I; Matyushin, A T; Milyutkin, V; Romanov, I; Seleznev, V; Sytin, A N; Clausen, M

    2001-01-01

    The beam diagnostic system of U-70 beam transfer lines (beam profiles, intensity and beam losses measurements) was designed in the beginning of 80-th on the base of 8-bit microprocessor, SUMMA hardware and home made serial communication link. Because of the maintenance problems the decision was taken to upgrade the hardware and software parts of the system.

  20. Establishing the Nude Mice Bone Metastasis Model of Lung Adenocarcinoma and Applying MicroCT into the Observation

    Directory of Open Access Journals (Sweden)

    Yongqi CUI

    2013-09-01

    Full Text Available Background and objective 50%-70% of patients with advanced lung cancer will develop bone metastases. The aim of this study is to establish the nude mice bone metastasis model of lung adenocarcinoma using A549, H1299, SPC-A-1 and XL-2, all of which own different invasion and migration abilities in vitro and supervise the bone metastases by MicroCT. Methods fifty BALB/C-nu/nu nude mice were grouped into five groups on average randomly. Cells of the four cell lines were injected into the left cardiac ventricle of mice in the four experimental groups (0.2 mL/mouse respectively; meanwhile, mice in the control group were injected with normal saline (0.2 mL/mouse in the same manner. Periodical radiological examination was carried out to supervise the variation of the mice since the second week after injection. When mice in each group became thin obviously, end the experiment of this group. Before the end, pathological sections of bone tissues were made. We classified the bone metastatic sites into axial skeleton and limb bone, in order to compare the metastatic rates of these two different parts. The bone metastatic abilities of the four cell lines was statistically analyzed by comparing the average time cost in the appearance of bone metastases and the percentage of bone metastases among the experimental groups. Results Different metastatic sites which had been identified both by MicroCT and pathological sections appeared in each group of the four experimental groups. By contrast, no metastasis was observed in the control group. The percentage of cancer metastasizing to axial skeleton was remarkably higher than the percentage of tumor metastasizing to the limb bone in each experimental group, which was consistent with the clinical regularity and characteristics of skeletal metastases with lung cancer. Thus, the model has been established triumphantly. However, there were no statistical differences in the average time consumed and skeletal metastatic

  1. Beam developments for the Harwell microprobe system

    International Nuclear Information System (INIS)

    A consequence of the rapid development of micron and submicron size electronic devices is the diminished applicability of high energy ion microprobes with their present resolution limitations to the study of such components. Although submicron beams have been reported the available beam current is barely sufficiently for PIXE and is not adequate for RBS. This lack of lateral resolution is due to low beam brightness at the microprobe object and aberrations in the focussing elements. As part of a program to address these problems the Harwell microprobe lens has been relocated on a new 5 MV Laddertron accelerator. The increased brightness and improved stability of this facility has so far led to a reduction in beam size from 3x3 μm2 to about 2x2 μm2. The feasibility of using a liquid metal ion source has been examined with a view to achieving more substantial increases in brightness. While such sources have brightness approximately 105 times greater than conventional gaseous sources the highly divergent nature of the beam presents problems for the beam transport system. The use of a liquid metal source on the accelerator has been successfully demonstrated but it indicates the need for a special low aberration injection lens if brightness is to be maintained. (orig.)

  2. Beam developments for the Harwell microprobe system

    International Nuclear Information System (INIS)

    A consequence of the rapid development of micron and submicron size electronic devices is the diminished applicability of high energy ion microprobes with their present resolution limitations to the study of such components. Although submicron beams have been reported the available beam current is barely sufficiently for PIXE and is not adequate for RBS. This lack of lateral resolution is due to low beam brightness at the microprobe object and aberrations in the focusing elements. As part of a program to address these problems the Harwell microprobe lens has been relocated on a new 5 MV Laddertron accelerator. The increased brightness and improved stability of this facility has so far led to a reduction in beam size from 3 x 3 μm2 to about 2 x 2 μm2. The feasibility of using a liquid metal ion source has been examined with a view to achieving more substantial increases in brightness. While such sources have brightness approximately 105 times greater than conventional gaseous sources the highly divergent nature of the beam presents problems for the beam transport system. The use of a liquid metal source on the accelerator has been successfully demonstrated but it indicates the need for a special low aberration injection lens if brightness is to be maintained

  3. The AGS Booster beam loss monitor system

    International Nuclear Information System (INIS)

    A beam loss monitor system has been developed for the Brookhaven National Laboratory Booster accelerator, and is designed for use with intensities of up to 1.5 x 1013 protons and carbon to gold ions at 50-3 x 109 ions per pulse. This system is a significant advance over the present AGS system by improving the sensitivity, dynamic range, and data acquisition. In addition to the large dynamic range achievable, it is adaptively shifted when high losses are detected. The system uses up to 80 argon filled ion chambers as detectors, as well as newly designed electronics for processing and digitizing detector outputs. The hardware simultaneously integrates each detector output, interfaces to the beam interrupt systems, and digitizes all 80 channels to 21 bits at 170 KHz. This paper discuses the design, construction, and operation of the system. 4 refs., 2 figs

  4. Beam loss monitor system for the SSC

    International Nuclear Information System (INIS)

    At full intensity the energy contained in each beam of the Superconducting Super Collider (SSC) is 400 MJ. The loss of a small fraction of that beam has the potential to cause magnet quenches or even severe damage to Collider components. To help protect the machine a sensitive and reliable beam loss monitor (BLM) system must be designed and built. In fact, BLM systems will be needed for all the accelerators of the SSC. The BLM system requirements for each of these accelerators will be discussed, but emphasis will be placed on the Collider. The discussion will include the preliminary design of BLM systems, the considerations that led to these designs, the calculations that were performed in development of the designs, and the problems that remain to be solved. A major tool in the design process has been a series of Monte Carlo calculations that were used to estimate beam loss distributions for the Collider arcs, the interaction regions, and the west utility region. These calculations were also used to study the fluence as a function of energy, the particle content, and the dose rate at selected positions. Detailed considerations such as detector spacing and sensitivity, loss fluctuations, reliability, and maintainability will be discussed. The proposed preliminary BLM system design for the Collider uses a radiation-hard, solid-state ionization detector and fast analog-to-digital conversion. Details of this design and relevant options will be discussed

  5. Modelling capillary trapping using finite-volume simulation of two-phase flow directly on micro-CT images

    Science.gov (United States)

    Raeini, Ali Q.; Bijeljic, Branko; Blunt, Martin J.

    2015-09-01

    We study capillary trapping in porous media using direct pore-scale simulation of two-phase flow on micro-CT images of a Berea sandstone and a sandpack. The trapped non-wetting phase saturations are predicted by solving the full Navier-Stokes equations using a volume-of-fluid based finite-volume framework to simulate primary drainage followed by water injection. Using these simulations, we analyse the effects of initial non-wetting-phase saturation, capillary number and flow direction on the residual saturation. The predictions from our numerical method are in agreement with published experimental measurements of capillary trapping curves. This shows that our direct simulation method can be used to elucidate the effect of pore structure and flow pattern of capillary trapping and provides a platform to study the physics of multiphase flow at the pore scale.

  6. Nondestructive Analysis of Apollo Samples by Micro-CT and Micro-XRF Analysis: A PET Style Examination

    Science.gov (United States)

    Zeigler, Ryan A.

    2014-01-01

    An integral part of any sample return mission is the initial description and classification of returned samples by the preliminary examination team (PET). The goal of a PET is to characterize and classify the returned samples, making this information available to the general research community who can then conduct more in-depth studies on the samples. A PET strives to minimize the impact their work has on the sample suite, which often limits the PET work to largely visual measurements and observations like optical microscopy. More modern techniques can also be utilized by future PET to nondestructively characterize astromaterials in a more rigorous way. Here we present our recent analyses of Apollo samples 14321 and 14305 by micro-CT and micro-XRF (respectively), assess the potential for discovery of "new" Apollo samples for scientific study, and evaluate the usefulness of these techniques in future PET efforts.

  7. Rotational micro-CT using a clinical C-arm angiography gantry

    International Nuclear Information System (INIS)

    Rotational angiography (RA) gantries are used routinely to acquire sequences of projection images of patients from which 3D renderings of vascular structures are generated using Feldkamp cone-beam reconstruction algorithms. However, these systems have limited resolution (10 lp/mm) but to date have relied either on rotating object imaging or small bore geometry for small animal imaging, and thus are not used for clinical imaging. The authors report here the development and use of a 3D rotational micro-angiography (RMA) system created by mounting a micro-angiographic fluoroscope (MAF) [35 μm pixel, resolution >10 lp/mm, field of view (FOV)=3.6 cm] on a standard clinical FPD-based RA gantry (Infinix, Model RTP12303J-G9E, Toshiba Medical Systems Corp., Tustin, CA). RA image sequences are obtained using the MAF and reconstructed. To eliminate artifacts due to image truncation, lower-dose (compared to MAF acquisition) full-FOV (FFOV) FPD RA sequences (194 μm pixel, FOV=20 cm) were also obtained to complete the missing data. The RA gantry was calibrated using a helical bead phantom. To ensure high-quality high-resolution reconstruction, the high-resolution images from the MAF were aligned spatially with the lower-dose FPD images, and the pixel values in the FPD image data were scaled to match those of the MAF. Images of a rabbit with a coronary stent placed in an artery in the Circle of Willis were obtained and reconstructed. The MAF images appear well aligned with the FPD images (average correlation coefficient before and after alignment: 0.65 and 0.97, respectively) Greater details without any visible truncation artifacts are seen in 3D RMA (MAF-FPD) images than in those of the FPD alone. The FWHM of line profiles of stent struts (100 μm diameter) are approximately 192±21 and 313±38 μm for the 3D RMA and FPD data, respectively. In addition, for the dual-acquisition 3D RMA, FFOV FPD data need not be of the highest quality, and thus may be acquired at lower dose

  8. Skull shape differentiation of black and white olms (Proteus anguinus anguinus and Proteus a. parkelj): an exploratory analysis with micro-CT scanning

    NARCIS (Netherlands)

    Ivanović, A.; Aljančič, G.; Artzen, J.W.

    2013-01-01

    We performed an exploratory analysis of the morphology of the cranium in the white olm (Proteus anguinus anguinus) and the black olm (P. a. parkelj) with micro-CT scanning and geometric morphometrics. The mudpuppy (Necturus maculosus) was used as an outgroup. The black olm falls outside the white ol

  9. ISR internal beam-dumping system

    CERN Multimedia

    1970-01-01

    Parts of the internal beam-dumping system. In the ring on the right are shown the four tanks containing the vertically deflecting magnets and in the ring on the left is the absorber block. Identical parts are on opposite sides in the other half of this intersection region.

  10. Systems analysis on laser beamed power

    Science.gov (United States)

    Zeiders, Glenn W., Jr.

    1993-01-01

    The NASA SELENE power beaming program is intended to supply cost-effective power to space assets via Earth-based lasers and active optics systems. Key elements of the program are analyzed, the overall effort is reviewed, and recommendations are presented.

  11. SU-E-I-84: Accuracy Comparison of Multi-Modality Image-Based Volumes of Rodent Solid Tumors Using In-Air Micro-CT Image Volume

    International Nuclear Information System (INIS)

    Purpose: Tumor volume is considered as a better predictor for therapy response monitoring and tumor staging over Response Evaluation Criteria In Solid Tumors (RECIST) or World Health Organization (WHO) criteria. In this study, the accuracy of subcutaneous rodent tumor volumes using preclinical magnetic resonance imaging (MRI), micro-computed tomography (micro-CT) and ultrasound (US) equipment and with an external caliper was compared using in-air micro-CT image volume of excised tumors determined as reference tumor volume in our prior study. Methods: MR, US and micro-CT images of subcutaneous SCC4 head and neck tumor xenografts were acquired 4, 6, 9, 11 and 13 days after tumor cell inoculation. Before MR and US scans, caliper measurements were made. After tumors were excised, in-air micro-CT imaging and ex vivo caliper measurements were performed. Tumor volumes were calculated using formula V = (π/6)*a*b*c where a, b and c are the maximum diameters in three perpendicular dimensions determined by the three image modalities and caliper, and compared with reference tumor volume by linear regression analysis as well as Bland-Altman plots. A one-way Analysis of Variance (ANOVA) test was also performed to compare volumes among caliper measurements. Results: The correlation coefficients (R2) of the regression lines for tumor volumes measured by the three imaging modalities and caliper were 0.9939, 0.9669, 0.9806, 0.9274, 0.9619 and 0.9819 for MRI, US and micro-CT, caliperbeforeMRI, caliperbeforeUS and ex vivo caliper respectively. In Bland-Altman plots, the average of tumor volume difference from reference tumor volume (bias) was significant for caliper and micro- CT, but not for MRI and US. Comparison of caliper measurements showed a significant difference (p < 0.05). Conclusion: Using the in-air micro-CT image volume, tumor volume measured by MRI was the most accurate among the three imaging modalities. In vivo caliper volume measurements showed unreliability while ex

  12. SU-E-I-84: Accuracy Comparison of Multi-Modality Image-Based Volumes of Rodent Solid Tumors Using In-Air Micro-CT Image Volume

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Y [University of Kansas Hospital, Kansas City, KS (United States); Fullerton, G; Goins, B [University of Texas Health Science Center at San Antonio, San Antonio, TX (United States)

    2015-06-15

    Purpose: Tumor volume is considered as a better predictor for therapy response monitoring and tumor staging over Response Evaluation Criteria In Solid Tumors (RECIST) or World Health Organization (WHO) criteria. In this study, the accuracy of subcutaneous rodent tumor volumes using preclinical magnetic resonance imaging (MRI), micro-computed tomography (micro-CT) and ultrasound (US) equipment and with an external caliper was compared using in-air micro-CT image volume of excised tumors determined as reference tumor volume in our prior study. Methods: MR, US and micro-CT images of subcutaneous SCC4 head and neck tumor xenografts were acquired 4, 6, 9, 11 and 13 days after tumor cell inoculation. Before MR and US scans, caliper measurements were made. After tumors were excised, in-air micro-CT imaging and ex vivo caliper measurements were performed. Tumor volumes were calculated using formula V = (π/6)*a*b*c where a, b and c are the maximum diameters in three perpendicular dimensions determined by the three image modalities and caliper, and compared with reference tumor volume by linear regression analysis as well as Bland-Altman plots. A one-way Analysis of Variance (ANOVA) test was also performed to compare volumes among caliper measurements. Results: The correlation coefficients (R2) of the regression lines for tumor volumes measured by the three imaging modalities and caliper were 0.9939, 0.9669, 0.9806, 0.9274, 0.9619 and 0.9819 for MRI, US and micro-CT, caliperbeforeMRI, caliperbeforeUS and ex vivo caliper respectively. In Bland-Altman plots, the average of tumor volume difference from reference tumor volume (bias) was significant for caliper and micro- CT, but not for MRI and US. Comparison of caliper measurements showed a significant difference (p < 0.05). Conclusion: Using the in-air micro-CT image volume, tumor volume measured by MRI was the most accurate among the three imaging modalities. In vivo caliper volume measurements showed unreliability while ex

  13. Development of beam flattening system using non-linear beam optics at J-PARC/JSNS

    International Nuclear Information System (INIS)

    As increasing in the beam power, the damage of the target becomes serious. Especially for a target for high power short pulse spallation neutron source, the damage due to the proton beam on the target vessel for liquid metal target such as mercury is reported to be proportional of 4th power of the peak intensity of the proton beam. Reduction of the peak intensity is important for the beam injection system. At the JSNS, beam profile can be described by the clear Gaussian functions. To reduce peak intensity, we have developed a beam transport system by non-linear beam optics using octupole magnets. (author)

  14. Ion beam pulse radiolysis system at HIMAC

    Energy Technology Data Exchange (ETDEWEB)

    Chitose, N.; Katsumura, Y.; Domae, M.; Ishigure, K. [Tokyo Univ. (Japan); Murakami, T.

    1997-03-01

    An ion beam pulse radiolysis system has been constructed at HIMAC facility. Ion beam of 24MeV He{sup 2+} with the duration longer than 1 {mu}s is available for irradiation. Three kinds of aqueous solutions, (C{sub 6}H{sub 5}){sub 2}CO, NaHCO{sub 3}, and KSCN, were irradiated and the absorption signals corresponding to (C{sub 6}H{sub 5}){sub 2}CO{sup -}, CO{sub 3}{sup -}, and (SCN){sub 2}{sup -} respectively were observed. Ghost signals which interfere with the measurement are also discussed. (author)

  15. The CMS Beam Halo Monitor Detector System

    CERN Document Server

    CMS Collaboration

    2015-01-01

    A new Beam Halo Monitor (BHM) detector system has been installed in the CMS cavern to measure the machine-induced background (MIB) from the LHC. This background originates from interactions of the LHC beam halo with the final set of collimators before the CMS experiment and from beam gas interactions. The BHM detector uses the directional nature of Cherenkov radiation and event timing to select particles coming from the direction of the beam and to suppress those originating from the interaction point. It consists of 40 quartz rods, placed on each side of the CMS detector, coupled to UV sensitive PMTs. For each bunch crossing the PMT signal is digitized by a charge integrating ASIC and the arrival time of the signal is recorded. The data are processed in real time to yield a precise measurement of per-bunch-crossing background rate. This measurement is made available to CMS and the LHC, to provide real-time feedback on the beam quality and to improve the efficiency of data taking. In this talk we will describ...

  16. The CMS Beam Halo Monitor Detector System

    CERN Document Server

    Stifter, Kelly Marie

    2015-01-01

    A new Beam Halo Monitor (BHM) detector system has been installed in the CMS cavern to measure the machine-induced background (MIB) from the LHC. This background originates from interactions of the LHC beam halo with the final set of collimators before the CMS experiment and from beam gas interactions. The BHM detector uses the directional nature of Cherenkov radiation and event timing to select particles coming from the direction of the beam and to supress those originating from the interaction point. It consists of 40 quartz rods, placed on each side of the CMS detector, coupled to UV sensitive PMTs. For each bunch crossing the PMT signal is digitized by a charge integrating ASIC and the arrival time of the signal is recorded. The data are processed in real time to yield a precise measurement of per-bunch-crossing background rate. This measurement is made available to CMS and the LHC, to provide real-time feedback on the beam quality and to improve the efficiency of data taking. In this talk we will descri...

  17. The CMS Beam Halo Monitor Detector System

    CERN Document Server

    Stifter, Kelly

    2015-01-01

    A new Beam Halo Monitor (BHM) detector system has been installed in the CMS cavern to measure the machine-induced background (MIB) from the LHC. This background originates from interactions of the LHC beam halo with the final set of collimators before the CMS experiment and from beam gas interactions. The BHM detector uses the directional nature of Cherenkov radiation and event timing to select particles coming from the direction of the beam and to suppress those originating from the interaction point. It consists of 40 quartz rods, placed on each side of the CMS detector, coupled to UV sensitive PMTs. For each bunch crossing the PMT signal is digitized by a charge integrating ASIC and the arrival time of the signal is recorded. The data are processed in real time to yield a precise measurement of per-bunch-crossing background rate. This measurement is made available to CMS and the LHC, to provide real-time feedback on the beam quality and to improve the efficiency of data taking. Here, I present the detector...

  18. Detection of the anatomic structure and pathology in animal lung specimens: comparison of micro CT and multi-detector row CT

    International Nuclear Information System (INIS)

    We wanted to compare the capability of micro CT and the clinically available thin-slice multi-detector row CT (MDCT) for demonstrating fine anatomic structures and pathological lesions in formalin-fixed lung specimens. The porcine lung with shark liver oil-induced lipoid pneumonia and the canine lung with pulmonary paragonimiasis were fixed by ventilating them with formalin vapor, and they were then sliced into one-centimeter thick sections. Micro CT (section thickness, 18 micrometer) and MDCT (section thickness, 0.75 mm) images were acquired in four of the lung slices of the lipoid pneumonia specimen and in five of the lung slices of the paragonimiasis specimen. On 62 pairs of micro CT and MDCT images, 169 pairs of rectangular ROIs were manually drawn in the corresponding locations. Two chest radiologists recorded the detectability of three kinds of anatomic structures (lobular core structure, interlobular septum and small bronchiolar lumen) and two kinds of pathological lesions (ground-glass opacity and consolidation) with using a five-point scale. The statistical comparison was performed by using the Wilcoxon signed rank test. Interobserver agreement was evaluated with kappa statistics. For all observers, all the kinds of anatomic structures and pathological lesions were detected better on the micro CT images than on the MDCT images (ρ < 0.01). Agreement was fair between two observers (κ = 0.38, ρ < 0.001). The fine anatomic structures and pathological lesions of the lung were more accurately demonstrated on micro CT than on thin-slice MDCT in the inflated and fixed lung specimens

  19. Detection of the anatomic structure and pathology in animal lung specimens: comparison of micro CT and multi-detector row CT

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Kun Young [National Cancer Center, Goyang (Korea, Republic of); Lee, Hyun Ju; Lee, Chang Hyun; Son, Kyu Ri; Goo, Jin Mo; Im, Jung Gi [Seoul National University Hospital and the Institute of Radiation Medicine, Seoul (Korea, Republic of); Seo, Joon Beom [Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    2006-05-15

    We wanted to compare the capability of micro CT and the clinically available thin-slice multi-detector row CT (MDCT) for demonstrating fine anatomic structures and pathological lesions in formalin-fixed lung specimens. The porcine lung with shark liver oil-induced lipoid pneumonia and the canine lung with pulmonary paragonimiasis were fixed by ventilating them with formalin vapor, and they were then sliced into one-centimeter thick sections. Micro CT (section thickness, 18 micrometer) and MDCT (section thickness, 0.75 mm) images were acquired in four of the lung slices of the lipoid pneumonia specimen and in five of the lung slices of the paragonimiasis specimen. On 62 pairs of micro CT and MDCT images, 169 pairs of rectangular ROIs were manually drawn in the corresponding locations. Two chest radiologists recorded the detectability of three kinds of anatomic structures (lobular core structure, interlobular septum and small bronchiolar lumen) and two kinds of pathological lesions (ground-glass opacity and consolidation) with using a five-point scale. The statistical comparison was performed by using the Wilcoxon signed rank test. Interobserver agreement was evaluated with kappa statistics. For all observers, all the kinds of anatomic structures and pathological lesions were detected better on the micro CT images than on the MDCT images ({rho} < 0.01). Agreement was fair between two observers ({kappa} = 0.38, {rho} < 0.001). The fine anatomic structures and pathological lesions of the lung were more accurately demonstrated on micro CT than on thin-slice MDCT in the inflated and fixed lung specimens.

  20. MicroCT for comparative morphology: simple staining methods allow high-contrast 3D imaging of diverse non-mineralized animal tissues

    Directory of Open Access Journals (Sweden)

    Metscher Brian D

    2009-06-01

    Full Text Available Abstract Background Comparative, functional, and developmental studies of animal morphology require accurate visualization of three-dimensional structures, but few widely applicable methods exist for non-destructive whole-volume imaging of animal tissues. Quantitative studies in particular require accurately aligned and calibrated volume images of animal structures. X-ray microtomography (microCT has the potential to produce quantitative 3D images of small biological samples, but its widespread use for non-mineralized tissues has been limited by the low x-ray contrast of soft tissues. Although osmium staining and a few other techniques have been used for contrast enhancement, generally useful methods for microCT imaging for comparative morphology are still lacking. Results Several very simple and versatile staining methods are presented for microCT imaging of animal soft tissues, along with advice on tissue fixation and sample preparation. The stains, based on inorganic iodine and phosphotungstic acid, are easier to handle and much less toxic than osmium, and they produce high-contrast x-ray images of a wide variety of soft tissues. The breadth of possible applications is illustrated with a few microCT images of model and non-model animals, including volume and section images of vertebrates, embryos, insects, and other invertebrates. Each image dataset contains x-ray absorbance values for every point in the imaged volume, and objects as small as individual muscle fibers and single blood cells can be resolved in their original locations and orientations within the sample. Conclusion With very simple contrast staining, microCT imaging can produce quantitative, high-resolution, high-contrast volume images of animal soft tissues, without destroying the specimens and with possibilities of combining with other preparation and imaging methods. Such images are expected to be useful in comparative, developmental, functional, and quantitative studies of

  1. Development of KSTAR Neutral Beam Heating System

    Energy Technology Data Exchange (ETDEWEB)

    Oh, B. H.; Song, W. S.; Yoon, B. J. (and others)

    2007-10-15

    The prototype components of a neutral beam injection (NBI) system have been developed for the KSTAR, and a capability of the manufactured components has been tested. High power ion source, acceleration power supply, other ion source power supplies, neutralizer, bending magnet for ion beam separation, calorimeter, and cryo-sorption pump have been developed by using the domestic technologies and tested for a neutral beam injection of 8 MW per beamline with a pulse duration of 300 seconds. The developed components have been continuously upgraded to achieve the design requirements. The development technology of high power and long pulse neutral beam injection system has been proved with the achievement of 5.2 MW output for a short pulse length and 1.6 MW output for a pulse length of 300 seconds. Using these development technologies, the domestic NB technology has been stabilized under the development of high power ion source, NB beamline components, high voltage and current power supplies, NB diagnostics, NB system operation and control.

  2. RHIC beam loss monitor system design

    International Nuclear Information System (INIS)

    The Beam Loss Monitor (BLM) System is designed to prevent the quenching of RHIC magnets due to beam loss, provide quantitative loss data, and the loss history in the event of a beam abort. The system uses 400 ion chambers of a modified Tevatron design. To satisfy fast (single turn) and slow (100 msec) loss beam criteria and provide sensitivity for studies measurements, a range of over 8 decades is needed. An RC pre-integrator reduces the dynamic range for a low current amplifier. This is digitized for data logging. The output is also applied to an analog multiplier which compensates the energy dependence, extending the range of the abort comparators. High and low pass filters separate the signal to dual comparators with independent programmable trip levels. Up to 64 channels, on 8 VME boards, are controlled by a micro-controller based VME module, decoupling it from the front-end computer (FEC) for real-time operation. Results with the detectors in the RHIC Sextant Test and the electronics in the AGS-to-RHIC (AtR) transfer line will be presented

  3. Indexing system for optical beam steering

    Science.gov (United States)

    Sullivan, Mark T.; Cannon, David M.; Debra, Daniel B.; Young, Jeffrey A.; Mansfield, Joseph A.; Carmichael, Roger E.; Lissol, Peter S.; Pryor, G. M.; Miklosy, Les G.; Lee, Jeffrey H.

    1990-01-01

    This paper describes the design and testing of an indexing system for optical-beam steering. The cryogenic beam-steering mechanism is a 360-degree rotation device capable of discrete, high-precision alignment positions. It uses low-precision components for its rough alignment and kinematic design to meet its stringent repeatability and stability requirements (of about 5 arcsec). The principal advantages of this design include a decoupling of the low-precision, large angular motion from the high-precision alignment, and a power-off alignment position that potentially extends the life or hold time of cryogenic systems. An alternate design, which takes advantage of these attributes while reducing overall motion, is also presented. Preliminary test results show the kinematic mount capable of sub-arc second repeatability.

  4. Ion beam figuring system in NUDT

    Science.gov (United States)

    Zhou, Lin; Xie, Xuhui; Dai, Yifan; Jiao, Changjun; Li, Shengyi

    2007-12-01

    Ion beam figuring (IBF) is an optical fabrication technique that provides highly deterministic process to correct surface figure error of previously polished surfaces by using a directed, inert and neutralized ion beam to physically sputter material from the optic surface. Recently, an ion beam figuring system KDIFS-500 has been designed and built in National University of Defense Technology (NUDT) of the P.R. China. KDIFS-500 is capable of processing workpiece up to Φ500mm. Line scanning process was discussed in detail for estimating the parameters of the beam removal function (BRF) in process. Experiments were conducted to demonstrate that the BRF increases gradually in process and by employing a stability control, the BRF can be kept stable in process. Finally, a Φ95 mm plano optical sample of CVD coated SiC substrate has been figured in two process iterations for demonstrating the correction capability of the KDIFS-500. Their figure convergence ratios reached 5.8 and 2.1 respectively. The actual figure residual errors were basically consistent with the predicted error. These consistencies indicated that the IBF processes on KDIFS-500 are predictable deterministic processes.

  5. Neutral particle beam distributed data acquisition system

    Energy Technology Data Exchange (ETDEWEB)

    Daly, R.T.; Kraimer, M.R.; Novick, A.H.

    1987-01-01

    A distributed data acquisition system has been designed to support experiments at the Argonne Neutral Particle Beam Accelerator. The system uses a host VAXstation II/GPX computer acting as an experimenter's station linked via Ethernet with multiple MicroVAX IIs and rtVAXs dedicated to acquiring data and controlling hardware at remote sites. This paper describes the hardware design of the system, the applications support software on the host and target computers, and the real-time performance.

  6. Beam dynamics in the SLC final focus system

    International Nuclear Information System (INIS)

    The SLC luminosity is reached by colliding beams focused to about 2 μm transverse sizes. The Final Focus System (FFS) must enable, beyond its basic optical design, the detection and correction of errors accumulated in the system. In this paper, after summarizing the design, we review the sensitivity to such errors and the ability to correct them. The overall tuning strategy involves three phases: single beam spot minimization, steering the beams in collision and luminosity optimization with beam-beam effects

  7. Beam diagnostics and data acquisition system for ion beam transport line used in applied research

    International Nuclear Information System (INIS)

    Ion beam transport line for applied research on U-400 cyclotron, beam diagnostics and data acquisition system for condensed matter studies are described. The main features of Windows-based real time program are considered

  8. Colliding beam fusion reactor space propulsion system

    Science.gov (United States)

    Wessel, Frank J.; Binderbauer, Michl W.; Rostoker, Norman; Rahman, Hafiz Ur; O'Toole, Joseph

    2000-01-01

    We describe a space propulsion system based on the Colliding Beam Fusion Reactor (CBFR). The CBFR is a high-beta, field-reversed, magnetic configuration with ion energies in the range of hundreds of keV. Repetitively-pulsed ion beams sustain the plasma distribution and provide current drive. The confinement physics is based on the Vlasov-Maxwell equation, including a Fokker Planck collision operator and all sources and sinks for energy and particle flow. The mean azimuthal velocities and temperatures of the fuel ion species are equal and the plasma current is unneutralized by the electrons. The resulting distribution functions are thermal in a moving frame of reference. The ion gyro-orbit radius is comparable to the dimensions of the confinement system, hence classical transport of the particles and energy is expected and the device is scaleable. We have analyzed the design over a range of 106-109 Watts of output power (0.15-150 Newtons thrust) with a specific impulse of, Isp~106 sec. A 50 MW propulsion system might involve the following parameters: 4-meters diameter×10-meters length, magnetic field ~7 Tesla, ion beam current ~10 A, and fuels of either D-He3,P-B11,P-Li6,D-Li6, etc. .

  9. Internally shielded beam transport and support system

    International Nuclear Information System (INIS)

    Due to environmental concerns, the Advanced Photon Source has a policy that disallows any exposed lead within the facility. This creates a real problem for the beam transport system, not so much for the pipe but for the flexible coupling (bellows) sections. A complete internally shielded x-ray transport system, consisting of long transport lines joined by flexible coupling sections, has been designed for CARS sector 14 to operate either at high vacuum or as a helium flight tube. It can effectively shield against air scattering of wiggler or undulator white beam with proper placement of apertures, collimators, and masks for direct beam control. The system makes use of male- and female-style fittings that create a labyrinth allowing for continuous shielding through the flexible coupling sections. These parts are precision machined from a ternary hypereutectic lead alloy (cast under 15 inches of head pressure to assure a pinhole-free casting) then pressed into either end (rotatable vacuum flanges) of the bellows assembly. The transport pipe itself consists of a four part construction using a stepped transition ring (Z-ring) to connect an inner tube to the vacuum flange and also to a protective and supportive outer tube. The inner tube is wrapped with 1/16 double-prime pure lead sheet to a predetermined thickness following the shape of the stepped transition ring for continuous shielding. This design has been prototyped and radiation tested. copyright 1996 American Institute of Physics

  10. Neutral Beam Power System for TPX

    International Nuclear Information System (INIS)

    The Tokamak Physics Experiment (TPX) will utilize to the maximum extent the existing Tokamak Fusion Test Reactor (TFTR) equipment and facilities. This is particularly true for the TFTR Neutral Beam (NB) system. Most of the NB hardware, plant facilities, auxiliary sub-systems, power systems, service infrastructure, and control systems can be used as is. The major changes in the NB hardware are driven by the new operating duty cycle. The TFTR Neutral Beam was designed for operation of the Sources for 2 seconds every 150 seconds. The TPX requires operation for 1000 seconds every 4500 seconds. During the Conceptual Design Phase of TPX every component of the TFTR NB Electrical Power System was analyzed to verify whether the equipment can meet the new operational requirements with our without modifications. The Power System converts 13.8 kV prime power to controlled pulsed power required at the NB sources. The major equipment involved are circuit breakers, auto and rectifier transformers surge suppression components, power tetrodes, HV Decks, and HVDC power transmission to sources. Thermal models were developed for the power transformers to simulate the new operational requirements. Heat runs were conducted for the power tetrodes to verify capability. Other components were analyzed to verify their thermal limitations. This paper describes the details of the evaluation and redesign of the electrical power system components to meet the TPX operational requirements

  11. Design of CMS Beam Halo Monitor system

    CERN Document Server

    AUTHOR|(CDS)2078842

    2015-01-01

    A fast and directional monitoring system for the CMS experiment is designed to provide an online, bunch-by-bunch measurement of beam background induced by beam halo interactions, separately for each beam. The background detection is based on Cherenkov radiation produced in synthetic fused silica read out by a fast, UV sensitive photomultiplier tube. Twenty detector units per end will be azimuthally distributed around the rotating shielding of CMS, covering ~408 cm2 at 20.6m from the interaction point, at a radius of ~180 cm. The directional and fast response of the system allows the discrimination of the background particles from the dominant flux in the cavern induced by pp collision debris, produced within the 25 ns bunch spacing. A robust multi-layered shielding will enclose each detector unit to protect the photomultiplier tube from the magnetic field and to eliminate the occupancy from low energy particles. The design of the front-end units is validated by experimental results. An overview of the new sy...

  12. Switched steerable multiple beam antenna system

    Science.gov (United States)

    Iwasaki, Richard S.

    1988-09-01

    A steerable multibeam five element cross-feed cluster antenna system is described. The feed power is divided into five branches. Each branch includes a switching network comprised of a plurality of time delay elements each individually controlled by a respective electromagnetic latching switch. Frequency independent individual two-dimensional beam steering at intermediate (IF) scanning frequencies is thereby provided wherein discrete incremental time delays are introduced by the switching networks into each branch and the signals recombined thereafter to form each beam. The electromagnetic latched switching reduces power consumption and permits higher power switching and reciprocal coincident tranmsit and receive operation. Frequency independence due to incremental time delay switching permits coincident reciprocal operation and steering for transmit-receive signal paths carrying different transmit-receive frequencies. Diagonal quarter wave plates in the waveguides alter polarization from the circular to orthogonal linear to provide transmitter-receiver isolation.

