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Sample records for dynamic neutron imaging

  1. Neutron Imaging Reveals Internal Plant Hydraulic Dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Jeffrey [ORNL; Bilheux, Hassina Z [ORNL; Kang, Misun [ORNL; Voisin, Sophie [ORNL; Cheng, Chu-Lin [ORNL; Horita, Jusuke [ORNL; Perfect, Edmund [ORNL

    2013-01-01

    Many terrestrial ecosystem processes are constrained by water availability and transport within the soil. Knowledge of plant water fluxes is thus critical for assessing mechanistic processes linked to biogeochemical cycles, yet resolution of root structure and xylem water transport dynamics has been a particularly daunting task for the ecologist. Through neutron imaging, we demonstrate the ability to non-invasively monitor individual root functionality and water fluxes within Zea mays L. (maize) and Panicum virgatum L. (switchgrass) seedlings growing in a sandy medium. Root structure and growth were readily imaged by neutron radiography and neutron computed tomography. Seedlings were irrigated with water or deuterium oxide and imaged through time as a growth lamp was cycled on to alter leaf demand for water. Sub-millimeter scale resolution reveals timing and magnitudes of root water uptake, redistribution within the roots, and root-shoot hydraulic linkages, relationships not well characterized by other techniques.

  2. Neutron imaging plates

    International Nuclear Information System (INIS)

    Niimura, Nobuo

    1995-01-01

    Imaging plates have been used in the field of medical diagnosis since long ago, but their usefulness was verified as the two-dimensional detector for analyzing the X-ray crystalline structure of high bio molecules like protein, and they have contributed to the remarkable progress in this field. The great contribution is due to the excellent features, such as the detection efficiency of about 100%, the positional resolution smaller than 0.2 mm, the dynamic range of five digits, and the area of several hundreds mm square. The neutron imaging plates have not yet obtained the sufficient results. It was planned to construct the neutron diffractometer for biological matters, and to put imaging plate neutron detectors (IP-ND) to practical use as the detector. The research on the development of IP-NDs was carried out, and the IPp-NDs having the performance comparable with that for X-ray were able to be produced. Imaging plates are the integral type two-dimensional radiation detector using photostimulated luminescence matters, and their principle is explained. As to neutron imaging plates, the converter, neutron detection efficiency and the flight of secondary particles in photo-stimulated luminescence matters are described. As for the present state of development of neutron imaging plates, the IP-NDs made for trial, the dynamic range, the positional resolution, the detection efficiency and the kinds of converters, and the application of IP-NDs are reported. (K.I.)

  3. Problems and prospects of neutron imaging

    International Nuclear Information System (INIS)

    Kobayashi, Hisao

    2008-01-01

    Technical problems and future prospects of neutron imaging and neutron radiography are reviewed and discussed for further development. For technical problems, neutron sources together with cold neutron, ultra-cold neutron, epithermal and fast-neutron beams, energy converters, and the intensity of neutron beam, dynamic range associated with imaging procedure, etc, are reviewed. As standardization, such indicators as beam purity, sensitivity, image quality, and beam quality are discussed and limitation of neutron radiography is also presented. As neutron imaging has developed as a nondestructive testing technique in industrial applications, further problems and prospects of quality control and qualification to perform neutron radiography, standardization and international cooperation of neutron imaging are discussed. (S. Ohno)

  4. Neutron image intensifier tubes

    International Nuclear Information System (INIS)

    Verat, M.; Rougeot, H.; Driard, B.

    1983-01-01

    The most frequently used techniques in neutron radiography employ a neutron converter consisting of either a scintillator or a thin metal sheet. The radiation created by the neutrons exposes a photographic film that is in contact with the converter: in the direct method, the film is exposed during the time that the object is irradiated with neutrons; in the transfer method, the film is exposed after the irradiation of the object with neutrons. In industrial non-destructive testing, when many identical objects have to be checked, these techniques have several disadvantages. Non-destructive testing systems without these disadvantages can be constructed around neutron-image intensifier tubes. A description and the operating characteristics of neutron-image intensifier tubes are given. (Auth.)

  5. Dynamic infrared imaging for cancer: research and development in the Argentine Boron neutron capture therapy

    International Nuclear Information System (INIS)

    Santa Cruz, Gustavo A.; Bertotti, J.; Marin, J.

    2009-01-01

    In the framework of the Argentine Boron Neutron Capture Therapy (BNCT) project for treating metastatic cutaneous melanoma, we have initiated a research and development program aimed at obtaining a noninvasive methodology for following-up the treated patients. The technique is called Dynamic Infrared Imaging (DIRI) and comprises the acquisition of infrared images as a function of time of the anatomical part under study, when the region is subjected to a mild cold stress. Vascular, metabolic and regulating differences between normal and tumor tissues appear as differences in the pattern of temperature evolution, which can be correlated with the anatomical and functional aspects of both. Two patients enrolled in the BNCT protocol were studied with DIRI. A good spatial correlation between dose, temperature recovery velocity and skin reaction distributions was observed at the time of maximum expression of the erythematous reaction. Melanoma nodules appear as highly localized hyperthermic regions, surrounded and interconnected by elevated temperature areas. Their temperature recovery velocity after the thermal cold stress was substantially faster than that of normal skin with an appreciably large temperature difference (6 degreesC to 10 degreesC). These tissue differences can be related with the thermal conductivity and metabolic rate as explained by a simple one-directional heat transport model. Compared with other imaging modalities (CT and Doppler ultrasound) DIRI has had a similar ability for confirming the already diagnosed nodules. Together with the clinical observation, DIRI provides a potentially useful amount of information, at a competitive cost-benefit relationship suitable for performing a non-invasive functional assessment of this kind of cutaneous lesions and the evaluation of the acute skin reaction following irradiation. (author)

  6. Neutron radiography using neutron imaging plate

    International Nuclear Information System (INIS)

    Chankow, Nares; Wonglee, Sarinrat

    2008-01-01

    Full text: The aims of this research are to study properties of neutron imaging plate, to obtain a suitable condition for neutron radiography and to use the neutron imaging plate for testing of materials nondestructively. The experiments were carried out by using a neutron beam from the Thai Research Reactor TRR-1/M1 at a power of 1.2 MW. A BAS-ND 2040 FUJI neutron imaging plate and a MX125 Kodak X-ray film/Gadolinium neutron converter screen combination were tested for comparison. It was found that the photostimulated light (PSL) read out of the imaging plate was directly proportional to the exposure time. It was also found that radiography with neutron using the imaging plate was approximately 40 times faster than the conventional neutron radiography using x-ray film/Gd converter screen combination. The sensitivity of the imaging plate to gamma-rays was investigated by using gamma-rays from an 192 Ir and a 60 Co radiographic sources. The imaging plate was found to be 5-6 times less sensitive to gamma-rays than a FUJI BAS-MS 2040 gamma-ray imaging plate. Finally, some specimens were selected to be radiographed with neutrons using the imaging plate and the x-ray film/Gd converter screen combination in comparison to x-rays. Parts containing light elements could be clearly observed by the two neutron radiographic techniques. It could be concluded that the image quality from the neutron imaging plate was comparable to the conventional x-ray film/Gd converter screen combination but the exposure time could be approximately reduced by a factor of 40

  7. Neutron imaging of a commercial Li-ion battery during discharge: Application of monochromatic imaging and polychromatic dynamic tomography

    International Nuclear Information System (INIS)

    Butler, Leslie G.; Schillinger, Burkhard; Ham, Kyungmin; Dobbins, Tabbetha A.; Liu, Ping; Vajo, John J.

    2011-01-01

    A commercial lithium-ion polymer battery of prismatic construction was imaged in 2D by monochromatic neutron radiography at wavelengths around a LiC 6 spectral feature. Over the range of 3-4 A, the neutron attenuation spectra for charged and discharged batteries are distinctly different. In a real-time experiment, a battery was observed during discharge at wavelengths spanning the LiC 6 spectral feature and its disappearance monitored. No evidence of 'staging' was detected in this preliminary experiment. A similar battery was imaged in 3D with a new tomographic data acquisition scheme based on the Greek golden ratio; the scheme allows convenient post-processing to establish 'time windows' for 3D image reconstruction. The 3D images at 5% state of charge intervals are compromised by beam hardening, but still show some asymmetric battery volume change with discharge. Finally comments on the future of neutron imaging for battery experiments, whether at continuous sources at nuclear reactors or at pulsed spallation sources, are discussed.

  8. Imaging with cold neutrons

    International Nuclear Information System (INIS)

    Lehmann, E.H.; Kaestner, A.; Josic, L.; Hartmann, S.; Mannes, D.

    2011-01-01

    Neutrons for imaging purposes are provided mainly from thermal beam lines at suitable facilities around the world. The access to cold neutrons is presently limited to very few places only. However, many challenging options for imaging with cold neutrons have been found out, given by the interaction behavior of the observed materials with neutrons in the cold energy range (3-10 A). For absorbing materials, the interaction probability increases proportionally with the wavelength with the consequence of more contrast but less transmission with cold neutrons. Many materials are predominantly scattering neutrons, in particular most of crystalline structural materials. In these cases, cold neutrons play an important role by covering the energy range of the most important Bragg edges given by the lattice planes of the crystallites. This particular behavior can be used for at least two important aspects-choosing the right energy of the initial beam enables to have a material more or less transparent, and a direct macroscopic visualization of the crystalline structure and its change in a manufacturing process. Since 2006, PSI operates its second beam line for neutron imaging, where cold neutrons are provided from a liquid deuterium cold source (operated at 25 K). It has been designed to cover the most current aspects in neutron imaging research with the help of high flexibility. This has been done with changeable inlet apertures, a turbine based velocity selector, two beam positions and variable detector systems, satisfying the demands of the individual investigation. The most important detection system was found to be a micro-tomography system that enables studies in the presently best spatial resolution. In this case, the high contrast from the sample interaction process and the high detection probability for the cold neutrons combines in an ideal combination for the best possible performance. Recently, it was found out that the energy selective studies might become a

  9. Imaging with Polarized Neutrons

    Directory of Open Access Journals (Sweden)

    Nikolay Kardjilov

    2018-01-01

    Full Text Available Owing to their zero charge, neutrons are able to pass through thick layers of matter (typically several centimeters while being sensitive to magnetic fields due to their intrinsic magnetic moment. Therefore, in addition to the conventional attenuation contrast image, the magnetic field inside and around a sample can be visualized by detecting changes of polarization in a transmitted beam. The method is based on the spatially resolved measurement of the cumulative precession angles of a collimated, polarized, monochromatic neutron beam that traverses a magnetic field or sample.

  10. Energy dependent neutron imaging

    International Nuclear Information System (INIS)

    Kupperman, D.S.; Hitterman, R.L.; Rhodes, E.

    1990-01-01

    A waste package consisting of a container and high-level nuclear waste is being developed for the permanent disposal of radioactive waste. Yucca Mountain, Nevada, is being studied as a potential site for the underground high-level nuclear waste repository. A major consideration for choosing Yucca Mountain is the presence of zeolite in tertiary ash-flow tuffs. The presence of zeolites could provide geological barriers to radionuclide migration. The suitability of the tuffaceous rocks at Yucca Mountain for the repository is being investigated since the properties of the environment around a waste site must be well characterized to reliably predict performance. The results of experiments at Lawrence Livermore National Laboratory (LLNL) to assess the possibility of imaging water in Nevada Test Site welded tuff samples showed that nuclear magnetic resonance imaging is not viable. This leaves neutron tomography and high-frequency electromagnetic geotomography as possibilities for the practical imaging of distribution and flow of fluids in rock, including tuff specimens. Water tracers are needed in electromagnetic tomography techniques since the contrast for detecting water in cracks of tuff is lower than in granite because of the higher porosity in tuff. The results of preliminary testing with geotomography by LLNL indicates relatively low spatial resolution. More sensitive techniques for detecting water is needed. This paper describes preliminary experiments to apply pulsed neutrons to image water in a sample of tuff. 3 refs., 3 figs

  11. Fast neutron radiography using photoluminescent imaging plates

    International Nuclear Information System (INIS)

    Rant, J.; Kristof, E.; Balasko, M.; Stade, J.

    1999-01-01

    Fast neutron radiography (FNR) and resonance neutron radiography (RNR) are complementary to the conventional radiography with high energy gamma-rays or brems-strahlung radiation used for the inspection of thick metal objects. In both non-destructive methods, the contrast sensitivity and the penetration power can be improved by using higher energy neutrons. At present direct techniques based either n Solid State Nuclear Track detectors (SSNTDs) or scintillating screens and transfer techniques using activation threshold detectors and radiographic films are applied for the detection of fast neutron images. Rather low detection sensitivity of film and SSNTD based fast neutron imaging methods and also rather poor inherent image contrast of SSNTD pose a problem for FNR in the fast neutron energy region 1-15 MeV interesting for NDT. For more efficient detection of fast neutron images the use of novel highly sensitive photoluminescent imaging plates (IP) in combination with threshold at the KFKI research reactor. The conventional IP produced by FUJI Photo Film Co. for the detection of beta and X-ray radiation were used. The threshold activation detectors were the reactions 115 In(n, n') 115m In, 64 Zn(n,p) 64 Cu, 56 Fe(n, p) 56 Mn, 24 Mg(n, p) 24 Na and 27 Al(n, α) 24 Na. These threshold reactions cover the fast neutron energy region between 0,7 MeV and 12 MeV. Pure, commercially available metals 0,1 mm to 0,25 mm thick made of In, Zn, Fe, Mg and Al were used as converter screens. The very high sensitivity of IP, the linearity of their response over 5 decades of exposure dose and the high dynamic digitalisation latitude enabled fast neutron radiography of image quality comparable to the quality of thermal NR. In our experimental conditions (φ n ∼ 10 8 n/cm 2 s, R Cd ∼ 2) the neutron exposure and IP exposure periods were still practical and comparable to the half life of the corresponding reaction products (half an hour to several hours). Even with the 27 Al(n.α) 24

  12. Dynamical theory of neutron diffraction

    International Nuclear Information System (INIS)

    Sears, V.F.