  13. A realistic projection simulator for laboratory based X-ray micro-CT

    Science.gov (United States)

    Dhaene, Jelle; Pauwels, Elin; De Schryver, Thomas; De Muynck, Amelie; Dierick, Manuel; Van Hoorebeke, Luc

    2015-01-01

    In X-ray computed tomography (CT) each voxel of the reconstructed image contains a calculated grey value which represents the linear attenuation coefficient for the materials in that voxel. Conventional laboratory based CT scanners use polychromatic X-ray sources and integrating detectors with an energy dependent efficiency. Consequently the reconstructed attenuation coefficients will depend on the spectrum of the source and the spectral sensitivity of the detector. Beam hardening will alter the spectrum significantly as the beam propagates through the sample. Therefore, sample composition and shape will affect the reconstructed attenuation coefficients as well. A polychromatic projection simulator has been developed at the "Centre for X-ray Tomography" of the Ghent University (UGCT) which takes into account the aforementioned variables, allowing for complete and realistic simulations of CT scans for a wide range of geometrical setups. Monte Carlo simulations of the X-ray tubes and detectors were performed to model their spectral behaviour. In this paper, the implementation and features of the program are discussed. Simulated and real CT scans are compared to demonstrate the quantitative correctness of the simulations. Experiments performed at two different UGCT scanners yield a maximum deviation of 3.9% and 6.5% respectively, between the measured and simulated reconstructed attenuation coefficients.

  14. A realistic projection simulator for laboratory based X-ray micro-CT

    Energy Technology Data Exchange (ETDEWEB)

    Dhaene, Jelle, E-mail: jelle.dhaene@ugent.be; Pauwels, Elin, E-mail: elin.pauwels@ugent.be; De Schryver, Thomas; De Muynck, Amelie; Dierick, Manuel; Van Hoorebeke, Luc

    2015-01-01

    In X-ray computed tomography (CT) each voxel of the reconstructed image contains a calculated grey value which represents the linear attenuation coefficient for the materials in that voxel. Conventional laboratory based CT scanners use polychromatic X-ray sources and integrating detectors with an energy dependent efficiency. Consequently the reconstructed attenuation coefficients will depend on the spectrum of the source and the spectral sensitivity of the detector. Beam hardening will alter the spectrum significantly as the beam propagates through the sample. Therefore, sample composition and shape will affect the reconstructed attenuation coefficients as well. A polychromatic projection simulator has been developed at the “Centre for X-ray Tomography” of the Ghent University (UGCT) which takes into account the aforementioned variables, allowing for complete and realistic simulations of CT scans for a wide range of geometrical setups. Monte Carlo simulations of the X-ray tubes and detectors were performed to model their spectral behaviour. In this paper, the implementation and features of the program are discussed. Simulated and real CT scans are compared to demonstrate the quantitative correctness of the simulations. Experiments performed at two different UGCT scanners yield a maximum deviation of 3.9% and 6.5% respectively, between the measured and simulated reconstructed attenuation coefficients.

  15. An interactive beam position monitor system simulator

    International Nuclear Information System (INIS)

    A system simulator has been implemented to aid the development of the RHIC position monitor system. Based on the LabVIEW software package by National Instruments, this simulator allows engineers and technicians to interactively explore the parameter space of a system during the design phase. Adjustable parameters are divided into three categories: beam, pickup, and electronics. The simulator uses these parameters in simple formulas to produce results in both time-domain and frequencydomain. During the prototyping phase, these simulated results can be compared to test data acquired with the same software package. The RHIC position monitor system is presented as an example, but the software is applicable to several other systems as well

  16. Multiplexed broadband beam steering system utilizing high speed MEMS mirrors

    OpenAIRE

    Knoernschild, Caleb; Kim, Changsoon; Lu, Felix P.; Kim, Jungsang

    2009-01-01

    We present a beam steering system based on micro-electromechanical systems technology that features high speed steering of multiple laser beams over a broad wavelength range. By utilizing high speed micromirrors with a broadband metallic coating, our system has the flexibility to simultaneously incorporate a wide range of wavelengths and multiple beams. We demonstrate reconfiguration of two independent beams at different wavelengths (780 and 635 nm) across a common 5x5 array with 4 us settlin...

  17. Permeability estimation of porous media by using an improved capillary bundle model based on micro-CT derived pore geometries

    Science.gov (United States)

    Jiang, Lanlan; Liu, Yu; Teng, Ying; Zhao, Jiafei; Zhang, Yi; Yang, Mingjun; Song, Yongchen

    2016-03-01

    The purpose of this work is to develop a permeability estimation method for porous media. This method is based on an improved capillary bundle model by introducing some pore geometries. We firstly carried out micro-CT scans to extract the 3D digital model of porous media. Then we applied a maximum ball extraction method to the digital model to obtain the topological and geometrical pore parameters such as the pore radius, the throat radius and length and the average coordination number. We also applied a random walker method to calculate the tortuosity factors of porous media. We improved the capillary bundle model by introducing the pore geometries and tortuosity factors. Finally, we calculated the absolute permeabilities of four kinds of porous media formed of glass beads and compared the results with experiments and several other models to verify the improved model. We found that the calculated permeabilities using this improved capillary bundle model show better agreement with the measured permeabilities than the other methods.

  18. Impact of micronutrients supplementation on bone repair around implants: microCT and counter-torque analysis in rats

    Science.gov (United States)

    Pimentel, Suzana Peres; Casarin, Renato Correa; Ribeiro, Fernanda Vieira; Cirano, Fabiano Ribeiro; Rovaris, Karla; Haiter, Francisco; Casati, Marcio Zaffalon

    2016-01-01

    ABSTRACT The use of natural substances and micronutritional approaches has been suggested as a therapeutic alternative to benefit the bone healing associated with no side effects. Nevertheless, the influence of micronutritional interventions with therapeutic proprieties on the bone repair has yet to be intensely evaluated, and no evidence is available exploring the impact of micronutrient supplementation on the peri-implant bone healing. Objective This study investigated the effect of micronutrients supplementation on the bone repair around implants. Material and Methods One screw-shaped titanium implant was inserted in each tibia of each rat, which were assigned to: daily administration, for 30 d, of the placebo solution (Placebo group-n:18) or micronutrients supplementation (Micronutrients group-n:18), based on calcium, magnesium, zinc, and vitamin D3 intake. After, the animals were sacrificed. One of the implants was removed by applying a counter-torque force to evaluate the force to rupture the bone-implant interface. The other implant was evaluated by microcomputed tomography (CT) examination to determine the bone-to-implant contact (BIC) and the bone volume (BV/TV). Results No statistically significant differences were observed between the groups for both counter-torque values and microCT parameters (p>0.05). Conclusion Within the limits of this study, micronutrients supplementation did not provide additional benefits to the bone healing around dental implants. PMID:27008256

  19. 3D configuration of mandibles and controlling muscles in rove beetles based on micro-CT technique

    Energy Technology Data Exchange (ETDEWEB)

    Li, Dee [Chinese Academy of Sciences, Key Laboratory of the Zoological Systematics and Evolution, Institute of Zoology, Beijing (China); Graduate School of the Chinese Academy of Sciences, Beijing (China); Zhang, Kai [Chinese Academy of Sciences, Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Beijing (China); Graduate School of the Chinese Academy of Sciences, Beijing (China); Zhu, Peiping [Chinese Academy of Sciences, Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Beijing (China); Wu, Ziyu [University of Science and Technology of China, National Synchrotron Radiation Laboratory, Hefei (China); Chinese Academy of Sciences, Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Beijing (China); Zhou, Hongzhang [Chinese Academy of Sciences, Key Laboratory of the Zoological Systematics and Evolution, Institute of Zoology, Beijing (China)

    2011-08-15

    X-ray micro-CT is a powerful tool to visualize without damage details of the inner structures of beetles, the largest order of insects with a hard external skeleton. This contribution shows the three-dimensional (3D) reconstruction of the head morphology of three rove beetle species (Insecta, Coleoptera, Staphylinidae) - Noddia sp., Creophilus maxillosus, and Hesperosoma sp. - using X-ray microtomography at a spatial resolution of 6 {mu}m. The details of skeletal muscle fiber insertions are described, giving a comprehensive overview of mandible mobility and organization. With the support of 3D rendering, we discuss the relationship among the mandible forms, the development of the muscles controlling the movement, and the head morphology. The well-developed posterior part of the head capsule is always accompanied by a well-developed mandible, a large adductor muscle, and a large apodeme for the wide areas of the muscle fiber attachment. In Noddia sp., muscles connected to the posterolateral angle of the head capsule are mainly short muscles, whereas in Creophilus maxillosus, the latter are mainly long muscles, and in Hesperosoma sp. no mandible adductor muscle fibers are present on the posterolateral angle of the head capsule. These results offer new invaluable information regarding the biting functions of beetle mandibles and the trend of their morphological change during their long-term evolution. (orig.)

  20. Impact of micronutrients supplementation on bone repair around implants: microCT and counter-torque analysis in rats

    Directory of Open Access Journals (Sweden)

    Suzana Peres Pimentel

    2016-02-01

    Full Text Available ABSTRACT The use of natural substances and micronutritional approaches has been suggested as a therapeutic alternative to benefit the bone healing associated with no side effects. Nevertheless, the influence of micronutritional interventions with therapeutic proprieties on the bone repair has yet to be intensely evaluated, and no evidence is available exploring the impact of micronutrient supplementation on the peri-implant bone healing. Objective This study investigated the effect of micronutrients supplementation on the bone repair around implants. Material and Methods One screw-shaped titanium implant was inserted in each tibia of each rat, which were assigned to: daily administration, for 30 d, of the placebo solution (Placebo group-n:18 or micronutrients supplementation (Micronutrients group-n:18, based on calcium, magnesium, zinc, and vitamin D3 intake. After, the animals were sacrificed. One of the implants was removed by applying a counter-torque force to evaluate the force to rupture the bone-implant interface. The other implant was evaluated by microcomputed tomography (CT examination to determine the bone-to-implant contact (BIC and the bone volume (BV/TV. Results No statistically significant differences were observed between the groups for both counter-torque values and microCT parameters (p>0.05. Conclusion Within the limits of this study, micronutrients supplementation did not provide additional benefits to the bone healing around dental implants.

  1. Impact of micronutrients supplementation on bone repair around implants: microCT and counter-torque analysis in rats.

    Science.gov (United States)

    Pimentel, Suzana Peres; Casarin, Renato Correa; Ribeiro, Fernanda Vieira; Cirano, Fabiano Ribeiro; Rovaris, Karla; Haiter Neto, Francisco; Casati, Marcio Zaffalon

    2016-02-01

    The use of natural substances and micronutritional approaches has been suggested as a therapeutic alternative to benefit the bone healing associated with no side effects. Nevertheless, the influence of micronutritional interventions with therapeutic proprieties on the bone repair has yet to be intensely evaluated, and no evidence is available exploring the impact of micronutrient supplementation on the peri-implant bone healing. Objective This study investigated the effect of micronutrients supplementation on the bone repair around implants. Material and Methods One screw-shaped titanium implant was inserted in each tibia of each rat, which were assigned to: daily administration, for 30 d, of the placebo solution (Placebo group-n:18) or micronutrients supplementation (Micronutrients group-n:18), based on calcium, magnesium, zinc, and vitamin D3 intake. After, the animals were sacrificed. One of the implants was removed by applying a counter-torque force to evaluate the force to rupture the bone-implant interface. The other implant was evaluated by microcomputed tomography (CT) examination to determine the bone-to-implant contact (BIC) and the bone volume (BV/TV). Results No statistically significant differences were observed between the groups for both counter-torque values and microCT parameters (p>0.05). Conclusion Within the limits of this study, micronutrients supplementation did not provide additional benefits to the bone healing around dental implants. PMID:27008256

  2. High-resolution three-dimensional visualization of the rat spinal cord microvasculature by synchrotron radiation micro-CT

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Jianzhong; Cao, Yong; Wu, Tianding; Li, Dongzhe [Department of Spine Surgery, Xiangya Hospital, Central South University, Changsha 410008 (China); Lu, Hongbin, E-mail: hongbinlu@hotmail.com [Department of Sports Medicine, Research Centre of Sports Medicine, Xiangya Hospital, Central South University, Changsha 410008 (China)

    2014-10-15

    Purpose: Understanding the three-dimensional (3D) morphology of the spinal cord microvasculature has been limited by the lack of an effective high-resolution imaging technique. In this study, synchrotron radiation microcomputed tomography (SRµCT), a novel imaging technique based on absorption imaging, was evaluated with regard to the detection of the 3D morphology of the rat spinal cord microvasculature. Methods: Ten Sprague-Dawley rats were used in this ex vivo study. After contrast agent perfusion, their spinal cords were isolated and scanned using conventional x-rays, conventional micro-CT (CµCT), and SRµCT. Results: Based on contrast agent perfusion, the microvasculature of the rat spinal cord was clearly visualized for the first time ex vivo in 3D by means of SRµCT scanning. Compared to conventional imaging techniques, SRµCT achieved higher resolution 3D vascular imaging, with the smallest vessel that could be distinguished approximately 7.4 μm in diameter. Additionally, a 3D pseudocolored image of the spinal cord microvasculature was generated in a single session of SRµCT imaging, which was conducive to detailed observation of the vessel morphology. Conclusions: The results of this study indicated that SRµCT scanning could provide higher resolution images of the vascular network of the spinal cord. This modality also has the potential to serve as a powerful imaging tool for the investigation of morphology changes in the 3D angioarchitecture of the neurovasculature in preclinical research.

  3. A Semiautomatic Segmentation Algorithm for Extracting the Complete Structure of Acini from Synchrotron Micro-CT Images

    Directory of Open Access Journals (Sweden)

    Luosha Xiao

    2013-01-01

    Full Text Available Pulmonary acinus is the largest airway unit provided with alveoli where blood/gas exchange takes place. Understanding the complete structure of acinus is necessary to measure the pathway of gas exchange and to simulate various mechanical phenomena in the lungs. The usual manual segmentation of a complete acinus structure from their experimentally obtained images is difficult and extremely time-consuming, which hampers the statistical analysis. In this study, we develop a semiautomatic segmentation algorithm for extracting the complete structure of acinus from synchrotron micro-CT images of the closed chest of mouse lungs. The algorithm uses a combination of conventional binary image processing techniques based on the multiscale and hierarchical nature of lung structures. Specifically, larger structures are removed, while smaller structures are isolated from the image by repeatedly applying erosion and dilation operators in order, adjusting the parameter referencing to previously obtained morphometric data. A cluster of isolated acini belonging to the same terminal bronchiole is obtained without floating voxels. The extracted acinar models above 98% agree well with those extracted manually. The run time is drastically shortened compared with manual methods. These findings suggest that our method may be useful for taking samples used in the statistical analysis of acinus.

  4. Iterative 4D cardiac micro-CT image reconstruction using an adaptive spatio-temporal sparsity prior

    Science.gov (United States)

    Ritschl, Ludwig; Sawall, Stefan; Knaup, Michael; Hess, Andreas; Kachelrieß, Marc

    2012-03-01

    Temporal-correlated image reconstruction, also known as 4D CT image reconstruction, is a big challenge in computed tomography. The reasons for incorporating the temporal domain into the reconstruction are motions of the scanned object, which would otherwise lead to motion artifacts. The standard method for 4D CT image reconstruction is extracting single motion phases and reconstructing them separately. These reconstructions can suffer from undersampling artifacts due to the low number of used projections in each phase. There are different iterative methods which try to incorporate some a priori knowledge to compensate for these artifacts. In this paper we want to follow this strategy. The cost function we use is a higher dimensional cost function which accounts for the sparseness of the measured signal in the spatial and temporal directions. This leads to the definition of a higher dimensional total variation. The method is validated using in vivo cardiac micro-CT mouse data. Additionally, we compare the results to phase-correlated reconstructions using the FDK algorithm and a total variation constrained reconstruction, where the total variation term is only defined in the spatial domain. The reconstructed datasets show strong improvements in terms of artifact reduction and low-contrast resolution compared to other methods. Thereby the temporal resolution of the reconstructed signal is not affected.

  5. A Novel Procedure for Rapid Imaging of Adult Mouse Brains with MicroCT Using Iodine-Based Contrast.

    Directory of Open Access Journals (Sweden)

    Ryan Anderson

    Full Text Available High-resolution Magnetic Resonance Imaging (MRI has been the primary modality for obtaining 3D cross-sectional anatomical information in animals for soft tissue, particularly brain. However, costs associated with MRI can be considerably high for large phenotypic screens for gross differences in the structure of the brain due to pathology and/or experimental manipulations. MicroCT (mCT, especially benchtop mCT, is becoming a common laboratory equipment with throughput rates equal or faster than any form of high-resolution MRI at lower costs. Here we explore adapting previously developed contrast based mCT to image adult mouse brains in-situ. We show that 2% weight per volume (w/v iodine-potassium iodide solution can be successfully used to image adult mouse brains within 48 hours post-mortem when a structural support matrix is used. We demonstrate that hydrogel can be effectively used as a perfusant which limits the tissue shrinkage due to iodine.

  6. 3D configuration of mandibles and controlling muscles in rove beetles based on micro-CT technique

    International Nuclear Information System (INIS)

    X-ray micro-CT is a powerful tool to visualize without damage details of the inner structures of beetles, the largest order of insects with a hard external skeleton. This contribution shows the three-dimensional (3D) reconstruction of the head morphology of three rove beetle species (Insecta, Coleoptera, Staphylinidae) - Noddia sp., Creophilus maxillosus, and Hesperosoma sp. - using X-ray microtomography at a spatial resolution of 6 μm. The details of skeletal muscle fiber insertions are described, giving a comprehensive overview of mandible mobility and organization. With the support of 3D rendering, we discuss the relationship among the mandible forms, the development of the muscles controlling the movement, and the head morphology. The well-developed posterior part of the head capsule is always accompanied by a well-developed mandible, a large adductor muscle, and a large apodeme for the wide areas of the muscle fiber attachment. In Noddia sp., muscles connected to the posterolateral angle of the head capsule are mainly short muscles, whereas in Creophilus maxillosus, the latter are mainly long muscles, and in Hesperosoma sp. no mandible adductor muscle fibers are present on the posterolateral angle of the head capsule. These results offer new invaluable information regarding the biting functions of beetle mandibles and the trend of their morphological change during their long-term evolution. (orig.)

  7. Applying microCT and 3D visualization to Jurassic silicified conifer seed cones: A virtual advantage over thin-sectioning 1

    OpenAIRE

    Gee, Carole T

    2013-01-01

    • Premise of the study: As an alternative to conventional thin-sectioning, which destroys fossil material, high-resolution X-ray computed tomography (also called microtomography or microCT) integrated with scientific visualization, three-dimensional (3D) image segmentation, size analysis, and computer animation is explored as a nondestructive method of imaging the internal anatomy of 150-million-year-old conifer seed cones from the Late Jurassic Morrison Formation, USA, and of recent and othe...

  8. Skull shape differentiation of black and white olms (Proteus anguinus anguinus and Proteus a. parkelj): an exploratory analysis with micro-CT scanning

    OpenAIRE

    Ivanović, A.; Aljančič, G.; Artzen, J.W.

    2013-01-01

    We performed an exploratory analysis of the morphology of the cranium in the white olm (Proteus anguinus anguinus) and the black olm (P. a. parkelj) with micro-CT scanning and geometric morphometrics. The mudpuppy (Necturus maculosus) was used as an outgroup. The black olm falls outside the white olm morphospace by a markedly wider skull, shorter vomers which are positioned further apart and by laterally positioned squamosals and quadrates relative to the palate (the shape of the buccal cavit...

  9. Dosimetric precision of an ion beam tracking system

    International Nuclear Information System (INIS)

    Scanned ion beam therapy of intra-fractionally moving tumors requires motion mitigation. GSI proposed beam tracking and performed several experimental studies to analyse the dosimetric precision of the system for scanned carbon beams. A beam tracking system has been developed and integrated in the scanned carbon ion beam therapy unit at GSI. The system adapts pencil beam positions and beam energy according to target motion. Motion compensation performance of the beam tracking system was assessed by measurements with radiographic films, a range telescope, a 3D array of 24 ionization chambers, and cell samples for biological dosimetry. Measurements were performed for stationary detectors and moving detectors using the beam tracking system. All detector systems showed comparable data for a moving setup when using beam tracking and the corresponding stationary setup. Within the target volume the mean relative differences of ionization chamber measurements were 0.3% (1.5% standard deviation, 3.7% maximum). Film responses demonstrated preserved lateral dose gradients. Measurements with the range telescope showed agreement of Bragg peak depth under motion induced range variations. Cell survival experiments showed a mean relative difference of -5% (-3%) between measurements and calculations within the target volume for beam tracking (stationary) measurements. The beam tracking system has been successfully integrated. Full functionality has been validated dosimetrically in experiments with several detector types including biological cell systems

  10. Dosimetric precision of an ion beam tracking system

    Directory of Open Access Journals (Sweden)

    Kraft Gerhard

    2010-06-01

    Full Text Available Abstract Background Scanned ion beam therapy of intra-fractionally moving tumors requires motion mitigation. GSI proposed beam tracking and performed several experimental studies to analyse the dosimetric precision of the system for scanned carbon beams. Methods A beam tracking system has been developed and integrated in the scanned carbon ion beam therapy unit at GSI. The system adapts pencil beam positions and beam energy according to target motion. Motion compensation performance of the beam tracking system was assessed by measurements with radiographic films, a range telescope, a 3D array of 24 ionization chambers, and cell samples for biological dosimetry. Measurements were performed for stationary detectors and moving detectors using the beam tracking system. Results All detector systems showed comparable data for a moving setup when using beam tracking and the corresponding stationary setup. Within the target volume the mean relative differences of ionization chamber measurements were 0.3% (1.5% standard deviation, 3.7% maximum. Film responses demonstrated preserved lateral dose gradients. Measurements with the range telescope showed agreement of Bragg peak depth under motion induced range variations. Cell survival experiments showed a mean relative difference of -5% (-3% between measurements and calculations within the target volume for beam tracking (stationary measurements. Conclusions The beam tracking system has been successfully integrated. Full functionality has been validated dosimetrically in experiments with several detector types including biological cell systems.

  11. A Bone Metastasis Nude Mouse Model Created by Ultrasound Guided Intracardiac Injection of Breast Cancer Cells: the Micro-CT, MRI and Bioluminescence Imaging Analysis

    International Nuclear Information System (INIS)

    The purpose of this study was to develop a nude mouse model of bone metastasis by performing intracardiac injection of breast cancer cells under ultrasonography guidance and we wanted to evaluate the development and the distribution of metastasis in vivo using micro-CT, MRI and bioluminescence imaging. Animal experiments were performed in 6-week-old female nude mice. The animals underwent left ventricular injection of 2x105 MDA-MB-231Bo-Luc cells. After injection of the tumor cells, serial bioluminescence imaging was performed for 7 weeks. The findings of micro-CT, MRI and the histology were correlated with the 'hot' lesions seen on the bioluminescence imaging. Metastasis was found in 62.3% of the animals. Two weeks after intracardiac injection, metastasis to the brain, spine and femur was detected with bioluminescence imaging with an increasing intensity by week 7. Micro-CT scan confirmed multiple osteolytic lesions at the femur, spine and skull. MRI and the histology were able to show metastasis in the brain and extraskeletal metastasis around the femur. The intracardiac injection of cancer cells under ultrasonography guidance is a safe and highly reproducible method to produce bone metastasis in nude mice. This bone metastasis nude mouse model will be useful to study the mechanism of bone metastasis and to validate new therapeutics

  12. A Bone Metastasis Nude Mouse Model Created by Ultrasound Guided Intracardiac Injection of Breast Cancer Cells: the Micro-CT, MRI and Bioluminescence Imaging Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Park, Young Jin; Song, Eun Hye; Kim, Seol Hwa; Song, Ho Taek; Suh, Jin Suck [Yonsei University College of Medicine, Seoul (Korea, Republic of); Choi, Sang Hyun [Korean Minjok Leadership Academy, Heongsung (Korea, Republic of)

    2011-01-15

    The purpose of this study was to develop a nude mouse model of bone metastasis by performing intracardiac injection of breast cancer cells under ultrasonography guidance and we wanted to evaluate the development and the distribution of metastasis in vivo using micro-CT, MRI and bioluminescence imaging. Animal experiments were performed in 6-week-old female nude mice. The animals underwent left ventricular injection of 2x105 MDA-MB-231Bo-Luc cells. After injection of the tumor cells, serial bioluminescence imaging was performed for 7 weeks. The findings of micro-CT, MRI and the histology were correlated with the 'hot' lesions seen on the bioluminescence imaging. Metastasis was found in 62.3% of the animals. Two weeks after intracardiac injection, metastasis to the brain, spine and femur was detected with bioluminescence imaging with an increasing intensity by week 7. Micro-CT scan confirmed multiple osteolytic lesions at the femur, spine and skull. MRI and the histology were able to show metastasis in the brain and extraskeletal metastasis around the femur. The intracardiac injection of cancer cells under ultrasonography guidance is a safe and highly reproducible method to produce bone metastasis in nude mice. This bone metastasis nude mouse model will be useful to study the mechanism of bone metastasis and to validate new therapeutics

  13. Electron beam accelerator energy control system

    International Nuclear Information System (INIS)

    A control system has been developed for the energy control of the electron beam accelerator using PLC. The accelerating voltage of 3 MV has been obtained by using parallel coupled voltage multiplier circuit. A autotransformer controlled variable 0-10 KV DC is fed to a tube based push pull oscillator to generate 120 Khz, 10 KV AC. Oscillator output voltage is stepped up to 0-300 KV/AC using a transformer. 0-300 KVAC is fed to the voltage multiplier column to generate the accelerating voltage at the dome 0-3 MV/DC. The control system has been designed to maintain the accelerator voltage same throughout the operation by adjusting the input voltage in close loop. Whenever there is any change in the output voltage either because of beam loading or arcing in the accelerator. The instantaneous accelerator voltage or energy is a direct proportional to 0-10 KVDC obtained from autotransformer. A PLC based control system with user settable energy level has been installed for 3 MeV, EB accelerator. The PLC takes the user defined energy value through a touch screen and compares it to the actual accelerating voltage (obtained using resistive divider). Depending upon the error the PLC generates the pulses to adjust the autotransformer to bring the actual voltage to the set value within the window of error (presently set to +/- 0.1%). (author)

  14. Non-Linear Beam Transport System for the LENS 7 MeV Proton Beam

    CERN Document Server

    Jones, William P; Derenchuk, Vladimir Peter; Rinckel, Thomas; Solberg, Keith

    2005-01-01

    A beam transport system has been designed to carry a high-intensity low-emittance proton beam from the exit of the RFQ-DTL acceleration system of the Indiana University Low Energy Neutron System (LENS)* to the neutron production target. The goal of the design was to provide a beam of uniform density over a 3cm by 3cm area at the target. Two octupole magnets** are employed in the beam line to provide the necessary beam phase space manipulations to achieve this goal. First order calculations were done using TRANSPORT and second order calculations have been performed using TURTLE. Second order simulations have been done using both a Gaussian beam distribution and a particle set generated by calculations of beam transport through the RFQ-DTL using PARMILA. Comparison of the design characteristics with initial measurements from the LENS commissioning process will be made.

  15. Longitudinal micro-CT provides biomarkers of lung disease that can be used to assess the effect of therapy in preclinical mouse models, and reveal compensatory changes in lung volume

    OpenAIRE

    Vande Velde, Greetje; Poelmans, Jennifer; De Langhe, Ellen; Hillen, Amy; Vanoirbeek, Jeroen; Himmelreich, Uwe; Lories, Rik J

    2016-01-01

    ABSTRACT In vivo lung micro-computed tomography (micro-CT) is being increasingly embraced in pulmonary research because it provides longitudinal information on dynamic disease processes in a field in which ex vivo assessment of experimental disease models is still the gold standard. To optimize the quantitative monitoring of progression and therapy of lung diseases, we evaluated longitudinal changes in four different micro-CT-derived biomarkers [aerated lung volume, lung tissue (including les...

  16. Conceptual Design of Neutral Beam Injection System for EAST

    Science.gov (United States)

    Hu, Chundong; NBI Team

    2012-06-01

    Neutral beam injection (NBI) system with two neutral beam injections will be constructed on the Experimental Advanced Superconducting Tokamak (EAST) in two stages for high power auxiliary plasmas heating and non-inductive current drive. Each NBI can deliver 2~4 MW beam power with 50~80 keV beam energy in 10~100 s pulse length. Each elements of the NBI system are presented in this contribution.

  17. The fast beam interlock system for JET neutral injection

    International Nuclear Information System (INIS)

    The JET Neutral Beam Injection (NBI) system poses severe interlock problems with the possibility of unsafe conditions arising on a fast timescale. In order to cope with this the high-security Fast Beam Interlock System (FBIS) has been developed. It is used to turn off the beams in a failsafe manner when a condition arises which could damage the beam line or torus on a timescale too short to be dealt with by the JET Central Interlock and Safety System (CISS). FBIS interfaces signals from many JET safety systems and processes them to act directly on the Neutral Beam power supplies. The interfaces and the fail safety operation of FBIS are described. It is presently planned to upgrade the system to include a real-time comparison of the ion beam deflection magnet currents and the beam extraction voltage and a system which will compensate for the effects of the Tokamak stray fields on the NBI beamlines

  18. Beam Tests of a Prototype Stripline Beam Position Monitoring System for the Drive Beam of the CLIC Two-beam Module at CTF3

    CERN Document Server

    Benot-Morell, Alfonso; Nappa, Jean-Marc; Vilalte, Sebastien; Wendt, Manfred

    2016-01-01

    In collaboration with LAPP and IFIC, two units of a prototype stripline Beam Position Monitor (BPM) for the CLIC Drive Beam (DB), and its associated readout electronics have been successfully installed and tested in the Two-Beam-Module (TBM) at the CLIC Test Facility 3 (CTF3) at CERN. This paper gives a short overview of the BPM system and presents the performance measured under different Drive Beam configurations.

  19. Implementation of visualization system for beam service time in RIBF

    International Nuclear Information System (INIS)

    Beam availability is one important factor affecting research productivity of accelerator facilities. In RI Beam Factory (RIBF), the beam availability is defined simply as the ratio of actual beam service time to scheduled beam service time. The availability was previously estimated based on the down time of beam service recorded in our log-books of the paper medium. However, manual estimation of actual beam service time has limitation in its accuracy especially in case of hardware trouble. Hence, in order to realize labor-saving and accurate recording of down time, we have developed a visualization system that automatically records down time by using insertion status of Faraday cups. Implementation of the system has been completed and the system has been successfully operated in recent beam services performed in RIBF. (author)

  20. Development of fast beam-stop system using RF chopper

    International Nuclear Information System (INIS)

    To avoid heat damage and radioactivation by beam loss of the J-PARC accelerator, Machine Protection System (MPS) has been developed. Actually, high responsibility and high reliability have been achieved in J-PARC. Beam-stop method in addition to a way of RFQ OFF has been requested in order to avoid damage to the RFQ. Therefore, we have been developing a fast beam-stop system by using a RF chopper. The fast beam-stop system, including beam test, is described in this paper. (author)

  1. Beam Instrumentation Using BPM System of the SPring-8 Linac

    CERN Document Server

    Yanagida, K; Dewa, H; Hanaki, H; Kobayashi, T; Mizuno, A; Suzuki, S; Taniuchi, T; Tomizawa, H

    2004-01-01

    A beam position monitor (BPM) system of the SPring-8 linac has been operated since 2002. The following upgrade programs have been carried out during this period: The BPMs were installed in the linac's dispersive sections. A synchronized accumulation of beam position data into the database system started. A feedback control of steering magnets for beam position stabilization has been under development. In this conference the authors report a performance of the BPM system, and discuss its usefulness for beam diagnostics, machine diagnostics and beam stabilization.

  2. The Saturne beam measurement system for orbit corrections and high and low intensity beam acceleration

    International Nuclear Information System (INIS)

    This paper summarizes the dipolar and multipolar correction system and the main beam diagnostics of Saturne II: wide-band RF electrostatic pick-up electrode for observation of bunches, beam position and tune measurement systems, special electrodes for observation of emittance blow-up when particles cross a resonance line. For low intensity beams, special electrodes and electronics have been developed. All this instrumentation is computer controlled

  3. 显微CT的研究及应用的初步评述%A Preliminary Review of Micro-CT and its Applications

    Institute of Scientific and Technical Information of China (English)

    《CT理论与应用研究》编辑部

    2002-01-01

    Since 1995, Industrial CT has gained a great progress to improve its spatial and temporal resolution[1], the Micro-CT getting large progress in United States, Europe and China; Prof. Chen Weichang et al. develop the research on Micro-CT and its method, they using the high resolution ICT scanner to image rat's organs[2]. Dr. Ge Wang, PhD, Director of the Micro-CT Lab, USA, provides reviews in some journal and Internet web,and cooperate with some university and CT-scanner company, to device micro-CT scanner. There are 5-company in United States and Europe, provide Micro-CT scanner with high resolution(5-50μm ). The resolution of the microscopic diagnosis is about 5-50μm. If the spatial resolution of medical CT can increase to 2~10 micrometer domain, then cells and tissues can be visualized and then the microscopic pathological diagnosis can be made by using the medical micro CT(μCT). μCT and 3D stereological will promote operation technique to a new period. It is obvious that the micro CT will give a great impact on the clinical medicine in the 21 century.%近五年来在国内外显微CT的研究和应用,得到了很大的发展;微观病理显微诊断的空间分辩为微米数量级.目前医学CT影像的空间分辨率已达到0.35mm,已能满足宏观病理学诊断的要求.如果医学CT的空间分辩率再提高到微米水平,即可清晰显示细胞和组织的微细结构,从而满足现代医学临床病理诊断金标准的要求.目前工业CT(ICT)的空间分辨率已达到5-20微米,从而为提高医学CT的空间分辨率提供技术依据.本文引述用工业微焦点CT机首次对小动物组织进行显微成像的结果;提出应用微焦点X线源,以及采用钨酸镉集成电路CCD检测技术,进一步缩小检测器元件探头的尺寸和增加检测器探头的数目,可以提高医学CT的空间分辨率;应用电子束快速扫描技术,可以提高医学CT的时间分辨率,达到动态的水平;应用双能X线束扫描技

  4. Improved beam spot measurements in the 2nd generation proton beam writing system

    International Nuclear Information System (INIS)

    Nanosized ion beams (especially proton and helium) play a pivotal role in the field of ion beam lithography and ion beam analysis. Proton beam writing has shown lithographic details down to the 20 nm level, limited by the proton beam spot size. Introducing a smaller spot size will allow smaller lithographic features. Smaller probe sizes, will also drastically improve the spatial resolution for ion beam analysis techniques. Among many other requirements, having an ideal resolution standard, used for beam focusing and a reliable focusing method, is an important pre-requisite for sub-10 nm beam spot focusing. In this paper we present the fabrication processes of a free-standing resolution standard with reduced side-wall projection and high side-wall verticality. The resulting grid is orthogonal (90.0° ± 0.1), has smooth edges with better than 6 nm side-wall projection. The new resolution standard has been used in focusing a 2 MeV H2+ beam in the 2nd generation PBW system at Center for Ion Beam Applications, NUS. The beam size has been characterized using on- and off-axis scanning transmission ion microscopy (STIM) and ion induced secondary electron detection, carried out with a newly installed micro channel plate electron detector. The latter has been shown to be a realistic alternative to STIM measurements, as the drawback of PIN diode detector damage is alleviated. With these improvements we show reproducible beam focusing down to 14 nm

  5. Beam systems without failures - What can be done?

    International Nuclear Information System (INIS)

    The beam dumps at 3.5 TeV triggered by interlocks not related to the magnet powering are discussed. This concerns the systems like the RF, the transverse feedbacks, beam instrumentation, beam dumping system, collimators and control systems. An analysis of the reasons of these dumps is presented together with a possible strategy to mitigate the effect of these failures. It is very important to notice that no system has been identified to have any structural problem

  6. High resolution micro-CT of low attenuating organic materials using large area photon-counting detector

    International Nuclear Information System (INIS)

    To overcome certain limitations of contemporary materials used for bone tissue engineering, such as inflammatory response after implantation, a whole new class of materials based on polysaccharide compounds is being developed. Here, nanoparticulate bioactive glass reinforced gelan-gum (GG-BAG) has recently been proposed for the production of bone scaffolds. This material offers promising biocompatibility properties, including bioactivity and biodegradability, with the possibility of producing scaffolds with directly controlled microgeometry. However, to utilize such a scaffold with application-optimized properties, large sets of complex numerical simulations using the real microgeometry of the material have to be carried out during the development process. Because the GG-BAG is a material with intrinsically very low attenuation to X-rays, its radiographical imaging, including tomographical scanning and reconstructions, with resolution required by numerical simulations might be a very challenging task. In this paper, we present a study on X-ray imaging of GG-BAG samples. High-resolution volumetric images of investigated specimens were generated on the basis of micro-CT measurements using a large area flat-panel detector and a large area photon-counting detector. The photon-counting detector was composed of a 010× 1 matrix of Timepix edgeless silicon pixelated detectors with tiling based on overlaying rows (i.e. assembled so that no gap is present between individual rows of detectors). We compare the results from both detectors with the scanning electron microscopy on selected slices in transversal plane. It has been shown that the photon counting detector can provide approx. 3× better resolution of the details in low-attenuating materials than the integrating flat panel detectors. We demonstrate that employment of a large area photon counting detector is a good choice for imaging of low attenuating materials with the resolution sufficient for numerical

  7. High resolution micro-CT of low attenuating organic materials using large area photon-counting detector

    Science.gov (United States)

    Kumpová, I.; Vavřík, D.; Fíla, T.; Koudelka, P.; Jandejsek, I.; Jakůbek, J.; Kytýř, D.; Zlámal, P.; Vopálenský, M.; Gantar, A.

    2016-02-01

    To overcome certain limitations of contemporary materials used for bone tissue engineering, such as inflammatory response after implantation, a whole new class of materials based on polysaccharide compounds is being developed. Here, nanoparticulate bioactive glass reinforced gelan-gum (GG-BAG) has recently been proposed for the production of bone scaffolds. This material offers promising biocompatibility properties, including bioactivity and biodegradability, with the possibility of producing scaffolds with directly controlled microgeometry. However, to utilize such a scaffold with application-optimized properties, large sets of complex numerical simulations using the real microgeometry of the material have to be carried out during the development process. Because the GG-BAG is a material with intrinsically very low attenuation to X-rays, its radiographical imaging, including tomographical scanning and reconstructions, with resolution required by numerical simulations might be a very challenging task. In this paper, we present a study on X-ray imaging of GG-BAG samples. High-resolution volumetric images of investigated specimens were generated on the basis of micro-CT measurements using a large area flat-panel detector and a large area photon-counting detector. The photon-counting detector was composed of a 010× 1 matrix of Timepix edgeless silicon pixelated detectors with tiling based on overlaying rows (i.e. assembled so that no gap is present between individual rows of detectors). We compare the results from both detectors with the scanning electron microscopy on selected slices in transversal plane. It has been shown that the photon counting detector can provide approx. 3× better resolution of the details in low-attenuating materials than the integrating flat panel detectors. We demonstrate that employment of a large area photon counting detector is a good choice for imaging of low attenuating materials with the resolution sufficient for numerical simulations.

  8. Beam extraction system in AIC-144 automatic isochronous cyclotron

    International Nuclear Information System (INIS)

    Project of beam extraction system in Cracow AIC-144 cyclotron is described. The problems of increase of beam emittance, and change of the magnetic field in the cyclotron chamber are discussed. Expected extraction coefficient of the beam is about 0.7. (S.B.)

  9. Practical use of the modified Bronnikov algorithm in micro-CT

    Science.gov (United States)

    Boone, M.; De Witte, Y.; Dierick, M.; Van den Bulcke, J.; Vlassenbroeck, J.; Van Hoorebeke, L.

    2009-04-01

    Through the years, the resolution of X-ray Computed Tomography (CT) systems has increased rapidly, in particular for the newer micro- and nano-CT systems. With this increasing resolution, the limits of absorption contrast CT are being reached. At the same time, a new type of contrast becomes visible: phase contrast. Mainly for low-absorbing objects such as insects and wood, phase contrast can lead to a new type of CT reconstruction using the modified Bronnikov algorithm (MBA) [A. Groso, R. Abela, M. Stampanoni, Implementation of a fast method for high 297 resolution phase contrast tomography, Opt. Express 14 (18) (2006) 8103.] Despite it's theoretical limitation to pure phase objects, the algorithm has some clear advantages with respect to filtered back-projection (FBP). The MBA is therefore commonly used at the Centre for X-ray Tomography of the Ghent University (UGCT) to obtain additional information for optimal scanning results.

  10. Practical use of the modified Bronnikov algorithm in micro-CT

    International Nuclear Information System (INIS)

    Through the years, the resolution of X-ray Computed Tomography (CT) systems has increased rapidly, in particular for the newer micro- and nano-CT systems. With this increasing resolution, the limits of absorption contrast CT are being reached. At the same time, a new type of contrast becomes visible: phase contrast. Mainly for low-absorbing objects such as insects and wood, phase contrast can lead to a new type of CT reconstruction using the modified Bronnikov algorithm (MBA) [A. Groso, R. Abela, M. Stampanoni, Implementation of a fast method for high 297 resolution phase contrast tomography, Opt. Express 14 (18) (2006) 8103.] Despite it's theoretical limitation to pure phase objects, the algorithm has some clear advantages with respect to filtered back-projection (FBP). The MBA is therefore commonly used at the Centre for X-ray Tomography of the Ghent University (UGCT) to obtain additional information for optimal scanning results.

  11. Practical use of the modified Bronnikov algorithm in micro-CT

    Energy Technology Data Exchange (ETDEWEB)

    Boone, M. [Ghent University, Department of Subatomic and Radiation Physics, Proeftuinstraat 86, 9000 Gent (Belgium)], E-mail: Matthieu.Boone@UGent.be; De Witte, Y.; Dierick, M. [Ghent University, Department of Subatomic and Radiation Physics, Proeftuinstraat 86, 9000 Gent (Belgium); Van den Bulcke, J. [Ghent University, Department of Forest and Water Management, Coupure Links 653, 9000 Gent (Belgium); Vlassenbroeck, J.; Van Hoorebeke, L. [Ghent University, Department of Subatomic and Radiation Physics, Proeftuinstraat 86, 9000 Gent (Belgium)

    2009-04-15

    Through the years, the resolution of X-ray Computed Tomography (CT) systems has increased rapidly, in particular for the newer micro- and nano-CT systems. With this increasing resolution, the limits of absorption contrast CT are being reached. At the same time, a new type of contrast becomes visible: phase contrast. Mainly for low-absorbing objects such as insects and wood, phase contrast can lead to a new type of CT reconstruction using the modified Bronnikov algorithm (MBA) [A. Groso, R. Abela, M. Stampanoni, Implementation of a fast method for high 297 resolution phase contrast tomography, Opt. Express 14 (18) (2006) 8103.] Despite it's theoretical limitation to pure phase objects, the algorithm has some clear advantages with respect to filtered back-projection (FBP). The MBA is therefore commonly used at the Centre for X-ray Tomography of the Ghent University (UGCT) to obtain additional information for optimal scanning results.

  12. Beam characterisation of the KIRAMS electron microbeam system

    International Nuclear Information System (INIS)

    An electron microbeam system has been installed at the Korea Inst. of Radiological and Medical Sciences (KIRAMS) for use in radiation biology studies. The electron beam is produced from a commercial electron gun, and the beam size is defined by a 5 μm diameter pinhole. Beam energy can be varied in the range of 1-100 keV, covering a range of linear energy transfer from 0.4 to 12.1 keV μm-1. The micrometer-sized electron beam selectively irradiates cells cultured in a Mylar-bottomed dish. The positioning of target cells one by one onto the beam exit is automated, as is beam shooting. The electron beam entering the target cells has been calibrated using a Passivated Implanted Planar Silicon (PIPS) detector. This paper describes the KIRAMS microbeam cell irradiation system and its beam characteristics. (authors)

  13. The beam delivery modeling and error sources analysis of beam stabilization system for lithography

    Science.gov (United States)

    Wang, Jun; Huang, Lihua; Hou, Liying; He, Guojun; Ren, Bingqiang; Zeng, Aijun; Huang, Huijie

    2013-12-01

    Beam stabilization system is one of the most important units for lithography, which can accomplish displacement and pointing detection and control and includes beam measurement unit(BMU) and beam steering unit(BSU). Our group has set up a beam stabilization system and verified preliminarily beam stabilization algorithm of precise control beam position and angle. In the article, we establish beam delivery mathematic model and analyze the system inherent error. This shows that the reason why image rotation effect arises at the output plane of beam stabilization is the fast steering mirror (FSM) rotation of BSU in the process of beam stabilization. Two FSMs rotation around 45o axis of FSM make the most contribution to image rotation which rotates 1.414 mrad as two FSMs rotation angle difference changes 1 mrad. It is found that error sources include three key points: FSM accuracy; measurement noise and beam translation by passing through of beam splitters changing as the ambient temperature changing. FSM accuracy leads to the maximum 13.2μm displacement error and 24.49μrad angle error. Measurement inaccuracy as a result of 5μm measurement noise results in the maximum 0.126mm displacement error and 57.2μrad angle error. Beam translation errors can be negligible if temperature is unchanged. We have achieved beam stability of about 15.5μrad for angle and 28μm for displacement (both 1σ) after correcting 2mm initial displacement deviation and 5mrad initial angle deviation with regard to the system rebuilt due to practical requirements.

  14. Distributed CPU multi-core implementation of SIRT with vectorized matrix kernel for micro-CT

    International Nuclear Information System (INIS)

    We describe an implementation of SIRT for execution using a cluster of multi-core PCs. Algorithmic techniques are presented for reducing the size and computational cost of a reconstruction including near-optimal relaxation, scalar preconditioning, orthogonalized ordered subsets, and data-driven focus of attention. Implementation wise, a scheme is outlined which provides each core mutex-free access to its local shared memory while also balancing the workload across the cluster, and the system matrix is computed on-the-fly using vectorized code. Experimental results show the efficacy of the approach. (orig.)

  15. An electrostatic beam rocking system on the Surrey nuclear microprobe

    International Nuclear Information System (INIS)

    The use of two sets of magnetic dipoles, producing opposite fields, to rock a focused MeV ion beam over the surface of a crystalline sample is now well established in several nuclear microprobe laboratories. Such a 'beam rocking' system allows ion channeling analysis from micron-size regions of the sample to be measured, with a beam displacement over the sample surface as small as a few microns, and no requirements for an automated goniometer. While magnetic beam rocking systems are ideal for many applications, they are limited in the speed at which the beam can be rocked in angle owing to hysteresis effects. This may also cause problems of non-reproducibility of the beam displacement on a micron scale. Also, heavier ions are more difficult to rock through a given angle using a magnetic beam rocking system, whereas an electrostatic beam rocking system gives a rocking angle which is independent of the ion mass. This paper describes the construction and uses of a fast electrostatic beam rocking system, which uses two sets of high voltage plates driven in opposition at high frequencies. Ion optics simulations are used to model the performance of the system. The optics of this beam rocking system, in which both sets of deflection plates are located before the quadruplet lens formation are discussed. The uses of this system to rapidly image the location of crystal planes and axes, and to carry out rapid channeling analysis are presented

  16. Coupling micro-CT with computer simulations to analyze dispersion in porous media

    Science.gov (United States)

    Sobhani, Sadaf; Dunnmon, Jared; Werer, Michael

    2015-11-01

    In recent years, table-top X-ray Computed Tomography (XCT) systems have been utilized to analyze various samples with a resolution on the order of 1 μm -100 μm . In this study, we explore the use of these systems both in extracting high-resolution topologies of porous structures for use as inputs into computational simulations and in directly characterizing gas dispersion within such structures using fluoroscopic imaging of dense gaseous tracers. The opaque-solid environment and small pore-scale effects in porous media restrict the use of conventional imaging techniques, thereby making XCT a potentially useful diagnostic technique for understanding internal flows in porous and optically inaccessible structures. In the present work, we extract the topology of various reticulated porous foams from 3D XCT data and perform numerical simulations of the flow inside these structures. Permeability and tortuosity, which are key parameters in volume-averaged models are evaluated from the resulting flow fields and knowledge of the solid structure.

  17. In vivo imaging of MSCT and Micro-CT. A comparison

    International Nuclear Information System (INIS)

    Purpose: To evaluate the potential of MSCT and a novel μCT system to assess the volume of malignant brain tumors in rats compared to histology. Materials and Methods: Fourteen rats underwent stereotactic implantation of GFP-marked F 98-glioma cells. On day 10 after implantation, animals received double-dose contrast-enhanced μCT and MSCT imaging using Iomeprol. MSCT- and μCT-derived tumor volumes were calculated and compared to histology (fluorescence staining) as the gold standard. Results: There was good correlation between the μCT-derived tumor volume (69 ± 23 mm3) and histology (81 ± 14 mm3; p > 0.14). MSCT, however, showed significantly smaller tumor volumes (55 ± 25 mm3) compared to histology (p < 0.01) but was able to detect the tumors in all animals. Conclusion: μCT allows in vivo imaging of the contrast-enhancing parts of experimental gliomas with high correlation to histology. Although MSCT is less suitable for assessing exact tumor volume, this method reliably detects tumors in rats. Due to the high spatial resolution, μCT-systems could play an important role for fusion imaging, e.g. to assess experimental brain gliomas with multimodal μCT/PET- or μCT/MRI-fusion images.

  18. Particle beam injector system and method

    Science.gov (United States)

    Guethlein, Gary

    2013-06-18

    Methods and devices enable coupling of a charged particle beam to a radio frequency quadrupole accelerator. Coupling of the charged particle beam is accomplished, at least in-part, by relying on of sensitivity of the input phase space acceptance of the radio frequency quadrupole to the angle of the input charged particle beam. A first electric field across a beam deflector deflects the particle beam at an angle that is beyond the acceptance angle of the radio frequency quadrupole. By momentarily reversing or reducing the established electric field, a narrow portion of the charged particle beam is deflected at an angle within the acceptance angle of the radio frequency quadrupole. In another configuration, beam is directed at an angle within the acceptance angle of the radio frequency quadrupole by the first electric field and is deflected beyond the acceptance angle of the radio frequency quadrupole due to the second electric field.

  19. Toward design of the Collider Beam Collimation System

    International Nuclear Information System (INIS)

    A multi-component beam collimation system for the Superconducting Super Collider is described. System choice justification and design requirements are presented. System consists of targets, scrapers, and collimators with appropriate cooling and radiation shielding. Each component has an independent control for positioning and aligning with respect to the beam. Results of beam loss distribution, energy deposition calculations, and thermal analyses, as well as cost estimate, are presented

  20. Reliability Analysis of the new Link between the Beam Interlock System and the LHC Beam Dumping System Zuverlässigkeitsanalyse der neuen Verbindung zwischen dem Beam Interlock System und dem LHC Beam Dumping System

    CERN Document Server

    Vatansever, Volkan

    The nominal stored energy in each LHC beam is 360 MJ, surpassing the beam energy of other accelerators by orders of magnitude. This energy threatens to damage accelerator components in case of uncontrolled beam losses To avoid damage of accelerator equipment due to impacting beam, the controlled removal of the LHC beams from the collider rings towards the dump block must be guaranteed at all times. Therefore, the LHC Beam Dumping System was built according to high reliability standards. To further reduce the risk of incapability to dump the beams in case of correlated failures in the redundant system, a new direct link from the LHC Beam Interlock System to the Re-triggering Lines of the LHC Beam Dumping System will be implemented for the startup with beam in 2015. This link represents a diverse redundancy to the current implementation, which should neither significantly increase the risk for so-called Asynchronous Beam Dumps nor compromise machine availability. Therefore, a reliability analysis down to the co...

  1. The N8 channel beam loss monitor system

    International Nuclear Information System (INIS)

    High intensity 70 GeV proton beam loss monitor system architecture in the area of single beam pass is described. The main system components choosing as detectors recording and controlling electronics are grounded on. There are list of the main system monitoring tasks and some experimental results. 12 refs.; 6 figs

  2. BeamOptics : a Symbolic Platform for Modeling and the Solution of Beam Optics System

    International Nuclear Information System (INIS)

    BeamOptics [1] is a Mathematica-based computing platform devoted to the following objectives: (1) Structured representation and manipulation of particle beam optics systems with symbolic capabilities, (2) Analytical and numerical modeling of beam optics system behaviors, (3) Solution to specific beam optical or general accelerator system problems, in algebraic form in certain cases, through customized algorithms. Taking advantage of and conforming to the highly formal and self-contained structure of Mathematica, BeamOptics provides a unique platform for developing accelerator design and analysis programs. The feature of symbolic computation and the ability to manipulate the beam optics system at the programming language level enable the user to solve or optimize his system with considerably more efficiency, rigour and insight than can be easily achieved with passive modeling or numerical simulation methods. BeamOptics is developed with continuous evolution in mind. New features and algorithms from diverse sources can be incorporated without major modification, due to its formal and generic structure. In this report, a survey is given of the basic structure and methodology of BeamOptics, as well as a demonstration of some of its more specialized applications, and possible direction of evolution

  3. High precision electron beam diagnostic system for high current long pulse beams

    International Nuclear Information System (INIS)

    As part of the effort to develop a multi-axis electron beam transport system using stripline kicker technology for DARHT II applications, it is necessary to precisely determine the position and extent of long high energy beams (6-40 MeV, 1-4 kA, 2 microseconds) for accurate position control. The kicker positioning system utilizes shot-to-shot adjustments for reduction of relatively slow (<20 MHz) motion of the beam centroid. The electron beams passing through the diagnostic systems have the potential for large halo effects that tend to corrupt measurements performed using capacitive pick-off probes. Likewise, transmission line traveling wave probes have problems with multi-bounce effects due to these longer pulse widths. Finally, the high energy densities experienced in these applications distort typical foil beam position measurements

  4. 微型CT建立数字化三维牙颌模型初探%Three-dimensional digital dental model based on micro-CT

    Institute of Scientific and Technical Information of China (English)

    李云霞; 白玉兴; 魏存峰

    2011-01-01

    Objective To establish a three-dimensional digital dental model through scanning dental impression directly with micro-CT. Methods The polyvinyl siloxane(PVS) impression of the plaster model was taken and scanned with micro-CT. VGStudio MAX and Imageware softwares were used to obtain the digital dental model. Results The three-dimensional digital model was established successfully. The scanning layer was 90 μm. Conclusions A new way of establishing the digital dental models could be achieved with micro-CT.%目的 利用微型CT对牙颌印模进行扫描,探索新的数字化三维牙颌模型的建立方法.方法 使用硅橡胶印模材料对石膏模型制取印模,利用微型CT对印模进行扫描,并通过VGStudioMAX和Imageware逆向工程软件对数据进行图像重建和处理.结果 通过微型CT系统扫描和逆向工程软件重建,得到了数字化三维牙颌模型,其层厚为90 μm.结论 利用微型CT直接扫描硅橡胶牙颌印模,可成功建立数字化三维牙颌模型,为今后的研究提供了一种新的数字化三维牙颌模型建立方法.

  5. From histology to micro-CT:Measuring and modeling resorption cavities and their relation to bone competence

    Institute of Scientific and Technical Information of China (English)

    Jef; Vanderoost; G; Harry; van; Lenthe

    2014-01-01

    The process of bone remodelling plays an essential role in the emergence and maintenance of bone geometry and its internal structure.Osteoclasts are one of the three main bone cell types that play a crucial role in the bone remodelling cycle.At the microstructural level,osteoclasts create bone deficits by eroding resorption cavities.Understanding how these cavities impair the mechanical quality of the bone is not only relevant in quantifying the impact of resorption cavities in healthy bone and normal aging,but maybe even more so in quantifying their role in metabolic bone diseases.Meta-bolic bone diseases and their treatment are both known to affect the bone remodelling cycle;hence,the bone mechanical competence can and will be affected.How-ever,the current knowledge of the precise dimensions of these cavities and their effect on bone competence is rather limited.This is not surprising considering the difficulties in deriving three-dimensional(3D)properties from two-dimensional(2D)histological sections.The measurement difficulties are reflected in the evalua-tion of how resorption cavities affect bone competence.Although detailed 3D models are generally being used to quantify the mechanical impact of the cavities,the representation of the cavities themselves has basicallybeen limited to simplified shapes and averaged cavityproperties.Qualitatively,these models indicate that cav-ity size and location are important,and that the effectof cavities is larger than can be expected from simplebone loss.In summary,the dimensions of osteoclastresorption cavities were until recently estimated from2D measures;hence,a careful interpretation of resorp-tion cavity dimensions is necessary.More effort needsto go into correctly quantifying resorption cavities usingmodern 3D imaging techniques like micro-computedtomography(micro-CT)and synchrotron radiation CT.Osteoclast resorption cavities affect bone competence.The structure-function relationships have been ana-lysed using

  6. Beam shaping in high-power laser systems with using refractive beam shapers

    Science.gov (United States)

    Laskin, Alexander; Laskin, Vadim

    2012-06-01

    Beam Shaping of the spatial (transverse) profile of laser beams is highly desirable by building optical systems of high-power lasers as well in various applications with these lasers. Pumping of the crystals of Ti:Sapphire lasers by the laser radiation with uniform (flattop) intensity profile improves performance of these ultrashort pulse high-power lasers in terms of achievable efficiency, peak-power and stability, output beam profile. Specifications of the solid-state lasers built according to MOPA configuration can be also improved when radiation of the master oscillator is homogenized and then is amplified by the power amplifier. Features of building these high power lasers require that a beam shaping solution should be capable to work with single mode and multimode beams, provide flattop and super-Gauss intensity distributions, the consistency and divergence of a beam after the intensity re-distribution should be conserved and low absorption provided. These specific conditions are perfectly fulfilled by the refractive field mapping beam shapers due to their unique features: almost lossless intensity profile transformation, low output divergence, high transmittance and flatness of output beam profile, extended depth of field, adaptability to real intensity profiles of TEM00 and multimode laser sources. Combining of the refractive field mapping beam shapers with other optical components, like beam-expanders, relay imaging lenses, anamorphic optics makes it possible to generate the laser spots of necessary shape, size and intensity distribution. There are plenty of applications of high-power lasers where beam shaping bring benefits: irradiating photocathode of Free Electron Lasers (FEL), material ablation, micromachining, annealing in display making techniques, cladding, heat treating and others. This paper will describe some design basics of refractive beam shapers of the field mapping type, with emphasis on the features important for building and applications

  7. Imaging the Aqueous Humor Outflow Pathway in Human Eyes by Three-dimensional Micro-computed Tomography (3D micro-CT)

    Energy Technology Data Exchange (ETDEWEB)

    C Hann; M Bentley; A Vercnocke; E Ritman; M Fautsch

    2011-12-31

    The site of outflow resistance leading to elevated intraocular pressure in primary open-angle glaucoma is believed to be located in the region of Schlemm's canal inner wall endothelium, its basement membrane and the adjacent juxtacanalicular tissue. Evidence also suggests collector channels and intrascleral vessels may have a role in intraocular pressure in both normal and glaucoma eyes. Traditional imaging modalities limit the ability to view both proximal and distal portions of the trabecular outflow pathway as a single unit. In this study, we examined the effectiveness of three-dimensional micro-computed tomography (3D micro-CT) as a potential method to view the trabecular outflow pathway. Two normal human eyes were used: one immersion fixed in 4% paraformaldehyde and one with anterior chamber perfusion at 10 mmHg followed by perfusion fixation in 4% paraformaldehyde/2% glutaraldehyde. Both eyes were postfixed in 1% osmium tetroxide and scanned with 3D micro-CT at 2 {mu}m or 5 {mu}m voxel resolution. In the immersion fixed eye, 24 collector channels were identified with an average orifice size of 27.5 {+-} 5 {mu}m. In comparison, the perfusion fixed eye had 29 collector channels with a mean orifice size of 40.5 {+-} 13 {mu}m. Collector channels were not evenly dispersed around the circumference of the eye. There was no significant difference in the length of Schlemm's canal in the immersed versus the perfused eye (33.2 versus 35.1 mm). Structures, locations and size measurements identified by 3D micro-CT were confirmed by correlative light microscopy. These findings confirm 3D micro-CT can be used effectively for the non-invasive examination of the trabecular meshwork, Schlemm's canal, collector channels and intrascleral vasculature that comprise the distal outflow pathway. This imaging modality will be useful for non-invasive study of the role of the trabecular outflow pathway as a whole unit.

  8. RHIC beam permit and quench detection communications system

    International Nuclear Information System (INIS)

    A beam permit module has been developed to concentrate RHIC, subsystem sensor outputs, permit beam, and initiate emergency shutdowns. The modules accept inputs from the vacuum, cryogenic, power supply, beam loss, and superconducting magnet quench detection systems. Modules are located at equipment locations around the RHIC ring. The modules are connected by three fiberoptic communications links; a beam permit link, and two magnet power supply interlock links. During operation, carrier presence allows beam. If a RHIC subsystem detects a fault, the beam permit carrier terminates - initiating a beam dump. If the fault was a superconducting magnet quench, a power supply interlock carrier terminates - initiating an emergency magnet power dump. In addition, the master module triggers an event to cause remote sensors to log and hold data at the time-of-failure

  9. LHC Beam Dump System: Analysis of beam commissioning, performance and the consequences of abnormal operation

    CERN Document Server

    Kramer, Thomas

    2011-01-01

    The LHC accelerates proton beams to a momentum of up to 7 TeV/c. At this energy level and with nominal beam intensity the stored energy of 360 MJ per beam is sufficient to melt 500 kg of copper. In addition up to 10 GJ are stored within the LHC magnet system at top energy. It is obvious that such a machine needs well designed safety and protection systems. The LHC Beam Dump System (LBDS) is such a system and one of the most critical once concerning machine protection and safe operation. It is used to dispose of high intensity beams between 450 GeV and 7 TeV and is thus designed to fast extract beam in a loss free way and to transfer it to an external absorber. For each ring systems of 15 horizontal fast kicker magnets (MKD), 15 vertically deflecting magnetic septa (MSD) and 10 diluter kicker magnets (MKB) are installed. This thesis is concerned with the analysis of the LBDS performance under normal operating parameters as well as under abnormal conditions like in the event of asynchronous beam abort or missin...

  10. Beam kicker control system for CSR project in Lanzhou

    International Nuclear Information System (INIS)

    The beam kicker system is a key part for beam extraction and injection in ring-like accelerator, which works under high voltage and huge current. This paper introduces the kicker control system based on ARM+DSP+FPGA for CSR project in Lanzhou, which has nanosecond timing precision. ARM mainly completes the control signals with the network communication, and the time control precision for the beam kicker system is performed mainly by FPGA and DSP. The sequence control signals through the optic fiber transmission, synchronous to kicker power supply the voltage to assign uses the signal isolators and ferrites to suppress the disturbance pulses. Scene test has proved that this system can meet beam kicker control's request and work safely and stably. The control system has extracted and injected the CSR beam successfully in October 2007. (authors)

  11. Beam monitor system for high-energy beam transportation at HIMAC

    International Nuclear Information System (INIS)

    Heavy-Ion Medical Accelerator in Chiba (HIMAC) provides ion beams for radiotherapy of cancers and for other basic researches. High-energy beam transport lines deliver the beams to three treatment rooms and two experiment rooms with the aid of 41 beam monitor units. Each monitor unit consists of a wire grid as a profile monitor, or a combined unit in which the wire grid and a parallel plate ionization chamber are united for an additional measurement of a beam intensity. They are operated in a mixed gas of 80% Ar and 20% CO2. The gas gain of the wire grid achieves about 8000 at an applied voltage of -2700 V. Dynamic ranges of the wire gird and the parallel plate ionization chamber were measured to be 8x105 and 1x106 in test using ion beams, respectively. A control system of these monitor units offers easy operation, so that operators are almost free from miss-operations. The monitor units are interlocked with a system which protects patients from the undesired irradiation. Five wire grids are used for continuously monitoring the beam during treatments, which play a role in keeping qualities of the treatments. The monitor system has been designed to meet requirements for medical uses, and works in a stable and reliable manner and satisfies the requirements. (author)

  12. Data acquisition system for KOMAC beam monitoring using EPICS middleware

    Science.gov (United States)

    Song, Young-Gi

    2015-10-01

    The beam diagnostics instrument used to measure the beam properties is one of the important devices for the 100-MeV proton linear accelerator of the KOrea Multi-purpose Accelerator Complex (KOMAC). A data acquisition system (DAQ) is required to collect the output beam signals conditioned in the analog front-end circuitry of a beam loss monitor (BLM) and a beam position monitor (BPM). The electrical beam signal must be digitized, and the sampling has to be synchronized to a global timing system that produces a pulse signal for the pulsed beam operation. The digitized data must be accessible by the experimental physics and industrial control system (EPICS)-based control system, which manages all accelerator control. An input output controller (IOC), which runs Linux on a central process unit (CPU) module with a peripheral component interconnect (PCI) express-based Analog-to-digital converter (ADC) card, has been adopted to satisfy the requirements. An associated Linux driver and EPICS device support module have also been developed. The IOC meets the requirements, and the development and maintenance of software for the IOC is very efficient. In this paper, the details of the DAQ system for the BLM and the BPM with the introduction of the KOMAC beam-diagnostics devices, along with the performance, are described.

  13. Application of X-ray micro-CT for micro-structural characterization of APCVD deposited SiC coatings on graphite conduit.

    Science.gov (United States)

    Agrawal, A K; Sarkar, P S; Singh, B; Kashyap, Y S; Rao, P T; Sinha, A

    2016-02-01

    SiC coatings are commonly used as oxidation protective materials in high-temperature applications. The operational performance of the coating depends on its microstructure and uniformity. This study explores the feasibility of applying tabletop X-ray micro-CT for the micro-structural characterization of SiC coating. The coating is deposited over the internal surface of pipe structured graphite fuel tube, which is a prototype of potential components of compact high-temperature reactor (CHTR). The coating is deposited using atmospheric pressure chemical vapor deposition (APCVD) and properties such as morphology, porosity, thickness variation are evaluated. Micro-structural differences in the coating caused by substrate distance from precursor inlet in a CVD reactor are also studied. The study finds micro-CT a potential tool for characterization of SiC coating during its future course of engineering. We show that depletion of reactants at larger distances causes development of larger pores in the coating, which affects its morphology, density and thickness. PMID:26722834

  14. Statistical Analysis of Yarn Feature Parameters in C/Epoxy Plain-Weave Composite Using Micro CT with High-Resolution Lens-Coupled Detector

    Science.gov (United States)

    Wang, Hao; Wang, Zhong-wei

    2016-02-01

    C/Epoxy plain-weave composite is difficult to clear imaging in Micro CT with flat panel detector due to the similar atomic numbers of component materials. To solve this problem, a new Micro CT equipment with high-resolution lens-coupled detector is used to reconstruct 3D images of C/Epoxy. Slice data correction with ellipse projection is used to acquire real yarn normal cross-section information. A reference period method suitable for plain-weave composite is then detailed to evaluate statistical properties of yarn feature parameters. In the process of determination of real extreme slices, dislocation phenomenon existed in the laminated composite is discovered. Several possible reasons caused this phenomenon are discussed. Systematic trends, standard deviations and correlation lengths of stochastic deviations with original and corrected data are evaluated respectively by the application of reference period method. The statistical results show that mean out-of-plane yarn waviness, semi-axes, cross-section area and aspect ratio exhibit periodic characteristics, and the maximum effect of slice data correction on all statistical properties of feature parameters is twist angle.

  15. Reduced dental calcium expression and dental mass in chronic sleep deprived rats: Combined EDS, TOF-SIMS, and micro-CT analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, Yi-Jie [Department of Orthopedics, Taipei Medical University Hospital, Taipei 110, Taiwan (China); Huang, Yung-Kai [School of Oral Hygiene, College of Oral Medicine, Taipei Medical University, Taipei 110, Taiwan (China); Chou, Hsiu-Chu; Pai, Man-Hui; Lee, Ai-Wei [Department of Anatomy and Cell Biology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan (China); Mai, Fu-Der [Department of Biochemistry and Molecular Cell Biology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan (China); Chang, Hung-Ming, E-mail: taiwanzoo@gmail.com [Department of Anatomy and Cell Biology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan (China)

    2015-08-01

    Highlights: • The growth of teeth is closely regulated by the circadian rhythmicity. • Sleep deprivation significantly disrupts the circadian regulation. • Sleep deprivation reduces the dental calcium level and impairs dental intensity. • This study highlights for the first time that sleep is essential for dental structure. • Establishing satisfactory sleep behavior may be a helpful strategy to prevent dental disability. - Abstract: Teeth are the hardest tissue in the body. The growth of teeth is closely regulated by circadian rhythmicity. Considering that sleep deprivation (SD) is a severe condition that disrupts normal circadian rhythmicity, this study was conducted to determine whether calcium expression (the major element participating in teeth constitution), and dental mass would be significantly impaired following SD. Adolescent rats subjected to 3 weeks of SD were processed for energy dispersive spectrum (EDS), time-of-flight secondary ion mass spectrometry (TOF-SIMS), and micro-computed tomography (micro-CT) analyses. The EDS and TOF-SIMS results indicated that high calcium intensity was detected in both the upper and lower incisors of untreated rats. Micro-CT analysis corresponded closely with spectral data in which an enhanced dental mass was calculated in intact animals. However, following SD, both calcium expression and the dental mass were remarkably decreased to nearly half those of the untreated values. Because SD plays a detrimental role in impairing dental structure, establishing satisfactory sleep behavior would therefore serve as a crucial strategy for preventing or improving prevalent dental dysfunctions.

  16. Reduced dental calcium expression and dental mass in chronic sleep deprived rats: Combined EDS, TOF-SIMS, and micro-CT analysis

    Science.gov (United States)

    Kuo, Yi-Jie; Huang, Yung-Kai; Chou, Hsiu-Chu; Pai, Man-Hui; Lee, Ai-Wei; Mai, Fu-Der; Chang, Hung-Ming

    2015-08-01

    Teeth are the hardest tissue in the body. The growth of teeth is closely regulated by circadian rhythmicity. Considering that sleep deprivation (SD) is a severe condition that disrupts normal circadian rhythmicity, this study was conducted to determine whether calcium expression (the major element participating in teeth constitution), and dental mass would be significantly impaired following SD. Adolescent rats subjected to 3 weeks of SD were processed for energy dispersive spectrum (EDS), time-of-flight secondary ion mass spectrometry (TOF-SIMS), and micro-computed tomography (micro-CT) analyses. The EDS and TOF-SIMS results indicated that high calcium intensity was detected in both the upper and lower incisors of untreated rats. Micro-CT analysis corresponded closely with spectral data in which an enhanced dental mass was calculated in intact animals. However, following SD, both calcium expression and the dental mass were remarkably decreased to nearly half those of the untreated values. Because SD plays a detrimental role in impairing dental structure, establishing satisfactory sleep behavior would therefore serve as a crucial strategy for preventing or improving prevalent dental dysfunctions.