    1978-01-01

    We present a review of the dynamical theory of neutron diffraction by macroscopic bodies which provides the theoretical basis for the study of neutron optics. We consider both the theory of dispersion, in which it is shown that the coherent wave in the medium satisfies a macroscopic one-body Schroedinger equation, and the theory of reflection, refraction, and diffraction in which the above equation is solved for a number of special cases of interest. The theory is illustrated with the help of experimental results obtained over the past 10 years by a number of new techniques such as neutron gravity refractometry. Pendelloesung interference, and neutron interferometry. (author)

  13. Neutron Imaging Developments at LANSCE

    Science.gov (United States)

    Nelson, Ron; Hunter, James; Schirato, Richard; Vogel, Sven; Swift, Alicia; Ickes, Tim; Ward, Bill; Losko, Adrian; Tremsin, Anton

    2015-10-01

    Neutron imaging is complementary to x-ray imaging because of its sensitivity to light elements and greater penetration of high-Z materials. Energy-resolved neutron imaging can provide contrast enhancements for elements and isotopes due to the variations with energy in scattering cross sections due to nuclear resonances. These cross section differences exist due to compound nuclear resonances that are characteristic of each element and isotope, as well as broader resonances at higher energies. In addition, multi-probe imaging, such as combined photon and neutron imaging, is a powerful tool for discerning properties and features in materials that cannot be observed with a single probe. Recently, we have demonstrated neutron imaging, both radiography and computed tomography, using the moderated (Lujan Center) and high-energy (WNR facility) neutron sources at LANSCE. Flat panel x-ray detectors with suitable scintillator-converter screens provide good sensitivity for both low and high neutron energies. Micro-Channel-Plate detectors and iCCD scintillator camera systems that provide the fast time gating needed for energy-resolved imaging have been demonstrated as well. Examples of recent work will be shown including fluid flow in plants and imaging through dense thick objects. This work is funded by the US Department of Energy, National Nuclear Security Administration, and performed by Los Alamos National Security LLC under Contract DE-AC52-06NA25396.

  14. Neutron Dark-Field Imaging

    Science.gov (United States)

    Mullins, David

    2017-09-01

    Neutron imaging is typically used to image and reconstruct objects that are difficult to image using X-Ray imaging techniques. X-Ray absorption is primarily determined by the electron density of the material. This makes it difficult to image objects within materials that have high densities such as metal. However, the neutron scattering cross section primarily depends on the strong nuclear force, which varies somewhat randomly across the periodic table. In this project, an imaging technique known as dark field imaging using a far-field interferometer has been used to study a sample of granite. With this technique, interferometric phase images are generated. The dispersion of the microstructure of the sample dephases the beam, reducing the visibility. Collecting tomographic projections at different autocorrelation lengths (from 100 nanometers to 1.74 micrometers) essentially creates a 3D small angle scattering pattern, enabling mapping of how the microstructure is distributed throughout the sample.

  15. Characterization of a neutron imaging setup at the INES facility

    Science.gov (United States)

    Durisi, E. A.; Visca, L.; Albertin, F.; Brancaccio, R.; Corsi, J.; Dughera, G.; Ferrarese, W.; Giovagnoli, A.; Grassi, N.; Grazzi, F.; Lo Giudice, A.; Mila, G.; Nervo, M.; Pastrone, N.; Prino, F.; Ramello, L.; Re, A.; Romero, A.; Sacchi, R.; Salvemini, F.; Scherillo, A.; Staiano, A.

    2013-10-01

    The Italian Neutron Experimental Station (INES) located at the ISIS pulsed neutron source (Didcot, United Kingdom) provides a thermal neutron beam mainly used for diffraction analysis. A neutron transmission imaging system was also developed for beam monitoring and for aligning the sample under investigation. Although the time-of-flight neutron diffraction is a consolidated technique, the neutron imaging setup is not yet completely characterized and optimized. In this paper the performance for neutron radiography and tomography at INES of two scintillator screens read out by two different commercial CCD cameras is compared in terms of linearity, signal-to-noise ratio, effective dynamic range and spatial resolution. In addition, the results of neutron radiographies and a tomography of metal alloy test structures are presented to better characterize the INES imaging capabilities of metal artifacts in the cultural heritage field.

  16. Dynamic imaging with a triggered and intensified CCD camera system in a high-intensity neutron beam

    International Nuclear Information System (INIS)

    Vontobel, P.; Frei, G.; Brunner, J.; Gildemeister, A.E.; Engelhardt, M.

    2005-01-01

    When time-dependent processes within metallic structures should be inspected and visualized, neutrons are well suited due to their high penetration through Al, Ag, Ti or even steel. Then it becomes possible to inspect the propagation, distribution and evaporation of organic liquids as lubricants, fuel or water. The principle set-up of a suited real-time system was implemented and tested at the radiography facility NEUTRA of PSI. The highest beam intensity there is 2x10 7 cm -2 s -1 , which enables to observe sequences in a reasonable time and quality. The heart of the detection system is the MCP intensified CCD camera PI-Max with a Peltier cooled chip (1300x1340 pixels). The intensifier was used for both gating and image enhancement, where as the information was accumulated over many single frames on the chip before readout. Although, a 16-bit dynamic range is advertised by the camera manufacturers, it must be less due to the inherent noise level from the intensifier. The obtained result should be seen as the starting point to go ahead to fit the different requirements of car producers in respect to fuel injection, lubricant distribution, mechanical stability and operation control. Similar inspections will be possible for all devices with repetitive operation principle. Here, we report about two measurements dealing with the lubricant distribution in a running motorcycle motor turning at 1200rpm. We were monitoring the periodic stationary movements of piston, valves and camshaft with a micro-channel plate intensified CCD camera system (PI-Max 1300RB, Princeton Instruments) triggered at exactly chosen time points

  17. Dynamic neutron radiography of a combustion engine

    International Nuclear Information System (INIS)

    Brunner, J.; Hillenbach, A.; Schillinger, B.

    2004-01-01

    Dynamic neutron radiography is a non-destructive testing method, which made big steps in the last years. Depending on the neutron flux, the object and the detector a time resolution down to 50 ms is possible. In the case of repetitive processes the object can be synchronized with the detector and better statistics in the image can be obtained by adding radiographies of the same phase. By delaying the trigger signal a radiography movie can be composed with a time resolution down to 100 μs. A combustion engine is an ideal sample for the explained technique, because the motor block of metal is relatively easy to penetrate, while oil and fuel attenuate the thermal neutron beam much stronger. Various experiments were performed at ILL and PSI. Soon the tomography station ANTARES at FRM-II will be ready for measurements. (author)

  18. Digital image processing in neutron radiography

    International Nuclear Information System (INIS)

    Koerner, S.

    2000-11-01

    Neutron radiography is a method for the visualization of the macroscopic inner-structure and material distributions of various samples. The basic experimental arrangement consists of a neutron source, a collimator functioning as beam formatting assembly and of a plane position sensitive integrating detector. The object is placed between the collimator exit and the detector, which records a two dimensional image. This image contains information about the composition and structure of the sample-interior, as a result of the interaction of neutrons by penetrating matter. Due to rapid developments of detector and computer technology as well as deployments in the field of digital image processing, new technologies are nowadays available which have the potential to improve the performance of neutron radiographic investigations enormously. Therefore, the aim of this work was to develop a state-of-the art digital imaging device, suitable for the two neutron radiography stations located at the 250 kW TRIGA Mark II reactor at the Atominstitut der Oesterreichischen Universitaeten and furthermore, to identify and develop two and three dimensional digital image processing methods suitable for neutron radiographic and tomographic applications, and to implement and optimize them within data processing strategies. The first step was the development of a new imaging device fulfilling the requirements of a high reproducibility, easy handling, high spatial resolution, a large dynamic range, high efficiency and a good linearity. The detector output should be inherently digitized. The key components of the detector system selected on the basis of these requirements consist of a neutron sensitive scintillator screen, a CCD-camera and a mirror to reflect the light emitted by the scintillator to the CCD-camera. This detector design enables to place the camera out of the direct neutron beam. The whole assembly is placed in a light shielded aluminum box. The camera is controlled by a

  19. Digital image processing in neutron radiography

    International Nuclear Information System (INIS)

    Koerner, S.

    2000-11-01

    Neutron radiography is a method for the visualization of the macroscopic inner-structure and material distributions of various materials. The basic experimental arrangement consists of a neutron source, a collimator functioning as beam formatting assembly and of a plane position sensitive integrating detector. The object is placed between the collimator exit and the detector, which records a two dimensional image. This image contains information about the composition and structure of the sample-interior, as a result of the interaction of neutrons by penetrating matter. Due to rapid developments of detector and computer technology as well as deployments in the field of digital image processing, new technologies are nowadays available which have the potential to improve the performance of neutron radiographic investigations enormously. Therefore, the aim of this work was to develop a state-of-the art digital imaging device, suitable for the two neutron radiography stations located at the 250 kW TRIGA Mark II reactor at the Atominstitut der Oesterreichischen Universitaeten and furthermore, to identify and develop two and three dimensional digital image processing methods suitable for neutron radiographic and tomographic applications, and to implement and optimize them within data processing strategies. The first step was the development of a new imaging device fulfilling the requirements of a high reproducibility, easy handling, high spatial resolution, a large dynamic range, high efficiency and a good linearity. The detector output should be inherently digitized. The key components of the detector system selected on the basis of these requirements consist of a neutron sensitive scintillator screen, a CCD-camera and a mirror to reflect the light emitted by the scintillator to the CCD-camera. This detector design enables to place the camera out of the direct neutron beam. The whole assembly is placed in a light shielded aluminum box. The camera is controlled by a

  20. Performance of a thermal neutron radiographic system using imaging plates

    International Nuclear Information System (INIS)

    Silvani, Maria Ines; Almeida, Gevaldo L. de; Furieri, Rosanne; Lopes, Ricardo T.

    2009-01-01

    A performance evaluation of a neutron radiographic system equipped with a thermal neutron sensitive imaging plate has been undertaken. It includes the assessment of spatial resolution, linearity, dynamic range and the response to exposure time, as well as a comparison of these parameters with the equivalent ones for neutron radiography employing conventional films and a gadolinium foil as converter. The evaluation and comparison between the radiographic systems have been performed at the Instituto de Engenharia Nuclear - CNEN, using the Argonauta Reactor as source of thermal neutrons and a commercially available imaging plate reader. (author)

  1. Applications of image plates in neutron radiography and neutron diffraction at BARC, Trombay

    International Nuclear Information System (INIS)

    Shaikh, A.M.

    2013-01-01

    Neutron radiography techniques based on Gd, Dy and In metallic foils and X-ray film have been used at this centre since early seventies for various NDT and R and D work in nuclear, defence and aerospace industries. In recent years use of photostimulated luminescence based phosphor imaging plate has been introduced in our work. This has enabled to achieve higher sensitivities and dynamic ranges of recording radiographs with acceptable spatial resolution. It also provides digital image information which is more convenient for quantitative evaluations. Neutron image plates have been used in variety of radiography techniques such as conventional neutron radiography (NR), neutron induced beta radiography (NIBR), hydrogen sensitive epithermal neutron radiography (HYSEN) and for neutron powder diffractometry using Apsara, CIRUS and Dhruva reactors as neutron sources. Recently the image plates have also been used for characterization of thermalized neutron beam from a plasma focus neutron source and recording neutron radiographs. Prior to the utilization image plates have been characterised for their performance. Details of the measurements and applications will be presented. (author)

  2. Characterization of a neutron imaging setup at the INES facility

    Energy Technology Data Exchange (ETDEWEB)

    Durisi, E.A., E-mail: elisabettaalessandra.durisi@unito.it [Università di Torino, Dipartimento di Fisica, Via Pietro Giuria 1, 10125 Torino (Italy); Istituto Nazionale di Fisica Nucleare—Sezione di Torino, Via Pietro Giuria 1, 10125 Torino (Italy); Visca, L. [Università di Torino, Dipartimento di Fisica, Via Pietro Giuria 1, 10125 Torino (Italy); Istituto Nazionale di Fisica Nucleare—Sezione di Torino, Via Pietro Giuria 1, 10125 Torino (Italy); Albertin, F.; Brancaccio, R. [Istituto Nazionale di Fisica Nucleare—Sezione di Torino, Via Pietro Giuria 1, 10125 Torino (Italy); Corsi, J. [Università di Torino, Dipartimento di Fisica, Via Pietro Giuria 1, 10125 Torino (Italy); Istituto Nazionale di Fisica Nucleare—Sezione di Torino, Via Pietro Giuria 1, 10125 Torino (Italy); Dughera, G. [Istituto Nazionale di Fisica Nucleare—Sezione di Torino, Via Pietro Giuria 1, 10125 Torino (Italy); Ferrarese, W. [Università di Torino, Dipartimento di Fisica, Via Pietro Giuria 1, 10125 Torino (Italy); Istituto Nazionale di Fisica Nucleare—Sezione di Torino, Via Pietro Giuria 1, 10125 Torino (Italy); Giovagnoli, A.; Grassi, N. [Fondazione Centro per la Conservazione ed il Restauro dei Beni Culturali “La Venaria Reale”, Piazza della Repubblica, 10078 Venaria Reale, Torino (Italy); Grazzi, F. [Consiglio Nazionale delle Ricerche, Istituto dei Sistemi Complessi, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Firenze (Italy); Lo Giudice, A.; Mila, G. [Università di Torino, Dipartimento di Fisica, Via Pietro Giuria 1, 10125 Torino (Italy); Istituto Nazionale di Fisica Nucleare—Sezione di Torino, Via Pietro Giuria 1, 10125 Torino (Italy); and others

    2013-10-21

    The Italian Neutron Experimental Station (INES) located at the ISIS pulsed neutron source (Didcot, United Kingdom) provides a thermal neutron beam mainly used for diffraction analysis. A neutron transmission imaging system was also developed for beam monitoring and for aligning the sample under investigation. Although the time-of-flight neutron diffraction is a consolidated technique, the neutron imaging setup is not yet completely characterized and optimized. In this paper the performance for neutron radiography and tomography at INES of two scintillator screens read out by two different commercial CCD cameras is compared in terms of linearity, signal-to-noise ratio, effective dynamic range and spatial resolution. In addition, the results of neutron radiographies and a tomography of metal alloy test structures are presented to better characterize the INES imaging capabilities of metal artifacts in the cultural heritage field. -- Highlights: A full characterization of the present INES imaging set-up was carried out. Two CCD cameras and two scintillators (ZnS/{sup 6}LiF) of different thicknesses were tested. Linearity, effective dynamic range and spatial resolution were determined. Radiographies of steep wedges were performed using the highest dynamic range setup. Tomography of a bronze cube was performed using the best spatial resolution setup.

  3. Characterization of a neutron imaging setup at the INES facility

    International Nuclear Information System (INIS)

    Durisi, E.A.; Visca, L.; Albertin, F.; Brancaccio, R.; Corsi, J.; Dughera, G.; Ferrarese, W.; Giovagnoli, A.; Grassi, N.; Grazzi, F.; Lo Giudice, A.; Mila, G.

    2013-01-01

    The Italian Neutron Experimental Station (INES) located at the ISIS pulsed neutron source (Didcot, United Kingdom) provides a thermal neutron beam mainly used for diffraction analysis. A neutron transmission imaging system was also developed for beam monitoring and for aligning the sample under investigation. Although the time-of-flight neutron diffraction is a consolidated technique, the neutron imaging setup is not yet completely characterized and optimized. In this paper the performance for neutron radiography and tomography at INES of two scintillator screens read out by two different commercial CCD cameras is compared in terms of linearity, signal-to-noise ratio, effective dynamic range and spatial resolution. In addition, the results of neutron radiographies and a tomography of metal alloy test structures are presented to better characterize the INES imaging capabilities of metal artifacts in the cultural heritage field. -- Highlights: A full characterization of the present INES imaging set-up was carried out. Two CCD cameras and two scintillators (ZnS/ 6 LiF) of different thicknesses were tested. Linearity, effective dynamic range and spatial resolution were determined. Radiographies of steep wedges were performed using the highest dynamic range setup. Tomography of a bronze cube was performed using the best spatial resolution setup

  4. Electronic imaging applied to neutron radiography

    International Nuclear Information System (INIS)

    Garrett, D.A.; Bracher, D.A.