  17. Direct simulations of two-phase flow on micro-CT images of porous media and upscaling of pore-scale forces

    Science.gov (United States)

    Raeini, Ali Q.; Blunt, Martin J.; Bijeljic, Branko

    2014-12-01

    Pore-scale forces have a significant effect on the macroscopic behaviour of multiphase flow through porous media. This paper studies the effect of these forces using a new volume-of-fluid based finite volume method developed for simulating two-phase flow directly on micro-CT images of porous media. An analytical analysis of the relationship between the pore-scale forces and the Darcy-scale pressure drops is presented. We use this analysis to propose unambiguous definitions of Darcy-scale viscous pressure drops as the rate of energy dissipation per unit flow rate of each phase, and then use them to obtain the relative permeability curves. We show that this definition is consistent with conventional laboratory/field measurements by comparing our predictions with experimental relative permeability. We present single and two-phase flow simulations for primary oil injection followed by water injection on a sandpack and a Berea sandstone. The two-phase flow simulations are presented at different capillary numbers which cover the transition from capillary fingering at low capillary numbers to a more viscous fingering displacement pattern at higher capillary numbers, and the effect of capillary number on the relative permeability curves is investigated. Overall, this paper presents a new finite volume-based methodology for the detailed analysis of two-phase flow directly on micro-CT images of porous media and upscaling of the results to the Darcy scale.

  18. Reduced dental calcium expression and dental mass in chronic sleep deprived rats: Combined EDS, TOF-SIMS, and micro-CT analysis

    International Nuclear Information System (INIS)

    Highlights: • The growth of teeth is closely regulated by the circadian rhythmicity. • Sleep deprivation significantly disrupts the circadian regulation. • Sleep deprivation reduces the dental calcium level and impairs dental intensity. • This study highlights for the first time that sleep is essential for dental structure. • Establishing satisfactory sleep behavior may be a helpful strategy to prevent dental disability. - Abstract: Teeth are the hardest tissue in the body. The growth of teeth is closely regulated by circadian rhythmicity. Considering that sleep deprivation (SD) is a severe condition that disrupts normal circadian rhythmicity, this study was conducted to determine whether calcium expression (the major element participating in teeth constitution), and dental mass would be significantly impaired following SD. Adolescent rats subjected to 3 weeks of SD were processed for energy dispersive spectrum (EDS), time-of-flight secondary ion mass spectrometry (TOF-SIMS), and micro-computed tomography (micro-CT) analyses. The EDS and TOF-SIMS results indicated that high calcium intensity was detected in both the upper and lower incisors of untreated rats. Micro-CT analysis corresponded closely with spectral data in which an enhanced dental mass was calculated in intact animals. However, following SD, both calcium expression and the dental mass were remarkably decreased to nearly half those of the untreated values. Because SD plays a detrimental role in impairing dental structure, establishing satisfactory sleep behavior would therefore serve as a crucial strategy for preventing or improving prevalent dental dysfunctions

  19. Micro-CT-based improvement of geometrical and mechanical controllability of selective laser melted Ti6Al4V porous structures

    International Nuclear Information System (INIS)

    Highlights: → Selective laser melting as a production tool for porous Ti6Al4V structures. → Significant mismatch between designed and as-produced properties. → Decreasing mismatch using a micro-CT-based protocol. → Mismatch of pore size decreased from 45% to 5%. → Increased morphological controllability increases mechanical controllability. - Abstract: Despite the fact that additive manufacturing (AM) techniques allow to manufacture complex porous parts with a controlled architecture, differences can occur between designed and as-produced morphological properties. Therefore this study aimed at optimizing the robustness and controllability of the production of porous Ti6Al4V structures using selective laser melting (SLM) by reducing the mismatch between designed and as-produced morphological and mechanical properties in two runs. In the first run, porous Ti6Al4V structures with different pore sizes were designed, manufactured by SLM, analyzed by microfocus X-ray computed tomography (micro-CT) image analysis and compared to the original design. The comparison was based on the following morphological parameters: pore size, strut thickness, porosity, surface area and structure volume. Integration of the mismatch between designed and measured properties into a second run enabled a decrease of the mismatch. For example, for the average pore size the mismatch decreased from 45% to 5%. The demonstrated protocol is furthermore applicable to other 3D structures, properties and production techniques, powder metallurgy, titanium alloys, porous materials, mechanical characterization, tomography.

  20. Beam transfer functions and beam stabilisation in a double RF system

    CERN Document Server

    Shaposhnikova, Elena; Linnecar, Trevor Paul R

    2005-01-01

    The high intensity proton beam for LHC accelerated in the CERN SPS is stabilised against coupled-bunch instabilities by a 4th harmonic RF system in bunch-shortening mode. Bunch-lengthening mode, which could also be useful to reduce peak line density and alleviate problems from e-cloud and kicker heating, does not give desirable results for beam stability. In this paper an analysis of the limitations of these two different modes of operation is presented together with measurements of the Beam Transfer Function for the double RF system. As predicted by theory, for sufficiently long bunches with the same noise excitation, the measured amplitude of the beam response in bunchlengthening mode is an order of magnitude higher than that for bunch-shortening mode or for a single RF system.

  1. Transverse oscillations of an underwater beam-cable system

    OpenAIRE

    Blanco, Max; Wilson, P.A.

    2010-01-01

    An Autonomous Underwater Vehicle refuel station is proposed. The power source is located on board a surface vessel, while the AUV is serviced at depth. The structure which connects the two craft is modelled as a cable-beam. Transverse oscillations of this cable-beam system are investigated through a fourth-order differential equation.

  2. Mechanical engineering problems in the TFTR neutral beam system

    International Nuclear Information System (INIS)

    A conceptual design of a prototype beam line for the TFTR Neutral Beam System has been developed. The basic components have been defined, cost estimates prepared, and the necessary development programs identified. Four major mechanical engineering problems, potential solutions and the required development programs are discussed

  3. Beam Position and Phase Monitor - Wire Mapping System

    Energy Technology Data Exchange (ETDEWEB)

    Watkins, Heath A [Los Alamos National Laboratory; Shurter, Robert B. [Los Alamos National Laboratory; Gilpatrick, John D. [Los Alamos National Laboratory; Kutac, Vincent G. [Los Alamos National Laboratory; Martinez, Derwin [Los Alamos National Laboratory

    2012-04-10

    The Los Alamos Neutron Science Center (LANSCE) deploys many cylindrical beam position and phase monitors (BPPM) throughout the linac to measure the beam central position, phase and bunched-beam current. Each monitor is calibrated and qualified prior to installation to insure it meets LANSCE requirements. The BPPM wire mapping system is used to map the BPPM electrode offset, sensitivity and higher order coefficients. This system uses a three-axis motion table to position the wire antenna structure within the cavity, simulating the beam excitation of a BPPM at a fundamental frequency of 201.25 MHz. RF signal strength is measured and recorded for the four electrodes as the antenna position is updated. An effort is underway to extend the systems service to the LANSCE facility by replacing obsolete electronic hardware and taking advantage of software enhancements. This paper describes the upgraded wire positioning system's new hardware and software capabilities including its revised antenna structure, motion control interface, RF measurement equipment and Labview software upgrades. The main purpose of the wire mapping system at LANSCE is to characterize the amplitude response versus beam central position of BPPMs before they are installed in the beam line. The wire mapping system is able to simulate a beam using a thin wire and measure the signal response as the wire position is varied within the BPPM aperture.

  4. Measurement system with high accuracy for laser beam quality.

    Science.gov (United States)

    Ke, Yi; Zeng, Ciling; Xie, Peiyuan; Jiang, Qingshan; Liang, Ke; Yang, Zhenyu; Zhao, Ming

    2015-05-20

    Presently, most of the laser beam quality measurement system collimates the optical path manually with low efficiency and low repeatability. To solve these problems, this paper proposed a new collimated method to improve the reliability and accuracy of the measurement results. The system accuracy controlled the position of the mirror to change laser beam propagation direction, which can realize the beam perpendicularly incident to the photosurface of camera. The experiment results show that the proposed system has good repeatability and the measuring deviation of M2 factor is less than 0.6%. PMID:26192526

  5. A beam waveguide linearly polarized KU band feed system

    Science.gov (United States)

    Flannery, J. B.

    The linearly polarized KU band beam waveguide feed system considered was designed for use with large Cassegrain antennas typical of those associated with satellite comunications earth stations. The beam waveguide technique permits fixed ground installations of the transmitters and low noise receivers and eliminates the large equipment room usually mounted behind the reflector vertex. The feed system consists of a tapered corrugated wall horn, a matching network, a TE21 mode coupler, three differential phase shifters, a choke coupled rotatable, orthogonal mode transducer, and a servo amplifier system. Attention is given to TE21 mode coupler operation, TE21 mode coupling and directivity, a horn description, a beam wave description, and polarization control.

  6. System for programmable micromachining by means of submicron ion beam

    International Nuclear Information System (INIS)

    A system with submicron ion beam is described. Very bright ion beams are generated by electrohydrodynamic source and are focused in electrostatic ion-optical column. An octupole deflector is used for astigmatism correction and beam deviation. Stabilized power supply of all elements is ensured. Lines of 0.1 μm minimum width are obtained. The micromachining process is controlled by an automated system in CAMAC standard on line with Odrenok computer. Specific features of programmable micromachining and operation of the system in the mode of scanning ion microscope are considered

  7. Development of compact quantum beam generation system and the application

    International Nuclear Information System (INIS)

    After the approval of the project as the 'High-Tech Research Center Project' conducted by MEXT at Waseda University, the laser driven photo-cathode RF-Gun (RF-Gun) has been developed very extensively. The system was developed to obtain the stable and high quality (i.e. very low emittance) electron beam in conjunction with the system stabilization such as RF power source and laser system for the electron emission. The high quality electron beams have been applied for the development of novel beam diagnostic system. At the same time, the beams (electron and laser) are applied for the inverse Compton scattering experiment for the generation of soft-X-ray with quasi-monochromatic energy and short time structure, and for the pump probe experiment (the pico-second pulse radiolysis) as the very compact system. (author)

  8. Scanning system for charged and neutral particle beams

    International Nuclear Information System (INIS)

    The present invention aims at providing a simple and reliable method and a reliable device for irradiating a confined volume of matter, preferably at great depth, with a beam of high energy charged or neutral particles. The basic feature of the invention is that the particle beam coming from a radiation source of charged particles is scanned electrically in two orthogonal directions, and that the beam scanned in one plane is deflected in space. For most practical purposes it is important that the radiation source is of small extension. Such a radiation source is realized by means of a beam optical system that includes two scanning magnets each of which admits scanning of the particle beam in one of two orthogonal planes. The beam scanned in one of the planes leaves the associated scanning magnet from an effective scanning centre. The optical system also includes a deflection magnet disposed between the scanning magnets for deflecting the path of the beam in space. By utilizing the optical properties of the deflection magnet in such a way that the deflection magnet produces an image of the effective scanning centre of the first scanning magnet which coincides with the effective scanning centre of the second scanning magnet, the beam scanned in two orthogonal planes will radiate isotropically from the scanning centre of the second scanning magnet. By using the deflection magnet a compact scanning system with a small distance between the scanning centres of the scanning magnets is obtained

  9. Multi-electron beam system for high resolution electron beam induced deposition

    OpenAIRE

    Van Bruggen, M.J.

    2008-01-01

    The development of a multi-electron beam system is described which is dedicated for electron beam induced deposition (EBID) with sub-10 nm resolution. EBID is a promising mask-less nanolithography technique which has the potential to become a viable technique for the fabrication of 20-2 nm structures after 2013, as described by the International Technology Roadmap for Semiconductors (ITRS), or can be used for rapid prototyping in research applications. The key point is to combine the throughp...

  10. Antenna systems with beam forming and beam steering capabilities for HF skywave radars

    OpenAIRE

    Uluışık, Çağatay

    2010-01-01

    Radiation characteristics of linearly phased, periodic, planar dipole arrays, which can be used as transmitting/ receiving antenna systems for HF skywave radars, are investigated. Rectangular, triangular and trapezoidal arrays are proposed in obtaining different beam shapes in the desired directions. Beam steering is achieved by adjusting the inter-element phase increments coherently. The effects of vertical array-tilt with a desired take-off angle (TOA) α are presented by a number of radiati...

  11. Antenna systems with beam forming and beam steering capabilities for HF skywave radars

    OpenAIRE

    ULUIŞIK, Çağatay

    2010-01-01

    Radiation characteristics of linearly phased, periodic, planar dipole arrays, which can be used as transmitting/receiving antenna systems for HF skywave radars, are investigated. Rectangular, triangular and trapezoidal arrays are proposed in obtaining different beam shapes in the desired directions. Beam steering is achieved by adjusting the inter-element phase increments coherently. The effects of vertical array-tilt with a desired take-off angle (TOA) a are presented by a number o...

  12. LHC Beam Loss Monitoring System Verification Applications

    CERN Document Server

    Dehning, B; Zamantzas, C; Jackson, S

    2011-01-01

    The LHC Beam Loss Mon­i­tor­ing (BLM) sys­tem is one of the most com­plex in­stru­men­ta­tion sys­tems de­ployed in the LHC. In ad­di­tion to protecting the col­lid­er, the sys­tem also needs to pro­vide a means of di­ag­nos­ing ma­chine faults and de­liv­er a feed­back of loss­es to the control room as well as to sev­er­al sys­tems for their setup and analysis. It has to trans­mit and pro­cess sig­nals from al­most 4’000 mon­i­tors, and has near­ly 3 mil­lion con­fig­urable pa­ram­e­ters. The system was de­signed with re­li­a­bil­i­ty and avail­abil­i­ty in mind. The spec­i­fied op­er­a­tion and the fail-safe­ty stan­dards must be guar­an­teed for the sys­tem to per­form its func­tion in pre­vent­ing su­per­con­duc­tive mag­net de­struc­tion caused by par­ti­cle flux. Main­tain­ing the ex­pect­ed re­li­a­bil­i­ty re­quires ex­ten­sive test­ing and ver­i­fi­ca­tion. In this paper we re­port our most re­cent ad­di­t...

  13. Neutral beam injection system design for KSTAR tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Choi, B.H.; Lee, K.W.; Chung, K.S.; Oh, B.H.; Cho, Y.S.; Bae, Y.D.; Han, J.M. [Korea Atomic Energy Research Institute, Taejon (Korea)

    1998-06-01

    The NBI system for KSTAR (Korean Superconducting Tokamak Advanced Research) has been designed based on conventional positive ion beam technology. One beam line consists of three ion sources, three neutralizers, one bending magnet, and one drift tube. This system will deliver 8 MW deuterium beam to KSTAR plasma in normal operation to support the advanced experiments on heating, current drive and profile control. The key technical issues in this design were high power ion source(120 kV, 65 A), long pulse operation (300 seconds; world record is 30 sec), and beam rotation from vertical to horizontal direction. The suggested important R and D points on ion source and beam line components are also included. (author). 7 refs., 27 figs., 1 tab.

  14. Internal beam abort system for the Tevatron upgrade

    International Nuclear Information System (INIS)

    In this paper, the authors examine the properties of an internal beam dump system for the Tevatron running in the p bar p collider mode. The authors assume that the beam energy can be as high as 1.8 TeV. The motivation behind this report comes from the fact that the present proton abort system is a single-turn fast-extraction system, which becomes progressively more difficult to perform as the beam energy is raised without lengthening the straight section. The authors examine three different designs. The first is a system comprised of two beam dumps at each end of the existing straight section, the second dump acting as an absorber for the secondary particles produced in the primary dump as well as functioning as the primary dump for the particles of the opposite sign

  15. The beam handling system of the Oslo Cyclotron

    International Nuclear Information System (INIS)

    The beam optic system of the Oslo Cyclotron is described. A computer program for the calculation of optimal settings of quadropoles is presented. The reliability of the computer program is confirmed by experimental data

  16. Optical manipulation with two beam traps in microfluidic polymer systems

    DEFF Research Database (Denmark)

    Khoury Arvelo, Maria; Matteucci, Marco; Sørensen, Kristian Tølbøl; Bilenberg, Brian; Vannahme, Christoph; Kristensen, Anders; Berg-Sørensen, Kirstine

    2015-01-01

    An optical trapping system with two opposing laser beams, also known as the optical stretcher, are naturally constructed inside a microfluidic lab-on-chip system. We present and compare two approaches to combine a simple microfluidic system with either waveguides directly written in the microflui......An optical trapping system with two opposing laser beams, also known as the optical stretcher, are naturally constructed inside a microfluidic lab-on-chip system. We present and compare two approaches to combine a simple microfluidic system with either waveguides directly written in the...... microfluidic chip or with optical fibers mounted in the chip....

  17. An advanced beam steering system for the SRS at Daresbury

    International Nuclear Information System (INIS)

    The Daresbury SRS is a 2 GeV electron storage ring dedicated to providing synchrotron radiation to approximately 32 stations on 10 beamlines. The storage ring beam steering systems are being replaced to allow automatic real time correction of the electron beam position. The stability problem and the proposed solutions are briefly summarized. Progress on development of the constituent systems is reviewed and some data from early performance trials is presented. (author) 7 refs.; 7 figs

  18. A beam guide system for laser-surgery

    International Nuclear Information System (INIS)

    A beam guide system for medical application is described. Using rotatable dielectric mirrors the transmission of the system is very high and the beam quality is not debased. A special end tube suitable for surgery in the nasal cavity is presented solving the problems of a clean optical end face. The instrument was applied clinically to surgery of the lower human turbinates using an argon ion laser with a power up to 4 W. (Author)

  19. Transient Beam Loading in the ALS Harmonic RF System

    International Nuclear Information System (INIS)

    We report on the commissioning of a higher harmonic radiofrequency system at the Advanced Light Source, designed to improve the beam lifetime. We have achieved an increase above a factor of two in our best results up to now. Transient beam loading of the harmonic cavities, due to the unequal fill patterns, creates the greatest limitations on lifetime improvement. We also describe several interesting effects on the operation of the longitudinal and transverse multibunch feedback systems

  20. BECOLA Beam Line Construction and Laser System

    Science.gov (United States)

    Pedicini, Eowyn; Minamisono, Kei; Barquest, Brad; Bollen, Georg; Klose, Andrew; Mantica, Paul; Morrissey, Dave; Ringle, Ryan; Schwarz, Stefan; Vinnikova, Sophia

    2010-11-01

    The BECOLA (BEam COoler and LAser spectroscopy) facility is being installed at NSCL for experiments on radioactive nuclides.ootnotetextK. Minamisono et al, Proc. Inst. Nucl. Theory 16, 180 (2009). Low energy ion beams will be cooled/bunched in an RFQ ion trap and then extracted to a max of 60 kV. The ion beam will be neutralized through a charge exchange cell (CEC), and remaining ions will be removed by a deflector and collected in a Faraday cup. Collinear laser spectroscopy will be used to measure the atomic hyperfine structure, and nuclear properties will be extracted. The assembly, vacuum testing, and optical alignment of the CEC have been completed and the ion deflector and Faraday cup were also assembled. Stabilization of the Ti:sapphire laser to be used for spectroscopy is achieved through a feedback loop using a precision wavelength meter that is calibrated by a stabilized He-Ne laser. Coupling the He-Ne laser into a single-mode optical fiber was optimized for stable operation of the feedback loop. Finally, a wall chart of nuclear moments was prepared to view trends in μ and Q for nuclear ground states for planning future measurements.

  1. Electron beam irradiation in polymeric systems

    International Nuclear Information System (INIS)

    The electron beam applications in the chemistry of polymers, such as the production of acrylamide polymers, which are of great interest in the treatment of waste industrial waters are given. These products have unique properties: the required dose is smaller by a factor of 10 to 50 as compared to the dose requirement for other polymeric materials and they are used in aqueous solutions in a concentration of one or two magnitude orders smaller than the conventional inorganic flocculants. The acrylamide polymers technologies was first developed at semi-industrial scale with IETI 10000 gamma rays source and then transferred to the ALIN-10 electron linear accelerator. The operation of the ALIN-10 built in the Accelerator Laboratory from the Institute of Atomic Physics is presented. An original feature of this accelerator, using an electron gun of the diode type is its capability to obtain programmed beam single shots and pulse trains. It is particularly useful for the automatic control of irradiation processing in order to provide the maximum efficiency of the electron beam application. The preliminary results obtained by ALIN-10 lead to the assumption that the low output power high energy linacs are economically attractive for the commercial production of acrylamide type polymers. (Author) 7 Figs. 2 Tabs., 10 Refs

  2. Beam monitor system for high-energy beam transportation at HIMAC

    CERN Document Server

    Torikoshi, M; Takada, E; Kanai, T; Yamada, S; Ogawa, H; Okumura, K; Narita, K; Ueda, K; Mizobata, M

    1999-01-01

    Heavy-Ion Medical Accelerator in Chiba (HIMAC) provides ion beams for radiotherapy of cancers and for other basic researches. High-energy beam transport lines deliver the beams to three treatment rooms and two experiment rooms with the aid of 41 beam monitor units. Each monitor unit consists of a wire grid as a profile monitor, or a combined unit in which the wire grid and a parallel plate ionization chamber are united for an additional measurement of a beam intensity. They are operated in a mixed gas of 80% Ar and 20% CO sub 2. The gas gain of the wire grid achieves about 8000 at an applied voltage of -2700 V. Dynamic ranges of the wire gird and the parallel plate ionization chamber were measured to be 8x10 sup 5 and 1x10 sup 6 in test using ion beams, respectively. A control system of these monitor units offers easy operation, so that operators are almost free from miss-operations. The monitor units are interlocked with a system which protects patients from the undesired irradiation. Five wire grids are use...

  3. A beam-synchronous gated peak-detector for the LHC beam observation system

    CERN Document Server

    Levens, T E; Wehrle, U

    2013-01-01

    Measurements of the bunch peak amplitude using the longitudinal wideband wall-current monitor are a vital tool used in the Large Hadron Collider (LHC) beam observation system. These peak-detected measurements can be used to diagnose bunch shape oscillations, for example coherent quadrupole oscillations, that occur at injection and during beam manipulations. Peak-detected Schottky diagnostics can also be used to obtain the synchrotron frequency distribution and other parameters from a bunched beam under stable conditions. For the LHC a beam-synchronous gated peak detector has been developed to allow individual bunches to be monitored without the influence of other bunches circulating in the machine. The requirement for the observation of both low intensity pilot bunches and high intensity bunches for physics requires a detector front-end with a high bandwidth and a large dynamic range while the usage for Schottky measurements requires low noise electronics. This paper will present the design of this detector s...

  4. Laser beam riding guided system principle and design research

    Science.gov (United States)

    Qu, Zhou; Jin, Yi; Xu, Zhou; Xing, Hao

    2016-01-01

    With the development of science and technology, precision-strike weapons has been considered to be important for winning victory in military field. Laser guidance is a major method to execute precision-strike in modern warfare. At present, the problems of primary stage of Laser guidance has been solved with endeavors of countries. Several technical aspects of laser-beam riding guided system have been mature, such as atmosphere penetration of laser beam, clutter inhibition on ground, laser irradiator, encoding and decoding of laser beam. Further, laser beam quality, equal output power and atmospheric transmission properties are qualified for warfare situation. Riding guidance instrument is a crucial element of Laser-beam riding guided system, and is also a vital element of airborne, vehicle-mounted and individual weapon. The optical system mainly consist of sighting module and laser-beam guided module. Photoelectric detector is the most important sensing device of seeker, and also the key to acquire the coordinate information of target space. Currently, in consideration of the 1.06 u m of wavelength applied in all the semi-active laser guided weapons systems, lithium drifting silicon photodiode which is sensitive to 1.06 u m of wavelength is used in photoelectric detector. Compared to Solid and gas laser, diode laser has many merits such as small volume, simple construction, light weight, long life, low lost and easy modulation. This article introduced the composition and operating principle of Laser-beam riding guided system based on 980 nm diode laser, and made a analysis of key technology; for instance, laser irradiator, modulating disk of component, laser zooming system. Through the use of laser diode, Laser-beam riding guided system is likely to have smaller shape and very light.

  5. Beam Tracking in Switched-Beam Antenna System for V2V Communication

    Directory of Open Access Journals (Sweden)

    Settawit Poochaya

    2016-01-01

    Full Text Available This paper presents the proposed switched beam antenna system for V2V communication including optimum antenna half power beamwidth determination in urban road environments. SQP optimization method is selected for the computation of optimum antenna half power beamwidth. In addition, beam tracking algorithm is applied to guarantee the best beam selection with maximum RSSI. The results present the success of the proposed system with the increasing of V2V performance metrics. Also, V2V data dissemination via the proposed system introduces the enhancement of V2V link in terms of RSSI, PER, BER, Tsafe, and Rsafe. The results indicate the improvement of V2V link reliability. Consequently, the road safety is improved.

  6. [Advanced development of particle beam probe diagnostic system

    International Nuclear Information System (INIS)

    This progress report under DOE Grant DE-FG02-85ER3211 covers the period 15 December 1992 through 15 October 1993. The major accomplishments of this period are summarized below: The basic TEXT heavy ion beam probe including the primary beam line, the upper secondary beam line with the old 500 keV analyzer, and the lower secondary beam line with the new 2 MeV analyzer is operational and system shake-down is now beginning. Several subsystems of the complete system design are still under development, including secondary beam line sweeps, primary beam detectors, the digital control and data acquisition system. The lower analyzer entrance aperture and detector plates also have very limited capabilities to make it possible to more rapidly obtain satisfactory initial alignment and calibration conditions. We have performed a variety of high voltage tests that establish the basic efficacy of the 2 MeV analyzer design. We have upgraded the ion optics and added vacuum chambers in our vertical test stand facility to allow us to test the 2 MeV analyzers. We have also constructed a facility for testing ion source characteristics. We analyzed data on primary beam modulation taken during the last run period and confirmed the accuracy of our simulation code. Analysis of magnetic field measurements continued

  7. Beam propagation considerations in the Aurora laser system

    International Nuclear Information System (INIS)

    Aurora is a high-power KrF laser system now being constructed for inertial confinement fusion (ICF) studies. It will use optical angular multiplexing and serial amplification by electron-beam-driven KrF amplifiers to deliver a stacked, multikilojoule 5-ns-duration laser pulse to ICF targets. The requirements of angular multiplexing KrF lasers at the multikilojoule level dictate path lengths on the order of 1 km. The inherent complicated path crossings produced by angular multiplexing and pulse stacking do not allow isolation of individual beam lines, so the optical quality of the long beam paths must be controlled. Propagation of the 248-nm light beams over long paths in air is affected by scattering, absorption thermal gradients and turbulence, beam alignment, and control and optical component figure errors

  8. Beam forming system modernization at the MMF linac proton injector

    CERN Document Server

    Derbilov, V I; Nikulin, E S; Frolov, O T

    2001-01-01

    The isolation improvements of the beam forming system (BFS) of the MMF linac proton injector ion source are reported. The mean beam current and,accordingly, BFS electrode heating were increased when the MMF linac has began to operate regularly in long beam sessions with 50 Hz pulse repetition rate. That is why the BFS electrode high-voltage isolation that was made previously as two consequently and rigidly glued solid cylinder insulators has lost mechanical and electric durability. The substitution of large (160 mm) diameter cylinder insulator for four small diameter (20 mm) tubular rods has improved vacuum conditions in the space of beam forming and has allowed to operate without failures when beam currents being up to 250 mA and extraction and focusing voltage being up to 25 and 40 kV respectively. Moreover,the construction provides the opportunity of electrode axial move. The insulators are free from electrode thermal expansion mechanical efforts in a transverse direction.

  9. Ion beam induced fluorescence imaging in biological systems

    Science.gov (United States)

    Bettiol, Andrew A.; Mi, Zhaohong; Vanga, Sudheer Kumar; Chen, Ce-belle; Tao, Ye; Watt, Frank

    2015-04-01

    Imaging fluorescence generated by MeV ions in biological systems such as cells and tissue sections requires a high resolution beam (system and a fluorescent probe that has a high quantum efficiency and low bleaching rate. For cutting edge applications in bioimaging, the fluorescence imaging technique needs to break the optical diffraction limit allowing for sub-cellular structure to be visualized, leading to a better understanding of cellular function. In a nuclear microprobe this resolution requirement can be readily achieved utilizing low beam current techniques such as Scanning Transmission Ion Microscopy (STIM). In recent times, we have been able to extend this capability to fluorescence imaging through the development of a new high efficiency fluorescence detection system, and through the use of new novel fluorescent probes that are resistant to ion beam damage (bleaching). In this paper we demonstrate ion beam induced fluorescence imaging in several biological samples, highlighting the advantages and challenges associated with using this technique.

  10. Control system for the text diagnostic neutral beam source

    International Nuclear Information System (INIS)

    A diagnostic neutral beam source (DNB) has been designed, built, and installed on the Texas Experimental Tokamak (TEXT). The control system, presented in this paper, coordinates the functioning of all associated subsystems necessary for neutral beam operation. These include the modulator/regulator, the capacitor bank charging system, the arc and filament supplies, the biased snubber supply, the deflection magnet supply, the suppressor switch, and the Culham vacuum system. The control system architecture is a hierarchical, decentralized, hardwired logic system designed to meet criteria of reliability, modularity, and flexibility

  11. Diagnostic Lithium Beam System for COMPASS Tokamak

    Czech Academy of Sciences Publication Activity Database

    Háček, P.; Weinzettl, Vladimír; Stöckel, Jan; Anda, G.; Veres, G.; Zoletnik, S.; Berta, M.

    Prague : MATFYZPRESS, 2011 - (Šafránková, J.; Pavlů, J.), s. 215-220 ISBN 978-80-7378-185-9. - (WDS. 2). [WDS 2011 - Annual Conference of Doctoral Students /20./. Prague (CZ), 31.05.2011-03.06.2011] R&D Projects: GA ČR GA202/09/1467 Institutional research plan: CEZ:AV0Z20430508 Keywords : plasma diagnostics * tokamak, COMPASS * beam diagnostics Subject RIV: BL - Plasma and Gas Discharge Physics http:// server .ipp.cas.cz/~vwei/work/wds2010_201_f2.pdf

  12. Empirical beam hardening correction (EBHC) for CT

    Energy Technology Data Exchange (ETDEWEB)

    Kyriakou, Yiannis; Meyer, Esther; Prell, Daniel; Kachelriess, Marc [Institute of Medical Physics, University of Erlangen-Nuernberg, 91052 Erlangen (Germany)

    2010-10-15

    C-arm CT scanner (Axiom Artis dTA, Siemens Healthcare, Forchheim, Germany). A large variety of phantom, small animal, and patient data were used to demonstrate the data and system independence of EBHC. Results: Although no physics apart from the initial segmentation procedure enter the correction process, beam hardening artifacts were significantly reduced by EBHC. The image quality for clinical CT, micro-CT, and C-arm CT was highly improved. Only in the case of C-arm CT, where high scatter levels and calibration errors occur, the relative improvement was smaller. Conclusions: The empirical beam hardening correction is an interesting alternative to conventional iterative higher order beam hardening correction algorithms. It does not tend to over- or undercorrect the data. Apart from the segmentation step, EBHC does not require assumptions on the spectra or on the type of material involved. Potentially, it can therefore be applied to any CT image.

  13. A high performance image processing platform based on CPU-GPU heterogeneous cluster with parallel image reconstroctions for micro-CT

    International Nuclear Information System (INIS)

    In this paper, we report the development of a high-performance image processing platform, which is based on CPU-GPU heterogeneous cluster. Currently, it consists of a Dell Precision T7500 and HP XW8600 workstations with parallel programming and runtime environment, using the message-passing interface (MPI) and CUDA (Compute Unified Device Architecture). We succeeded in developing parallel image processing techniques for 3D image reconstruction of X-ray micro-CT imaging. The results show that a GPU provides a computing efficiency of about 194 times faster than a single CPU, and the CPU-GPU clusters provides a computing efficiency of about 46 times faster than the CPU clusters. These meet the requirements of rapid 3D image reconstruction and real time image display. In conclusion, the use of CPU-GPU heterogeneous cluster is an effective way to build high-performance image processing platform. (authors)

  14. JET neutral beam injection system, construction and component tests

    International Nuclear Information System (INIS)

    The two neutral injection systems for JET are each determined by 40 mw beam power extracted from eight sources during 10 s pulses. Under the existing spatial restrictions, this has led to a complex beam-line system design. The applied manufacturing techniques and the approach to quality assurance are discussed. The beam sources have been operated at 80 kv, 60 a, 5 s in hydrogen. Plasma source development has increased the H+ yield to approximately 84%. Beamlet steering by aperture offset has experimentally been adjusted to the values required for the restricted tokamak entrance geometry. A beam source has also been operated at 160 kv, 37 a in deuterium. At the tokamak the 7 m high injector vacuum box has been installed incorporating a fast shutter and a cryopump. This LHE cooled pump with 40 m2 entrance area and 45% pumping efficiency has successfully been tested as well as the flexible cryoliquid transfer-lines. The bakeable valve between injector box and tokamak vacuum (1.1 m x 0.5 m gate cross-section) has been operated with leak rates <10-9 mbar1/s. The sub-system commissioning is completed by short-pulse operation of the beam sources with their final power supplies in situ at the tokamak and, in parallel to this, testing of the beam-line system in the neutral injection testbed

  15. Synchrotron radiation micro-CT at the micrometer scale for the analysis of the three-dimensional morphology of microcracks in human trabecular bone.

    Directory of Open Access Journals (Sweden)

    Aymeric Larrue

    Full Text Available Bone quality is an important concept to explain bone fragility in addition to bone mass. Among bone quality factors, microdamage which appears in daily life is thought to have a marked impact on bone strength and plays a major role in the repair process. The starting point for all studies designed to further our understanding of how bone microdamage initiate or dissipate energy, or to investigate the impact of age, gender or disease, remains reliable observation and measurement of microdamage. In this study, 3D Synchrotron Radiation (SR micro-CT at the micrometric scale was coupled to image analysis for the three-dimensional characterization of bone microdamage in human trabecular bone specimens taken from femoral heads. Specimens were imaged by 3D SR micro-CT with a voxel size of 1.4 µm. A new tailored 3D image analysis technique was developed to segment and quantify microcracks. Microcracks from human trabecular bone were observed in different tomographic sections as well as from 3D renderings. New 3D quantitative measurements on the microcrack density and morphology are reported on five specimens. The 3D microcrack density was found between 3.1 and 9.4/mm3 corresponding to a 2D density between 0.55 and 0.76 /mm2. The microcrack length and width measured in 3D on five selected microcrack ranged respectively from 164 µm to 209 µm and 100 µm to 120 µm. This is the first time that various microcracks in unloaded human trabecular bone--from the simplest linear crack to more complex cross-hatch cracks--have been examined and quantified by 3D imaging at this scale. The suspected complex morphology of microcracks is here considerably more evident than in the 2D observations. In conclusion, this technique opens new perspective for the 3D investigation of microcracks and the impact of age, disease or treatment.

  16. Synchrotron radiation micro-CT at the micrometer scale for the analysis of the three-dimensional morphology of microcracks in human trabecular bone.

    Science.gov (United States)

    Larrue, Aymeric; Rattner, Aline; Peter, Zsolt-Andrei; Olivier, Cécile; Laroche, Norbert; Vico, Laurence; Peyrin, Françoise

    2011-01-01

    Bone quality is an important concept to explain bone fragility in addition to bone mass. Among bone quality factors, microdamage which appears in daily life is thought to have a marked impact on bone strength and plays a major role in the repair process. The starting point for all studies designed to further our understanding of how bone microdamage initiate or dissipate energy, or to investigate the impact of age, gender or disease, remains reliable observation and measurement of microdamage. In this study, 3D Synchrotron Radiation (SR) micro-CT at the micrometric scale was coupled to image analysis for the three-dimensional characterization of bone microdamage in human trabecular bone specimens taken from femoral heads. Specimens were imaged by 3D SR micro-CT with a voxel size of 1.4 µm. A new tailored 3D image analysis technique was developed to segment and quantify microcracks. Microcracks from human trabecular bone were observed in different tomographic sections as well as from 3D renderings. New 3D quantitative measurements on the microcrack density and morphology are reported on five specimens. The 3D microcrack density was found between 3.1 and 9.4/mm3 corresponding to a 2D density between 0.55 and 0.76 /mm2. The microcrack length and width measured in 3D on five selected microcrack ranged respectively from 164 µm to 209 µm and 100 µm to 120 µm. This is the first time that various microcracks in unloaded human trabecular bone--from the simplest linear crack to more complex cross-hatch cracks--have been examined and quantified by 3D imaging at this scale. The suspected complex morphology of microcracks is here considerably more evident than in the 2D observations. In conclusion, this technique opens new perspective for the 3D investigation of microcracks and the impact of age, disease or treatment. PMID:21750707

  17. Micro-CT analysis and mechanical properties of Ti spherical and polyhedral void composites made with saccharose as a space holder material

    International Nuclear Information System (INIS)

    The paper describes the formation, morphology and mechanical properties of Ti void composites. The Ti void composites were made using 100 and 325 mesh Ti powder for solid scaffold formation. The spherical and polyhedral voids (pores) were formed using saccharose particles (table sugar) of different shapes. The Ti void composite morphology was investigated by microcomputed tomography and scanning electron microscopy. The Ti void composites of designed porosity of 50–70% were made. Compression test was applied for mechanical properties estimation. It has been found, that Ti void composites made from 100 mesh Ti and those having spherical pores have a higher strength and elastic modulus, i.e. for the designed porosity of 50% for 100 and 325 mesh Ti void composites, a compressive strength was 32.32 and 20.13 MPa, respectively. It has been shown that this is related to better sintering of the 100 mesh Ti powders compared with the 325 mesh Ti powders. A correlation between microcomputed tomography data and mechanical properties has also been shown. The Ti void composites, made with the use of saccharose as a space holder, described in this work should be a promising material for biomedical applications, where interconnected pores and good mechanical properties are required. - Highlights: • Ti scaffolds of the porosity of 50–70% were made. • Saccharose particles as space holder were applied. • The voids in the scaffolds were designed with spherical and polyhedral shape. • The scaffold structure was investigated by SEM and micro-CT. • Micro-CT data and mechanical properties of the Ti scaffold have been correlated

  18. Computer modelling integrated with micro-CT and material testing provides additional insight to evaluate bone treatments: Application to a beta-glycan derived whey protein mice model.

    Science.gov (United States)

    Sreenivasan, D; Tu, P T; Dickinson, M; Watson, M; Blais, A; Das, R; Cornish, J; Fernandez, J

    2016-01-01

    The primary aim of this study was to evaluate the influence of a whey protein diet on computationally predicted mechanical strength of murine bones in both trabecular and cortical regions of the femur. There was no significant influence on mechanical strength in cortical bone observed with increasing whey protein treatment, consistent with cortical tissue mineral density (TMD) and bone volume changes observed. Trabecular bone showed a significant decline in strength with increasing whey protein treatment when nanoindentation derived Young׳s moduli were used in the model. When microindentation, micro-CT phantom density or normalised Young׳s moduli were included in the model a non-significant decline in strength was exhibited. These results for trabecular bone were consistent with both trabecular bone mineral density (BMD) and micro-CT indices obtained independently. The secondary aim of this study was to characterise the influence of different sources of Young׳s moduli on computational prediction. This study aimed to quantify the predicted mechanical strength in 3D from these sources and evaluate if trends and conclusions remained consistent. For cortical bone, predicted mechanical strength behaviour was consistent across all sources of Young׳s moduli. There was no difference in treatment trend observed when Young׳s moduli were normalised. In contrast, trabecular strength due to whey protein treatment significantly reduced when material properties from nanoindentation were introduced. Other material property sources were not significant but emphasised the strength trend over normalised material properties. This shows strength at the trabecular level was attributed to both changes in bone architecture and material properties. PMID:26599826

  19. High-resolution micro-CT for morphologic and quantitative assessment of the sinusoid in human cavernous hemangioma of the liver.

    Directory of Open Access Journals (Sweden)

    Jinghao Duan

    Full Text Available Hepatic sinusoid plays a vital role in human cavernous hemangioma of the liver (CHL, and its morphologic investigation facilitates the understanding of microcirculation mechanism and pathological change of CHL. However, precise anatomical view of the hepatic sinusoid has been limited by the resolution and contrast available from existing imaging techniques. While liver biopsy has traditionally been the reliable method for the assessment of hepatic sinusoids, the invasiveness and sampling error are its inherent limitations. In this study, imaging of CHL samples was performed using in-line phase-contrast imaging (ILPCI technique with synchrotron radiation. ILPCI allowed clear visualization of soft tissues and revealed structural details that were invisible to conventional radiography. Combining the computed tomography (CT technique, ILPCI-CT was used to acquire the high-resolution micro-CT images of CHL, and three dimensional (3D microstructures of hepatic sinusoids were provided for the morphologic depiction and quantitative assessment. Our study demonstrated that ILPCI-CT could substantially improve the radiographic contrast of CHL tissues in vitro with no contrast agent. ILPCI-CT yielded high-resolution micro-CT image of CHL sample at the micron scale, corresponding to information on actual structures revealed at histological section. The 3D visualization provided an excellent view of the hepatic sinusoid. The accurate view of individual hepatic sinusoid was achieved. The valuable morphological parameters of hepatic sinusoids, such as thrombi, diameters, surface areas and volumes, were measured. These parameters were of great importance in the evaluation of CHL, and they provided quantitative descriptors that characterized anatomical properties and pathological features of hepatic sinusoids. The results highlight the high degree of sensitivity of the ILPCI-CT technique and demonstrate the feasibility of accurate visualization of hepatic

  20. Wave Propagation in an Ion Beam-Plasma System

    DEFF Research Database (Denmark)

    Jensen, T. D.; Michelsen, Poul; Juul Rasmussen, Jens

    1979-01-01

    The spatial evolution of a velocity- or density-modulated ion beam is calculated for stable and unstable ion beam plasma systems, using the linearized Vlasov-Poisson equations. The propagation properties are found to be strongly dependent on the form of modulation. In the case of velocity...... modulation, the perturbation grows initially and then shows a periodic change of amplitude along the beam, while in the case of a density modulation only an instability causes growth. The findings are in agreement with experimental results obtained by SATO et al. (1977)....

  1. Molecular beam sampling system with very high beam-to-background ratio: The rotating skimmer concept

    International Nuclear Information System (INIS)

    A novel method of reducing the background pressure in a vacuum system used for sampling a molecular beam from a high pressure region is presented. A triple differential pumping stage is constructed with a chopper with rotating skimmer within the first pumping stage, which serves effectively as a valve separating periodically the vacuum system from the ambient environment. The mass spectrometry measurement of the species in the molecular beam show an excellent beam-to-background ratio of 14 and a detection limit below 1 ppm. The potential of this method for detection of low density reactive species in atmospheric pressure plasmas is demonstrated for the detection of oxygen atoms generated in an atmospheric pressure microplasma source.

  2. A large distributed digital camera system for accelerator beam diagnostics

    Science.gov (United States)

    Catani, L.; Cianchi, A.; Di Pirro, G.; Honkavaara, K.

    2005-07-01

    Optical diagnostics, providing images of accelerated particle beams using radiation emitted by particles impinging a radiator, typically a fluorescent screen, has been extensively used, especially on electron linacs, since the 1970's. Higher intensity beams available in the last decade allow extending the use of beam imaging techniques to perform precise measurements of important beam parameters such as emittance, energy, and energy spread using optical transition radiation (OTR). OTR-based diagnostics systems are extensively used on the superconducting TESLA Test Facility (TTF) linac driving the vacuum ultraviolet free electron laser (VUV-FEL) at the Deutsches Elektronen-Synchrotron facility. Up to 30 optical diagnostic stations have been installed at various positions along the 250-m-long linac, each equipped with a high-performance digital camera. This paper describes the new approach to the design of the hardware and software setups required by the complex topology of such a distributed camera system.

  3. A large distributed digital camera system for accelerator beam diagnostics

    International Nuclear Information System (INIS)

    Optical diagnostics, providing images of accelerated particle beams using radiation emitted by particles impinging a radiator, typically a fluorescent screen, has been extensively used, especially on electron linacs, since the 1970's. Higher intensity beams available in the last decade allow extending the use of beam imaging techniques to perform precise measurements of important beam parameters such as emittance, energy, and energy spread using optical transition radiation (OTR). OTR-based diagnostics systems are extensively used on the superconducting TESLA Test Facility (TTF) linac driving the vacuum ultraviolet free electron laser (VUV-FEL) at the Deutsches Elektronen-Synchrotron facility. Up to 30 optical diagnostic stations have been installed at various positions along the 250-m-long linac, each equipped with a high-performance digital camera. This paper describes the new approach to the design of the hardware and software setups required by the complex topology of such a distributed camera system

  4. Upgrade of Beam Energy Measurement System at BEPC-II

    CERN Document Server

    Zhang, Jian-Yong; Mo, Xiao-Hu; Guo, Di-Zhou; Wang, Jian-Li; Liu, Bai-Qi; Achasov, M N; Krasnov, A A; Muchnoi, N Yu; Pyata, E E; Mamoshkina, E V; Harris, F A

    2015-01-01

    The beam energy measurement system is of great importance and profit for both BEPC-II accelerator and BES-III detector. The system is based on measuring the energies of Compton back-scattered photons. Many advanced techniques and precise instruments are employed to realize the highly accurate measurement of positron/electron beam energy. During five year's running period, in order to meet the requirement of data taking and improve the capacity of measurement itself, the upgradation of system is continued, which involve the component reformation of laser and optics subsystem, replacement of view-port of the laser to vacuum insertion subsystem, the purchase of electric cooling system for high purity germanium detector, and the improvement of data acquisition and processing subsystem. The upgrading of system guarantees the smooth and efficient measuring of beam energy at BEPC-II and accommodates the accurate offline energy values for further physics analysis at BES-III.

  5. Electron beam diagnostic system using computed tomography and an annular sensor

    Energy Technology Data Exchange (ETDEWEB)

    Elmer, John W.; Teruya, Alan T.

    2015-08-11

    A system for analyzing an electron beam including a circular electron beam diagnostic sensor adapted to receive the electron beam, the circular electron beam diagnostic sensor having a central axis; an annular sensor structure operatively connected to the circular electron beam diagnostic sensor, wherein the sensor structure receives the electron beam; a system for sweeping the electron beam radially outward from the central axis of the circular electron beam diagnostic sensor to the annular sensor structure wherein the electron beam is intercepted by the annular sensor structure; and a device for measuring the electron beam that is intercepted by the annular sensor structure.

  6. Electron beam diagnostic system using computed tomography and an annular sensor

    Science.gov (United States)

    Elmer, John W.; Teruya, Alan T.

    2014-07-29

    A system for analyzing an electron beam including a circular electron beam diagnostic sensor adapted to receive the electron beam, the circular electron beam diagnostic sensor having a central axis; an annular sensor structure operatively connected to the circular electron beam diagnostic sensor, wherein the sensor structure receives the electron beam; a system for sweeping the electron beam radially outward from the central axis of the circular electron beam diagnostic sensor to the annular sensor structure wherein the electron beam is intercepted by the annular sensor structure; and a device for measuring the electron beam that is intercepted by the annular sensor structure.

  7. Beam transport optics for high-power laser systems

    International Nuclear Information System (INIS)

    Beam transport optics receive output energy from the laser cavity and deliver it to the work site. Depending on the application, this may require a few simple elements or large complex systems. Collection of the laser energy depends on the spatial and temporal energy distribution as well as the wavelength and polarization of the laser cavity and output coupler. Transport optics can perform a variety of functions, including beam formatting, frequency doubling, and distribution to one or more work sites while maintaining or even improving the beam quality. The beam may be delivered to work sites as focused spots or images, projected to distant targets, or propagated through various media for sensing or photochemical processing. Design may involve optical modeling of the system, including diffraction effects and thermal management. A Gaussian beam profile is often used for convenience in modeling. When deviations from this ideal profile need to be considered, it is necessary to characterize the laser beam in detail. Design of the transport system requires understanding of the interaction of the laser energy with optical materials and components. Practical considerations include mounting the optics without stress and with the stability suitable for the intended application. Requirements for beam direction, stability, size, shape, and quality dictate the design approach for each specific situation. Attention also must be given to reliability, environmental, and commercial requirements. Damage to optics in high-power laser systems is a common concern. Environmental problems such as atmospheric turbulence, contamination by dust or vapor from the work site or other sources, or absorption of water vapor can directly degrade beam quality. Other potentially significant optical performance effects may result from instability and aging of the optics, temperature, humidity, pressure, transmitted vibration, and contamination from the work site or other sources

  8. A micromechanical beam-steering device for terahertz systems

    OpenAIRE

    Drysdale, T.D.; Cumming, D.R.S.

    2004-01-01

    Beam-steering techniques are required to fully exploit terahertz imaging systems. We propose and model a device employing artificial dielectric techniques to provide a variable phase-control medium. The device consists of two interlocking artificial dielectric surfaces that are initially aligned parallel to each other. By mechanically introducing a relative tilt between the plates, a transmitted wave is subjected to a graded phase delay and thus the beam is steered away from the normal. Conti...

  9. Beam commissioning of KEKB crab cavity RF system

    International Nuclear Information System (INIS)

    KEKB started the first crab crossing operation in February 2007 with two superconducting crab cavities. After four months operation dedicated for machine tuning, physics run with high-current beams resumed in October with the crab crossing. The crab cavities have been working stably for one and a half years. The crab cavity RF system, commissioning process and performance of the crab cavities with high-current beams are presented. (author)

  10. ISABELLE accelerator software, control system, and beam diagnostic philosophy

    International Nuclear Information System (INIS)

    The ISABELLE Project combines two large proton accelerators with two storage rings in the same facility using superconducting magnet technology. This combination leads to severe constraints on beam loss in magnets and involves complex treatment of magnetic field imperfections and correction elements. The consequent demands placed upon beam diagnostics, accelerator model programs, and the computer oriented control system are discussed in terms of an illustrative operation scenario

  11. Development of a Micro-Computed Tomography-Based Image-Guided Conformal Radiotherapy System for Small Animals

    International Nuclear Information System (INIS)

    Purpose: To report on the physical aspects of a system in which radiotherapy functionality was added to a micro-computed tomography (microCT) scanner, to evaluate the accuracy of this instrument, and to and demonstrate the application of this technology for irradiating tumors growing within the lungs of mice. Methods and Materials: A GE eXplore RS120 microCT scanner was modified by the addition of a two-dimensional subject translation stage and a variable aperture collimator. Quality assurance protocols for these devices, including measurement of translation stage positioning accuracy, collimator aperture accuracy, and collimator alignment with the X-ray beam, were devised. Use of this system for image-guided radiotherapy was assessed by irradiation of a solid water phantom as well as of two mice bearing spontaneous MYC-induced lung tumors. Radiation damage was assessed ex vivo by immunohistochemical detection of γH2AX foci. Results: The positioning error of the translation stage was found to be <0.05 mm, whereas after alignment of the collimator with the X-ray axis through adjustment of its displacement and rotation, the collimator aperture error was <0.1 mm measured at isocenter. Computed tomography image-guided treatment of a solid water phantom demonstrated target localization accuracy to within 0.1 mm. Gamma-H2AX foci were detected within irradiated lung tumors in mice, with contralateral lung tissue displaying background staining. Conclusions: Addition of radiotherapy functionality to a microCT scanner is an effective means of introducing image-guided radiation treatments into the preclinical setting. This approach has been shown to facilitate small-animal conformal radiotherapy while leveraging existing technology.

  12. IFMIF-LIPAc Beam Diagnostics. Profiling and Loss Monitoring Systems

    International Nuclear Information System (INIS)

    The IFMIF accelerator will accelerate two 125 mA continuous wave (cw) deuteron beams up to 40 MeV and blasts them onto a liquid lithium target to release neutrons. The very high beam power of 10 MW pose unprecedented challenges for the accelerator development. Therefore, it was decided to build a prototype accelerator, the Linear IFMIF Prototype Accelerator (LIPAc), which has the very same beam characteristic, but is limited to 9 MeV only. In the frame of this thesis, diagnostics devices for IFMIF and LIPAc have been developed. The diagnostics devices consist of beam loss monitors and interceptive as well as non-interceptive profile monitors. For the beam loss monitoring system, ionization chambers and diamond detectors have been tested and calibrated for neutron and γ radiation in the energy range expected at LIPAc. During these tests, for the first time, diamond detectors were successfully operated at cryogenic temperatures. For the interceptive profilers, thermal simulations were performed to ensure safe operation. For the non-interceptive profiler, Ionization Profile Monitors (IPMs) were developed. A prototype has been built and tested, and based on the findings, the final IPMs were designed and built. To overcome the space charge of accelerator beam, a software algorithm was written to reconstruct the actual beam profile. (author)

  13. A set of dosimetry systems for electron beam irradiation

    International Nuclear Information System (INIS)

    To follow the rapid development of radiation processing with electron beams, it is urgent to set up a set of dosimetric standards to provide Quality Assurance (QA) of electron beam irradiation and unify the values of the quality of the absorbed dose measurements for electron beams. This report introduces a set of dosimetry systems established in Radiometrology Center of China Institute of Atomic Energy (RCCIAE), which have been or will be used as dosimetric standards in the Nuclear Industry System (NIS) in China. For instance, the potassium (silver) dichromate and ceric-cerous sulfate dosimetry systems will be used as standard dosimeters, while alanine-ESR dosimetry system as a transfer dosimeter, and FJL-01 CTA as a routine dosimeter. (author)

  14. A beam position monitor system for electron cooler in HIRFL-CSR

    International Nuclear Information System (INIS)

    The efficient electron cooling requires that the ion beam and electron beam are parallel and overlapped. In order to measure the positions of ion beam and electron beam simultaneously, a beam position monitor system is developed for the HIRFL-CSR electron cooler device, which probe consists of four capacitive cylinder linear-cut poles. One can get the both beam positions from the picking up signals of four poles by using Fourier transform (FFT) method. The measurement results show that the beam position monitor system is accurate. This system is suitable for investigating the relation between electron cooling processing and the angle of ion beam and electron beam. (authors)

  15. Absolute nodal coordinate plane beam formulation for multibody systems dynamics

    International Nuclear Information System (INIS)

    A new plane beam dynamic formulation for constrained multibody system dynamics is developed. Flexible multibody system dynamics includes rigid body dynamics and superimposed vibratory motions. The complexity of mechanical system dynamics originates from rotational kinematics, but the natural coordinate formulation does not use rotational coordinates, so that simple dynamic formulation is possible. These methods use only translational coordinates and simple algebraic constraints. A new formulation for plane flexible multibody systems are developed utilizing the curvature of a beam and point masses. Using absolute nodal coordinates, a constant mass matrix is obtained and the elastic force becomes a nonlinear function of the nodal coordinates. In this formulation, no infinitesimal or finite rotation assumptions are used and no assumption on the magnitude of the element rotations is made. The distributed body mass and applied forces are lumped to the point masses. Closed loop mechanical systems consisting of elastic beams can be modeled without constraints since the loop closure constraints can be substituted as beam longitudinal elasticity. A curved beam is modeled automatically. Several numerical examples are presented to show the effectiveness of this method.

  16. Absolute nodal coordinate plane beam formulation for multibody systems dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Souh, Byungyil, E-mail: bysouh@dyu.ac.kr [Dongyang University (Korea, Republic of)

    2013-06-15

    A new plane beam dynamic formulation for constrained multibody system dynamics is developed. Flexible multibody system dynamics includes rigid body dynamics and superimposed vibratory motions. The complexity of mechanical system dynamics originates from rotational kinematics, but the natural coordinate formulation does not use rotational coordinates, so that simple dynamic formulation is possible. These methods use only translational coordinates and simple algebraic constraints. A new formulation for plane flexible multibody systems are developed utilizing the curvature of a beam and point masses. Using absolute nodal coordinates, a constant mass matrix is obtained and the elastic force becomes a nonlinear function of the nodal coordinates. In this formulation, no infinitesimal or finite rotation assumptions are used and no assumption on the magnitude of the element rotations is made. The distributed body mass and applied forces are lumped to the point masses. Closed loop mechanical systems consisting of elastic beams can be modeled without constraints since the loop closure constraints can be substituted as beam longitudinal elasticity. A curved beam is modeled automatically. Several numerical examples are presented to show the effectiveness of this method.

  17. High-speed screen beam-profile-monitor system for high-energy beam-transport line at the HIMAC

    International Nuclear Information System (INIS)

    A screen monitor system was developed for beam profile monitors at the new High-Energy Beam-Transport (HEBT) section out the HIMAC. This monitor consists of the very thin fluorescent screen and the high-speed CCD camera. In addition to perform high-speed and high-resolution, this monitor does not almost destroy the beam. (author)

  18. An automatic beam steering system for the NSLS X-17T beam line using closed orbit feedback

    International Nuclear Information System (INIS)

    Initial observations of motion of the undulator radiation in the NSLS X-17T beam line clearly indicated that the beam had to be stabilized in both directions to be usable for the planned soft X-ray imaging experiments. The low frequency spectra of beam motion contained peaks in the range from dc to 60 Hz and at higher frequencies. A beam steering system employing closed orbit feedback has been designed and installed to stabilize the beam in both planes. In each plane of motion, beam position is measured with a beam position detector and a correction signal is fed back to a local four magnet orbit bump to dynamically control the angle of the radiation at the source. This paper describes the design and performance of the beam steering system

  19. Electromagnetic instability in an electron beam-ion channel system

    Science.gov (United States)

    Su, D.; Tang, C. J.

    2009-05-01

    The transverse electromagnetic instability in the electron beam-ion channel system is investigated using kinetic theory. The equilibrium distribution function of a relativistic electron beam, which takes into account a strong ion channel effect, is obtained. The linearized Vlasov equation is solved and the dispersion relation of the system is derived by perturbing the equilibrium with a high frequency electromagnetic wave (EMW). Analysis of the dispersion relation shows that the coupling of the electron beam with the transverse high frequency EMW is achieved through the deflection of the beam electrons due to the synergistic effects of the transverse high frequency EMW and transverse betatron oscillation. The numerical calculation finds that a branch of slow wave instability (SWI) with a wide frequency band is excited. The attenuation index of the SWI increases and its frequency band broadens as the normalized beam radii increases. Besides, the SWI will be suppressed as the longitudinal velocity of the electron beam increases to a certain value; meanwhile, a bunch of fast wave instability (FWI) is excited, which is equal to the increase of the relativistic factor. Also both the SWI and the FWI reach maximum when the EMW frequency meets a resonance condition.

  20. Electromagnetic instability in an electron beam-ion channel system

    International Nuclear Information System (INIS)

    The transverse electromagnetic instability in the electron beam-ion channel system is investigated using kinetic theory. The equilibrium distribution function of a relativistic electron beam, which takes into account a strong ion channel effect, is obtained. The linearized Vlasov equation is solved and the dispersion relation of the system is derived by perturbing the equilibrium with a high frequency electromagnetic wave (EMW). Analysis of the dispersion relation shows that the coupling of the electron beam with the transverse high frequency EMW is achieved through the deflection of the beam electrons due to the synergistic effects of the transverse high frequency EMW and transverse betatron oscillation. The numerical calculation finds that a branch of slow wave instability (SWI) with a wide frequency band is excited. The attenuation index of the SWI increases and its frequency band broadens as the normalized beam radii increases. Besides, the SWI will be suppressed as the longitudinal velocity of the electron beam increases to a certain value; meanwhile, a bunch of fast wave instability (FWI) is excited, which is equal to the increase of the relativistic factor. Also both the SWI and the FWI reach maximum when the EMW frequency meets a resonance condition.

  1. Rapid cycling medical synchrotron and beam delivery system

    Science.gov (United States)

    Peggs, Stephen G.; Brennan, J. Michael; Tuozzolo, Joseph E.; Zaltsman, Alexander

    2008-10-07

    A medical synchrotron which cycles rapidly in order to accelerate particles for delivery in a beam therapy system. The synchrotron generally includes a radiofrequency (RF) cavity for accelerating the particles as a beam and a plurality of combined function magnets arranged in a ring. Each of the combined function magnets performs two functions. The first function of the combined function magnet is to bend the particle beam along an orbital path around the ring. The second function of the combined function magnet is to focus or defocus the particle beam as it travels around the path. The radiofrequency (RF) cavity is a ferrite loaded cavity adapted for high speed frequency swings for rapid cycling acceleration of the particles.

  2. Instrumentation architecture for ITER diagnostic neutral beam power supply system

    International Nuclear Information System (INIS)

    A Neutral Beam (NB) Injection system is used for heating or diagnostics of the plasma in a Tokamak. The Diagnostics Neutral Beam (DNB) system for ITER (International Thermonuclear Experimental Reactor) based on acceleration of negative ions; injects a neutral (H0) beam at 100 KeV with specified modulation into the plasma for charge exchange recombination spectroscopy. DNB Power Supply (DNBPS) system consists of various high voltage power supplies, high current power supplies and RF Generators. The system operates in a given operating sequence; very high electromagnetic transients are intrinsically generated during frequent short circuit at the accelerator grid (breakdowns) and sudden loss of load (Beam off). Instrumentation is to be provided to operate the DNBPS system remotely with required control and protection in synchronisation with ITER operation as directed by CODAC (COntrol Data Access and Communication); the central control system for ITER. Instrumentation functionality includes 1. Operation and control of DNBPS subsystems and associated auxiliaries 2. Protection of DNB components and power supplies using interlock system, 3. To ensure safe operation of high voltage hazardous systems 4. Acquisition of injector performance parameters and 5. To facilitate test and maintenance of individual subsystem. This paper discusses about proposed DNBPS instrumentation architecture. The design generally follows the protocols from the ITER- Plant Control Design Handbook (PCDH). (author)

  3. A high energy neutral beam system for reactors

    International Nuclear Information System (INIS)

    High energy neutral beams provide a promising method of heating and driving current in steady-stage tokamak fusion reactors. As an example, we have made a conceptual design of a neutral beam system for current drive on the International Thermonuclear Experimental Reactor (ITER). The system, based on electrostatic acceleration of Dions, can deliver up to 100 MW of 1.6 MeV Do neutrals through three ports. Radiation protection is provided by locating sensitive beamlime components 35 to 50 m from the reactor. In an application to a 3300 MW power reactor, a system delivering 120 MW of 2-2.4 MeV deuterium beams assisted by 21 MW of lower hybrid wave power drives 25 MA provides an adequate plasma power again (Q = 24) for a commercial fusion power plant. (author). 8 refs.; 1 fig.; 2 tabs

  4. A mass sensitivity analysis of lunar orbiting beam power systems

    Science.gov (United States)

    Stavnes, Mark W.; Cull, Ronald C.

    1991-01-01

    At NASA Lewis Research Center, the feasibility of beaming power from orbiting satellites to the surface of the moon was studied. Reference microwave and laser beam power concepts were found to be 1/3 to 1/6 the mass of surface solar systems. Further analysis was performed to determine the sensitivity of the reference concepts to technology performance levels and mission architecture scenarios, such as beaming to multiple surface sites and lunar rovers. Previous studies concluded that frequencies above 35 GHz for the microwave systems were not critical for reducing the main base mass; however, when multiple sites and rovers are considered, this may become necessary. In addition, for the laser system, the pointing accuracy of the satellites becomes a critical factor for rover applications. These issues and other important results of the parametric studies, are discussed.

  5. Neutron imaging system for neutron tomography, radiography, and beam diagnostics

    International Nuclear Information System (INIS)

    A neutron imaging system (NIS) has been recently installed at the University of Texas TRIGA reactor facility. The imaging system establishes new capabilities for beam diagnostics at the Texas Cold Neutron Source (TCNS) for real-time neutron radiography (RTNR) and for neutron computed tomography (NCT) research. The NIS will also be used for other research projects. The system consists of two subsystems as follows: (1) Thomson 9-in. neutron image intensifier (NII) tube sensitive to cold, thermal, and epithermal neutrons, (2) image-processing unit consisting of vidicon camera, two high-resolution monitors, image enhancement and measurement processor, and video printer. The NIS is installed at the cold neutron beam of the TCNS for testing and cold neutron beam diagnostics

  6. 3D strain measurement in soft tissue: demonstration of a novel inverse finite element model algorithm on MicroCT images of a tissue phantom exposed to negative pressure wound therapy.

    Science.gov (United States)

    Wilkes, R; Zhao, Y; Cunningham, K; Kieswetter, K; Haridas, B

    2009-07-01

    This study describes a novel system for acquiring the 3D strain field in soft tissue at sub-millimeter spatial resolution during negative pressure wound therapy (NPWT). Recent research in advanced wound treatment modalities theorizes that microdeformations induced by the application of sub-atmospheric (negative) pressure through V.A.C. GranuFoam Dressing, a reticulated open-cell polyurethane foam (ROCF), is instrumental in regulating the mechanobiology of granulation tissue formation [Saxena, V., Hwang, C.W., Huang, S., Eichbaum, Q., Ingber, D., Orgill, D.P., 2004. Vacuum-assisted closure: Microdeformations of wounds and cell proliferation. Plast. Reconstr. Surg. 114, 1086-1096]. While the clinical response is unequivocal, measurement of deformations at the wound-dressing interface has not been possible due to the inaccessibility of the wound tissue beneath the sealed dressing. Here we describe the development of a bench-test wound model for microcomputed tomography (microCT) imaging of deformation induced by NPWT and an algorithm set for quantifying the 3D strain field at sub-millimeter resolution. Microdeformations induced in the tissue phantom revealed average tensile strains of 18%-23% at sub-atmospheric pressures of -50 to -200 mmHg (-6.7 to -26.7 kPa). The compressive strains (22%-24%) and shear strains (20%-23%) correlate with 2D FEM studies of microdeformational wound therapy in the reference cited above. We anticipate that strain signals quantified using this system can then be used in future research aimed at correlating the effects of mechanical loading on the phenotypic expression of dermal fibroblasts in acute and chronic ulcer models. Furthermore, the method developed here can be applied to continuum deformation analysis in other contexts, such as 3D cell culture via confocal microscopy, full scale CT and MRI imaging, and in machine vision. PMID:19627832

  7. Configuration and Validation of the LHC Beam Loss Monitoring System

    CERN Document Server

    Zamantzas, C; Emery, J; Fitzek, J; Follin, F; Jackson, S; Kain, V; Kruk, G; Misiowiec, M; Roderick, C; Sapinski, M

    2009-01-01

    The LHC Beam Loss Monitoring (BLM) system is one of the most complex instrumentation systems deployed in the LHC. As well as protecting the machine, the system is also used as a means of diagnosing machine faults, and providing feedback of losses to the control room and several systems such as the Collimation, the Beam Dump and the Post-Mortem. The system has to transmit and process signals from over 4’000 monitors, and has approaching 3 million configurable parameters. This paper describes the types of configuration data needed, the means used to store and deploy all the parameters in such a distributed system and how operators are able to alter the operating parameters of the system, particularly with regard to the loss threshold values. The various security mechanisms put in place, both at the hardware and software level, to avoid accidental or malicious modification of these BLM parameters are also shown for each case.

  8. First Experience with the LHC Beam Loss Monitoring System

    CERN Document Server

    Böhlen, T; Effinger, E; Emery, J; Follin, F; Holzer, E; Jackson, S; Kramer, Daniel; Kruk, G; Le Roux, P; Mariethoz, J; Misiowiec, M; Ponce, L; Roderick, C; Sapinski, M; Zamantzas, C; Stockner, M; Bocian, D; Grishin, V; Ikeda, H; Priebe, A

    2010-01-01

    The LHC beam loss monitoring system (BLM) consists of about 4000 monitors observing losses at all quadrupole magnets and many other likely loss locations. At the first LHC operation in August and September 2008 all monitors were active and used to observe the losses during the initial beam steerings, at collimators, at the LHC dump and during aperture scans. The different acquisition modes and their presentation are shown. Aperture scan loss patterns and a detailed loss pattern leading to a magnet quench are discussed. The observed signals of the BLM system are analyzed in terms of response time, sensitivity and noise performance.

  9. Distributed real time TV system for beam diagnostics

    International Nuclear Information System (INIS)

    The work is aimed at describing the distributed TV-system for the beam real time diagnostics. The Component Object Model (COM) was selected as the must general technology for the architectural program software basis for the Windows. Special attention is paid to the errors treatment. General peculiarities of the TV-systems application for measuring the beam parameters are identified. The conclusion is made, that this methodology may be used for provision of excellent accuracy of measurements under the condition of careful equipment selection

  10. A Versatile Beam Loss Monitoring System for CLIC

    CERN Document Server

    Kastriotou, Maria; Farabolini, Wilfrid; Holzer, Eva Barbara; Nebot Del Busto, Eduardo; Tecker, Frank; Welsch, Carsten

    2016-01-01

    The design of a potential CLIC beam loss monitoring (BLM) system presents multiple challenges. To successfully cover the 48 km of beamline, ionisation chambers and optical fibre BLMs are under investigation. The former fulfils all CLIC requirements but would need more than 40000 monitors to protect the whole facility. For the latter, the capability of reconstructing the original loss position with a multi-bunch beam pulse and multiple loss locations still needs to be quantified. Two main sources of background for beam loss measurements are identified for CLIC. The two-beam accelerator scheme introduces so-called crosstalk, i.e. detection of losses originating in one beam line by the monitors protecting the other. Moreover, electrons emitted from the inner surface of RF cavities and boosted by the high RF gradients may produce signals in neighbouring BLMs, limiting their ability to detect real beam losses. This contribution presents the results of dedicated experiments performed in the CLIC Test Facility to qu...

  11. Fibre Monitoring System for the Beam Permit Loops at the LHC and Future Evolution of the Beam Interlock System

    CERN Document Server

    García-Argos, Carlos; Gabourin, Stéphane; Martin, Christophe; Puccio, Bruno; Siemko, Andrzej P

    2015-01-01

    The optical fibres that transmit the beam permit loop signals at the CERN accelerator complex are deployed along radiation areas. This may result in increased attenuation of the fibres, which reduces the power margin of the links. In addition, other events may cause the links to not function properly and result in false dumps, reducing the availability of the accelerator chain and affecting physics data taking. In order to evaluate the state of the fibres, an out-of-band fibre monitoring system is proposed, working in parallel to the actual beam permit loops. The future beam interlock system to be deployed during LHC long shutdown 2 will implement online, real-time monitoring of the fibres, a feature the current system lacks. Commercial off-the-shelf components to implement the optical transceivers are proposed whenever possible instead of ad-hoc designs.