    1976-01-01

    A commercially - available image intensifier was used with a scan conversion memory and a mobile 252 Cf based neutron radiography system to obtain neutron radiographs on a television monitor in 0.5 minutes to 10.0 minutes

  5. Neutron imaging integrated circuit and method for detecting neutrons

    Science.gov (United States)

    Nagarkar, Vivek V.; More, Mitali J.

    2017-12-05

    The present disclosure provides a neutron imaging detector and a method for detecting neutrons. In one example, a method includes providing a neutron imaging detector including plurality of memory cells and a conversion layer on the memory cells, setting one or more of the memory cells to a first charge state, positioning the neutron imaging detector in a neutron environment for a predetermined time period, and reading a state change at one of the memory cells, and measuring a charge state change at one of the plurality of memory cells from the first charge state to a second charge state less than the first charge state, where the charge state change indicates detection of neutrons at said one of the memory cells.

  6. Development of a new electronic neutron imaging system

    CERN Document Server

    Brenizer, J S; Gibbs, K M; Mengers, P; Stebbings, C T; Polansky, D; Rogerson, D J

    1999-01-01

    An electronic neutron imaging camera system was developed for use with thermal, epithermal, and fast neutrons in applications that include nondestructive inspection of explosives, corrosion, turbine blades, electronics, low Z components, etc. The neutron images are expected to provide information to supplement that available from X-ray tests. The primary camera image area was a 30x30 cm field-of-view with a spatial resolution approaching 1.6 line pairs/mm (lp/mm). The camera had a remotely changeable second lens to limit the field-of-view to 7.6x7.6 cm for high spatial resolution (at least 4 lp/mm) thermal neutron imaging, but neutron and light scatter will limit resolution for fast neutrons to about 0.5 lp/mm. Remote focus capability enhanced camera set-up for optimum operation. The 75 dB dynamic range camera system included sup 6 Li-based screens for imaging of thermal and epithermal neutrons and ZnS(Ag)-based screens for fast neutron imaging. The fast optics was input to a Super S-25 Gen II image intensifi...

  7. A polarizing neutron periscope for neutron imaging

    International Nuclear Information System (INIS)

    Schulz, Michael; Boeni, Peter; Calzada, Elbio; Muehlbauer, Martin; Neubauer, Andreas; Schillinger, Burkhard

    2009-01-01

    Optical neutron polarizers like guides or benders destroy the collimation of a neutron beam due to multiple reflections or scattering. This makes them unsuitable for their use in polarized neutron radiography, because the beam collimation is essential to obtain high spatial resolution. We have developed a neutron polarizer based on the principle of an optical periscope with a zigzag double reflection on two parallel high-m supermirror polarizers. If the supermirrors are perfectly parallel and flat, the beam collimation is left unchanged by such a device. A first proof of concept version of this type of polarizer was built and tested. We expect to achieve a beam polarization of up to 99% with an improved version yet to be built.

  8. The neutron imaging diagnostic at NIF (invited).

    Science.gov (United States)

    Merrill, F E; Bower, D; Buckles, R; Clark, D D; Danly, C R; Drury, O B; Dzenitis, J M; Fatherley, V E; Fittinghoff, D N; Gallegos, R; Grim, G P; Guler, N; Loomis, E N; Lutz, S; Malone, R M; Martinson, D D; Mares, D; Morley, D J; Morgan, G L; Oertel, J A; Tregillis, I L; Volegov, P L; Weiss, P B; Wilde, C H; Wilson, D C

    2012-10-01

    A neutron imaging diagnostic has recently been commissioned at the National Ignition Facility (NIF). This new system is an important diagnostic tool for inertial fusion studies at the NIF for measuring the size and shape of the burning DT plasma during the ignition stage of Inertial Confinement Fusion (ICF) implosions. The imaging technique utilizes a pinhole neutron aperture, placed between the neutron source and a neutron detector. The detection system measures the two dimensional distribution of neutrons passing through the pinhole. This diagnostic has been designed to collect two images at two times. The long flight path for this diagnostic, 28 m, results in a chromatic separation of the neutrons, allowing the independently timed images to measure the source distribution for two neutron energies. Typically the first image measures the distribution of the 14 MeV neutrons and the second image of the 6-12 MeV neutrons. The combination of these two images has provided data on the size and shape of the burning plasma within the compressed capsule, as well as a measure of the quantity and spatial distribution of the cold fuel surrounding this core.

  9. The neutron imaging diagnostic at NIF (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Merrill, F. E.; Clark, D. D.; Danly, C. R.; Drury, O. B.; Fatherley, V. E.; Gallegos, R.; Grim, G. P.; Guler, N.; Loomis, E. N.; Martinson, D. D.; Mares, D.; Morley, D. J.; Morgan, G. L.; Oertel, J. A.; Tregillis, I. L.; Volegov, P. L.; Wilde, C. H.; Wilson, D. C. [Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States); Bower, D.; Dzenitis, J. M. [Livermore National Laboratory, Livermore, California 94550 (United States); and others

    2012-10-15

    A neutron imaging diagnostic has recently been commissioned at the National Ignition Facility (NIF). This new system is an important diagnostic tool for inertial fusion studies at the NIF for measuring the size and shape of the burning DT plasma during the ignition stage of Inertial Confinement Fusion (ICF) implosions. The imaging technique utilizes a pinhole neutron aperture, placed between the neutron source and a neutron detector. The detection system measures the two dimensional distribution of neutrons passing through the pinhole. This diagnostic has been designed to collect two images at two times. The long flight path for this diagnostic, 28 m, results in a chromatic separation of the neutrons, allowing the independently timed images to measure the source distribution for two neutron energies. Typically the first image measures the distribution of the 14 MeV neutrons and the second image of the 6-12 MeV neutrons. The combination of these two images has provided data on the size and shape of the burning plasma within the compressed capsule, as well as a measure of the quantity and spatial distribution of the cold fuel surrounding this core.

  10. Application of imaging plate neutron detector to neutron radiography

    CERN Document Server

    Fujine, S; Kamata, M; Etoh, M

    1999-01-01

    As an imaging plate neutron detector (IP-ND) has been available for thermal neutron radiography (TNR) which has high resolution, high sensitivity and wide range, some basic characteristics of the IP-ND system were measured at the E-2 facility of the KUR. After basic performances of the IP were studied, images with high quality were obtained at a neutron fluence of 2 to 7x10 sup 8 n cm sup - sup 2. It was found that the IP-ND system with Gd sub 2 O sub 3 as a neutron converter material has a higher sensitivity to gamma-ray than that of a conventional film method. As a successful example, clear radiographs of the flat view for the fuel side plates with boron burnable poison were obtained. An application of the IP-ND system to neutron radiography (NR) is presented in this paper.

  11. Development of a new electronic neutron imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Brenizer, J.S. [Department of Mechanical, Aerospace and Nuclear Engineering, Thornton Hall, University of Virginia, Charlottesville, VA 22903-2442 (United States); Berger, H. [Industrial Quality, Inc., Gaithersburg, MD (United States); Gibbs, K.M. [Industrial Quality, Inc., Gaithersburg, MD (United States); Mengers, P. [Paultek Systems, Inc., Nevada City, CA (United States); Stebbings, C.T. [Department of Mechanical, Aerospace and Nuclear Engineering, Thornton Hall, University of Virginia, Charlottesville, VA 22903-2442 (United States); Polansky, D. [Industrial Quality, Inc., Gaithersburg, MD (United States); Rogerson, D.J. [Naval Air Warfare Center, China Lake, CA (United States)

    1999-11-03

    An electronic neutron imaging camera system was developed for use with thermal, epithermal, and fast neutrons in applications that include nondestructive inspection of explosives, corrosion, turbine blades, electronics, low Z components, etc. The neutron images are expected to provide information to supplement that available from X-ray tests. The primary camera image area was a 30x30 cm field-of-view with a spatial resolution approaching 1.6 line pairs/mm (lp/mm). The camera had a remotely changeable second lens to limit the field-of-view to 7.6x7.6 cm for high spatial resolution (at least 4 lp/mm) thermal neutron imaging, but neutron and light scatter will limit resolution for fast neutrons to about 0.5 lp/mm. Remote focus capability enhanced camera set-up for optimum operation. The 75 dB dynamic range camera system included {sup 6}Li-based screens for imaging of thermal and epithermal neutrons and ZnS(Ag)-based screens for fast neutron imaging. The fast optics was input to a Super S-25 Gen II image intensifier, fiber optically coupled to a 1134 (h)x486 (v) frame transfer CCD camera. The camera system was designed to be compatible with a Navy-sponsored accelerator neutron source. The planned neutron source is an RF quadrupole accelerator that will provide a fast neutron flux of 10{sup 7} n/cm{sup 2}-s (at a source distance of 1 m) at an energy of about 2.2 MeV and a thermal neutron flux of 10{sup 6} n/cm{sup 2}-s at a source L/D ratio of 30. The electronic camera produced good quality real-time images at these neutron levels. On-chip integration could be used to improve image quality for low flux situations. The camera and accelerator combination provided a useful non-reactor neutron inspection system.

  12. Neutron imaging and applications a reference for the imaging community

    CERN Document Server

    McGreevy, Robert L; Bilheux, Hassina Z

    2009-01-01

    Offers an introduction to the basics of neutron beam production in addition to the wide scope of techniques that enhance imaging application capabilities. This title features a section that describes imaging single grains in polycrystalline materials, neutron imaging of geological materials and other materials science and engineering areas.

  13. New feature of the neutron color image intensifier

    Science.gov (United States)

    Nittoh, Koichi; Konagai, Chikara; Noji, Takashi; Miyabe, Keisuke

    2009-06-01

    We developed prototype neutron color image intensifiers with high-sensitivity, wide dynamic range and long-life characteristics. In the prototype intensifier (Gd-Type 1), a terbium-activated Gd 2O 2S is used as the input-screen phosphor. In the upgraded model (Gd-Type 2), Gd 2O 3 and CsI:Na are vacuum deposited to form the phosphor layer, which improved the sensitivity and the spatial uniformity. A europium-activated Y 2O 2S multi-color scintillator, emitting red, green and blue photons with different intensities, is utilized as the output screen of the intensifier. By combining this image intensifier with a suitably tuned high-sensitive color CCD camera, higher sensitivity and wider dynamic range could be simultaneously attained than that of the conventional P20-phosphor-type image intensifier. The results of experiments at the JRR-3M neutron radiography irradiation port (flux: 1.5×10 8 n/cm 2/s) showed that these neutron color image intensifiers can clearly image dynamic phenomena with a 30 frame/s video picture. It is expected that the color image intensifier will be used as a new two-dimensional neutron sensor in new application fields.

  14. New feature of the neutron color image intensifier

    International Nuclear Information System (INIS)

    Nittoh, Koichi; Konagai, Chikara; Noji, Takashi; Miyabe, Keisuke

    2009-01-01

    We developed prototype neutron color image intensifiers with high-sensitivity, wide dynamic range and long-life characteristics. In the prototype intensifier (Gd-Type 1), a terbium-activated Gd 2 O 2 S is used as the input-screen phosphor. In the upgraded model (Gd-Type 2), Gd 2 O 3 and CsI:Na are vacuum deposited to form the phosphor layer, which improved the sensitivity and the spatial uniformity. A europium-activated Y 2 O 2 S multi-color scintillator, emitting red, green and blue photons with different intensities, is utilized as the output screen of the intensifier. By combining this image intensifier with a suitably tuned high-sensitive color CCD camera, higher sensitivity and wider dynamic range could be simultaneously attained than that of the conventional P20-phosphor-type image intensifier. The results of experiments at the JRR-3M neutron radiography irradiation port (flux: 1.5x10 8 n/cm 2 /s) showed that these neutron color image intensifiers can clearly image dynamic phenomena with a 30 frame/s video picture. It is expected that the color image intensifier will be used as a new two-dimensional neutron sensor in new application fields.

  15. New neutron imaging using pulsed sources. Characteristics of a pulsed neutron source and principle of pulsed neutron imaging

    International Nuclear Information System (INIS)

    Kiyanagi, Yoshiaki

    2012-01-01

    Neutron beam is one of important tools to obtain the transmission image of an object. Until now, steady state neutron sources such as reactors are mainly used for this imaging purpose. Recently, it has been demonstrated that pulsed neutron imaging based on accelerator neutron sources can provide a real-space distribution of physical information of materials such as crystallographic structure, element, temperature, hydrogen bound state, magnetic field and so on, by analyzing wavelength dependent transmission spectrum, which information cannot be observed or difficult to obtain with a traditional imaging method using steady state neutrons. Here, characteristics of the pulsed neutron source and principle of the pulsed neutron imaging are explained as a basic concept of the new method. (author)

  16. Neutron imaging system based on a video camera

    International Nuclear Information System (INIS)

    Dinca, M.

    2004-01-01

    The non-destructive testing with cold, thermal, epithermal or fast neutrons is nowadays more and more useful because the world-wide level of industrial development requires considerably higher standards of quality of manufactured products and reliability of technological processes especially where any deviation from standards could result in large-scale catastrophic consequences or human loses. Thanks to their properties, easily obtained and very good discrimination of the materials that penetrate, the thermal neutrons are the most used probe. The methods involved for this technique have advanced from neutron radiography based on converter screens and radiological films to neutron radioscopy based on video cameras, that is, from static images to dynamic images. Many neutron radioscopy systems have been used in the past with various levels of success. The quality of an image depends on the quality of the neutron beam and the type of the neutron imaging system. For real time investigations there are involved tube type cameras, CCD cameras and recently CID cameras that capture the image from an appropriate scintillator through the agency of a mirror. The analog signal of the camera is then converted into digital signal by the signal processing technology included into the camera. The image acquisition card or frame grabber from a PC converts the digital signal into an image. The image is formatted and processed by image analysis software. The scanning position of the object is controlled by the computer that commands the electrical motors that move horizontally, vertically and rotate the table of the object. Based on this system, a lot of static image acquisitions, real time non-destructive investigations of dynamic processes and finally, tomographic investigations of the small objects are done in a short time. A system based on a CID camera is presented. Fundamental differences between CCD and CID cameras lie in their pixel readout structure and technique. CIDs

  17. Neutron beam applications - A development of real-time imaging processing for neutron radiography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Whoi Yul; Lee, Sang Yup; Choi, Min Seok; Hwang, Sun Kyu; Han, Il Ho; Jang, Jae Young [Hanyang University, Seoul (Korea)

    1999-08-01

    This research is sponsored and supported by KAERI as a part of {sup A}pplication of Neutron Radiography Beam.{sup M}ain theme of the research is to develop a non-destructive inspection system for the task of studying the real-time behaviour of dynamic motion using neutron beam with the aid of a special purpose real-time image processing system that allows to capture an image of internal structure of a specimen. Currently, most off-the-shelf image processing programs designed for visible light or X-ray are not adequate for the applications that require neutron beam generated by the experimental nuclear reactor. In addition, study of dynamic motion of a specimen is severely constrained by such image processing systems. In this research, a special image processing system suited for such application is developed which not only supplements the commercial image processing system but allows to use neutron beam directly in the system for the study. 18 refs., 21 figs., 1 tab. (Author)

  18. Musashi dynamic image processing system

    International Nuclear Information System (INIS)

    Murata, Yutaka; Mochiki, Koh-ichi; Taguchi, Akira

    1992-01-01

    In order to produce transmitted neutron dynamic images using neutron radiography, a real time system called Musashi dynamic image processing system (MDIPS) was developed to collect, process, display and record image data. The block diagram of the MDIPS is shown. The system consists of a highly sensitive, high resolution TV camera driven by a custom-made scanner, a TV camera deflection controller for optimal scanning, which adjusts to the luminous intensity and the moving speed of an object, a real-time corrector to perform the real time correction of dark current, shading distortion and field intensity fluctuation, a real time filter for increasing the image signal to noise ratio, a video recording unit and a pseudocolor monitor to realize recording in commercially available products and monitoring by means of the CRTs in standard TV scanning, respectively. The TV camera and the TV camera deflection controller utilized for producing still images can be applied to this case. The block diagram of the real-time corrector is shown. Its performance is explained. Linear filters and ranked order filters were developed. (K.I.)

  19. Optics for Advanced Neutron Imaging and Scattering

    International Nuclear Information System (INIS)

    Moncton, David E.; Khaykovich, Boris

    2016-01-01

    During the report period, we continued the work as outlined in the original proposal. We have analyzed potential optical designs of Wolter mirrors for the neutron-imaging instrument VENUS, which is under construction at SNS. In parallel, we have conducted the initial polarized imaging experiment at Helmholtz Zentrum, Berlin, one of very few of currently available polarized-imaging facilities worldwide.

  20. The National Ignition Facility Neutron Imaging System

    International Nuclear Information System (INIS)

    Wilke, Mark D.; Batha, Steven H.; Bradley, Paul A.; Day, Robert D.; Clark, David D.; Fatherley, Valerie E.; Finch, Joshua P.; Gallegos, Robert A.; Garcia, Felix P.; Grim, Gary P.; Jaramillo, Steven A.; Montoya, Andrew J.; Morgan, George L.; Oertel, John A.; Ortiz, Thomas A.; Payton, Jeremy R.; Pazuchanics, Peter; Schmidt, Derek W.; Valdez, Adelaida C.; Wilde, Carl H.

    2008-01-01

    The National Ignition Facility (NIF) is scheduled to begin deuterium-tritium (DT) shots possibly in the next several years. One of the important diagnostics in understanding capsule behavior and to guide changes in Hohlraum illumination, capsule design, and geometry will be neutron imaging of both the primary 14 MeV neutrons and the lower-energy downscattered neutrons in the 6-13 MeV range. The neutron imaging system (NIS) described here, which we are currently building for use on NIF, uses a precisely aligned set of apertures near the target to form the neutron images on a segmented scintillator. The images are recorded on a gated, intensified charge coupled device. Although the aperture set may be as close as 20 cm to the target, the imaging camera system will be located at a distance of 28 m from the target. At 28 m the camera system is outside the NIF building. Because of the distance and shielding, the imager will be able to obtain images with little background noise. The imager will be capable of imaging downscattered neutrons from failed capsules with yields Y n >10 14 neutrons. The shielding will also permit the NIS to function at neutron yields >10 18 , which is in contrast to most other diagnostics that may not work at high neutron yields. The following describes the current NIF NIS design and compares the predicted performance with the NIF specifications that must be satisfied to generate images that can be interpreted to understand results of a particular shot. The current design, including the aperture, scintillator, camera system, and reconstruction methods, is briefly described. System modeling of the existing Omega NIS and comparison with the Omega data that guided the NIF design based on our Omega results is described. We will show NIS model calculations of the expected NIF images based on component evaluations at Omega. We will also compare the calculated NIF input images with those unfolded from the NIS images generated from our NIS numerical

  1. Combined neutron imaging techniques for cultural heritage purpose

    International Nuclear Information System (INIS)

    Materna, T.

    2009-01-01

    This article presents the different new neutron techniques developed by the Ancient Charm collaboration to image objects of cultural heritage importance: Prompt-gamma-ray activation imaging (PGAI) coupled to cold/thermal neutron transmission tomography, Neutron Resonance Capture Imaging (NRCI) and Neutron Resonance Tomography.

  2. Phase transitions in neutron matter and dynamics of neutron stars

    International Nuclear Information System (INIS)

    Migdal, A.B.; Chernoutsan, A.I.; Mishustin, I.N.

    1980-01-01

    The neutron star dynamics during the formation of the superdense core is considered, and the instability conditions with respect to this formation are described. Within the framework of a simple model the equation of motion of the superdense core radius is investigated, its solutions in a simple model are found analytically for some limiting cases, and the results of numerical solution of the equation of motion are presented. The possible ways for the envelope to be blown off are considered

  3. High frame-rate neutron radiography of dynamic events

    International Nuclear Information System (INIS)

    Bossi, R.H.; Robinson, A.H.; Barton, J.P.

    1981-01-01

    A system has been developed to perform neutron radiographic analysis of dynamic events having a duration of several milliseconds. The system has been operated in the range of 2000 to 10,000 frames/second. Synchronization has provided high-speed-motion neutron radiographs for evaluation of the firing cycle of 7.62 mm munition rounds within a steel rifle barrel. The system has also been used to demonstrate the ability to produce neutron radiographic movies of two-phase flow. The equipment uses the Oregon State University TRIGA reactor capable of pulsing to 3000 MW peak power, a neutron beam collimator, a scintillator neutron conversion screen coupled to an image intensifier, and a 16 mm high speed movie camera. The peak neutron flux incident at the object position is approximately 4 x 10 11 n/cm 2 s with a pulse, full width at half maximum, of 9 ms. Special studies have been performed on the scintillator conversion screens and on the effects of statistical limitations on the image quality. Modulation transfer function analysis has been used to assist in the evaluation of the system performance

  4. High frame-rate neutron radiography of dynamic events

    International Nuclear Information System (INIS)

    Bossi, R.H.; Robinson, A.H.; Barton, J.P.

    1983-01-01

    A system has been developed to perform neutron radiographic analysis of dynamic events having a duration of several milliseconds. The system has been operated in the range of 2000 to 10,000 frames/second. Synchronization has provided high-speed-motion neutron radiographs for evaluation of the firing cycle of 7.62 mm munition rounds within a steel rifle barrel. The system has also been used to demonstrate the ability to produce neutron radiographic movies of two phase flow. The equipment uses the Oregon State University TRIGA reactor capable of pulsing to 3000 MW peak power, a neutron beam collimator, a scintillator neutron conversion screen coupled to an image intensifier, and a 16 mm high speed movie camera. The peak neutron flux incident at the object position is approximately 4 x 10 11 n/cm 2 s with a pulse, full width at half maximum, of 9 ms. Special studies have been performed on the scintillator conversion screens and on the effects of statistical limitations on the image quality. Modulation transfer function analysis has been used to assist in the evaluation of the system performance. (Auth.)

  5. LISe pixel detector for neutron imaging

    Energy Technology Data Exchange (ETDEWEB)

    Herrera, Elan; Hamm, Daniel [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN (United States); Wiggins, Brenden [Technology Development, Y-12 National Security Complex, Oak Ridge, TN (United States); Department of Physics and Astronomy, Vanderbilt University, Nashville, TN (United States); Milburn, Rob [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN (United States); Burger, Arnold [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN (United States); Department of Life and Physical Sciences, Fisk University, Nashville, TN (United States); Bilheux, Hassina [Chemical and Engineering Materials Division, Oak Ridge National Laboratory, Oak Ridge, TN (United States); Santodonato, Louis [Instrument and Source Division, Oak Ridge National Laboratory, Oak Ridge National Laboratory, Oak Ridge, TN (United States); Chvala, Ondrej [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN (United States); Stowe, Ashley [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN (United States); Technology Development, Y-12 National Security Complex, Oak Ridge, TN (United States); Department of Physics and Astronomy, Vanderbilt University, Nashville, TN (United States); Lukosi, Eric, E-mail: elukosi@utk.edu [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN (United States)

    2016-10-11

    Semiconducting lithium indium diselenide, {sup 6}LiInSe{sub 2} or LISe, has promising characteristics for neutron detection applications. The 95% isotopic enrichment of {sup 6}Li results in a highly efficient thermal neutron-sensitive material. In this study, we report on a proof-of-principle investigation of a semiconducting LISe pixel detector to demonstrate its potential as an efficient neutron imager. The LISe pixel detector had a 4×4 of pixels with a 550 µm pitch on a 5×5×0.56 mm{sup 3} LISe substrate. An experimentally verified spatial resolution of 300 µm was observed utilizing a super-sampling technique.

  6. Temperature imaging using epithermal neutrons

    International Nuclear Information System (INIS)

    Fowler, P.H.; Taylor, A.D.

    1987-08-01

    The paper concerns the temperature measurement of suitable targets, both remotely and non-invasively, using epithermal neutrons. The text was presented at the Neutron Resonance Radiography Workshop, Los Alamos, U.S.A., 1987. The technique is demonstrated for tantalum foils at different temperatures, using a pulsed beam of epithermal neutrons, at both Los Alamos and ISIS (United Kingdom). Results on the measured time-of-flight spectra and the tantalum resonances are presented. Beam properties and fluxes at ISIS are discussed. Features of the proposed detectors suitable for the temperature technique are outlined, along with the data analysis, the moving targets, the cyclic temperature variations and transients, and the usefulness of the technique. (U.K.)

  7. Dynamic neutron radiography instrumentation and applications in Central Europe

    International Nuclear Information System (INIS)

    Balasko, M.

    1996-01-01

    Characteristic features of simultaneous dynamic neutron and gamma radiography installations built in the last ten years at the Budapest/Hungary and at the Seibersdorf/Austria research reactors are surveyed. For image detection scintillation detectors and a low-light level television camera with video output are used, thereby providing the possibility for visualizing medium speed movements inside the investigated object. The radiography stations have been used for inspecting industrial products, with the aim of research and development. (orig.)

  8. Fiber optic neutron imaging system: calibration

    International Nuclear Information System (INIS)

    Malone, R.M.; Gow, C.E.; Thayer, D.R.

    1981-01-01

    Two neutron imaging experiments using fiber optics have been performed at the Nevada Test Site. In each experiment, an array of scintillator fluor tubes is exposed to neutrons. Light is coupled out through radiation resistant PCS fibers (8-m long) into high-bandwidth, graded index fibers. For image reconstruction to be accurate, common timing differences and transmission variations between fiber optic channels are needed. The calibration system featured a scanning pulsed dye laser, a specially designed fiber optic star coupler, a tektronix 7912AD transient digitizer, and a DEC PDP 11/34 computing system

  9. Neutron beam imaging with GEM detectors

    International Nuclear Information System (INIS)

    Albani, G.; Cazzaniga, C.; Rebai, M.; Gorini, G.; Croci, G.; Muraro, A.; Cippo, E. Perelli; Tardocchi, M.; Cavenago, M.; Murtas, F.; Claps, G.; Pasqualotto, R.

    2015-01-01

    Neutron GEM-based detectors represent a new frontier of devices in neutron physics applications where a very high neutron flux must be measured such as future fusion experiments (e.g. ITER Neutral beam Injector) and spallation sources (e.g. the European Spallation source). This kind of detectors can be properly adapted to be used both as beam monitors but also as neutron diffraction detectors that could represent a valid alternative for the 3 He detectors replacement. Fast neutron GEM detectors (nGEM) feature a cathode composed by one layer of polyethylene and one of aluminium (neutron scattering on hydrogen generates protons that are detected in the gas) while thermal neutron GEM detectors (bGEM) are equipped with a borated aluminium cathode (charged particles are generated through the 10 B(n,α) 7 Li reaction). GEM detectors can be realized in large area (1 m 2 ) and their readout can be pixelated. Three different prototypes of nGEM and one prototype of bGEM detectors of different areas and equipped with different types of readout have been built and tested. All the detectors have been used to measure the fast and thermal neutron 2D beam image at the ISIS-VESUVIO beamline. The different kinds of readout patterns (different areas of the pixels) have been compared in similar conditions. All the detectors measured a width of the beam profile consitent with the expected one. The imaging property of each detector was then tested by inserting samples of different material and shape in the beam. All the samples were correctly reconstructed and the definition of the reconstruction depends on the type of readout anode. The fast neutron beam profile reconstruction was then compared to the one obtained by diamond detectors positioned on the same beamline while the thermal neutron one was compared to the imaged obtained by cadmium-coupled x-rays films. Also efficiency and the gamma background rejection have been determined. These prototypes represent the first step towards

  10. The pin pixel detector--neutron imaging

    CERN Document Server

    Bateman, J E; Derbyshire, G E; Duxbury, D M; Marsh, A S; Rhodes, N J; Schooneveld, E M; Simmons, J E; Stephenson, R

    2002-01-01

    The development and testing of a neutron gas pixel detector intended for application in neutron diffraction studies is reported. Using standard electrical connector pins as point anodes, the detector is based on a commercial 100 pin connector block. A prototype detector of aperture 25.4 mmx25.4 mm has been fabricated, giving a pixel size of 2.54 mm which matches well to the spatial resolution typically required in a neutron diffractometer. A 2-Dimensional resistive divide readout system has been adapted to permit the imaging properties of the detector to be explored in advance of true pixel readout electronics. The timing properties of the device match well to the requirements of the ISIS-pulsed neutron source.

  11. The method of neutron imaging as a tool for the study of the dynamics of water movement in wet aramid-based ballistic body armour panels

    Science.gov (United States)

    Reifler, Felix A.; Lehmann, Eberhard H.; Frei, Gabriel; May, Hans; Rossi, René

    2006-07-01

    A new non-destructive method based on neutron imaging (neutron radiography) to determine the exact water content in aramid-based soft body armour panels is presented. While investigating the ballistic resistance of aramid-based body armour panels under a wet condition, it is important to precisely determine their water content and its chronological development. Using the presented method, the influence of water amount and location on impact testing as well as its time dependence was shown. In the ballistic panels used, spreading of water strongly depended on the kind of quilting. Very fast water migration could be observed when the panels were held vertically. Some first results regarding the water distribution in wet panels immediately after the impact are presented. On the basis of the presented results, requirements for a standard for testing the performance of ballistic panels in the wet state are deduced.

  12. Computed image analysis of neutron radiographs

    International Nuclear Information System (INIS)

    Dinca, M.; Anghel, E.; Preda, M.; Pavelescu, M.