  12. Model calibration and beam control systems for storage rings

    International Nuclear Information System (INIS)

    Electron beam storage rings and linear accelerators are rapidly gaining worldwide popularity as scientific devices for the production of high-brightness synchrotron radiation. Today, everybody agrees that there is a premium on calibrating the storage ring model and determining errors in the machine as soon as possible after the beam is injected. In addition, the accurate optics model enables machine operators to predictably adjust key performance parameters, and allows reliable identification of new errors that occur during operation of the machine. Since the need for model calibration and beam control systems is common to all storage rings, software packages should be made that are portable between different machines. In this paper, we report on work directed toward achieving in-situ calibration of the optics model, detection of alignment errors, and orbit control techniques, with an emphasis on developing a portable system incorporating these tools

  13. Electronics and Calibration system for the CMS Beam Halo Monitor

    CERN Document Server

    Tosi, Nicolò; Fabbri, Franco L; Finkel, Alexey; Orfanelli, Stella; Loos, R; Montanari, Alessandro; Rusack, R; Stickland, David P

    2014-01-01

    In the context of increasing luminosity of LHC, it will be important to accurately measure the Machine Induced Background. A new monitoring system will be installed in the cavern of the Compact Muon Solenoid (CMS) experiment for measuring the beam background at high radius. This detector is composed of synthetic quartz Cherenkov radiators, coupled to fast photomultiplier tubes (PMT). The readout chain of this detector will make use of many components developed for the Phase 1 upgrade to the CMS Hadron Calorimeter electronics, with a dedicated firmware and readout adapted to the beam monitoring requirements. The PMT signal will be digitized by a charge integrating ASIC (QIE10), providing both the signal rise time and the charge integrated over one bunch crossing. The backend electronics will record bunch-by-bunch histograms, which will be published to CMS and the LHC using the newly designed CMS beam instrumentation specific DAQ. A calibration monitoring system has been designed to generate triggered pulses of...

  14. Instrumentation system for long-pulse MFTF neutral beams

    International Nuclear Information System (INIS)

    The instrumentation system for long pulse neutral beams for MFTFS consists of monitoring and protective circuitry. Global synchronization of high speed monitoring data across twenty-four neutral beams is achieved via an experiment wide fiber optic timing system. Fiber optics are also used as a means of isolating signals at elevated voltages. An excess current monitor, interrupt monitor, sparkdown detector, spot detector and gradient grid ratio detector form the primary protection for the neutral beam source. A unique hierarchical interlocking scheme allows other protective devices to be factored into the shutdown circuitry of the power supply so that the initiating cause of a shutdown can be isolated and even allows some non-critical devices to be safely ignored for a period of time

  15. Large area, direct write focused ion beam lithography system

    International Nuclear Information System (INIS)

    A system for maskless ion beam milling based on a high brightness RF plasma ion source and a compact focusing column using electrostatic elements is designed and developed. So far 1.5 μm spot size with current density of 350 mA/cm2 could be achieved. Pattering is carried out by scanning the sample using high precision 3-axis stage. The size of the micropattering area is only limited by the span of the translation stage which is 25 mm x 25 mm in our case. Measurements to estimate the focused spot size and ion beam profile at the focal plane are carried out by using knife edge scanning method. This article describes the micromachining system, a few examples of micro pattering and possible future programs. This paper also addresses a few issues on focusing low energy beam from plasma sources to micron and submicron dimensions and challenges of measuring their sizes. (author)

  16. Progress on the development of APS beam position monitoring system

    International Nuclear Information System (INIS)

    This paper describes the development status of the beam position monitoring system for the Advanced Photon Source (APS), a third-generation light source now under construction at Argonne National Laboratory. The accelerator complex will consist of an electron linac, a positron linac, a positron accumulator ring (PAR), an injector synchrotron and a storage ring. For beam position measurement, striplines will be used on the linacs, while button-type pickups will be used on the injector synchrotron and the storage ring. A test stand with a prototype injector synchrotron beam position monitor (BPM) unit has been built, and we present the results of position calibration measurements using a wire. Comparison of the results with theoretical calculations will be presented. The current effort on similar storage ring BPM system measurements will also be discussed. 4 refs., 5 figs., 2 tabs

  17. Development of KOMAC Beam Monitoring System Using EPICS

    International Nuclear Information System (INIS)

    The beam loss signals must be digitized and the sampling has to be synchronized to a reference signal which is an external trigger for beam operation. The digitized data must be accessible by the Experimental Physics and Industrial Control System (EPICS)-based control system, which manages the whole accelerator control. In order to satisfy the requirement, an Input /Output Controller (IOC), which runs Linux on a CPU module with PCI express based Analog to Digital Converter (ADC) modules, has been adopted. An associated linux driver and EPICS device support module also have been developed. The IOC meets the requirements and the development and maintenance of the software for the IOC is considerably efficient. The data acquisition system running EPICS will be used in increasing phase of KOrea Multi-purpose Accelerator Complex (KOMAC) beam power. The beam monitoring system integrates BLM and BPM signals into control system and offers real-time data to operators. The IOC, which is implemented with Linux and PCI driver, has supported data acquisition as a very flexible solution

  18. Development of KOMAC Beam Monitoring System Using EPICS

    Energy Technology Data Exchange (ETDEWEB)

    Song, Young-Gi; Yun, Sang-Pil; Kim, Han-Sung; Kwon, Hyeok-Jung; Cho, Yong-Sub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    The beam loss signals must be digitized and the sampling has to be synchronized to a reference signal which is an external trigger for beam operation. The digitized data must be accessible by the Experimental Physics and Industrial Control System (EPICS)-based control system, which manages the whole accelerator control. In order to satisfy the requirement, an Input /Output Controller (IOC), which runs Linux on a CPU module with PCI express based Analog to Digital Converter (ADC) modules, has been adopted. An associated linux driver and EPICS device support module also have been developed. The IOC meets the requirements and the development and maintenance of the software for the IOC is considerably efficient. The data acquisition system running EPICS will be used in increasing phase of KOrea Multi-purpose Accelerator Complex (KOMAC) beam power. The beam monitoring system integrates BLM and BPM signals into control system and offers real-time data to operators. The IOC, which is implemented with Linux and PCI driver, has supported data acquisition as a very flexible solution.

  19. Neutral beam control systems for the Tandem Mirror Experiment

    International Nuclear Information System (INIS)

    The Tandem Mirror Experiment (TMX) is presently developing the technology and approaches which will be used in larger fusion systems. This paper describes some of the designs which were used in creating the control system for the TMX neutral beams. To create a system of controls that would work near these large, rapid switching current sources required a mixture of different technologies: fiberoptic data transmission, printed circuit and wirewrap techniques, etc

  20. Active MMW/Terahertz Security System Based on Bessel Beams

    OpenAIRE

    Igor Minin; Oleg Minin

    2013-01-01

    The novel concept of the security system based on THz Bessel beams is offered. The system is based on a novel THz diffractive optics for scanning the person (without the application of THz laser) and on a sensitive scheme for the detection of the reflected and scattered THz radiation. The development of enabling technology, namely, sensitive detector arrays and Millimeter wave/THz diffractive optics, will allow building compact, easy-to-use millimeter wave/THz imaging systems without expensiv...

  1. Design study of a beam energy recovery system for a negative-ion-based neutral beam injector

    International Nuclear Information System (INIS)

    A beam energy recovery system for future neutral beam injectors based on negative ions has been designed. Residual negative ions are recovered electrically, while residual positive ions are decelerated on a soft-landing beam dump. This design simplifies the beam energy recovery power supply system an reduces the heat flux on the beam dump. Residual ions are separated into negative and positive ions by the stray magnetic field from the Fusion Engineering Reactor (FER). The next Japanese tokamak reactor. Each ion beam is also guided to the collector electrode and the soft-landing beam dump by the stray magnetic field. In the 500-keV/20-MW injector designed for FER, the total power efficiency can be improved from 46 to 59% by recovering the negative ions

  2. Particle in cell simulations of beam plasma system

    International Nuclear Information System (INIS)

    The propagation of relativistic electron beam in dense plasma is studied with the help of Particle in Cell simulations for both 2D and 3D configurations. The background plasma system provides for the return currents balancing the beam current. These two current systems are unstable to Weibel destabilization as a result of which the forward and return currents separate spatially. This leads to the generation of magnetic fields. The present paper focuses on the study of the spatial and temporal profiles of the generated magnetic fields. In the normal case of infinite and/or periodic simulation box with homogeneous plasma density the observed magnetic field dominates at the scale length of skin depth. The role of plasma density inhomogeneity and the finite transverse width of the beam electrons are investigated in the work. It is shown that when the plasma density inhomogeneity with scales sharper than the skin depth is chosen, the magnetic field structures with similar short scales form. It is also observed that when the beam width is finite magnetic fields with structures at the scale length of beam width form. (author)

  3. A molecular beam/quadrupole mass spectrometer system with synchronized beam modulation and digital waveform analysis

    Science.gov (United States)

    Pellett, G. L.; Adams, B. R.

    1983-01-01

    A performance evaluation is conducted for a molecular beam/mass spectrometer (MB/MS) system, as applied to a 1-30 torr microwave-discharge flow reactor (MWFR) used in the formation of the methylperoxy radical and a study of its subsequent destruction in the presence or absence of NO(x). The modulated MB/MS system is four-staged and differentially pumped. The results obtained by the MWFR study is illustrative of overall system performance, including digital waveform analysis; significant improvements over previous designs are noted in attainable S/N ratio, detection limit, and accuracy.

  4. MEMS-Based Optical Beam Steering System for Quantum Information Processing in 2D Atomic Systems

    OpenAIRE

    Knoernschild, Caleb; Kim, Changsoon; Liu, Bin; Lu, Felix P.; Kim, Jungsang

    2007-01-01

    In order to provide scalability to quantum information processors utilizing trapped atoms or ions as quantum bits (qubits), the capability to address multiple individual qubits in a large array is needed. Micro-electromechanical systems (MEMS) technology can be used to create a flexible and scalable optical system to direct the necessary laser beams to multiple qubit locations. We developed beam steering optics using controllable MEMS mirrors that enable one laser beam to address multiple qub...

  5. A safety system for a laser-beam utilising facility

    International Nuclear Information System (INIS)

    A safety system for a laser-beam utilising facility incorporates a safety enclosure and an infra-red monitoring system for detecting the development of hot spots at internal surfaces of the enclosure walls and ceiling which may occur as a result of stray laser radiation impinging on such surfaces. The development of a hot spot leads to shutting off the laser source or interruption of the beams by means of a shutter. The facility may be a welding or cutting apparatus and may be used with nuclear fuel elements. The monitoring system may be a scanning system. Two such scanning systems may be provided, scanning at different speeds, to detect respectively hot spots and the presence of a human body within the safety enclosure. (author)

  6. Computer and network applications in beam measurement system of accelerator

    International Nuclear Information System (INIS)

    The applications of computer and its network in beam measurement system for Beijing Electron Positron Collider (BEPC) are described. It includes the instrumentation interfaces, the hardware and software implementations for the network connection between microcomputers and VAX series minicomputers. The communication program using Windows socket, a network programming interface for Microsoft Windows, are also described

  7. A scanned beam THz imaging system for medical applications

    Science.gov (United States)

    Taylor, Zachary D.; Li, Wenzao; Suen, Jon; Tewari, Priyamvada; Bennett, David; Bajwa, Neha; Brown, Elliott; Culjat, Martin; Grundfest, Warren; Singh, Rahul

    2011-10-01

    THz medical imaging has been a topic of increased interest recently due largely to improvements in source and detector technology and the identification of suitable applications. One aspect of THz medical imaging research not often adequately addressed is pixel acquisition rate and phenomenology. The majority of active THz imaging systems use translation stages to raster scan a sample beneath a fixed THz beam. While these techniques have produced high resolution images of characterization targets and animal models they do not scale well to human imaging where clinicians are unwilling to place patients on large translation stages. This paper presents a scanned beam THz imaging system that can acquire a 1 cm2 area with 1 mm2 pixels and a per-pixel SNR of 40 dB in less than 5 seconds. The system translates a focused THz beam across a stationary target using a spinning polygonal mirror and HDPE objective lens. The illumination is centered at 525 GHz with ~ 125 GHz of response normalized bandwidth and the component layout is designed to optically co-locate the stationary source and detector ensuring normal incidence across a 50 mm × 50 mm field of view at standoff of 190 mm. Component characterization and images of a test target are presented. These results are some of the first ever reported for a short standoff, high resolution, scanned beam THz imaging system and represent an important step forward for practical integration of THz medical imaging where fast image acquisition times and stationary targets (patients) are requisite.

  8. A Laser Lock System using Multiple Overlapping Beams

    Science.gov (United States)

    Harper, Stuart; Francis, Ben; Erickson, Christopher; Durfee, Dallin

    2010-10-01

    We describe a system wherein the lock of trapping, ionizing, and ion resonance lasers for a Sr experiment are bootstrapped together in a single neutral atom vapor cell. This is done by overlapping beams to optically pump the atoms into the necessary states.

  9. Beam position monitor system of J-PARC RCS

    International Nuclear Information System (INIS)

    The J-PARC RCS is a 25 Hz Rapid-Cycling proton Synchrotron and its designed beam power is 1 MW. The beam position monitor (BPM) system at J-PARC RCS is described in this paper. The pre-defined diameter of the BPM detectors is larger than 250 mm, however, the system has to measure the beam position very accurately. In addition, it is necessary to have a large dynamic range. The system should work not only for the high intensity but also for low intensity, such as during beam commissioning, when the intensity is below 1% of the design intensity. There are 54 BPM detectors around the ring and most of them are placed inside steering magnets because of quite limited space. The BPM detector is an electro-static type and it has four electrodes, and a pair of electrodes gives a good linear response with a diagonal cut shape to detect the charge center precisely. The signal processing units, which are equipped with 14-bit 40 MS/s ADC and 600 MHz DSP, have been developed. They are accessed via shared memory space and controlled by EPICS. Such a processing unit is capable of recording the full 25 Hz pulse data for the so-called “COD mode” (averaged beam position calculation) and it can also store the whole waveform data for further analysis, like turn-by-turn position calculation. The resolution was estimated to be 20μm for “COD mode” and to be 0.3 mm for the turn-by-turn mode with relatively low intensity of 8×1011ppp. The position accuracy is estimated to be about 0.5 mm using a newly developed Beam Based Alignment (BBA) method.

  10. Rapid Process to Generate Beam Envelopes for Optical System Analysis

    Science.gov (United States)

    Howard, Joseph; Seals, Lenward

    2012-01-01

    The task of evaluating obstructions in the optical throughput of an optical system requires the use of two disciplines, and hence, two models: optical models for the details of optical propagation, and mechanical models for determining the actual structure that exists in the optical system. Previous analysis methods for creating beam envelopes (or cones of light) for use in this obstruction analysis were found to be cumbersome to calculate and take significant time and resources to complete. A new process was developed that takes less time to complete beam envelope analysis, is more accurate and less dependent upon manual node tracking to create the beam envelopes, and eases the burden on the mechanical CAD (computer-aided design) designers to form the beam solids. This algorithm allows rapid generation of beam envelopes for optical system obstruction analysis. Ray trace information is taken from optical design software and used to generate CAD objects that represent the boundary of the beam envelopes for detailed analysis in mechanical CAD software. Matlab is used to call ray trace data from the optical model for all fields and entrance pupil points of interest. These are chosen to be the edge of each space, so that these rays produce the bounding volume for the beam. The x and y global coordinate data is collected on the surface planes of interest, typically an image of the field and entrance pupil internal of the optical system. This x and y coordinate data is then evaluated using a convex hull algorithm, which removes any internal points, which are unnecessary to produce the bounding volume of interest. At this point, tolerances can be applied to expand the size of either the field or aperture, depending on the allocations. Once this minimum set of coordinates on the pupil and field is obtained, a new set of rays is generated between the field plane and aperture plane (or vice-versa). These rays are then evaluated at planes between the aperture and field, at a

  11. Daily check of the electron beams with a diode system

    Energy Technology Data Exchange (ETDEWEB)

    Pilette, P. [Hospital Civil de Charleroi (Belgium). Centre for Radiotherapy

    1995-12-01

    A fast systems to check all the accelerator beams on a daily basis has been developed. A cheap home-made detector, based on non-medical diodes (type 1N5408), has been used since July 1992 to verify all the electron beams every day. The relative energy and Top-cGy correspondence is verified with one single irradiation of less than 1 minute by 6 diodes fixed in a polystyrene phantom. The principle of construction, software implementation and results are presented.

  12. Steerable beam systems for electron cyclotron resonance heating

    International Nuclear Information System (INIS)

    Several methods are discussed for steering a 200 kW pencil beam of electromagnetic waves in the 60 GHz to 200 GHz frequency range. These include methods incorporating swivelling mirrors, phased arrays, mode converters, and optical materials. It is found that for the near term, the mechanical systems are best, capable of steering times of 3 ms to 100 ms and losses of less than 5%. Optical methods, as yet virtually uninvestigated, appear to offer the only means of beam-steering in the 5μs to 100μs range necessary for MHD mode tracking

  13. An electron beam treatment planning system based on CT images

    International Nuclear Information System (INIS)

    This is a report on the computerization of the electron beam treatment planning system at the Cancer Institute Hospital. The computer aided calculation of electron beam dose distributions utilizes table look-up and interpolation of measured central axis depth doses and off-center ratios (OCR). Inhomogeneity correction is applied by the absorption equivalent thickness (AET) method. When OCR is expressed as a function of x-L instead of x/L, OCR is nearly independent of field size and shape, where x is the distance of the point from the central axis and L is half width. (author)

  14. Effect of finite beam width on current separation in beam plasma system: Particle-in-Cell simulations

    CERN Document Server

    Shukla, Chandrasekhar; Patel, Kartik

    2015-01-01

    The electron beam propagation in a plasma medium is susceptible to several instabilities. In the relativistic regime typically the weibel instability leading to the current separation dominates. The linear instability analysis is carried out for a system wherein the transverse extent of the beam is infinite. Even in simulations, infinite transverse extent of the beam has been chosen. In real situations, however, beam width will always be finite. keeping this in view the role of finite beam width on the evolution of the beam plasma system has been studied here using Particle - in - Cell simulations. It is observed that the current separation between the forward and return shielding current for a beam with finite beam occurs at the scale length of the beam width itself. Consequently the magnetic field structures that form have maximum power at the scale length of the beam width. This behaviour is distinct from what happens with a beam with having an infinite extent represented by simulations in a periodic box, ...

  15. Active steering system for the neutral beam injector for ITER

    International Nuclear Information System (INIS)

    ITER requires an additional power injection of 33 MW from neutral beams, which can be provided by two injectors, delivering 16.5 MW each, having an ion current of 40 A and an accelerating voltage of 1 MV. The requirement of on-axis and off-axis injection into ITER is presently accomplished by mechanical tilting of the injector source. To preserve the integrity of the beam line components, on the horizontal plane, very tight misalignment is tolerable (±3 mrad); such accuracy requires precise installation of the components. Breaking the vacuum and executing a long series of operations is required to provide proper beam alignment. It would be helpful if such alignments could be performed remotely. A study has been conducted on the possibility of steering the negative ions by suitable magnetic fields, generated by dedicated coils located at the exit of the accelerator. It results that the magnetic system can meet the requirements in terms of beam alignment. The steering system will heavily affect the trajectory of the electrons extracted from the accelerator and can be used to deflect the electrons onto suitable dump plates. The system can steer the ions and dump the electrons in a controlled way, even in case of modulation of the acceleration voltage; a flexible beam aiming system can be used to adapt the power deposition profile in ITER to the plasma characteristics; active steering can provide a suitable way to control the power deposition with respect to the possibility of exciting Alfven eigenmodes, which can reduce the performances of ITER plasmas. The present contribution reviews the preliminary design of the active steering system and provides an analysis of advantages and disadvantages. (author)

  16. Physics Design Considerations of Diagnostic X Beam Transport System

    CERN Document Server

    Chen, Y J; Chen, Yu-Jiuan; Paul, Arthur C.

    2000-01-01

    Diagnostic X (D-X) transport system would extract the beam from the downstream transport line of the second- axis of the Dual Axis Radiographic Hydrodynamic Test facility (DARHT-II) and transport this beam to the D-X firing point via four branches of the beamline in order to provide four lines of sight for x-ray radiography. The design goal is to generate four DARHT-II-like x-ray pulses on each line of sight. In this paper, we discuss several potential beam quality degradation processes in the passive magnet lattice beamline and indicate how they constrain the D-X beamline design parameters, such as the background pressure, the pipe size, and the pipe material

  17. The software for the CERN LEP beam orbit measurement system

    International Nuclear Information System (INIS)

    The Beam Orbit Measurement (BOM) system of LEP consists of 504 pickups, distributed all around the accelerator, that are capable of measuring the positions of the two beams. Their activity has to be synchronized, and the data produced by them have to be collected together, for example to form a 'closed orbit measurement' or a 'trajectory measurement'. On the user side, several clients can access simultaneously the results from this instrument. An automatic acquisition mode, and an 'on request' one, can run in parallel. This results in a very flexible and powerful system. The functionality of the BOM system is fully described, as well as the structure of the software processes which constitute the system, and their interconnections. Problems solved during the implementation are emphasized. (author)

  18. Design of Database System of HIRFL-CSR Beam Line

    International Nuclear Information System (INIS)

    This paper introduces the database design and optimization for the power supply system of Lanzhou Heavy Ion Accelerator CSR (HIRFL-CSR) beam line. Based on HIFEL-CSR main Oracle database system, the interface was designed to read parameters of the power supply while achieving real-time monitoring. A new database system to store the history data of power supplies was established at the same time, and it realized the data exchange between Oracle database system and Access database system. Meanwhile, the interface was designed conveniently for printing and query parameters. (authors)

  19. Ion beam induced fluorescence imaging in biological systems

    International Nuclear Information System (INIS)

    Imaging fluorescence generated by MeV ions in biological systems such as cells and tissue sections requires a high resolution beam (<100 nm), a sensitive detection system and a fluorescent probe that has a high quantum efficiency and low bleaching rate. For cutting edge applications in bioimaging, the fluorescence imaging technique needs to break the optical diffraction limit allowing for sub-cellular structure to be visualized, leading to a better understanding of cellular function. In a nuclear microprobe this resolution requirement can be readily achieved utilizing low beam current techniques such as Scanning Transmission Ion Microscopy (STIM). In recent times, we have been able to extend this capability to fluorescence imaging through the development of a new high efficiency fluorescence detection system, and through the use of new novel fluorescent probes that are resistant to ion beam damage (bleaching). In this paper we demonstrate ion beam induced fluorescence imaging in several biological samples, highlighting the advantages and challenges associated with using this technique

  20. Low-energy High-current Electron Beam Generation in Plasma System and Beam-Plasma Interaction

    International Nuclear Information System (INIS)

    The review of results of experimental investigations and computer simulations of low-energy high-current electron beam generation in a low-impedance system and dynamics of beam-plasma system are given. The system includes a long plasma-filled diode, an auxiliary thermionic cathode and an explosive emission cathode. The auxiliary cathode is used to generate the a low-current, low-voltage electron beam to form long plasma anode by means of a residual gas ionisation in an external longitudinal magnetic field. The high-current low-energy electron beam is generated from the explosive emission cathode embedded in preliminary prepared plasma. Peculiarities of the system are due to: 1) the generation of electron beams with currents exceeding Alfven's limit; 2) the charge density of the beam close to the plasma density. These peculiarities complicate beam-plasma interaction significantly due to sharp non-uniform distribution of the beam current density, dominant transverse motion of the beam electrons and redistribution of ion-plasma density under the influence of fields. Computer simulation was performed using electromagnetic PIC code KARAT for different geometry's of the system

  1. A beam radiation monitoring and protection system for AGS secondary beams

    International Nuclear Information System (INIS)

    A commercially available radiation monitor using a scintillation detector was modified for charged particle beam monitoring. The device controls access to secondary beams of the AGS and limits beam intensity

  2. Modified read-out system of the beam phase measurement system for CSNS

    International Nuclear Information System (INIS)

    The customized beam phase measurement system can meet the requirement of beam loss control of the radio-frequency quadrupole (RFQ). However, its read-out part cannot satisfy the requirement of China Spallation Neutron Source (CSNS). CSNS uses the Experimental Physics and Industrial Control System (EPICS) as its control system. So it is necessary to develop the EPICS read-out system consisting of EPICS IOC databases, driver support and OPIs. The new system has been successfully tested in the RFQ. In the future, it will be applied to the beam diagnostics of CSNS. (authors)

  3. Tooth periodontal ligament: Direct 3D microCT visualization of the collagen network and how the network changes when the tooth is loaded.

    Science.gov (United States)

    Naveh, Gili R S; Brumfeld, Vlad; Shahar, Ron; Weiner, Steve

    2013-02-01

    The periodontal ligament (PDL), a soft tissue connecting the tooth and the bone, is essential for tooth movement, bone remodeling and force dissipation. A collagenous network that connects the tooth root surface to the alveolar jaw bone is one of the major components of the PDL. The organization of the collagenous component and how it changes under load is still poorly understood. Here using a state-of-the-art custom-made loading apparatus and a humidified environment inside a microCT, we visualize the PDL collagenous network of a fresh rat molar in 3D at 1 μm voxel size without any fixation or contrasting agents. We demonstrate that the PDL collagen network is organized in sheets. The spaces between sheets vary thus creating dense and sparse networks. Upon vertical loading, the sheets in both networks are stretched into well aligned arrays. The sparse network is located mainly in areas which undergo compressive loading as the tooth moves towards the bone, whereas the dense network functions mostly in tension as the tooth moves further from the bone. This new visualization method can be used to study other non-mineralized or partially mineralized tissues, and in particular those that are subjected to mechanical loads. The method will also be valuable for characterizing diseased tissues, as well as better understanding the phenotypic expressions of genetic mutants. PMID:23110851

  4. Investigation of water and CO{sub 2} (carbon dioxide) flooding using micro-CT (micro-computed tomography) images of Berea sandstone core using finite element simulations

    Energy Technology Data Exchange (ETDEWEB)

    Gunde, Akshay C.; Bera, Bijoyendra; Mitra, Sushanta K. [Department of Mechanical Engineering Micro and Nano-Scale Transport Laboratory, University of Alberta, Edmonton (Canada)

    2010-12-15

    The present study reports a numerical investigation of water and CO{sub 2} (carbon dioxide) flooding at the pore scale of a porous medium. We use high resolution micro-computed tomography (micro-CT) images of Berea sandstone core to obtain the pore geometry. The numerical solution used for the simulation was carried out by a finite element based software package. Level Set method is used to determine the position of the interface between two immiscible fluids when oil is displaced by water and CO{sub 2}, respectively. The present formulation is validated against single-phase flow through the porous structure. It is found that, fluid flow inside the pore space takes place through preferential inlet and outlet pores. For two-phase flow, it is observed that continuous displacement of oil occurs during water flooding but CO{sub 2} is able to displace oil at certain locations in the pores. Also, the separation of flow front is observed in the case of CO{sub 2} flooding. A quantitative comparison of the results obtained in two types of flooding simulations suggests that water displaces a higher volume of oil than CO{sub 2} in the time period for which the simulations are performed. (author)

  5. 3D-imaging of selective laser melting defects in a Co–Cr–Mo alloy by synchrotron radiation micro-CT

    International Nuclear Information System (INIS)

    Microstructure defects set the mechanical property limits for solid Co–Cr–Mo alloy prepared by selective laser melting (SLM). Previous studies were mainly based on 2D SEM images and thus not able to provide information of the 3D morphologies of the complex defects. In this paper, the remaining porosities in Co–Cr–Mo alloy parts prepared by selective laser melting were presented in relation to the laser processing parameters. In order to understand the defect forming mechanism, accurate 3D images of defects inside SLM fabricated Co–Cr–Mo samples were provided by synchrotron radiation micro-CT imaging of 300 μm thick slices cut from a 10 mm cube. With 3D reconstructed images distinctive morphologies of SLM defects spanning across the consolidated powder layers were generated. The faults can be classified as single layer or multi-layers defects. The accidental single layer defects form as gaps between adjacent laser melt tracks or melt track discontinuousness caused by inherent fluid instability under various disturbances. The first formed single layer defect generates often a multi-layer defect spanning for 2–3 subsequent powder layers. By stabilizing the melt pool flow and by reducing the surface roughness through adjusting processing parameters it appears possible to reduce the defect concentrations

  6. Investigation of water and CO2 (carbon dioxide) flooding using micro-CT (micro-computed tomography) images of Berea sandstone core using finite element simulations

    International Nuclear Information System (INIS)

    The present study reports a numerical investigation of water and CO2 (carbon dioxide) flooding at the pore scale of a porous medium. We use high resolution micro-computed tomography (micro-CT) images of Berea sandstone core to obtain the pore geometry. The numerical solution used for the simulation was carried out by a finite element based software package. Level Set method is used to determine the position of the interface between two immiscible fluids when oil is displaced by water and CO2, respectively. The present formulation is validated against single-phase flow through the porous structure. It is found that, fluid flow inside the pore space takes place through preferential inlet and outlet pores. For two-phase flow, it is observed that continuous displacement of oil occurs during water flooding but CO2 is able to displace oil at certain locations in the pores. Also, the separation of flow front is observed in the case of CO2 flooding. A quantitative comparison of the results obtained in two types of flooding simulations suggests that water displaces a higher volume of oil than CO2 in the time period for which the simulations are performed.

  7. Evaluation of the implantation position of mini-screws for orthodontic treatment in the maxillary molar area by a micro CT

    International Nuclear Information System (INIS)

    The interalveolar septum between the upper first molar and the second premolar of the separated human maxillary bone was three-dimensionally observed by micro CT to evaluate the appropriate mini-screw type implant placement position by considering the relationship between the tooth roots and the maxillary sinus. After taking micro CTs of 5 human maxillary bones, horizontally sectioned images of the interalveolar septum area 2, 4, 6, 8, 10, and 12 mm deep from the crest of the alveolar ridge were reconstructed by three-dimensional reconstruction software. The bucco-lingual and mesio-distal lengths and area in each sectioned interalveolar septum were measured using digital image measurement software. Using the results, the interalveolar septum area between the upper first molar and the second premolar approximately 6-8 mm deep from the alveolar crest in the tooth root apical direction was determined to be the safest position for mini-screw implantation. Furthermore, lateral implantation from the palatal side was deduced to be the safest approach. (author)

  8. P.I.X.S.C.A.N.: a micro-CT scanner for small animal based on hybrid pixel detectors

    International Nuclear Information System (INIS)

    Since more than a dozen years, efforts were led in the field of X-ray tomography for small animals, principally for the improvement of spatial resolution and the diminution of the absorbed dose. The C.P.P.M. developed the micro-CT P.I.X.S.C.A.N. based on the hybrid pixel detector X.P.A.D.2. In this context, my thesis work consists in studying the demonstrator P.I.X.S.C.A.N./X.P.A.D.2 and the contribution of the hybrid pixels in the imaging of small animals. A fast analytical simulation, FastSimu, was developed. An extrapolation of the performance of the demonstrator P.I.X.S.C.A.N, as well as the validation of the results obtained with the measured data, were led by means of the analytical simulator FastSimu. The demonstrator P.I.X.S.C.A.N./X.P.A.D.2 allowed to obtain reconstructed images with a rather good quality for a relatively weak absorbed dose. Its spatial resolution is degraded by the high number of defective pixels of the detector X.P.A.D.2. Beyond this study, a new version of the demonstrator P.I.X.S.C.A.N./X.P.A.D.2 is under construction. This latter, characterized by two and a half times smaller pixels and about no defective pixels will bring a considerable improvement on spatial resolution. (author)

  9. Beam loading effect on rf system in proton synchrotrons

    International Nuclear Information System (INIS)

    This report describes the stability of an rf system in the presence of beam loading. The analysis is based on the transfer function method given in F. Pedersen (IEEE Trans. Nucl. Sci. NS-22, 1906 (1975)). First, the Routh-Hurwitz criterion is applied to the analysis of the stability of the rf system with a wideband cavity. Then the simplified model in which the loading effect is treated as a reduction in gain of the phase loop is developed. Secondly, the critical damping criteria of the phase loop in the rf system are derived. These criteria give a stability limit appreciably smaller than that given by the Routh-Hurwitz criterion. Finally, we discussed the technique by which the beam loading effect will be compensated. (author)

  10. A New Beam and Delivery System for Radiotherapy

    International Nuclear Information System (INIS)

    The new beam delivery system consists of an electron accelerator and a system of magnets (one or more). Introducing a transverse magnetic field in and near the tumor, causes the electrons to spiral in this region, thereby producing an effective peak in the depth dose distribution, within the tumor volume. Although the basic idea is not new, we suggest here for the first time, a viable as well as a workable, magnetic field configuration, which in addition to focusing the beam does not interfere with its propagation to the target. Prototypes were successfully tested by means of computer simulation. The electron accelerator : can be a linear accelerator or any other type electron accelerator, capable of producing different electron energies for different depths and dose absorptionaccumulation . The Field size can be as small as a pencil beam and as big as any of the other standard field sizes that are used in radiotherapy. The scatter filter can be used or removed. The dose rate accumulation can be as higher as possible. The magnets are able to produce magnetic fields. The order, direction, width, place, shape and number of the magnetic fields define the shape and the Percentage Depth Dose (PDD) curve of the electron beam.

  11. Interference-aware random beam selection for spectrum sharing systems

    KAUST Repository

    Abdallah, Mohamed M.

    2012-09-01

    Spectrum sharing systems have been introduced to alleviate the problem of spectrum scarcity by allowing secondary unlicensed networks to share the spectrum with primary licensed networks under acceptable interference levels to the primary users. In this paper, we develop interference-aware random beam selection schemes that provide enhanced throughput for the secondary link under the condition that the interference observed at the primary link is within a predetermined acceptable value. For a secondary transmitter equipped with multiple antennas, our schemes select a random beam, among a set of power- optimized orthogonal random beams, that maximizes the capacity of the secondary link while satisfying the interference constraint at the primary receiver for different levels of feedback information describing the interference level at the primary receiver. For the proposed schemes, we develop a statistical analysis for the signal-to-noise and interference ratio (SINR) statistics as well as the capacity of the secondary link. Finally, we present numerical results that study the effect of system parameters including number of beams and the maximum transmission power on the capacity of the secondary link attained using the proposed schemes. © 2012 IEEE.

  12. Particle beam digital phase control system for COSY

    International Nuclear Information System (INIS)

    Particle accelerators require that the orbit of the charged particles in the vacuum chamber is controlled to fulfil narrow limits. This is done by magnetic deflection systems and exactly adjusted rf-acceleration. Up to now the necessary control-functions were realised with analogue parts. This work describes a digital phase control system that works in real time and is used with the proton accelerator COSY. The physical design of the accelerator sets the accuracy-specifications of the revolution frequency (<1 Hz in the whole range from 400 kHz to 1.6 MHz), the phase-difference (<0.01 ), the signal-to-noise-ratio (<-60 dBc) and the update rate (<1 μs) of the parameters. In a typical operation the beam is first bunched and synchronised to the reference oscillator. After that the beam influences the rf-system with the help of charge detectors and now the rf-systems will be synchronised with the bunched beam. This control-loop is modelled and simulated with PSPICE. (orig.)