    2008-01-01

    Similar with X-radiography, using neutron like penetrating particle, there is in practice a nondestructive technique named neutron radiology. When the registration of information is done on a film with the help of a conversion foil (with high cross section for neutrons) that emits secondary radiation (β,γ) that creates a latent image, the technique is named neutron radiography. A radiographic industrial film that contains the image of the internal structure of an object, obtained by neutron radiography, must be subsequently analyzed to obtain qualitative and quantitative information about the structural integrity of that object. There is possible to do a computed analysis of a film using a facility with next main components: an illuminator for film, a CCD video camera and a computer (PC) with suitable software. The qualitative analysis intends to put in evidence possibly anomalies of the structure due to manufacturing processes or induced by working processes (for example, the irradiation activity in the case of the nuclear fuel). The quantitative determination is based on measurements of some image parameters: dimensions, optical densities. The illuminator has been built specially to perform this application but can be used for simple visual observation. The illuminated area is 9x40 cm. The frame of the system is a comparer of Abbe Carl Zeiss Jena type, which has been adapted to achieve this application. The video camera assures the capture of image that is stored and processed by computer. A special program SIMAG-NG has been developed at INR Pitesti that beside of the program SMTV II of the special acquisition module SM 5010 can analyze the images of a film. The major application of the system was the quantitative analysis of a film that contains the images of some nuclear fuel pins beside a dimensional standard. The system was used to measure the length of the pellets of the TRIGA nuclear fuel. (authors)

  13. Dynamic Optically Multiplexed Imaging

    Science.gov (United States)

    2015-07-29

    Dynamic Optically Multiplexed Imaging Yaron Rachlin, Vinay Shah, R. Hamilton Shepard, and Tina Shih Lincoln Laboratory, Massachusetts Institute of...V. Shah, and T. Shih “Design Architectures for Optically Multiplexed Imaging,” in submission 9 R. Gupta , P. Indyk, E. Price, and Y. Rachlin

  14. A Review of Significant Advances in Neutron Imaging from Conception to the Present

    Science.gov (United States)

    Brenizer, J. S.

    This review summarizes the history of neutron imaging with a focus on the significant events and technical advancements in neutron imaging methods, from the first radiograph to more recent imaging methods. A timeline is presented to illustrate the key accomplishments that advanced the neutron imaging technique. Only three years after the discovery of the neutron by English physicist James Chadwick in 1932, neutron imaging began with the work of Hartmut Kallmann and Ernst Kuhn in Berlin, Germany, from 1935-1944. Kallmann and Kuhn were awarded a joint US Patent issued in January 1940. Little progress was made until the mid-1950's when Thewlis utilized a neutron beam from the BEPO reactor at Harwell, marking the beginning of the application of neutron imaging to practical applications. As the film method was improved, imaging moved from a qualitative to a quantitative technique, with applications in industry and in nuclear fuels. Standards were developed to aid in the quantification of the neutron images and the facility's capabilities. The introduction of dynamic neutron imaging (initially called real-time neutron radiography and neutron television) in the late 1970's opened the door to new opportunities and new challenges. As the electronic imaging matured, the introduction of the CCD imaging devices and solid-state light intensifiers helped address some of these challenges. Development of improved imaging devices for the medical community has had a major impact on neutron imaging. Additionally, amorphous silicon sensors provided improvements in temporal resolution, while providing a reasonably large imaging area. The development of new neutron imaging sensors and the development of new neutron imaging techniques in the past decade has advanced the technique's ability to provide insight and understanding of problems that other non-destructive techniques could not provide. This rapid increase in capability and application would not have been possible without the

  15. Study of scattering in bi-dimensional neutron radiographic images

    International Nuclear Information System (INIS)

    Oliveira, K.A.M. de; Crispim, V.R.; Silva, F.C.

    2009-01-01

    The effect of neutron scattering frequently causes distortions in neutron radiographic images and, thus, reduces the quality. In this project, a type of filter, comprised of cadmium (a neutron absorber), was used in the form of a grid to correct this effect. This device generated image data in the discrete shadow bands of the absorber, components relative to neutron scattering on the test object and surroundings. Scattering image data processing, together with the original neutron radiographic image, resulted in a corrected image with improved edge delineation and, thus, greater definition in the neutron radiographic image of the test object. The objective of this study is to propose a theoretical/experimental methodology that is capable of eliminating the components relative to neutron scattering in neutron radiographic images, coming from the material that composes the test object and the materials that compose the surrounding area. (author)

  16. Neutron Imaging of Diesel Particulate Filters

    International Nuclear Information System (INIS)

    Strzelec, Andrea; Bilheux, Hassina Z.; Finney, Charles E.A.; Daw, C. Stuart; Foster, Dave; Rutland, Christopher J.; Schillinger, Burkhard; Schulz, Michael

    2009-01-01

    This article presents nondestructive neutron computed tomography (nCT) measurements of Diesel Particulate Filters (DPFs) as a method to measure ash and soot loading in the filters. Uncatalyzed and unwashcoated 200cpsi cordierite DPFs exposed to 100% biodiesel (B100) exhaust and conventional ultra low sulfur 2007 certification diesel (ULSD) exhaust at one speed-load point (1500rpm, 2.6bar BMEP) are compared to a brand new (never exposed) filter. Precise structural information about the substrate as well as an attempt to quantify soot and ash loading in the channel of the DPF illustrates the potential strength of the neutron imaging technique

  17. Performance assessment of imaging plates for the JHR transfer Neutron Imaging System

    Science.gov (United States)

    Simon, E.; Guimbal, P. AB(; )

    2018-01-01

    The underwater Neutron Imaging System to be installed in the Jules Horowitz Reactor (JHR-NIS) is based on a transfer method using a neutron activated beta-emitter like Dysprosium. The information stored in the converter is to be offline transferred on a specific imaging system, still to be defined. Solutions are currently under investigation for the JHR-NIS in order to anticipate the disappearance of radiographic films commonly used in these applications. We report here the performance assessment of Computed Radiography imagers (Imaging Plates) performed at LLB/Orphée (CEA Saclay). Several imaging plate types are studied, in one hand in the configuration involving an intimate contact with an activated dysprosium foil converter: Fuji BAS-TR, Fuji UR-1 and Carestream Flex XL Blue imaging plates, and in the other hand by using a prototypal imaging plate doped with dysprosium and thus not needing any contact with a separate converter foil. The results for these imaging plates are compared with those obtained with gadolinium doped imaging plate used in direct neutron imaging (Fuji BAS-ND). The detection performances of the different imagers are compared regarding resolution and noise. The many advantages of using imaging plates over radiographic films (high sensitivity, linear response, high dynamic range) could palliate its lower intrinsic resolution.

  18. Formation of tomographic images with neutrons

    International Nuclear Information System (INIS)

    Duarte, A.; Tenreiro, C; Valencia, J; Steinman, G.; Henriquez, C

    2000-01-01

    The possibility of having a non-destructive method of analysis for archaeological and paleontological samples is of interest. A special group of fossil samples has come to our attention, which because of their value should be preserved and, therefore, the availability of an indirect, non-destructive, non contaminating analytical technique is important. The strong absorption of usual kinds of radiation by a fossilized sample restricts the application of conventional methods of analysis. A type of radiation that is not completely attenuated by thick samples, in sizes that are typical in paleontology, is necessary. Neutrons may be considered as an ideal non-invasive probe with the possibility of developing a technique for the formation and analysis of images. A technique has been developed for the spatial reconstruction of the contents of a fossilized sample (tomography) with neutrons, without touching or altering the sample in any way. The neutron beam was extracted from the RECH-1 reactor belonging to the CCHEN, La Reina. The tomographic images of the contents of a fossilized egg are presented for the first time and represent views or cuts of the content as well as a set that permits the three dimensional reconstruction of the inside of the object and its subsequent animation in graphic format. This project developed a technique for taking neutron radiographs of this kind of sample including the numerical algorithms and the treatment and formation of the images (CW)

  19. Studies of the dynamic properties of materials using neutron scattering

    International Nuclear Information System (INIS)

    Lovesey, S.W.; Windsor, C.G.

    1985-09-01

    The dynamic properties of materials using the neutron scattering technique is reviewed. The basic properties of both nuclear scattering and magnetic scattering are summarized. The experimental methods used in neutron scattering are described, along with access to neutron sources, and neutron inelastic instruments. Applied materials science using inelastic neutron scattering; rotational tunnelling of a methyl group; molecular diffusion from quasi-elastic scattering; and the diffusion of colloidal particles and poly-nuclear complexes; are also briefly discussed. (U.K.)

  20. Fast-neutron, coded-aperture imager

    Science.gov (United States)

    Woolf, Richard S.; Phlips, Bernard F.; Hutcheson, Anthony L.; Wulf, Eric A.

    2015-06-01

    This work discusses a large-scale, coded-aperture imager for fast neutrons, building off a proof-of concept instrument developed at the U.S. Naval Research Laboratory (NRL). The Space Science Division at the NRL has a heritage of developing large-scale, mobile systems, using coded-aperture imaging, for long-range γ-ray detection and localization. The fast-neutron, coded-aperture imaging instrument, designed for a mobile unit (20 ft. ISO container), consists of a 32-element array of 15 cm×15 cm×15 cm liquid scintillation detectors (EJ-309) mounted behind a 12×12 pseudorandom coded aperture. The elements of the aperture are composed of 15 cm×15 cm×10 cm blocks of high-density polyethylene (HDPE). The arrangement of the aperture elements produces a shadow pattern on the detector array behind the mask. By measuring of the number of neutron counts per masked and unmasked detector, and with knowledge of the mask pattern, a source image can be deconvolved to obtain a 2-d location. The number of neutrons per detector was obtained by processing the fast signal from each PMT in flash digitizing electronics. Digital pulse shape discrimination (PSD) was performed to filter out the fast-neutron signal from the γ background. The prototype instrument was tested at an indoor facility at the NRL with a 1.8-μCi and 13-μCi 252Cf neutron/γ source at three standoff distances of 9, 15 and 26 m (maximum allowed in the facility) over a 15-min integration time. The imaging and detection capabilities of the instrument were tested by moving the source in half- and one-pixel increments across the image plane. We show a representative sample of the results obtained at one-pixel increments for a standoff distance of 9 m. The 1.8-μCi source was not detected at the 26-m standoff. In order to increase the sensitivity of the instrument, we reduced the fastneutron background by shielding the top, sides and back of the detector array with 10-cm-thick HDPE. This shielding configuration led

  1. A study of television imaging system for fast neutron radiography

    International Nuclear Information System (INIS)

    Yoshii, Koji

    1992-01-01

    The neutron radiography with fast neutron beam is a very useful imaging technique for thicker objects, especially those composed of hydrogen-rich materials which are sometimes difficult to image by thermal neutron radiography. The fast neutron radiography has not been studied so much as the thermal neutron radiography. The fast neutron radiography has been studied at the fast neutron source reactor 'Yayoi' of the University of Tokyo built in Tokai-mura. The average neutron energy of the Yayoi is about 1 MeV, and the peak neutron flux at the core center is 0.8 x 10 12 at the maximum operating power of 2 kW. In the experiment on fast neutron radiography, a CR39 nuclear track detector has been used successfully. But in the Yayoi radiography procedure, about 24 hours were required for obtaining an imaging result. To get a prompt imaging result and a real-time imaging result, it is necessary to develop a fast neutron television system, and in this paper, a new fast neutron TV system is proposed. The main difference is the converter material sensitive to fast neutrons. The study on the fast neutron TV system was carried out by using the Baby Cyclotron of Japan Steel Works, and the good images were realized. (K.I.)

  2. Neutron Ghost Imaging Technology Research on CARR Reactor

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Ghost imaging is also known as quantum imaging. Different from the classical imaging, the neutron ghost imaging is based on the quantum mechanics properties of light field and its intrinsic parallel characteristic, and developed by new optical

  3. Fast-neutron, coded-aperture imager

    International Nuclear Information System (INIS)

    Woolf, Richard S.; Phlips, Bernard F.; Hutcheson, Anthony L.; Wulf, Eric A.

    2015-01-01

    This work discusses a large-scale, coded-aperture imager for fast neutrons, building off a proof-of concept instrument developed at the U.S. Naval Research Laboratory (NRL). The Space Science Division at the NRL has a heritage of developing large-scale, mobile systems, using coded-aperture imaging, for long-range γ-ray detection and localization. The fast-neutron, coded-aperture imaging instrument, designed for a mobile unit (20 ft. ISO container), consists of a 32-element array of 15 cm×15 cm×15 cm liquid scintillation detectors (EJ-309) mounted behind a 12×12 pseudorandom coded aperture. The elements of the aperture are composed of 15 cm×15 cm×10 cm blocks of high-density polyethylene (HDPE). The arrangement of the aperture elements produces a shadow pattern on the detector array behind the mask. By measuring of the number of neutron counts per masked and unmasked detector, and with knowledge of the mask pattern, a source image can be deconvolved to obtain a 2-d location. The number of neutrons per detector was obtained by processing the fast signal from each PMT in flash digitizing electronics. Digital pulse shape discrimination (PSD) was performed to filter out the fast-neutron signal from the γ background. The prototype instrument was tested at an indoor facility at the NRL with a 1.8-μCi and 13-μCi 252Cf neutron/γ source at three standoff distances of 9, 15 and 26 m (maximum allowed in the facility) over a 15-min integration time. The imaging and detection capabilities of the instrument were tested by moving the source in half- and one-pixel increments across the image plane. We show a representative sample of the results obtained at one-pixel increments for a standoff distance of 9 m. The 1.8-μCi source was not detected at the 26-m standoff. In order to increase the sensitivity of the instrument, we reduced the fastneutron background by shielding the top, sides and back of the detector array with 10-cm-thick HDPE. This shielding configuration led

  4. Fast-neutron, coded-aperture imager

    Energy Technology Data Exchange (ETDEWEB)

    Woolf, Richard S., E-mail: richard.woolf@nrl.navy.mil; Phlips, Bernard F., E-mail: bernard.phlips@nrl.navy.mil; Hutcheson, Anthony L., E-mail: anthony.hutcheson@nrl.navy.mil; Wulf, Eric A., E-mail: eric.wulf@nrl.navy.mil

    2015-06-01

    This work discusses a large-scale, coded-aperture imager for fast neutrons, building off a proof-of concept instrument developed at the U.S. Naval Research Laboratory (NRL). The Space Science Division at the NRL has a heritage of developing large-scale, mobile systems, using coded-aperture imaging, for long-range γ-ray detection and localization. The fast-neutron, coded-aperture imaging instrument, designed for a mobile unit (20 ft. ISO container), consists of a 32-element array of 15 cm×15 cm×15 cm liquid scintillation detectors (EJ-309) mounted behind a 12×12 pseudorandom coded aperture. The elements of the aperture are composed of 15 cm×15 cm×10 cm blocks of high-density polyethylene (HDPE). The arrangement of the aperture elements produces a shadow pattern on the detector array behind the mask. By measuring of the number of neutron counts per masked and unmasked detector, and with knowledge of the mask pattern, a source image can be deconvolved to obtain a 2-d location. The number of neutrons per detector was obtained by processing the fast signal from each PMT in flash digitizing electronics. Digital pulse shape discrimination (PSD) was performed to filter out the fast-neutron signal from the γ background. The prototype instrument was tested at an indoor facility at the NRL with a 1.8-μCi and 13-μCi 252Cf neutron/γ source at three standoff distances of 9, 15 and 26 m (maximum allowed in the facility) over a 15-min integration time. The imaging and detection capabilities of the instrument were tested by moving the source in half- and one-pixel increments across the image plane. We show a representative sample of the results obtained at one-pixel increments for a standoff distance of 9 m. The 1.8-μCi source was not detected at the 26-m standoff. In order to increase the sensitivity of the instrument, we reduced the fastneutron background by shielding the top, sides and back of the detector array with 10-cm-thick HDPE. This shielding configuration led

  5. Scintillator Based Coded-Aperture Imaging for Neutron Detection

    International Nuclear Information System (INIS)

    Hayes, Sean-C.; Gamage, Kelum-A-A.