  13. Microcontroller based two axis microtron beam extraction system

    International Nuclear Information System (INIS)

    Microtron is an electron accelerator which is used to accelerate the electron beam. The Microtron consists of electro magnet with two poles separated by yoke for completion of path for magnetic flux lines. A compact Microtron capable of accelerating electrons up to 12 MeV has been developed in RRCAT. The beam from the Microtron has to be extracted from various orbits depending upon the user requirement (X-Y stage is built with an accuracy of 100 μm). This paper describes the design and development of microcontroller based two axis beam extraction system for Microtron, with a resolution of 50 μm to position the extraction tube with respect to selected orbit. Two axis motion controller is developed using current controlled micro-stepping driver mechanism, which uses Bipolar Chopper Drive for driving stepper motors. Each phase has 2A continuous driving capability. The system is provided with user selectable controls like speed, steps, direction, and mode. This system is provided with RS-232 interface, to accept commands from PC. This system also has local keyboard and LCD interface to use in Stand-alone mode (local Mode). (author)

  14. Cavity Beam Position Monitor System for ATF2

    Energy Technology Data Exchange (ETDEWEB)

    Boogert, Stewart; /Oxford U., JAI; Boorman, Gary; /Oxford U., JAI; Swinson, Christina; /Oxford U., JAI; Ainsworth, Robert; /Royal Holloway, U. of London; Molloy, Stephen; /Royal Holloway, U. of London; Aryshev, Alexander; /KEK, Tsukuba; Honda, Yosuke; /KEK, Tsukuba; Tauchi, Toshiaki; /KEK, Tsukuba; Terunuma, Nobuhiro; /KEK, Tsukuba; Urakawa, Junji; /KEK, Tsukuba; Frisch, Josef; /SLAC; May, Justin; /SLAC; McCormick, Douglas; /SLAC; Nelson, Janice; /SLAC; Smith, Tonee; /SLAC; White, Glen; /SLAC; Woodley, Mark; /SLAC; Heo, Ae-young; /Kyungpook Natl. U.; Kim, Eun-San; /Kyungpook Natl. U.; Kim, Hyoung-Suk; /Kyungpook Natl. U.; Kim, Youngim; /Kyungpook Natl. U. /University Coll. London /Kyungpook Natl. U. /Fermilab /Pohang Accelerator Lab.

    2012-07-09

    The Accelerator Test Facility 2 (ATF2) in KEK, Japan, is a prototype scaled demonstrator system for the final focus required for a future high energy lepton linear collider. The ATF2 beam-line is instrumented with a total of 38 C and S band resonant cavity beam position monitors (CBPM) with associated mixer electronics and digitizers. The current status of the BPM system is described, with a focus on operational techniques and performance. The ATF2 C-band system is performing well, with individual CBPM resolution approaching or at the design resolution of 50 nm. The changes in the CBPM calibration observed over three weeks can probably be attributed to thermal effects on the mixer electronics systems. The CW calibration tone power will be upgraded to monitor changes in the electronics gain and phase. The four S-band CBPMs are still to be investigated, the main problem associated with these cavities is a large cross coupling between the x and y ports. This combined with the large design dispersion in that degion makes the digital signal processing difficult, although various techniques exist to determine the cavity parameters and use these coupled signals for beam position determination.

  15. Preliminary estimates of the calcium/phosphorus ratio at different cortical bone sites using synchrotron microCT

    International Nuclear Information System (INIS)

    The Ca/P ratio was measured in cortical bone samples from the femoral neck, front and rear tibia of female rats (1.5 years of age), using synchrotron radiation microtomography. The use of a monoenergetic x-ray beam, as provided by the synchrotron facility, generates accurate 3D maps of the linear attenuation coefficient within the sample and hence gives the ability to map different chemical components. Data sets were taken at 20 keV for each bone sample and calibration phantoms. From the 3D data sets, multiple 2D slices were reconstructed with a slice thickness of ∼28 μm and converted to Ca/P ratios using the calibration phantom results. Mean values (M ± SD) for cortical femoral, front and rear tibias are 2.12 ± 0.08, 1.75 ± 0.06 and 1.94 ± 0.07 respectively. These values were compared with those derived from different animals. Differences between the same bone sites from different animals are not significant (0.1 -3) demonstrating a dependence upon life style and bone use

  16. Current status of electron beam processing system and its applications

    International Nuclear Information System (INIS)

    The feature and application fields of electron beam processing systems (EPS), the selection of machine ratings and safety measures for EPS are described. EPS has the various features: a) Chemical reactions occurs independent of the temperature, b) it occurs without any added substances such as catalysts, c) mass productivity, d) easy operation, as is exemplified by switch ON and OFF, and e) easy maintenance, compared with radioisotope sources. After briefly explaining acceleration type (DC or AC), power supply (Van-de-Graaf or Cockcroft-walton and others), beam scanning to be used for large area irradiation, and some typical applications (cross-linking, radical polymerization, the paper describes necessary safety measures such as X-ray shielding, ozone control including ozone generation and its disposal, interlock system, warning buzzer, and monitoring and measuring. (S. Ohno)

  17. Successful synchronization of the LHC's clockwise beam transfer system

    CERN Multimedia

    2008-01-01

    LHC synchronization test successful The synchronization of the LHC's clockwise beam transfer system and the rest of CERN's accelerator chain was successfully achieved last weekend. Tests began on Friday 8 August when a single bunch of a few particles was taken down the transfer line from the SPS accelerator to the LHC. After a period of optimization, one bunch was kicked up from the transfer line into the LHC beam pipe and steered about 3 kilometres around the LHC itself on the first attempt. On Saturday, the test was repeated several times to optimize the transfer before the operations group handed the machine back for hardware commissioning to resume on Sunday. The anti-clockwise synchronization systems will be tested over the weekend of 22 August.

  18. Beam injection system into an electron ring compressor

    International Nuclear Information System (INIS)

    A system for three-turn injection of the beam into the electronic ring compressor is elaborated. The electron beam is rejected from the linear accelerator at an average energy of 1.5 MeV through the screening nozzle at a radius of 26 cm into the growing magnetic field. The energy of the injected electrons and the strength of the magnetic field are varied so that injection is always performed onto the equilibrium radius. In this case, the ring will feature an electron pulse spread of +-3.5% which makes it possible to accumulate up to 1013 particles in the ring, never exceeding the threshold of the azimuthal coherent non-stability. From the point of view of its design and technology, the injection system provides for creating superhigh vacuum of about 10-9 mm Hg in the compressor chamber which ensures the life of the ring of up to 2 ms

  19. The system of RF beam control for electron gun

    Science.gov (United States)

    Barnyakov, A. M.; Chernousov, Yu. D.; Ivannikov, V. I.; Levichev, A. E.; Shebolaev, I. V.

    2015-06-01

    The system of RF control of three-electrode electron gun current is described. It consists of a source of microwave signal, coaxial line, coaxial RF switch and RF antenna lead. The system allows one to get the electron beam in the form of bunches with the frequency of the accelerating section to achieve the capture of particles in the acceleration mode close to 100%. The results of calculation and analysis of the elements of the system are presented. Characteristics of the devices are obtained experimentally. The results of using RF control in three-electrode electron gun at electron linear accelerator are described.

  20. The system of RF beam control for electron gun

    International Nuclear Information System (INIS)

    The system of RF control of three-electrode electron gun current is described. It consists of a source of microwave signal, coaxial line, coaxial RF switch and RF antenna lead. The system allows one to get the electron beam in the form of bunches with the frequency of the accelerating section to achieve the capture of particles in the acceleration mode close to 100%. The results of calculation and analysis of the elements of the system are presented. Characteristics of the devices are obtained experimentally. The results of using RF control in three-electrode electron gun at electron linear accelerator are described

  1. Development of beam current control system in RF-knockout slow extraction

    Energy Technology Data Exchange (ETDEWEB)

    Mizushima, K., E-mail: mizshima@nirs.go.jp [Department of Accelerator and Medical Physics, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Graduate School of Science and Technology, Chiba University, Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Sato, S.; Shirai, T.; Furukawa, T.; Katagiri, K.; Takeshita, E.; Iwata, Y.; Himukai, T.; Noda, K. [Department of Accelerator and Medical Physics, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan)

    2011-12-15

    A raster scanning method has been developed for cancer therapy at NIRS-HIMAC. This method requires a high-accuracy beam current control and fast beam-on/off switching. We have developed a feedback control system of the beam current with the RF-knockout slow extraction method. The system has allowed a stable response to beam-on/off switching using a feedback control delay function with a beam-current ripple of 7%.

  2. The LCLS Undulator Beam Loss Monitor Readout System

    Energy Technology Data Exchange (ETDEWEB)

    Dusatko, John; Browne, M.; Fisher, A.S.; Kotturi, D.; Norum, S.; Olsen, J.; /SLAC

    2012-07-23

    The LCLS Undulator Beam Loss Monitor System is required to detect any loss radiation seen by the FEL undulators. The undulator segments consist of permanent magnets which are very sensitive to radiation damage. The operational goal is to keep demagnetization below 0.01% over the life of the LCLS. The BLM system is designed to help achieve this goal by detecting any loss radiation and indicating a fault condition if the radiation level exceeds a certain threshold. Upon reception of this fault signal, the LCLS Machine Protection System takes appropriate action by either halting or rate limiting the beam. The BLM detector consists of a PMT coupled to a Cherenkov radiator located near the upstream end of each undulator segment. There are 33 BLMs in the system, one per segment. The detectors are read out by a dedicated system that is integrated directly into the LCLS MPS. The BLM readout system provides monitoring of radiation levels, computation of integrated doses, detection of radiation excursions beyond set thresholds, fault reporting and control of BLM system functions. This paper describes the design, construction and operational performance of the BLM readout system.

  3. Conceptual design for the ZEPHYR neutral-beam injection system

    International Nuclear Information System (INIS)

    In June 1980, the Lawrence Berkeley Laboratory began a conceptual design study for a neutral beam injection system for the ZEPHYR ignition tokamak proposed by the Max-Planck-Institut fur Plasmaphysik in Garching, Germany. The ZEPHYR project was cancelled, and the LBL design effort concluded prematurely in January 1981. This report describes the conceptual design as it existed at that time, and gives brief consideration to a schedule, but does not deal with costs

  4. Neutral beam interlock system on TFTR using infrared pyrometry

    International Nuclear Information System (INIS)

    Although the region of the TFTR vacuum vessel wall which is susceptible to damage by neutral beam strike is armored with a mosaic of TiC-clad POCO graphite titles, at power deposition levels above 2.5 kW/cm2 the armor surface temperature exceeds 12000C within 250 ms and itself becomes susceptible to damage. In order to protect the wall armor, a neutral beam interlock system based on infrared pyrometry measurement of the armor surface temperature was installed on TFTR. For each beamline, a three-fiber-optic telescope views three areas of approx.30 cm diameter centered on the armor hot spots for the three ion sources. Each signal is fiber-optic coupled to a remote 900 nm pyrometer which feeds analog signals to the neutral beam interrupt circuits. The pyrometer interlock system is designed to interrupt each of the twelve ion sources independently within 10 ms of the temperature exceeding a threshold settable in the range of 500 to 23000C. A description of the pyrometer interlock system and its performance will be presented

  5. Neutral beam interlock system on TFTR using infrared pyrometry

    International Nuclear Information System (INIS)

    This paper discuss how although the region of the TFTR vacuum vessel wall which is susceptible to damage by neutral beam strike is armored with a mosaic of TiC clad POCO graphite tiles, at power deposition levels above 2.5 kW/cm2 the armor surface temperature exceeds 1200 degrees C within 250 ms and itself becomes susceptible to damage. In order to protect the wall armor, a neutral beam interlock system based on infrared pyrometry measurement of the armor surface temperature was installed on TFTR. For each beamline, a three-fiber optic telescope views three areas of ∼30 cm diameter centered on the armor hot spots for the three the ion sources. Each signal is fiber-optic coupled to a remote 1-μ pyrometer which feeds analog signals to the neutral beam interrupt circuits. The pyrometer interlock system is designed to interrupt each of the twelve ion sources independently within 10 ms of the temperature exceeding a threshold settable in the range of 500-1800C. A description of the pyrometer interlock system and its performance is presented

  6. Neutral beam interlock system on TFTR using infrared pyrometry

    International Nuclear Information System (INIS)

    Although the region of the Tokamak Fusion Test Reactor (TFTR) vacuum vessel wall which is susceptible to damage by neutral beam strike is armored with a mosaic of TiC-clad POCO graphite tiles, at power deposition levels above 2.5 kW/cm2 the armor surface temperature exceeds 1200 0C within 250 ms, and itself becomes susceptible to damage. In order to protect the wall armor, a neutral beam interlock system based on infrared pyrometry measurement of the armor surface temperature was installed on TFTR. For each beamline, a three-fiber-optic telescope views three areas of --30 cm diameter centered on the armor hot spots for the three ion sources. Each signal is fiber-optic coupled to a remote 900-nm pyrometer which feeds analog signals to the neutral beam interrupt circuits. The pyrometer interlock system is designed to interrupt each of the 12 ion sources independently within 10 ms of the temperature exceeding a threshold which can be set in the range of 500--2300 0C. A description of the pyrometer interlock system and its performance will be presented

  7. Method and system for treating an interior surface of a workpiece using a charged particle beam

    Science.gov (United States)

    Swenson, David Richard

    2007-05-23

    A method and system of treating an interior surface on an internal cavity of a workpiece using a charged particle beam. A beam deflector surface of a beam deflector is placed within the internal cavity of the workpiece and is used to redirect the charged particle beam toward the interior surface to treat the interior surface.

  8. RFI hydrogen beam source system for materials testing

    International Nuclear Information System (INIS)

    A Radio Frequency Induction (RFI) ion source system has been designed, constructed and tested for integration as a fast rise time (≅100μsec), long pulse to CW heat source for the Sandia National Laboratories Plasma and Materials Test Facility (PMTF). The ion source system to be described is capable of producing a 40kV, 20A hydrogen beam and providing a uniform heat flux of up to 2.0 kWatt/cm/sup 2/ at targets, with areas in excess of 100cm/sup 2/, located ≅4. meters from the accelerator. An intense plasma is produced in the RFI ion source by inductive coupling of RF energy at a frequency of 1.5MHz to plasma electrons which are collisionally heated and maintain the discharge. Since no hot cathode structures are required with this plasma production techniques, source impurities are reduced and system control and reliability is enhanced. Source current density and extracted beam current is determined for a given source geometry, solely by the quantity of RF power coupled to the source. The beam current is thus controlled by the amplitude to the low level oscillator feeding the PA. Previous RFI sources we have built have been operated to extractable hydrogen or deuterium current densities of up to 500mA/cm/sup 2/ and have provided measured beam species fractions of 72/17/11% for H/sup +//H/sub 2//sup +//H/sub 3//sup +/, respectively, during 80k Volt extraction tests at LBL

  9. Electronics and Calibration system for the CMS Beam Halo Monitor

    CERN Document Server

    Tosi, Nicolo

    2014-01-01

    In the context of increasing luminosity of LHC, it will be important to accurately measure the Machine Induced Background. A new monitoring system will be installed in the CMS cavern for measuring the beam background at high radius. This detector is composed of synthetic quartz Cherenkov radiators, coupled to fast photomultiplier tubes (PMT). The readout chain of this detector will make use of many components developed for the Phase 1 upgrade to the CMS Hadron Calorimeter electronics, with a dedicated firmware and readout adapted to the beam monitoring requirements. The PMT signal will be digitized by a charge integrating ASIC (QIE10), providing both the signal rise time and the charge integrated over one bunch crossing.The backend electronics will record bunch-by-bunch histograms, which will be published to CMS and the LHC using the newly designed CMS beam instrumentation specific DAQ. A calibration monitoring system has been designed to generate triggered pulses of light to monitor the efficiency of the sys...

  10. Electron beam final focus system for Thomson scattering at ELBE

    Science.gov (United States)

    Krämer, J. M.; Budde, M.; Bødker, F.; Irman, A.; Jochmann, A.; Kristensen, J. P.; Lehnert, U.; Michel, P.; Schramm, U.

    2016-09-01

    The design of an electron beam final focus system (FFS) aiming for high-flux laser-Thomson backscattering X-ray sources at ELBE is presented. A telescope system consisting of four permanent magnet based quadrupoles was found to have significantly less chromatic aberrations than a quadrupole doublet or triplet as commonly used. Focusing properties like the position of the focal plane and the spot size are retained for electron beam energies between 20 and 30 MeV by adjusting the position of the quadrupoles individually on a motorized stage. The desired ultra-short electron bunches require an increased relative energy spread up to a few percent and, thus, second order chromatic effects must be taken into account. We also present the design and test results of the permanent magnet quadrupoles. Adjustable shunts allow for correction of the field strength and compensation of deviations in the permanent magnet material. For a beam emittance of 13 mm mrad, we predict focal spot sizes of about 40 μm (rms) and divergences of about 10 mrad using the FFS.

  11. Electron beam final focus system for Thomson scattering at ELBE

    CERN Document Server

    Krämer, J.M.; Bødker, F.; Irman, A.; .Jochmann A.; Kristensen, J.P.; Lehnert U., HZDR; Michel, P.; Schrammb, U.; 10.1016/j.nima.2015.10.067

    2016-01-01

    The design of an electron beam final focus system (FFS) aiming for high-flux laser-Thomson backscattering X-ray sources at ELBE is presented. A telescope system consisting of four permanent magnet based quadrupoles was found to have significantly less chromatic aberrations than a quadrupole doublet or triplet as commonly used. Focusing properties like the position of the focal plane and the spot size are retained for electron beam energies between 20 and 30 MeV by adjusting the position of the quadrupoles individually on a motorized stage. The desired ultra-short electron bunches require an increased relative energy spread up to a few percent and, thus, second order chromatic effects must be taken into account. We also present the design and test results of the permanent magnet quadrupoles. Adjustable shunts allow for correction of the field strength and compensation of deviations in the permanent magnet material. For a beam emittance of 13 mm mrad, we predict focal spot sizes of about 40 μm (rms) and diverg...

  12. Electron Beam Final Focus System For Thomson Scattering At Elbe

    CERN Document Server

    Krämer, J.M.; Bødkera, F.; Irman, A.; Jochmann, A.; Kristensena, J.P.; Lehnert, U.; Michel, P.; Schramm, U.; 10.1016/j.nima.2015.10.067

    2016-01-01

    The design of an electron beam final focus system (FFS) aiming for high-flux laser-Thomson backscattering X-ray sources at ELBE is presented. A telescope system consisting of four permanent magnet based quadrupoles was found to have significantly less chromatic aberrations than a quadrupole doublet or triplet as commonly used. Focusing properties like the position of the focal plane and the spot size are retained for electron beam energies between 20 and 30 MeV by adjusting the position of the quadrupoles individually on a motorized stage. The desired ultra-short electron bunches require an increased relative energy spread up to a few percent and, thus, second order chromatic effects must be taken into account. We also present the design and test results of the permanent magnet quadrupoles. Adjustable shunts allow for correction of the field strength and compensation of deviations in the permanent magnet material. For a beam emittance of 13 mm mrad, we predict focal spot sizes of about 40 μm (rms) and diverg...

  13. 显微CT对兔骨质疏松模型的实验研究%Experimental study on a rabbit osteoporosis model with micro-CT

    Institute of Scientific and Technical Information of China (English)

    徐铮; 李冠武; 汤光宇; 刘勇; 张晓

    2011-01-01

    目的 探讨去势法联合皮质激素快速诱导兔骨质疏松模型椎体骨小梁Micro-CT动态变化规律.方法 40只8个月龄雌性大白兔随机分为假手术组(A组,n=20)及去势+肌注甲强龙组(B组,n=20).术后第2、4、8、10周行血清骨转化标志物检测及离体腰5椎体Micro-CT扫描.每组在每个时间点动物数5只.结果 两组vBMD在术后第8周开始,差异有统计学意义,而BVF、Tb.N、Conn.D、Tb.Sp、SMI及Tb.Th分别在术后4、8周开始,差异有统计学意义.B组术后TRAP-5b迅速增高,至第4周达峰值,术后第4、8、10周,两组TRAP-5b差异有统计学意义;而BALP缓慢逐渐增高,至第8周才达峰值,术后第8、10周,两组BALP差异有统计学意义.结论 去卵巢+肌注甲强龙可在8周内快速建立兔OP模型,骨微结构衰败早于vBMD变化而与骨转化标志物同步.%Objective To observe the morphological characteristics of osteoporosis ( OP) in a overiectomized rabbit model with micro-computed tomography (micro-CT). Methods Forty 8-month-old, skeletally mature, female New Zealand white rabbits were randomly allocated into two groups; group B (n = 20) underwent bilateral overiectomy ( OVX) combined with intramuscular injection of methylprednisolone hemisuccinate(MPH); group A(n =20) were used as sham operation controls. Five rabbits from both groups were sacrificed at 2, 4, 8 and 10 weeks after OVX, respectively. The serum bone metabolism markers were measured and micro-CT scanning of L5 vertebral body was performed. Results The bone mineral density (BMD) of group B at 8 and 10 weeks after OVX was significantly decreased compared to that of group A(P<0.01). The microstructural parameters BVF, Conn. D, Tb. N, SMI, Tb. Sp and Tb. Th in group B were significantly lower than those in group A at 4 and 8 weeks after OVX. Serum TRAP-5b in group B was significantly increased at 4, 8 and 10weeks after OVX compared to group A(P <0. 01); while serum BALP was significantly increased

  14. Using a method based on Potts Model to segment a micro-CT image stack of trabecular bones of femoral region

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Pedro H.A. de; Cabral, Manuela O.M., E-mail: andrade.pha@gmail.com [Universidade Federal de Pernambuco (DEN/UFPE), Recife, PE (Brazil). Departamento de Engenharia Nuclear; Vieira, Jose W.; Correia, Filipe L. de B., E-mail: jose.wilson59@uol.com.br [Instituto Federal de Educacao, Ciencia e Tecnologia de Pernambuco (IFPE), Recife, PE (Brazil); Lima, Fernando R. De A., E-mail: falima@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (brazil)

    2015-07-01

    Exposure Computational Models are composed basically of an anthropomorphic phantom, a Monte Carlo (MC) code, and an algorithm simulator of the radioactive source. Tomographic phantoms are developed from medical images and must be pre-processed and segmented before being coupled to a MC code (which simulates the interaction of radiation with matter). This work presents a methodology used for treatment of micro-CT images stack of a femur, obtained from a 30 year old female skeleton provided by the Imaging Laboratory for Anthropology of the University of Bristol, UK. These images contain resolution of 60 micrometers and from these a block containing only 160 x 60 x 160 pixels of trabecular tissues and bone marrow was cut and saved as ⁎.sgi file (header + ⁎.raw file). The Grupo de Dosimetria Numerica (Recife-PE, Brazil) developed a software named Digital Image Processing (DIP), in which a method for segmentation based on a physical model for particle interaction known as Potts Model (or q-Ising) was implemented. This model analyzes the statistical dependence between sites in a network. In Potts Model, when the values of spin variables at neighboring sites are identical, it is assigned an 'energy of interaction' between them. Otherwise, it is said that the sites do not interact. Making an analogy between network sites and the pixels of a digital image and, moreover, between the spins variables and the intensity of the gray scale, it was possible to apply this model to obtain texture descriptors and segment the image. (author)

  15. 3D mapping of water in oolithic limestone at atmospheric and vacuum saturation using X-ray micro-CT differential imaging

    International Nuclear Information System (INIS)

    Determining the distribution of fluids in porous sedimentary rocks is of great importance in many geological fields. However, this is not straightforward, especially in the case of complex sedimentary rocks like limestone, where a multidisciplinary approach is often needed to capture its broad, multimodal pore size distribution and complex pore geometries. This paper focuses on the porosity and fluid distribution in two varieties of Massangis limestone, a widely used natural building stone from the southeast part of the Paris basin (France). The Massangis limestone shows locally varying post-depositional alterations, resulting in different types of pore networks and very different water distributions within the limestone. Traditional techniques for characterizing the porosity and pore size distribution are compared with state-of-the-art neutron radiography and X-ray computed microtomography to visualize the distribution of water inside the limestone at different imbibition conditions. X-ray computed microtomography images have the great advantage to non-destructively visualize and analyze the pore space inside of a rock, but are often limited to the larger macropores in the rock due to resolution limitations. In this paper, differential imaging is successfully applied to the X-ray computed microtomography images to obtain sub-resolution information about fluid occupancy and to map the fluid distribution in three dimensions inside the scanned limestone samples. The detailed study of the pore space with differential imaging allows understanding the difference in the water uptake behavior of the limestone, a primary factor that affects the weathering of the rock. - Highlights: • The water distribution in a limestone was visualized in 3D with micro-CT. • Differential imaging allowed to map both macro and microporous zones in the rock. • The 3D study of the pore space clarified the difference in water uptake behavior. • Trapped air is visualized in the moldic

  16. Using a method based on Potts Model to segment a micro-CT image stack of trabecular bones of femoral region

    International Nuclear Information System (INIS)

    Exposure Computational Models are composed basically of an anthropomorphic phantom, a Monte Carlo (MC) code, and an algorithm simulator of the radioactive source. Tomographic phantoms are developed from medical images and must be pre-processed and segmented before being coupled to a MC code (which simulates the interaction of radiation with matter). This work presents a methodology used for treatment of micro-CT images stack of a femur, obtained from a 30 year old female skeleton provided by the Imaging Laboratory for Anthropology of the University of Bristol, UK. These images contain resolution of 60 micrometers and from these a block containing only 160 x 60 x 160 pixels of trabecular tissues and bone marrow was cut and saved as ⁎.sgi file (header + ⁎.raw file). The Grupo de Dosimetria Numerica (Recife-PE, Brazil) developed a software named Digital Image Processing (DIP), in which a method for segmentation based on a physical model for particle interaction known as Potts Model (or q-Ising) was implemented. This model analyzes the statistical dependence between sites in a network. In Potts Model, when the values of spin variables at neighboring sites are identical, it is assigned an 'energy of interaction' between them. Otherwise, it is said that the sites do not interact. Making an analogy between network sites and the pixels of a digital image and, moreover, between the spins variables and the intensity of the gray scale, it was possible to apply this model to obtain texture descriptors and segment the image. (author)

  17. 3D mapping of water in oolithic limestone at atmospheric and vacuum saturation using X-ray micro-CT differential imaging

    Energy Technology Data Exchange (ETDEWEB)

    Boone, M.A., E-mail: marijn.boone@ugent.be [Department of Geology and Soil Science—UGCT, Ghent University, Krijgslaan 281 S8, 9000 Ghent (Belgium); Unit Sustainable Materials Management, VITO, Boerentang 200, 2400 Mol (Belgium); De Kock, T.; Bultreys, T. [Department of Geology and Soil Science—UGCT, Ghent University, Krijgslaan 281 S8, 9000 Ghent (Belgium); De Schutter, G. [Magnel Laboratory for Concrete Research, Department of Structural Engineering, Ghent University, Technologiepark-Zwijnaarde 904, 9052 Ghent (Belgium); Vontobel, P. [Spallation Neutron Source Division, Paul Scherrer Institute (PSI), 5232 Villigen (Switzerland); Van Hoorebeke, L. [Department of Physics and Astronomy—UGCT, Ghent University, Proeftuinstraat 86, 9000 Ghent (Belgium); Cnudde, V. [Department of Geology and Soil Science—UGCT, Ghent University, Krijgslaan 281 S8, 9000 Ghent (Belgium)

    2014-11-15

    Determining the distribution of fluids in porous sedimentary rocks is of great importance in many geological fields. However, this is not straightforward, especially in the case of complex sedimentary rocks like limestone, where a multidisciplinary approach is often needed to capture its broad, multimodal pore size distribution and complex pore geometries. This paper focuses on the porosity and fluid distribution in two varieties of Massangis limestone, a widely used natural building stone from the southeast part of the Paris basin (France). The Massangis limestone shows locally varying post-depositional alterations, resulting in different types of pore networks and very different water distributions within the limestone. Traditional techniques for characterizing the porosity and pore size distribution are compared with state-of-the-art neutron radiography and X-ray computed microtomography to visualize the distribution of water inside the limestone at different imbibition conditions. X-ray computed microtomography images have the great advantage to non-destructively visualize and analyze the pore space inside of a rock, but are often limited to the larger macropores in the rock due to resolution limitations. In this paper, differential imaging is successfully applied to the X-ray computed microtomography images to obtain sub-resolution information about fluid occupancy and to map the fluid distribution in three dimensions inside the scanned limestone samples. The detailed study of the pore space with differential imaging allows understanding the difference in the water uptake behavior of the limestone, a primary factor that affects the weathering of the rock. - Highlights: • The water distribution in a limestone was visualized in 3D with micro-CT. • Differential imaging allowed to map both macro and microporous zones in the rock. • The 3D study of the pore space clarified the difference in water uptake behavior. • Trapped air is visualized in the moldic

  18. 3D micro-CT analysis of void formations and push-out bonding strength of resin cements used for fiber post cementation

    Science.gov (United States)

    2016-01-01

    PURPOSE To investigate the void parameters within the resin cements used for fiber post cementation by micro-CT (µCT) and regional push-out bonding strength. MATERIALS AND METHODS Twenty-one, single and round shaped roots were enlarged with a low-speed drill following by endodontic treatment. The roots were divided into three groups (n=7) and fiber posts were cemented with Maxcem Elite, Multilink N and Superbond C&B resin cements. Specimens were scanned using µCT scanner at resolution of 13.7 µm. The number, area, and volume of voids between dentin and post were evaluated. A method of analysis based on the post segmentation was used, and coronal, middle and apical thirds considered separately. After the µCT analysis, roots were embedded in epoxy resin and sectioned into 2 mm thick slices (63 sections in total). Push-out testing was performed with universal testing device at 0.5 mm/min cross-head speed. Data were analyzed with Kruskal–Wallis and Mann–Whitney U tests (α=.05). RESULTS Overall, significant differences between the resin cements and the post level were observed in the void number, area, and volume (P.05). CONCLUSION µCT proved to be a powerful non-destructive 3D analysis tool for visualizing the void parameters. Multilink N had the lowest void parameters. When efficiency of all cements was evaluated, direct relationship between the post region and push-out bonding strength was not observed. PMID:27141253

  19. Study of Electron Beam Curing Process Using Epoxy Resin System

    International Nuclear Information System (INIS)

    The competition among industries in the current globalization system has required a systematic cost reduction without affecting the quality of the final product. This fact has encouraged the use of new technologies application on productive process, especially on polymeric composites, to assure the competitiveness. The possibility of producing a new type of carbon fiber reinforced composite by radiation process with excellent thermal and mechanical properties, has been researched since 90's and it can be a potential application in aerospace, marine and automobile industries. The polymeric composites cured by thermal process (furnace or autoclave) are an example of long curing cycles, which requires time and energy consumption. Electron beam curing technology allows the process at room temperature and reduces curing time; consequently, it becomes the main difference of this technology over thermal curing process. The aim of this work was to study electron beam curable epoxy formulation for filament winding process, as well as to investigate the electron beam curing process parameters using a DC 1500/25 - Job 188 Dynamitron model linear accelerator as radiation source, with 0.5 to 1.5 MeV, 0.1 to 25 mA and 60 to 120 cm scanning electron beam. The resin system consists of commercial epoxy resin (diglycidyl ether of bisphenol A - DGEBA) and cationic initiator (diaryliodonium hexafluoantimonate) and the polymerization carried out at room temperature with controlled dose rate. Thermal post cure took part of the process to improve the degree of cure and glass transition temperature (Tg) similar to thermal curable resin properties

  20. Charged particle beam structure having electrostatic coarse and fine double deflection system with dynamic focus and diverging beam

    International Nuclear Information System (INIS)

    An electron beam or other charged particle beam tube of the compound fly's eye type having a coarse deflection system is described. The beam tube comprises an evacuated housing together with an electron gun or other charged particle beam producing means disposed at one end of the evacuated housing for producing a beam of electrons or other charged particles. A coarse deflector, a compound micro lens assembly, and a fine deflector are disposed in the housing in the path of the electron or other charged particle beam for first selecting a lenslet and thereafter finely deflecting an electron or other charged particle beam to a desired spot on a target plane. The electron or other charged particle beam tube is designed in a manner such that the electron or other charged particle beam is caused to diverge at a small angle of divergence in advance of passing through the coarse deflector by appropriately locating the virtual origin or point source of the charged particle a small distance in advance of the coarse deflector. In addition, a dynamic focusing correction potential is supplied to the micro lens assembly along with a high voltage energizing potential with the dynamic focusing correction potential being derived from components of both the coarse deflection potentials and the fine deflection potentials

  1. Transport of intense proton beam in the presence of subdominant species in a low energy beam transport system

    Science.gov (United States)

    Babu, P. Sing; Goswami, A.; Pandit, V. S.

    2016-04-01

    The dynamics of space-charge-dominated low energy proton beam in the presence of H2+ and H3+ beams has been studied in a solenoid based transport system using particle-in-cell (PIC) simulation method. Multispecies envelope equation and random search technique have been used to transport and match the primary beam considering two options. The PIC simulation shows the formation of hollow distribution of H2+ and H3+ beams around the proton beam in the first case where the waist of the proton beam is formed in between the solenoids and it is absent in the second case where the beam size is kept large in between the solenoids. Separation of hollow distribution appears more distinct as the proton fraction is increased and is almost independent of the combination of H2+ and H3+ beams for a given proton fraction. This effect helps to reject the unwanted species more effectively. The evolution of rms size and emittance of the proton beam has been studied in the presence of a circular aperture using KV and Gaussian distributions for the species in both the cases.

  2. Whole-Body Imaging of a Hypercholesterolemic Female Zebrafish by Using Synchrotron X-Ray Micro-CT

    OpenAIRE

    Seo, Eunseok; Lim, Jae-Hong; Seo, Seung Jun; Lee, Sang Joon

    2015-01-01

    Zebrafish has been used as a powerful model system in biological and biomedical studies studying development and diseases. Comparative, functional, and developmental studies on zebrafish morphology require precise visualization of 3D morphological structures. Few methods that can visualize whole-volume of zebrafish tissues are available because optical bio-imaging methods are limited by pigmentation and hard tissues. To overcome these limitations, the 3D microstructures of a hypercholesterole...

  3. Time rectification system for in-beam TOF-PET

    International Nuclear Information System (INIS)

    A time rectification system for a In-Beam TOF-PET was described.It consists of a pair of BaF2(φ40 mm x 45 mm) crystals coupled to Philips photomultipliers XP2020Q and a time coincidence electronic system using standard NIM modules. The best coincidence timing resolution of the system for pairs of 511 keV gamma rays is 576 ps. Some factors affecting the time resolution were primarily discussed, such as the types of photomultiplier tubes (PMT), the model of signal readout, the effects of different discriminators and timing amplifiers. The experiment results show that the signal read from the PMT dynode can get the optimum resolution; the PMT types, especially the rise time and electronic transmit time greatly affect the system performance. The shorter the rise time and electronic transmit time for the PMTs is, the better the timing performance is. The system timing performance is also related to the electronic combination. (authors)

  4. Upgrade of beam energy measurement system at BEPC-II

    Science.gov (United States)

    Zhang, Jian-Yong; Cai, Xiao; Mo, Xiao-Hu; Guo, Di-Zhou; Wang, Jian-Li; Liu, Bai-Qi; Achasov, M. N.; Krasnov, A. A.; Muchnoi, N. Yu.; Pyata, E. E.; Mamoshkina, E. V.; Harris, F. A.