    2013-06-01

    In this paper we are going to assess the variations of neutron images using a series of Monte Carlo simulations. We are going to study neutron images of the same neutron source with different source locations, using a scintillator based coded-aperture system. The Monte Carlo simulations have been conducted making use of the EJ-426 neutron scintillator detector. This type of detector has a low sensitivity to gamma rays and is therefore of particular use in a system with a source that emits a mixed radiation field. From the use of different source locations, several neutron images have been produced, compared both qualitatively and quantitatively for each case. This allows conclusions to be drawn on how suited the scintillator based coded-aperture neutron imaging system is to detecting various neutron source locations. This type of neutron imaging system can be easily used to identify and locate nuclear materials precisely. (authors)

  6. A dynamical description of neutron star crusts

    International Nuclear Information System (INIS)

    Mota, V de la; S, F; Eudes, Ph

    2013-01-01

    Neutron Stars are natural laboratories where fundamental properties of matter under extreme conditions can be explored. Modern nuclear physics input as well as many-body theories are valuable tools which may allow us to improve our understanding of the physics of those compact objects. In this work the occurrence of exotic structures in the outermost layers of neutron stars is investigated within the framework of a microscopic model. In this approach the nucleonic dynamics is described by a time-dependent mean field approach at around zero temperature. Starting from an initial crystalline lattice of nuclei at subnuclear densities the system evolves toward a manifold of self-organized structures with different shapes and similar energies. These structures are studied in terms of a phase diagram in density and the corresponding sensitivity to the isospin-dependent part of the equation of state and to the isotopic composition is investigated.

  7. Fluence-compensated down-scattered neutron imaging using the neutron imaging system at the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Casey, D. T., E-mail: casey21@llnl.gov; Munro, D. H.; Grim, G. P.; Landen, O. L.; Spears, B. K.; Fittinghoff, D. N.; Field, J. E.; Smalyuk, V. A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Volegov, P. L.; Merrill, F. E. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2016-11-15

    The Neutron Imaging System at the National Ignition Facility is used to observe the primary ∼14 MeV neutrons from the hotspot and down-scattered neutrons (6-12 MeV) from the assembled shell. Due to the strong spatial dependence of the primary neutron fluence through the dense shell, the down-scattered image is convolved with the primary-neutron fluence much like a backlighter profile. Using a characteristic scattering angle assumption, we estimate the primary neutron fluence and compensate the down-scattered image, which reveals information about asymmetry that is otherwise difficult to extract without invoking complicated models.

  8. Status of the Neutron Imaging and Diffraction Instrument IMAT

    Science.gov (United States)

    Kockelmann, Winfried; Burca, Genoveva; Kelleher, Joe F.; Kabra, Saurabh; Zhang, Shu-Yan; Rhodes, Nigel J.; Schooneveld, Erik M.; Sykora, Jeff; Pooley, Daniel E.; Nightingale, Jim B.; Aliotta, Francesco; Ponterio, Rosa C.; Salvato, Gabriele; Tresoldi, Dario; Vasi, Cirino; McPhate, Jason B.; Tremsin, Anton S.

    A cold neutron imaging and diffraction instrument, IMAT, is currently being constructed at the ISIS second target station. IMAT will capitalize on time-of-flight transmission and diffraction techniques available at a pulsed neutron source. Analytical techniques will include neutron radiography, neutron tomography, energy-selective neutron imaging, and spatially resolved diffraction scans for residual strain and texture determination. Commissioning of the instrument will start in 2015, with time-resolving imaging detectors and two diffraction detector prototype modules. IMAT will be operated as a user facility for material science applications and will be open for developments of time-of-flight imaging methods.

  9. Neutron Imaging at LANSCE—From Cold to Ultrafast

    Directory of Open Access Journals (Sweden)

    Ronald O. Nelson

    2018-02-01

    Full Text Available In recent years, neutron radiography and tomography have been applied at different beam lines at Los Alamos Neutron Science Center (LANSCE, covering a very wide neutron energy range. The field of energy-resolved neutron imaging with epi-thermal neutrons, utilizing neutron absorption resonances for contrast as well as quantitative density measurements, was pioneered at the Target 1 (Lujan center, Flight Path 5 beam line and continues to be refined. Applications include: imaging of metallic and ceramic nuclear fuels, fission gas measurements, tomography of fossils and studies of dopants in scintillators. The technique provides the ability to characterize materials opaque to thermal neutrons and to utilize neutron resonance analysis codes to quantify isotopes to within 0.1 atom %. The latter also allows measuring fuel enrichment levels or the pressure of fission gas remotely. More recently, the cold neutron spectrum at the ASTERIX beam line, also located at Target 1, was used to demonstrate phase contrast imaging with pulsed neutrons. This extends the capabilities for imaging of thin and transparent materials at LANSCE. In contrast, high-energy neutron imaging at LANSCE, using unmoderated fast spallation neutrons from Target 4 [Weapons Neutron Research (WNR facility] has been developed for applications in imaging of dense, thick objects. Using fast (ns, time-of-flight imaging, enables testing and developing imaging at specific, selected MeV neutron energies. The 4FP-60R beam line has been reconfigured with increased shielding and new, larger collimation dedicated to fast neutron imaging. The exploration of ways in which pulsed neutron beams and the time-of-flight method can provide additional benefits is continuing. We will describe the facilities and instruments, present application examples and recent results of all these efforts at LANSCE.

  10. Neutron Imaging at Compact Accelerator-Driven Neutron Sources in Japan

    Directory of Open Access Journals (Sweden)

    Yoshiaki Kiyanagi

    2018-03-01

    Full Text Available Neutron imaging has been recognized to be very useful to investigate inside of materials and products that cannot be seen by X-ray. New imaging methods using the pulsed structure of neutron sources based on accelerators has been developed also at compact accelerator-driven neutron sources and opened new application fields in neutron imaging. The world’s first dedicated imaging instrument at pulsed neutron sources was constructed at J-PARC in Japan owing to the development of such new methods. Then, usefulness of the compact accelerator-driven neutron sources in neutron science was recognized and such facilities were newly constructed in Japan. Now, existing and new sources have been used for neutron imaging. Traditional imaging and newly developed pulsed neutron imaging such as Bragg edge transmission have been applied to various fields by using compact and large neutron facilities. Here, compact accelerator-driven neutron sources used for imaging in Japan are introduced and some of their activities are presented.

  11. Polarized neutron inelastic scattering experiments on spin dynamics

    International Nuclear Information System (INIS)

    Kakurai, Kazuhisa

    2016-01-01

    The principles of polarized neutron scattering are introduced and examples of polarized neutron inelastic scattering experiments on spin dynamics investigation are presented. These examples should demonstrate the importance of the polarized neutron utilization for the investigation of non-trivial magnetic ground and excited states in frustrated and low dimensional quantum spin systems. (author)

  12. Neutron radiography of thick hydrogenous materials with use of an imaging plate neutron detector

    International Nuclear Information System (INIS)

    Kato, K.; Matsumoto, G.; Karasawa, Y.; Niimura, N.; Matsubayashi, M.; Tsuruno, A.

    1996-01-01

    The value of the neutron mass attenuation coefficient of hydrogen being very high, it is extremely difficult to image normal size, living animals with neutron radiography. However, the authors suggest the possibility of applying neutron radiography for biomedical specimens. The organs in the breast, bones and cartilages in the extremities, and the tail of mice and rats were clearly imaged by neutron radiography with Gd foils as neutron converters and X-ray films. However, no contours of the organs in the mouse abdomen were visible with neutron radiography with an exposure time of 200 s. By adding Gd or Li compounds as neutron converters to imaging X-ray plates, imaging plates have been developed for neutron detectors. A trial using these imaging plates for neutron radiography of water-filled containers and the abdomen of mice was completed. The roundness of a 100 ml-beaker was imaged with a neutron exposure of 180 s. Obscure contours of the liver and kidneys of the mouse were imaged with a neutron exposure of 100 s. (orig.)

  13. Development of a novel neutron detector for imaging and analysis

    International Nuclear Information System (INIS)

    Darambara, D.G.; Beach, A.C.; Spyrou, N.M.

    1993-01-01

    A hardware system employing dynamic Random Access Memory (dRAM) has been designed to make possible the detection of neutrons. One recognised difficulty with dynamic memory devices is the alpha-particle problem. That is alpha-particle 'contamination' present within the dRAM encapsulating material may interact sufficiently as to corrupt stored data. These corruptions, 'known as soft errors', may be induced in dRAMs by the interaction of charged particles with the chip itself as a basis for system function. A preliminary feasibility study has been carried out to use dynamic RAMs as alpha-particle detectors. The initial system tests provide information upon detection efficiency, soft error reading rate, energy dependence of the soft error rate and the soft error reading rate, energy dependence of the soft error rate and the soft error operating bias relationship. These findings highlight the usefulness of such a device in neutron dosimetry, imaging and analysis, by using a neutron converter with a high cross section for the (n, α) capture reaction. (author) 20 refs.; 8 figs

  14. A prototype detector using the neutron image intensifier and multi-anode type photomultiplier tube for pulsed neutron imaging

    International Nuclear Information System (INIS)

    Ishikawa, Hirotaku; Sato, Hirotaka; Hara, Kaoru Y.; Kamiyama, Takashi

    2016-01-01

    We developed a neutron two-dimensional (2-D) detector for pulsed neutron imaging as a prototype detector, which was composed of a neutron image intensifier and a multi-anode type photomultiplier tube. A neutron transmission spectrum of α-Fe plate was measured by the prototype detector, and compared with the one measured by a typical neutron 2-D detector. The spectrum was in reasonable agreement with the one measured by the typical detector in the neutron wavelength region above 0.15 nm. In addition, a neutron transmission image of a cadmium indicator was obtained by the prototype detector. The usefulness of the prototype detector for pulsed neutron imaging was demonstrated. (author)

  15. Quantum mechanical aspects of dynamical neutron polarization

    International Nuclear Information System (INIS)

    Betz, T.; Badurek, G.; Jericha, E.

    2007-01-01

    Dynamic Neutron Polarization (DNP) is a concept which allows to achieve complete polarization of slow neutrons, virtually without any loss of intensity. There the neutrons pass through a combination of a static and a rotating magnetic field in resonance, like in a standard NMR apparatus. Depending on their initial spin state, they end up with different kinetic energies and therefore different velocity. In a succeeding magnetic precession field this distinction causes a different total precession angle. Tuning the field strength can lead to a final state where two original anti-parallel spin states are aligned parallel and hence to polarization. The goal of this work is to describe the quantum mechanical aspects of DNP and to work out the differences to the semi-classical treatment. We show by quantum mechanical means, that the concept works and DNP is feasible, indeed. Therefore, we have to take a closer look to the behavior of neutron wave functions in magnetic fields. In the first Section we consider a monochromatic continuous beam. The more realistic case of a pulsed, polychromatic beam requires a time-dependent field configuration and will be treated in the second Section. In particular the spatial separation of the spin up- and down-states is considered, because it causes an effect of polarization damping so that one cannot achieve a fully polarized final state. This effect is not predicted by the semi-classical treatment of DNP. However, this reduction of polarization is very small and can be neglected in realistic DNP-setups

  16. One-dimensional neutron imager for the Sandia Z facility.

    Science.gov (United States)

    Fittinghoff, David N; Bower, Dan E; Hollaway, James R; Jacoby, Barry A; Weiss, Paul B; Buckles, Robert A; Sammons, Timothy J; McPherson, Leroy A; Ruiz, Carlos L; Chandler, Gordon A; Torres, José A; Leeper, Ramon J; Cooper, Gary W; Nelson, Alan J

    2008-10-01

    A multiinstitution collaboration is developing a neutron imaging system for the Sandia Z facility. The initial system design is for slit aperture imaging system capable of obtaining a one-dimensional image of a 2.45 MeV source producing 5x10(12) neutrons with a resolution of 320 microm along the axial dimension of the plasma, but the design being developed can be modified for two-dimensional imaging and imaging of DT neutrons with other resolutions. This system will allow us to understand the spatial production of neutrons in the plasmas produced at the Z facility.

  17. Results from neutron imaging of ICF experiments at NIF

    Science.gov (United States)

    Merrill, F. E.; Danly, C. R.; Fittinghoff, D. N.; Grim, G. P.; Guler, N.; Volegov, P. L.; Wilde, C. H.

    2016-03-01

    In 2011 a neutron imaging diagnostic was commissioned at the National Ignition Facility (NIF). This new system has been used to collect neutron images to measure the size and shape of the burning DT plasma and the surrounding fuel assembly. The imaging technique uses a pinhole neutron aperture placed between the neutron source and a neutron detector. The detection system measures the two-dimensional distribution of neutrons passing through the pinhole. This diagnostic collects two images at two times. The long flight path for this diagnostic, 28 m, results in a chromatic separation of the neutrons, allowing the independently timed images to measure the source distribution for two neutron energies. Typically one image measures the distribution of the 14 MeV neutrons, and the other image measures the distribution of the 6-12 MeV neutrons. The combination of these two images has provided data on the size and shape of the burning plasma within the compressed capsule, as well as a measure of the quantity and spatial distribution of the cold fuel surrounding this core. Images have been collected for the majority of the experiments performed as part of the ignition campaign. Results from this data have been used to estimate a burn-averaged fuel assembly as well as providing performance metrics to gauge progress towards ignition. This data set and our interpretation are presented.

  18. The neutron imaging system fielded at the National Ignition Facility

    Directory of Open Access Journals (Sweden)

    Fittinghoff D.N.

    2013-11-01

    Full Text Available We have fielded a neutron imaging system at the National Ignition Facility to collect images of fusion neutrons produced in the implosion of inertial confinement fusion experiments and scattered neutrons from (n, n′ reactions of the source neutrons in the surrounding dense material. A description of the neutron imaging system is presented, including the pinhole array aperture, the line-of-sight collimation, the scintillator-based detection system and the alignment systems and methods. Discussion of the alignment and resolution of the system is presented. We also discuss future improvements to the system hardware.