    2016-07-01

    The beam energy measurement system is of great importance for both BEPC-II accelerator and BES-III detector. The system is based on measuring the energies of Compton back-scattered photons. In order to meet the requirements of data taking and improve the measurement accuracy, the system has continued to be upgraded, which involves the updating of laser and optics subsystems, replacement of a view-port of the laser to the vacuum insertion subsystem, the use of an electric cooling system for a high purity germanium detector, and improvement of the data acquisition and processing subsystem. The upgrade system guarantees the smooth and efficient measurement of beam energy at BEPC-II and enables accurate offline energy values for further physics analysis at BES-III. Supported in part by National Natural Science Foundation of China (NSFC)(11375206, 10775142, 10825524, 11125525, 11235011), the Ministry of Science and Technology of China (2015CB856700, 2015CB856705), State key laboratory of particle and detection and electronics; and the CAS Center for Excellence in Particle Physics (CCEPP); the RFBR grant(14-02-00129-a), U.S. Department of Energy (DE-FG02-04ER41291, DE-FG02-05ER41374, DE-FG02-94ER40823, DESC0010118), U.S. National Science Foundation, part of this work related to the design of ZnSe viewports is supported by the Russian Science Foundation (14-50-00080)

  5. Condition monitoring for a neutral beam injector cryopumping system

    Energy Technology Data Exchange (ETDEWEB)

    Wright, N., E-mail: n.wright@lboro.ac.uk [School of Electronic and Electrical Engineering, Loughborough University, Loughborough LE11 3TU (United Kingdom); Dixon, R., E-mail: r.dixon@lboro.ac.uk [School of Electronic and Electrical Engineering, Loughborough University, Loughborough LE11 3TU (United Kingdom); Verhoeven, R., E-mail: roel.verhoeven@ccfe.ac.uk [JET-EFDA, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)

    2013-10-15

    Highlights: ► The development of a cryopumping condition monitoring scheme is presented. ► A residual generation scheme is used to detect two faults. ► Kalman filtering is used to generate the residuals. ► A filtering and voting arrangement is used to evaluate the residuals. ► A non-linear simulation model is used to verify the scheme. -- Abstract: For neutral beam injection systems, the maintenance of a vacuum inside the injector box is essential for normal operation. Cryogenic pumping systems are often used to create and maintain this vacuum. Cryogenic pumping systems have been deployed on the neutral beam heating systems supporting the Joint European Torus. With these as a target application, the development of a condition monitoring scheme is presented. The scheme uses a residual generation approach. A bank of Kalman filters is used to estimate measured process variables. A residual evaluator is used to map residual signals onto a set of faults. Two example faults are simulated to demonstrate the response of the scheme. This paper contributes to the wider fusion development programme by demonstrating how a contemporary condition monitoring technique can be applied to a fusion support system, in order to improve its availability.

  6. Conceptual design of the JT-60 neutral beam injection system (interim report)

    International Nuclear Information System (INIS)

    This is an interim report on conceptual design of the JT-60 neutral beam injection system. Requirements for the JT-60 neutral beam injector are injection of a 20 MW neutral hydrogen beam into the plasma in the vicinity of energy 75 keV as long as 10 sec, keeping thermal gas flow rate into the torus vacuum chamber below 15% the neutral beam flux. On the basis of these requirements and recent results of research and development of ion sources and beam line components, system conceptual design is now proceeding. Scale of the JT-60 neutral beam injection system is discussed, indicating also future problems. (auth.)

  7. Upgrade of the beam transport lines and the beam-abort system and development of a tune compensator in KEKB

    Science.gov (United States)

    Iida, Naoko; Kikuchi, Mitsuo; Mimashi, Toshihiro; Nakayama, Hisayoshi; Sakamoto, Yutaka; Satoh, Kotaro; Takasaki, Seiji; Tawada, Masafumi

    2013-03-01

    The KEKB collider achieved a maximum peak luminosity of 2.1×1034 cm-2 s-1 and an integrated luminosity of 1 ab-1 in its ten-year operation. Behind these glorious records there have been uncountable improvements in every subsystem. This paper describes the improvements in the beam transport line, injection kickers, septum magnets, the beam-abort system, and a newly developed pulsed-quadrupole system in detail.

  8. Beam propagation analysis of a multi-laser diode FSO system through free space

    International Nuclear Information System (INIS)

    In this paper beam propagation analysis of a multi-beam multi-collimator optical communication system through free space is studied. For this purpose, the propagation properties of Gaussian multi-beams through a multi-optical path including collimators in transmitters are studied and an analytical formula for intensity distribution is derived. The effects of beam divergence and beam separation distances on the propagation properties of Gaussian multi-beams are studied in detail by calculating the beam width and power in bucket (PIB). The analyses are illustrated by numerical examples

  9. Beam Pipe HOM Absorber for 750 MHz RF Cavity Systems

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Rolland; Neubauer, Michael

    2014-10-29

    This joint project of Muons, Inc., Cornell University and SLAC was supported by a Phase I and Phase II grant monitored by the SBIR Office of Science of the DOE. Beam line HOM absorbers are a critical part of future linear colliders. The use of lossy materials at cryogenic temperatures has been incorporated in several systems. The design in beam pipes requires cylinders of lossy material mechanically confined in such a way as to absorb the microwave energy from the higher-order modes and remove the heat generated in the lossy material. Furthermore, the potential for charge build-up on the surface of the lossy material requires the conductivity of the material to remain consistent from room temperature to cryogenic temperatures. In this program a mechanical design was developed that solved several design constraints: a) fitting into the existing Cornell load vacuum component, b) allowing the use of different material compositions, c) a thermal design that relied upon the compression of the lossy ceramic material without adding stress. Coating experiments were performed that indicated the design constraints needed to fully implement this approach for solving the charge build-up problem inherent in using lossy ceramics. In addition, the ACE3P program, used to calculate the performance of lossy cylinders in beam pipes in general, was supported by this project. Code development and documentation to allow for the more wide spread use of the program was a direct result of this project was well.

  10. Beam Switching Cylindrical Array Antenna System for Communication

    Directory of Open Access Journals (Sweden)

    V. C. Misra

    1998-10-01

    Full Text Available The beam switching cylindrical array, which is a unique system, has been designed and developed to cover 360° in azimuth plane by generating 16 beams with specified elevation coverage.In this design, the concept of fast aperture selection (4 x 4 in microseconds from the total cylindrical array has been realised successfully to meet the requirement of point-to-multipoint communication. The components of the array, viz., radiating elements, powder dividers, switches, etc., are designed in printed circuit type, and hence, objectives of lightweight and ease of reproducibility are achieved. The lightweight of the array makes it accessible for easy mounting at a specified height for achieving longer communication range. Finally, a low-loss radome is incorporated to protect the array from environmental conditions. The various parameters, viz., return loss, gain, and switched-beam radiation patterns were measured over a bandwidth of 300 MHz in L- band and typical measured results are presented in this paper.

  11. DIII-D Neutral Beam control system operator interface

    International Nuclear Information System (INIS)

    A centralized graphical user interface has been added to the DIII-D Neutral Beam (NB) control systems for status monitoring and remote control applications. This user interface provides for automatic data acquisition, alarm detection and supervisory control of the four NB programmable logic controllers (PLC) as well as the Mode Control PLC. These PLCs are used for interlocking, control and status of the NB vacuum pumping, gas delivery, and water cooling systems as well as beam mode status and control. The system allows for both a friendly user interface as well as a safe and convenient method of communicating with remote hardware that formerly required interns to access. In the future, to enable high level of control of PLC subsystems, complete procedures is written and executed at the touch of a screen control panel button. The system consists of an IBM compatible 486 computer running the FIX DMACS trademark for Windows trademark data acquisition and control interface software, a Texas Instruments/Siemens communication card and Phoenix Digital optical communications modules. Communication is achieved via the TIWAY (Texas Instruments protocol link utilizing both fiber optic communications and a copper local area network (LAN). Hardware and software capabilities will be reviewed. Data and alarm reporting, extended monitoring and control capabilities will also be discussed

  12. Medium and high energy electron beam processing system

    International Nuclear Information System (INIS)

    Electron Beam Processing System (EPS) is a useful and powerful tool for industrial irradiation process. The specification of EPS is decided by consideration to irradiate what material with how thick and wide, how much dose, how to handle, in what atmosphere. In designing an EPS, it is necessary to consider safety measure such as x-ray shielding, ozone control and interlock system. The initial costs to install typical EPS are estimated for acceleration voltages from 500 kV to 5 MV, including following items; those are electron beam machine, x-ray shielding, auxiliary equipment, material handling, survey for installation, ozone exhaust duct, cooling water system, wiring and piping. These prices are reference only because the price should be changed for each case. The price of x-ray shielding should be changed by construction cost. Auxiliary equipment includes window, cooling blower, ozone exhaust blower and SF6 gas handling equipment. In installation work at site, actual workers of 3 - 4 persons for 2 months are necessary. Material handling system is considered only rolls provided in the shielding room as reference. In addition to the initial installation, operators and workers may be required to wear a personal radiation monitor. An x-ray monitor of suitable design should be installed outside the shield room to monitor x-ray level in the working area. (Y. Tanaka)

  13. Individual information beam broadcasting system using a PAL-SLM based CGH beam former for the location based information services

    Science.gov (United States)

    Osawa, Shunichi; Itoh, Hideo; Nakamura, Yoshiyuki; Nishimura, Takuichi; Lin, Xin; Tokuda, Masamitsu

    2006-01-01

    As an implementation of ubiquitous information service environments, we have been researching location-based information service systems at indoor and short distance area. The system should provide adequate information services, which fit the user's attributes, such as language, knowledge level and the volume of information, what is so-called "Right now, Here, and for Me" information services. Keeping privacy and security of the user is an important issue. Spatial optical communication technique is used for the system because the technique is easy to implement a location- and direction-based communication system. Information broadcasting in an area can be realized by an omnidirectional modulated light emission. However, the omnidirectional beam causes spill out of secure information to others, and has lower energy conservation than a focused beam communication. In this paper, a new spatial optical information broadcasting system, which can focus modulated beams only to intended users. CGH (Computer Generated Hologram) technique on a SLM (Spatial Light Modulator) is proposed and demonstrated. The system is composed of a PAL-SLM (Parallel Aligned Nematic Liquid Crystal Spatial Light Modulator), an eye-safe semiconductor laser or a semiconductor laser pumped YAG laser for the beam emitter, and an infrared video camera with an infrared LED illuminator for user locator. Experimental results of beam deflecting characteristics are described on beam uniformity, deflecting angle and the enhancement, communication characteristics, and real time tracking of user with a corner-reflecting sheet.

  14. Design foundation of vacuum system for electron beam machine

    International Nuclear Information System (INIS)

    Vacuum system is a main part of electron beam Machine because (EBM) the electron can not be produced without this vacuum. Vacuum system consists of vacuum pump, connecting pipe, valve, and vacuum gauge. The design vacuum system of EBM, basis knowledge and technology of vacuum is needed. The paper describes types of vacuum pump, calculation of pipe conductance and pumping time of vacuum system then there are used as consideration of criteria to choose vacuum pump for EBM. From the result of study, it is concluded that for EBM of 500 keV/10 mA which is going to use for wood coating and with consideration of economic and technic factor it is better to use diffusion pump. (author)

  15. Interlock system of electron beam machine GJ-2

    International Nuclear Information System (INIS)

    As an irradiation installation facility, the electron beam machine (EBM) irradiation facility which use radionuclide as radiation source. There are three safety aspects to be considered in the facility i.e the safeties for human, machines, and samples to be irradiated. The safety aspect for human is to the radiation hazard and the safety aspect for machine and sample is to the damage as the result of operating failure. In the EBM GJ-2 (made in China) twelve interlock system parameter are installed to keep all of the safety aspects. Each interlock system consist transducer that controls a certain switch, a magnetic relay, and visible and audible interlock indicators to improve the reliability of interlock systems a method called redundancy method is applied to the systems of operation of high voltage. (author)

  16. Computerized treatment planning systems for external photon beam radiotherapy

    International Nuclear Information System (INIS)

    Computerized treatment planning systems (TPSs) are used in external beam radiotherapy to generate beam shapes and dose distributions with the intent to maximize tumour control and minimize normal tissue complications. Patient anatomy and tumour targets can be represented as 3-D models. The entire process of treatment planning involves many steps and the medical physicist is responsible for the overall integrity of the computerized TPS to accurately and reliably produce dose distributions and associated calculations for external beam radiotherapy. The planning itself is most commonly carried out by a dosimetrist, and the plan must be approved by a radiation oncologist before implementation in actual patient treatments. Treatment planning prior to the 1970s was generally carried out through the manual manipulation of standard isodose charts on to patient body contours that were generated by direct tracing or lead wire representation, and relied heavily on the judicious choice of beam weight and wedging by an experienced dosimetrist. The simultaneous development of computed tomography (CT), along with the advent of readily accessible computing power from the 1970s on, led to the development of CT based computerized treatment planning, providing the ability to view dose distributions directly superimposed upon a patient's axial anatomy. The entire treatment planning process involves many steps, beginning from beam data acquisition and entry into the computerized TPS, through patient data acquisition, to treatment plan generation and the final transfer of data to the treatment machine. Successive improvements in treatment planning hardware and software have been most notable in the graphics, calculation and optimization aspects of current systems. Systems encompassing the 'Virtual Patient' are able to display beam's eye views (BEVs) of radiation beams and digitally reconstructed radiographs (DRRs) for arbitrary dose distributions. Dose calculations have evolved from

  17. Dual-energy X-ray micro-CT imaging of hybrid Ni/Al open-cell foam

    Science.gov (United States)

    Fíla, T.; Kumpová, I.; Koudelka, P.; Zlámal, P.; Vavřík, D.; Jiroušek, O.; Jung, A.

    2016-01-01

    In this paper, we employ dual-energy X-ray microfocus tomography (DECT) measurement to develop high-resolution finite element (FE) models that can be used for the numerical assessment of the deformation behaviour of hybrid Ni/Al foam subjected to both quasi-static and dynamic compressive loading. Cubic samples of hybrid Ni/Al open-cell foam with an edge length of [15]mm were investigated by the DECT measurement. The material was prepared using AlSi7Mg0.3 aluminium foam with a mean pore size of [0.85]mm, coated with nanocrystalline nickel (crystallite size of approx. [50]nm) to form a surface layer with a theoretical thickness of [0.075]mm. CT imaging was carried out using state-of-the-art DSCT/DECT X-ray scanner developed at Centre of Excellence Telč. The device consists of a modular orthogonal assembly of two tube-detector imaging pairs, with an independent geometry setting and shared rotational stage mounted on a complex 16-axis CNC positioning system to enable unprecedented measurement variability for highly-detailed tomographical measurements. A sample of the metal foam was simultaneously irradiated using an XWT-240-SE reflection type X-ray tube and an XWT-160-TCHR transmission type X-ray tube. An enhanced dual-source sampling strategy was used for data acquisition. X-ray images were taken using XRD1622 large area GOS scintillator flat panel detectors with an active area of [410 × 410]mm and resolution [2048 × 2048]pixels. Tomographic scanning was performed in 1,200 projections with a 0.3 degree angular step to improve the accuracy of the generated models due to the very complex microstructure and high attenuation of the investigated material. Reconstructed data was processed using a dual-energy algorithm, and was used for the development of a 3D model and voxel model of the foam. The selected parameters of the models were compared with nominal parameters of the actual foam and showed good correlation.

  18. Dual-energy X-ray micro-CT imaging of hybrid Ni/Al open-cell foam

    International Nuclear Information System (INIS)

    In this paper, we employ dual-energy X-ray microfocus tomography (DECT) measurement to develop high-resolution finite element (FE) models that can be used for the numerical assessment of the deformation behaviour of hybrid Ni/Al foam subjected to both quasi-static and dynamic compressive loading. Cubic samples of hybrid Ni/Al open-cell foam with an edge length of [15]mm were investigated by the DECT measurement. The material was prepared using AlSi7Mg0.3 aluminium foam with a mean pore size of [0.85]mm, coated with nanocrystalline nickel (crystallite size of approx. [50]nm) to form a surface layer with a theoretical thickness of [0.075]mm. CT imaging was carried out using state-of-the-art DSCT/DECT X-ray scanner developed at Centre of Excellence Telč. The device consists of a modular orthogonal assembly of two tube-detector imaging pairs, with an independent geometry setting and shared rotational stage mounted on a complex 16-axis CNC positioning system to enable unprecedented measurement variability for highly-detailed tomographical measurements. A sample of the metal foam was simultaneously irradiated using an XWT-240-SE reflection type X-ray tube and an XWT-160-TCHR transmission type X-ray tube. An enhanced dual-source sampling strategy was used for data acquisition. X-ray images were taken using XRD1622 large area GOS scintillator flat panel detectors with an active area of [410 × 410]mm and resolution [2048 × 2048]pixels. Tomographic scanning was performed in 1,200 projections with a 0.3 degree angular step to improve the accuracy of the generated models due to the very complex microstructure and high attenuation of the investigated material. Reconstructed data was processed using a dual-energy algorithm, and was used for the development of a 3D model and voxel model of the foam. The selected parameters of the models were compared with nominal parameters of the actual foam and showed good correlation

  19. Control and monitoring system for internal beam diagnostics facility of SCC

    International Nuclear Information System (INIS)

    The first Ion beam will be accelerated in K-500 Superconducting Cyclotron at VECC soon. The acceleration zone employs Main probe and Beam viewer probe for internal beam diagnostics. The ion beam, during acceleration inside the cyclotron, is needed to be maintained in median plane. The deviation of beam at various radial positions is to be monitored by Main-Probe head. The characteristics of beam e.g. size and shape information is required at the time of beam tuning. A Beam Viewer Probe, made of a borescope fitted with a fluorescent plate is used to display the beam characteristics. High resolution probe head driving systems are developed along with VB GUI to control both the drives and monitor the beam properties (e.g. magnitude, deviation, size, shape). This paper describes the control instrumentation and monitoring scheme for main probe and viewer probe. (author)

  20. Development of the IHEP booster beam injection system

    International Nuclear Information System (INIS)

    A brief description of the IHEP synchrotron booster injection system equipment is given and results of experiments on two-turn injection are presented. The circuit of kicker-magnet switching is provided. At linear accelerator current of 80 mA the two-turn injection ensured the accumulation of 1.3 x 1012 proton/booster cycle; the total (per 29 injection cycles into the main accelerator) intensity of the accelerated beam in the booster bunch exceeded 2 X 1013, which is far in excess of the needs of the U-70 accelerator presently

  1. Vacuum Chamber for the Measurement System of the Beam Energy

    Science.gov (United States)

    Abakumova, E.; Achasov, M.; Dong, HaiYi; Qu, HuaMin; Krasnov, A.; Kosarev, A.; Muchnoi, N.; Pyata, E.; Xiao, Qiong; Mo, XiaoHu; Wang, YiFang; Zhukov, A.

    Vacuum chamber for the beam energy measurement system based on the Compton backscattering method is presented. The main elements of the chamber are GaAs entrance viewport and a copper mirror. The viewport design provides baking out of the vacuum chamber up to 250 °C. To produce the viewport, an original technology based on brazing GaAs plate by lead has been developed. The vacuum chambers were installed at the BEPC-II and VEPP-4 M colliders. After installation the residual gas pressure is about 10-10 Torr.

  2. Tuning of the Compact Linear Collider Beam Delivery System

    CERN Document Server

    Garcia, H; Inntjore Levinsen, Y; Latina, A; Tomas, R; Snuverink, J

    2014-01-01

    Tuning the Compact Linear Collider (CLIC) BeamDelivery System (BDS), and in particular the Final Focus (FF), is a challenging task. In simulations without misalignments, the goal is to reach 120%o f the nominal luminosity target, in order to allow for 10% loss due to static imperfections, and another 10% loss from dynamic imperfections. Various approaches have been considered to correct the magnet misalignments, including 1-1 correction, Dispersion Free Steering (DFS), and several minimization methods utilizing multipole movers. In this paper we report on the recent advancements towards a feasible tuning approach that reaches the required luminosity target.

  3. Laser beam plasma pinch x-ray system

    International Nuclear Information System (INIS)

    A system is provided for producing plasma pinch X-rays usable in X-ray lithography. Ionized heated plasma vapor is repeatably generated directly from solid material by impingement of a plurality of circumferentially spaced laser beams to generate an annulus of plasma. X-rays are generated by passing high current through the annular plasma in an axial gap between the solid material target electrode and another electrode, causing magnetic field radial inward plasma pinching to a central constricted area further heating the plasma and emitting X-rays. A central axially directed laser may further heat the plasma in the pinched area

  4. A high intensity beam handling system at the KEK-PS new experimental hall

    International Nuclear Information System (INIS)

    We would like to summarize newly developed technology for handling high-intensity beams. This was practically employed in the beam-handling system of primary protons at the KEK-PS new experimental hall. (author)

  5. Radially Polarized Bessel-Gauss Beams in ABCD Optical Systems and Fiber-Based Generation

    OpenAIRE

    Schimpf, Damian; Putnam, William P.; Grogan, Michael D.; Ramachandran, Siddharth; Kaertner, Franz

    2013-01-01

    We derive solutions for radially polarized Bessel-Gauss beams in ABCD optical systems by superimposing decentered Gaussian beams with linear polarization states. We experimentally confirm the expression by employing a fiber-based mode-converter.

  6. Development of laser beam injection system for the Edge Thomson Scattering (ETS) in ITER

    International Nuclear Information System (INIS)

    This paper focuses on the design and development of the laser injection system for the ITER Edge Thomson Scattering system (ETS). The ITER ETS achieves a temporal resolution of 100 Hz by firing two 50 Hz laser beams alternatively. The use of dual lasers enables us to perform the Thomson scattering measurements at a temporal resolution of 50 Hz in case that one of the laser systems stops functioning. A new type of beam combiner was developed to obtain a single beam that is collinear and fixed linearly polarized from two laser beams using a motor-driven rotating half-wave plate. The rotating half-wave plate method does not induce misalignment even if the rotating mechanism malfunctions. The combined beam is relayed from the diagnostic hall to the plasma using mirror optics and is absorbed at the beam dump integrated on the inner blanket. The beam alignment system was designed to direct the laser beam onto the center of the beam dump head. The beam position at the beam dump is monitored by four alignment laser beams which propagate parallel to the diagnostic Nd:YAG laser beam and imaging systems installed outside the diagnostic port

  7. Development of laser beam injection system for the Edge Thomson Scattering (ETS) in ITER

    Science.gov (United States)

    Yatsuka, E.; Hatae, T.; Suitoh, S.; Ohara, M.; Hagita, K.; Inoue, K.; Bassan, M.; Walsh, M.; Itami, K.

    2016-01-01

    This paper focuses on the design and development of the laser injection system for the ITER Edge Thomson Scattering system (ETS). The ITER ETS achieves a temporal resolution of 100 Hz by firing two 50 Hz laser beams alternatively. The use of dual lasers enables us to perform the Thomson scattering measurements at a temporal resolution of 50 Hz in case that one of the laser systems stops functioning. A new type of beam combiner was developed to obtain a single beam that is collinear and fixed linearly polarized from two laser beams using a motor-driven rotating half-wave plate. The rotating half-wave plate method does not induce misalignment even if the rotating mechanism malfunctions. The combined beam is relayed from the diagnostic hall to the plasma using mirror optics and is absorbed at the beam dump integrated on the inner blanket. The beam alignment system was designed to direct the laser beam onto the center of the beam dump head. The beam position at the beam dump is monitored by four alignment laser beams which propagate parallel to the diagnostic Nd:YAG laser beam and imaging systems installed outside the diagnostic port.

  8. A new SPM at Fudan university. System construction and calculation of beam optics

    CERN Document Server

    Liu Bo; Sun Min De; Shi Xian Feng; Sun Chuan Chen; Shen Hao; Mi Yong

    2002-01-01

    High Energy ion beams accelerated by the tandem (9SDH-2) can be focused to a beam diameter about 1 mu m by quadrupole triplet magnetic lens. The detection system consists of several detectors. Several ion beam analytical techniques, such as PIXE, RBS, STIM, etc. are available with the new SPM system. The facility can promote interdisciplinary researches of different fields including material science, environment science, geology and biology. In order to minimize the diameter of the ion beam, a simulation calculation of beam optics is carried out for the new SPM system. The calculation results are helpful to the installation of the whole microbeam system

  9. Propagation of partially polarized Gaussian Schell-model beams through aligned and misaligned optical systems

    Institute of Scientific and Technical Information of China (English)

    戈迪; 蔡阳健; 林强

    2005-01-01

    By use of a tensor method, the transform formulae for the beam coherence-polarization matrix of the partially polarized Gaussian Schell-model (GSM) beams through aligned and misaligned optical systems are derived. As an example, the propagation properties of the partially polarized GSM beam passing through a misaligned thin lens are illustrated numerically and discussed in detail. The derived formulae provide a convenient way to study the propagation properties of the partially polarized GSM beams through aligned and misaligned optical systems.

  10. Two-Pipe Chilled Beam System for Both Cooling and Heating of Office Buildings

    DEFF Research Database (Denmark)

    Afshari, Alireza; Gordnorouzi, Rouzbeh; Hultmark, Göran;

    2013-01-01

    Simulations were performed to compare a conventional 4-pipe chilled beam system and a 2-pipe chilled beam system. The objective was to establish requirements, possibilities and limitations for a well-functioning 2-pipe chilled beam system for both cooling and heating of office buildings. The...... consumption and hence energy savings in the 2-pipe chilled beam system in comparison with the 4-pipe system. The 2-pipe chilled beam system used high temperature cooling and low temperature heating with a water temperature of 20°C to 23°C, available for free most of the year. The system can thus take...... advantage of renewable energy. The results showed that the energy consumption was 3% less in the 2-pipe chilled beam system in comparison with the conventional 4-pipe system when moving cooled and heated water through the building, transferring the energy to where it is needed. Using free cooling (taking...

  11. The effect of object shape and laser beam shape on lidar system resolution

    Science.gov (United States)

    Cheng, Hongchang; Wang, Jingyi; Ke, Jun

    2016-06-01

    In a LIDAR system, a pulsed laser beam is propagated to a scene, and then reflected back by objects. Ideally if the beam diameter and the pulse width are close to zero, then the reflected beam in time domain is similar to a delta function, which can accurately locate an object's position. However, in a practical system, the beam has finite size. Therefore, even if the pulse width is small, an object shape will make the reflected beam stretched along the time axis, then affect system resolution. In this paper, we assume the beam with Gaussian shape. The beam can be formulated as a delta function convolved with a shape function, such as a rectangular function, in time domain. Then the reflected beam can be defined as a system response function convolved with the shape function. We use symmetric objects to analyze the reflected beam. Corn, sphere, and cylinder objects are used to find a LIDAR system's response function. The case for large beam size is discussed. We assume the beam shape is similar to a plane wave. With this assumption, we get the simplified LIDAR system response functions for the three kinds of objects. Then we use tiny spheres to emulate an arbitrary object, and study its effect to the returned beam.

  12. Free vibrations of a multi-span Timoshenko beam carrying multiple spring-mass systems

    Indian Academy of Sciences (India)

    Yusuf Yesilce; Oktay Demirdag; Seval Catal

    2008-08-01

    Structural elements supporting motors or engines are frequently seen in technological applications. The operation of a machine may introduce additional dynamic stresses on the beam. It is important, then, to know the natural frequencies of the coupled beam-mass system, in order to obtain a proper design of the structural elements. The literature regarding the free vibration analysis of Bernoulli–Euler single-span beams carrying a number of spring-mass system and Bernoulli–Euler multi-span beams carrying multiple spring-mass systems are plenty, but on Timoshenko multi-span beams carrying multiple spring-mass systems is fewer. This paper aims at determining the natural frequencies and mode shapes of a Timoshenko multi-span beam. The model allows to analyse the influence of the shear effect and spring-mass systems on the dynamic behaviour of the beams by using Timoshenko Beam Theory (TBT). The effects of attached spring-mass systems on the free vibration characteristics of the 1–4 span beams are studied. The natural frequencies of Timoshenko multi-span beam calculated by using secant method for non-trivial solution are compared with the natural frequencies of multi-span beam calculated by using Bernoulli–Euler Beam Theory (EBT) in literature; the mode shapes are presented in graphs.

  13. Fault detection and protection system for neutral beam generators on the Neutral Beam Engineering Test Facility (NBETF)

    International Nuclear Information System (INIS)

    Neutral beam sources, their power supplies and instrumentation can be damaged from high voltage sparkdown or from overheating due to excessive currents. The Neutral Beam Engineering Test Facility (NBETF) in Berkeley has protective electronic hardware that senses a condition outside a safe operating range and generates a response to terminate such a fault condition. A description of this system is presented in this paper. 8 references, 2 figures, 2 tables

  14. Research progress of micro CT used in mini-implants of orthodontic miniscrew%显微 CT 应用于正畸微种植体的研究进展

    Institute of Scientific and Technical Information of China (English)

    田亚敏; 陈岩; 郭立娜

    2014-01-01

    Mini-implant anchorage for the orthodontic treatment is an effective method ,the stability is critical in the achievement of reliable anchorage .Micro-computed tomography (Micro-CT) technique is a new device using X -ray imaging principle of ultra-high-resolution three-dimen-sional imaging equipment, without destroying sample , bones arond the mini-implant with ultra high-resolution X-ray imaging to obtain high precision three -dimensional images and quantitative analysis of the structure, density and mechanics.Micro-CT is a powerful tool to study hard tissue material .In this paper, the current application of micro-CT in the field of orthodontic micro-implants is reviewed.%微种植体支抗技术是正畸治疗中一种有效和理想的办法,而其稳定性是获得可靠支抗的必要条件。显微 CT 是一种新型的采用 X 线成像原理进行超高分辨率三维成像技术,可以在不破坏样品的情况下对微种植体周围的骨质进行超高分辨率 X 线成像,获得高精度三维图像,并进行结构、密度和力学的定量分析,是研究硬组织材料的强大工具。本文对显微 CT 目前在正畸微种植体领域方面的应用予以综述。

  15. Beam self-excited rf cavity driver for a deflector or focusing system

    Energy Technology Data Exchange (ETDEWEB)

    Wadlinger, E.A.

    1996-09-01

    A bunched beam from and accelerator can excite and power an rf cavity which then drives either a deflecting or focusing (including nonlinear focusing) rf cavity with and amplitude related to beam current. Rf power, generated when a bunched beam loses energy to an rf field when traversing an electric field that opposes the particle`s motion, is used to drive a separate (or the same) cavity to either focus or deflect the beam. The deflected beam can be stopped by an apertures or directed to a different area of a target depending on beam current. The beam-generated rf power can drive a radio-frequency quadrupole (RFQ) that can change the focusing properties of a beam channel as a function of beam current (space- charge force compensation or modifying the beam distribution on a target). An rf deflector can offset a beam to a downstream sextupole, effectively producing a position-dependent quadrupole field. The combination of rf deflector plus sextupole will produce a beam current dependent quadropole-focusing force. A static quadrupole magnet plus another rf deflector can place the beam back on the optic axis. This paper describes the concept, derives the appropriate equations for system analysis, and fives examples. A variation on this theme is to use the wake field generated in an rf cavity to cause growth in the beam emittance. The beam current would then be apertured by emittance defining slits.

  16. Differential pumping system for electron beam extraction in atmosphere

    International Nuclear Information System (INIS)

    The design of a differential pumping system (DPS) for extraction of an electron beam from the shaping region with a pressure of approximately 10-5 torr into the atmosphere is described. The system consists of five sections, with individual vacuum pumping. To reduce the dimensions of DPS the first three sections are pumped out through intermediate volumes connected to vapour-oil pumps. At the DPS outlet, a diaphragm with a small opening is replaced by an air ejector, which considerably improves the operation of DPS and makes it possible to increase the opening in the outlet diaphragm to 4-6 mm. The pressure in the DPS sections has been calculated, and the results are confirmed by experimental data

  17. 3-D reconstruction and analysis of X-ray micro-CT images by using VoxBlast software. The effect of raloxifene on the lumbar vertebrae in ovariectomized mice

    International Nuclear Information System (INIS)

    To evaluate the skeletal efficacy of raloxifene on the osteoporosis in ovariectomized mice model, the sixth lumbar vertebrae was scanned by X-ray micro-CT, and these resulting 8-bit gray-scale images were analyzed by using commercial three-dimensional (3-D) reconstruction software (VoxBlastTM Mac, VayTek, Inc., USA). In this paper, it is described how to use VoxBlast software practically for processing sequential datasets from CT scanners. Furthermore, we demonstrate in 3-D visualization that new trabecular bones build compact bridge constructions in the lumbar vertebrae after the treatment with raloxifene. (author)

  18. Development of beam expander system using non-linear beam optics at J-PARC spallation neutron source

    International Nuclear Information System (INIS)

    In the Japanese Spallation Neutron Source (JSNS) of Japan Proton Accelerator Research Complex (J-PARC), proton beam with a high power such as 1 MW is induced to the target consisted of mercury. As increasing in the beam power, the damage of the target becomes serious. Especially for a target for high power short pulse spallation neutron source, the damage due to the proton beam on the target vessel for liquid metal target such as mercury is reported to be proportional of 4th power of the peak intensity of the proton beam. Reduction of the peak current density at the target is a key for a constant beam operation. For reduction of the peak current density, a non-linear beam optics using octupole magnets has been developed. In order to achieve completely flat distribution, higher order magnets than the octupole are required. It was found that a considerable flat distribution can be obtained by only using octupole magnets with reduction of the magnetic field. By using the present beam expander system, the peak current density can be reduced as much as 40%, which mitigates 90% of the pitting damage at the target. (author)

  19. Beam manipulation and compression using broadband rf systems in the Fermilab Main Injector and Recycler

    Energy Technology Data Exchange (ETDEWEB)

    G William Foster et al.

    2004-07-09

    A novel method for beam manipulation, compression, and stacking using a broad band RF system in circular accelerators is described. The method uses a series of linear voltage ramps in combination with moving barrier pulses to azimuthally compress, expand, or cog the beam. Beam manipulations can be accomplished rapidly and, in principle, without emittance growth. The general principle of the method is discussed using beam dynamics simulations. Beam experiments in the Fermilab Recycler Ring convincingly validate the concept. Preliminary experiments in the Fermilab Main Injector to investigate its potential for merging two ''booster batches'' to produce high intensity proton beams for neutrino and antiproton production are described.

  20. Intense relativistic electron beam injector system for tokamak current drive

    International Nuclear Information System (INIS)

    We report experimental and theoretical studies of an intense relativistic electron beam (REB) injection system designed for tokamak current drive experiments. The injection system uses a standard high-voltage pulsed REB generator and a magnetically insulated transmission line (MITL) to drive an REB-accelerating diode in plasma. A series of preliminary experiments has been carried out to test the system by injecting REBs into a test chamber with preformed plasma and applied magnetic field. REBs were accelerated from two types of diodes: a conventional vacuum diode with foil anode, and a plasma diode, i.e., an REB cathode immersed in the plasma. REB current was in the range of 50 to 100 kA and REB particle energy ranged from 0.1 to 1.0 MeV. MITL power density exceeded 10 GW/cm2. Performance of the injection system and REB transport properties is documented for plasma densities from 5 x 1012 to 2 x 1014 cm-3. Injection system data are compared with numerical calculations of the performance of the coupled system consisting of the generator, MITL, and diode