  19. Neutron spin precession in samples of polarised nuclei and neutron spin phase imaging

    International Nuclear Information System (INIS)

    Piegsa, Florian Michael

    2009-01-01

    The doublet neutron-deuteron (nd) scattering length b 2,d , which is at present only known with an accuracy of 5%, is particularly well suited to fix three-body forces in novel effective field theories at low energies. The understanding of such few-nucleon systems is essential, e.g. for predictions of element abundances in the big-bang and stellar fusion. b 2,d can be obtained via a linear combination of the spin-independent nd scattering length b c,d and the spin-dependent one, b i,d . The aim of this thesis was to perform a high-accuracy measurement of the latter to improve the relative accuracy of b 2,d below 1%. The experiment was performed at the fundamental neutron physics beam line FUNSPIN at the Paul Scherrer Institute in Switzerland. It utilises the effect that the spin of a neutron passing through a target with polarised nuclei performs a pseudomagnetic precession proportional to the spin-dependent scattering length of the nuclei. An ideal method to measure this precession angle very accurately is Ramsey's atomic beam technique, adapted to neutrons. The most crucial part of the experimental setup is the so-called frozen spin target, which consists of a specially designed dilution refrigerator and contains a sample with dynamically polarised nuclear spins. The polarisation of the sample is determined by nuclear magnetic resonance (NMR) techniques. It turned out that the relaxation of the nuclear spins during the necessary ''cross-calibration'' of the two employed NMR systems is ultimately limiting the achievable accuracy of b i,d . During the extensive use of the Ramsey resonance method in the neutron-deuteron experiment, an idea emerged that the applied technique could be exploited in a completely different context, namely polarised neutron radiography. Hence, the second part of the thesis covers the development of a novel neutron radiography technique, based on the spin-dependent interaction of the neutron with ferromagnetic samples and magnetic fields

  20. Neutron spin precession in samples of polarised nuclei and neutron spin phase imaging

    Energy Technology Data Exchange (ETDEWEB)

    Piegsa, Florian Michael

    2009-07-09

    The doublet neutron-deuteron (nd) scattering length b{sub 2,d}, which is at present only known with an accuracy of 5%, is particularly well suited to fix three-body forces in novel effective field theories at low energies. The understanding of such few-nucleon systems is essential, e.g. for predictions of element abundances in the big-bang and stellar fusion. b{sub 2,d} can be obtained via a linear combination of the spin-independent nd scattering length b{sub c,d} and the spin-dependent one, b{sub i,d}. The aim of this thesis was to perform a high-accuracy measurement of the latter to improve the relative accuracy of b{sub 2,d} below 1%. The experiment was performed at the fundamental neutron physics beam line FUNSPIN at the Paul Scherrer Institute in Switzerland. It utilises the effect that the spin of a neutron passing through a target with polarised nuclei performs a pseudomagnetic precession proportional to the spin-dependent scattering length of the nuclei. An ideal method to measure this precession angle very accurately is Ramsey's atomic beam technique, adapted to neutrons. The most crucial part of the experimental setup is the so-called frozen spin target, which consists of a specially designed dilution refrigerator and contains a sample with dynamically polarised nuclear spins. The polarisation of the sample is determined by nuclear magnetic resonance (NMR) techniques. It turned out that the relaxation of the nuclear spins during the necessary ''cross-calibration'' of the two employed NMR systems is ultimately limiting the achievable accuracy of b{sub i,d}. During the extensive use of the Ramsey resonance method in the neutron-deuteron experiment, an idea emerged that the applied technique could be exploited in a completely different context, namely polarised neutron radiography. Hence, the second part of the thesis covers the development of a novel neutron radiography technique, based on the spin-dependent interaction of the

  1. Stereoscopic radiographic images with thermal neutrons

    International Nuclear Information System (INIS)

    Silvani, M.I.; Almeida, G.L.; Rogers, J.D.; Lopes, R.T.

    2011-01-01

    Spatial structure of an object can be perceived by the stereoscopic vision provided by eyes or by the parallax produced by movement of the object with regard to the observer. For an opaque object, a technique to render it transparent should be used, in order to make visible the spatial distribution of its inner structure, for any of the two approaches used. In this work, a beam of thermal neutrons at the main port of the Argonauta research reactor of the Instituto de Engenharia Nuclear in Rio de Janeiro/Brazil has been used as radiation to render the inspected objects partially transparent. A neutron sensitive Imaging Plate has been employed as a detector and after exposure it has been developed by a reader using a 0.5 μm laser beam, which defines the finest achievable spatial resolution of the acquired digital image. This image, a radiographic attenuation map of the object, does not represent any specific cross-section but a convoluted projection for each specific attitude of the object with regard to the detector. After taking two of these projections at different object attitudes, they are properly processed and the final image is viewed by a red and green eyeglass. For monochromatic images this processing involves transformation of black and white radiographies into red and white and green and white ones, which are afterwards merged to yield a single image. All the processes are carried out with the software ImageJ. Divergence of the neutron beam unfortunately spoils both spatial and contrast resolutions, which become poorer as object-detector distance increases. Therefore, in order to evaluate the range of spatial resolution corresponding to the 3D image being observed, a curve expressing spatial resolution against object-detector gap has been deduced from the Modulation Transfer Functions experimentally. Typical exposure times, under a reactor power of 170 W, were 6 min for both quantitative and qualitative measurements. In spite of its intrinsic constraints

  2. Stereoscopic radiographic images with thermal neutrons

    Science.gov (United States)

    Silvani, M. I.; Almeida, G. L.; Rogers, J. D.; Lopes, R. T.

    2011-10-01

    Spatial structure of an object can be perceived by the stereoscopic vision provided by eyes or by the parallax produced by movement of the object with regard to the observer. For an opaque object, a technique to render it transparent should be used, in order to make visible the spatial distribution of its inner structure, for any of the two approaches used. In this work, a beam of thermal neutrons at the main port of the Argonauta research reactor of the Instituto de Engenharia Nuclear in Rio de Janeiro/Brazil has been used as radiation to render the inspected objects partially transparent. A neutron sensitive Imaging Plate has been employed as a detector and after exposure it has been developed by a reader using a 0.5 μm laser beam, which defines the finest achievable spatial resolution of the acquired digital image. This image, a radiographic attenuation map of the object, does not represent any specific cross-section but a convoluted projection for each specific attitude of the object with regard to the detector. After taking two of these projections at different object attitudes, they are properly processed and the final image is viewed by a red and green eyeglass. For monochromatic images this processing involves transformation of black and white radiographies into red and white and green and white ones, which are afterwards merged to yield a single image. All the processes are carried out with the software ImageJ. Divergence of the neutron beam unfortunately spoils both spatial and contrast resolutions, which become poorer as object-detector distance increases. Therefore, in order to evaluate the range of spatial resolution corresponding to the 3D image being observed, a curve expressing spatial resolution against object-detector gap has been deduced from the Modulation Transfer Functions experimentally. Typical exposure times, under a reactor power of 170 W, were 6 min for both quantitative and qualitative measurements. In spite of its intrinsic constraints

  3. Results from the Coded Aperture Neutron Imaging System (CANIS)

    International Nuclear Information System (INIS)

    Brubaker, Erik; Steele, John T.; Brennan, James S.; Hilton, Nathan R.; Marleau, Peter

    2010-01-01

    Because of their penetrating power, energetic neutrons and gamma rays (∼1 MeV) offer the best possibility of detecting highly shielded or distant special nuclear material (SNM). Of these, fast neutrons offer the greatest advantage due to their very low and well understood natural background. We are investigating a new approach to fast-neutron imaging- a coded aperture neutron imaging system (CANIS). Coded aperture neutron imaging should offer a highly efficient solution for improved detection speed, range, and sensitivity. We have demonstrated fast neutron and gamma ray imaging with several different configurations of coded masks patterns and detectors including an 'active' mask that is composed of neutron detectors. Here we describe our prototype detector and present some initial results from laboratory tests and demonstrations.

  4. Results from the coded aperture neutron imaging system

    International Nuclear Information System (INIS)

    Brubaker, Erik; Steele, John T.; Brennan, James S.; Marleau, Peter

    2010-01-01

    Because of their penetrating power, energetic neutrons and gamma rays (∼1 MeV) offer the best possibility of detecting highly shielded or distant special nuclear material (SNM). Of these, fast neutrons offer the greatest advantage due to their very low and well understood natural background. We are investigating a new approach to fast-neutron imaging - a coded aperture neutron imaging system (CANIS). Coded aperture neutron imaging should offer a highly efficient solution for improved detection speed, range, and sensitivity. We have demonstrated fast neutron and gamma ray imaging with several different configurations of coded masks patterns and detectors including an 'active' mask that is composed of neutron detectors. Here we describe our prototype detector and present some initial results from laboratory tests and demonstrations.

  5. Real time neutron reflectometry using neutron optical imaging

    International Nuclear Information System (INIS)

    Smith, Gregory S.; Majewski, Jaroslaw

    2001-01-01

    We will describe recent improvements to the SPEAR reflectometer at the Manuel Lujan Jr. Neutron Scattering Center at Los Alamos. One of the changes consists of wider convergent, incident-beam, collimation to take advantage of optical imaging for specular scattering. In addition, the instrument now views a partially coupled liquid hydrogen moderator as opposed to the decoupled moderator that was previous in-place. While the wavelength distribution is poorer, it matches the time (wavelength) resolution of the reflectometer more closely with the angular resolution. Since the integrated intensity of the partially coupled moderator is higher than the decoupled moderator, we show a similar gain in incident beam flux on the sample without loss of the ability to separate fringes. The increases in intensity from the moderator gain and the improved collimation combine to allow us to measure reflectivities with good statistics down to 10 -4 in a matter of minutes and reflectivities of 10 -6 in an hour. Examples of measurements showing the gain in data accumulation rates are presented. (author)

  6. Television imaging system for fast neutron radiography using baby cyclotron

    International Nuclear Information System (INIS)

    Yoshii, Koji; Miya, Kenzo; Katoh, Norihiko.

    1993-01-01

    A television imaging system for fast neutron radiography (FNR-TV) developed using the fast neutron source reactor YAYOI was applied to the baby-cyclotron based fast neutron source to get images of thick objects quickly. In the system the same technique as a current television imaging system of thermal neutron radiography was applied, while the luminescent converter was used to detect fast neutrons. Using the CR39 track etch method it took about 7 h to get an image, while the FNR-TV only 20 s enough for taking the same object. However the FNR-TV imaging result of the simulation model of a large explosive device for the space launch vehicle of H-2 type was not so good as the image taken with the CR39 track etch method. The reason was that the luminescence intensity of the FNR-TV converter was a quarter of that in the YAYOI. (author)

  7. Future prospects of imaging at spallation neutron sources

    International Nuclear Information System (INIS)

    Strobl, M.

    2009-01-01

    The advent of state-of-the-art spallation neutron sources is a major step forward in efficient neutron production for most neutron scattering techniques. Although they provide lower time-averaged neutron flux than high flux reactor sources, advantage for different instrumental techniques can be derived from the pulsed time structure of the available flux, which can be translated into energy, respectively, wavelength resolution. Conventional neutron imaging on the other hand relies on an intense continuous beam flux and hence falls short in profiting from the new development. Nevertheless, some recently developed novel imaging techniques require and some can benefit from energy resolution. The impact of the emerging spallation sources on different imaging techniques has been investigated, ways to benefit will be identified (where possible) and prospects of future imaging instruments and possible options and layouts at a spallation neutron source will be discussed and outlined.

  8. Neutron beams. Tracks analysis, imaging and medicine

    International Nuclear Information System (INIS)

    Pepy, G.

    2006-01-01

    Thermal neutron beams can supply informations about the arrangement of atoms and molecules and about their movement inside the matter. This article treats of the preparation of thermal neutron beams and of the applications that use their penetration and matter activation properties: 1 - thermal neutrons production; 2 - basic properties of thermal neutrons: neutrons scattering, absorbing materials, activating materials, transparent materials, preparation of a neutron beam; 3 - tracks measurement by activation: activation method, measurement of marine pollution by heavy elements, historical evolution of glass composition; 4 - neutron radiography: neutronography, neutronoscopy: viscosity measurement; 5 - cancer treatment. (J.S.)

  9. Numerical simulation for neutron pinhole imaging in ICF

    International Nuclear Information System (INIS)

    Chen Faxin; Yang Jianlun; Wen Shuhuai

    2005-01-01

    Pinhole imaging of the neutron production in laser-driven inertial confinement fusion experiments can provide important information about performance of various capsule designs. In order to get good results in experiments, it is needed to judge performance of various pinhole designs qualitatively or quantitatively before experiment. Calculation of imaging can be simply separated into pinhole imaging and image spectral analysis. In this paper, pinhole imaging is discussed, codes for neutron pinhole imaging and image showing is programed. The codes can be used to provide theoretical foundation for pinhole designing and simulating data for image analysing. (authors)

  10. Elements and process for recording direct image neutron radiographs

    International Nuclear Information System (INIS)

    Poignant, R.V. Jr.; Przybylowicz, E.P.

    1975-01-01

    An element is provided for recording a direct image neutron radiograph, thus eliminating the need for a transfer step (i.e., the use of a transfer screen). The element is capable of holding an electrostatic charge and comprises a first layer for absorbing neutrons and generating a current by dissipation of said electrostatic charge in proportion to the number of neutrons absorbed, and a second layer for conducting the current generated by the absorbed neutrons, said neutron absorbing layer comprising an insulative layer comprising neutron absorbing agents in a concentration of at least 10 17 atoms per cm 3 . An element for enhancing the effect of the neutron beam by utilizing the secondary emanations of neutron absorbing materials is also disclosed along with a process for using the device. (U.S.)

  11. Dynamically Polarized Sample for Neutron Scattering At the Spallation Neutron Source

    International Nuclear Information System (INIS)

    Pierce, Josh; Zhao, J. K.; Crabb, Don

    2009-01-01

    The recently constructed Spallation Neutron Source at the Oak Ridge National Laboratory is quickly becoming the world's leader in neutron scattering sciences. In addition to the world's most intense pulsed neutron source, we are continuously constructing state of the art neutron scattering instruments as well as sample environments to address today and tomorrow's challenges in materials research. The Dynamically Polarized Sample project at the SNS is aimed at taking maximum advantage of polarized neutron scattering from polarized samples, especially biological samples that are abundant in hydrogen. Polarized neutron scattering will allow us drastically increase the signal to noise ratio in experiments such as neutron protein crystallography. The DPS project is near completion and all key components have been tested. Here we report the current status of the project.

  12. Backtracing neutron analysis in the fusion-fission dynamics study

    International Nuclear Information System (INIS)

    Brennand, E. de Goes; Hanappe, F.; Stuttge, L.

    2001-01-01

    A new method for the analysis of multi parametric experimental data is used in the study of the dynamics of the fission process for the compound system 126 Ba. We apply this method to obtain the correlation between thermal energy related to the neutron total multiplicity and the correlation between pre-scission neutron and pos-scission neutron multiplicities. The results obtained are interpreted into the framework of a dynamical model. From this interpretation we have access to the following information: the friction intensity which drives the dynamical evolution of the system; the initial deformation of the compound system; the barrier evolution with temperature and angular momentum, and fission times. (author)

  13. DUNBID, the Delft University neutron backscattering imaging detector

    International Nuclear Information System (INIS)

    Bom, V.R.; Eijk, C.W.E. van; Ali, M.A.

    2005-01-01

    In the search for low-metallic land mines, the neutron backscattering technique may be applied if the soil is sufficiently dry. An advantage of this method is the speed of detection: the scanning speed may be made comparable to that of a metal detector. A two-dimensional position sensitive detector is tested to obtain an image of the back scattered thermal neutron radiation. Results of experiments using a radionuclide neutron source are presented. The on-mine to no-mine signal ratio can be improved by the application of a window on the neutron time-of-flight. Results using a pulsed neutron generator are also presented

  14. Neutron and thermal dynamics of a gaseous core fission reactor

    International Nuclear Information System (INIS)

    van Dam, H.; Kuijper, J.C.; Stekelenburg, A.J.C.; Hoogenboom, J.E.; Boersma-Klein, W.; Kistemaker, J.

    1989-01-01

    In this paper neutron kinetics and thermal dynamics of a Gaseous Core Fission Reactor with magnetical pumping are shown to have many unconventional aspects. Attention is focused on the properties of the fuel gas, the non-linear neutron kinetics and the energy balance in thermodynamical cycles

  15. Inelastic neutron scattering and lattice dynamics of minerals

    Indian Academy of Sciences (India)

    We review current research on minerals using inelastic neutron scattering and lattice dynamics calculations. Inelastic neutron scattering studies in combination with first principles and atomistic calculations provide a detailed understanding of the phonon dispersion relations, density of states and their manifestations in ...

  16. Inelastic neutron scattering and lattice dynamics of minerals

    Indian Academy of Sciences (India)

    Abstract. We review current research on minerals using inelastic neutron scattering and lattice dynamics calculations. Inelastic neutron scattering studies in combination with first principles and atomistic calculations provide a detailed understanding of the phonon dispersion relations, density of states and their ...

  17. Fractional neutron point kinetics equations for nuclear reactor dynamics

    International Nuclear Information System (INIS)

    Espinosa-Paredes, Gilberto; Polo-Labarrios, Marco-A.; Espinosa-Martinez, Erick-G.; Valle-Gallegos, Edmundo del

    2011-01-01

    The fractional point-neutron kinetics model for the dynamic behavior in a nuclear reactor is derived and analyzed in this paper. The fractional model retains the main dynamic characteristics of the neutron motion in which the relaxation time associated with a rapid variation in the neutron flux contains a fractional order, acting as exponent of the relaxation time, to obtain the best representation of a nuclear reactor dynamics. The physical interpretation of the fractional order is related with non-Fickian effects from the neutron diffusion equation point of view. The numerical approximation to the solution of the fractional neutron point kinetics model, which can be represented as a multi-term high-order linear fractional differential equation, is calculated by reducing the problem to a system of ordinary and fractional differential equations. The numerical stability of the fractional scheme is investigated in this work. Results for neutron dynamic behavior for both positive and negative reactivity and for different values of fractional order are shown and compared with the classic neutron point kinetic equations. Additionally, a related review with the neutron point kinetics equations is presented, which encompasses papers written in English about this research topic (as well as some books and technical reports) published since 1940 up to 2010.

  18. Modeling the National Ignition Facility neutron imaging system.

    Science.gov (United States)

    Wilson, D C; Grim, G P; Tregillis, I L; Wilke, M D; Patel, M V; Sepke, S M; Morgan, G L; Hatarik, R; Loomis, E N; Wilde, C H; Oertel, J A; Fatherley, V E; Clark, D D; Fittinghoff, D N; Bower, D E; Schmitt, M J; Marinak, M M; Munro, D H; Merrill, F E; Moran, M J; Wang, T-S F; Danly, C R; Hilko, R A; Batha, S H; Frank, M; Buckles, R

    2010-10-01

    Numerical modeling of the neutron imaging system for the National Ignition Facility (NIF), forward from calculated target neutron emission to a camera image, will guide both the reduction of data and the future development of the system. Located 28 m from target chamber center, the system can produce two images at different neutron energies by gating on neutron arrival time. The brighter image, using neutrons near 14 MeV, reflects the size and symmetry of the implosion "hot spot." A second image in scattered neutrons, 10-12 MeV, reflects the size and symmetry of colder, denser fuel, but with only ∼1%-7% of the neutrons. A misalignment of the pinhole assembly up to ±175 μm is covered by a set of 37 subapertures with different pointings. The model includes the variability of the pinhole point spread function across the field of view. Omega experiments provided absolute calibration, scintillator spatial broadening, and the level of residual light in the down-scattered image from the primary neutrons. Application of the model to light decay measurements of EJ399, BC422, BCF99-55, Xylene, DPAC-30, and Liquid A suggests that DPAC-30 and Liquid A would be preferred over the BCF99-55 scintillator chosen for the first NIF system, if they could be fabricated into detectors with sufficient resolution.

  19. Neutron imaging for inertial confinement fusion and molecular optic imaging

    International Nuclear Information System (INIS)

    Delage, O.

    2010-01-01

    Scientific domains that require imaging of micrometric/nano-metric objects are dramatically increasing (Plasma Physics, Astrophysics, Biotechnology, Earth Sciences...). Difficulties encountered in imaging smaller and smaller objects make this research area more and more challenging and in constant evolution. The two scientific domains, through which this study has been led, are the neutron imaging in the context of the inertial confinement fusion and the fluorescence molecular imaging. Work presented in this thesis has two main objectives. The first one is to describe the instrumentation characteristics that require such imagery and, relatively to the scientific domains considered, identify parameters likely to optimize the imaging system accuracy. The second one is to present the developed data analysis and reconstruction methods able to provide spatial resolution adapted to the size of the observed object. Similarities of numerical algorithms used in these two scientific domains, which goals are quiet different, show how micrometric/nano-metric object imaging is a research area at the border of a large number of scientific disciplines. (author)

  20. Thermal neutron imaging in an active interrogation environment

    International Nuclear Information System (INIS)

    Vanier, P.E.; Forman, L.; Norman, D.R.

    2009-01-01

    We have developed a thermal-neutron coded-aperture imager that reveals the locations of hydrogenous materials from which thermal neutrons are being emitted. This imaging detector can be combined with an accelerator to form an active interrogation system in which fast neutrons are produced in a heavy metal target by means of excitation by high energy photons. The photo-induced neutrons can be either prompt or delayed, depending on whether neutronemitting fission products are generated. Provided that there are hydrogenous materials close to the target, some of the photo-induced neutrons slow down and emerge from the surface at thermal energies. These neutrons can be used to create images that show the location and shape of the thermalizing materials. Analysis of the temporal response of the neutron flux provides information about delayed neutrons from induced fission if there are fissionable materials in the target. The combination of imaging and time-of-flight discrimination helps to improve the signal-to-background ratio. It is also possible to interrogate the target with neutrons, for example using a D-T generator. In this case, an image can be obtained from hydrogenous material in a target without the presence of heavy metal. In addition, if fissionable material is present in the target, probing with fast neutrons can stimulate delayed neutrons from fission, and the imager can detect and locate the object of interest, using appropriate time gating. Operation of this sensitive detection equipment in the vicinity of an accelerator presents a number of challenges, because the accelerator emits electromagnetic interference as well as stray ionizing radiation, which can mask the signals of interest.

  1. Magnetic Dynamics of Fine Particles Studied by Inelastic Neutron Scattering

    DEFF Research Database (Denmark)

    Hansen, Mikkel Fougt; Bødker, Franz; Mørup, Steen

    2000-01-01

    We give an introduction to inelastic neutron scattering and the dynamic scattering function for magnetic nanoparticles. Differences between ferromagnetic and antiferromagnetic nanoparticles are discussed and we give a review of recent results on ferromagnetic Fe nanoparticles and canted antiferro......We give an introduction to inelastic neutron scattering and the dynamic scattering function for magnetic nanoparticles. Differences between ferromagnetic and antiferromagnetic nanoparticles are discussed and we give a review of recent results on ferromagnetic Fe nanoparticles and canted...

  2. Zone plate imaging of 14-MeV neutrons

    International Nuclear Information System (INIS)

    Lerche, R.A.; Lane, S.M.; Hawryluk, A.M.; Ceglio, N.M.

    1986-01-01

    At Livermore we are interested in imaging the thermonuclear burn region of fusion targets irradiated at our Nova laser facility. We expect compressed core diameters to be 10's of microns, and would like images with better than 10-μm resolution. Alpha particle images provided the first direct information about the thermonuclear burn geometry in thin walled exploding pusher targets. In future high density target experiments, only highly penetrating radiations like the 14-MeV neutrons will escape the target core to provide information about the burn region. To make the measurement with a neutron ''pinhole'' camera requires a 10μm pinhole through about 10 cm of material and 10 14 to 10 15 source neutrons. Penumbral imaging offers some improvement over a pinhole. Zone plate coded imaging (ZPCI) techniques are particularly well suited for imaging small objects like the compressed core of a laser fusion target. We have been using ZPCI techniques to image nonpenetrating radiations like x rays and alpha particles for about 10 years. The techniques are well developed. Imaging penetrating radiations like 14-MeV neutrons using ZPCI techniques has several possible advantages. The large solid angle subtended by the Zone plate might substantially reduce the required target neutron yield needed to produce a useful image, and a neutron zone plate system with 10-μm resolution might be easier to fabricate and characterize than a pinhole system. This paper explores the use of ZPCI techniques with penetrating radiation

  3. Development of Neutron Imaging System for Neutron Tomography at Thai Research Reactor TRR-1/M1

    Science.gov (United States)

    Wonglee, S.; Khaweerat, S.; Channuie, J.; Picha, R.; Liamsuwan, T.; Ratanatongchai, W.

    2017-09-01

    The neutron imaging is a powerful non-destructive technique to investigate the internal structure and provides the information which is different from the conventional X-ray/Gamma radiography. By reconstruction of the obtained 2-dimentional (2D) images from the taken different angle around the specimen, the tomographic image can be obtained and it can provide the information in more detail. The neutron imaging system at Thai Research Reactor TRR-1/M1 of Thailand Institute of Nuclear Technology (Public Organization) has been developed to conduct the neutron tomography since 2014. The primary goal of this work is to serve the investigation of archeological samples, however, this technique can also be applied to various fields, such as investigation of industrial specimen and others. This research paper presents the performance study of a compact neutron camera manufactured by Neutron Optics such as speed and sensitivity. Furthermore, the 3-dimentional (3D) neutron image was successfully reconstructed at the developed neutron imaging system of TRR-1/M1.

  4. Visualisation of diesel injector with neutron imaging

    Science.gov (United States)

    Lehmann, E.; Grünzweig, C.; Jollet, S.; Kaiser, M.; Hansen, H.; Dinkelacker, F.

    2015-12-01

    The injection process of diesel engines influences the pollutant emissions. The spray formation is significantly influenced by the internal flow of the injector. One of the key parameters here is the generation of cavitation caused by the geometry and the needle lift. In modern diesel engines the injection pressure is established up to 3000 bar. The details of the flow and phase change processes inside the injector are of increasing importance for such injectors. With these experimental measurements the validation of multiphase and cavitation models is possible for the high pressure range. Here, for instance, cavitation effects can occur. Cavitation effects in the injection port area destabilize the emergent fuel jet and improve the jet break-up. The design of the injection system in direct-injection diesel engines is an important challenge, as the jet breakup, the atomization and the mixture formation in the combustion chamber are closely linked. These factors have a direct impact on emissions, fuel consumption and performance of an engine. The shape of the spray at the outlet is determined by the internal flow of the nozzle. Here, geometrical parameters, the injection pressure, the injection duration and the cavitation phenomena play a major role. In this work, the flow dependency in the nozzles are analysed with the Neutron-Imaging. The great advantage of this method is the penetrability of the steel structure while a high contrast to the fuel is given due to the interaction of the neutrons with the hydrogen amount. Compared to other methods (optical with glass structures) we can apply real components under highest pressure conditions. During the steady state phase of the injection various cavitation phenomena are visible in the injector, being influenced by the nozzle geometry and the fuel pressure. Different characteristics of cavitation in the sac and spray hole can be detected, and the spray formation in the primary breakup zone is influenced.

  5. Problems in the neutron dynamics of source-driven systems

    International Nuclear Information System (INIS)

    Ravetto, P.

    2001-01-01

    The present paper presents some neutronic features of source-driven neutron multiplying systems, with special regards to dynamics, discussing the validity and limitations of classical methods, developed for systems in the vicinity of criticality. Specific characteristics, such as source dominance and the role of delayed neutron emissions are illustrated. Some dynamic peculiarities of innovative concepts proposed for accelerator-driven systems, such as fluid-fuel, are also discussed. The second portion of the work formulates the quasi-static methods for source-driven systems, evidencing its novel features and presenting some numerical results. (author)

  6. Scintillation neutron detector with dynamic threshold

    International Nuclear Information System (INIS)

    Kornilov, N.; Massey, T.; Grimes, S.

    2014-01-01

    Scintillation neutron detectors with hydrogen are a common tool for neutron spectroscopy. They provide good time resolution, neutron-gamma discrimination and high efficiency of neutron counting. The real open problems connected with application of these detectors are in the energy range >10 MeV. There are no standard neutron spectra known with high accuracy for this energy range. Therefore, traditional methods for experimental investigation of the efficiency function fail for these neutrons. The Monte Carlo simulation cannot provide reasonable accuracy due to unknown characteristics of the reactions for charged particle production (p, α and so on, light output, reaction cross-sections). The application of fission chamber with fissile material as a neutron detector did not help to solve the problem. We may avoid many problems if we use the traditional neutron detector with non-traditional data analysis. In this report we give main relations, and demonstrate the method for Cf-source. Experimental detector efficiency is compared with MC simulation. (authors)

  7. Displacement damage effects on CMOS APS image sensors induced by neutron irradiation from a nuclear reactor

    International Nuclear Information System (INIS)

    Wang, Zujun; Huang, Shaoyan; Liu, Minbo; Xiao, Zhigang; He, Baoping; Yao, Zhibin; Sheng, Jiangkun

    2014-01-01

    The experiments of displacement damage effects on CMOS APS image sensors induced by neutron irradiation from a nuclear reactor are presented. The CMOS APS image sensors are manufactured in the standard 0.35 μm CMOS technology. The flux of neutron beams was about 1.33 × 10 8 n/cm 2 s. The three samples were exposed by 1 MeV neutron equivalent-fluence of 1 × 10 11 , 5 × 10 11 , and 1 × 10 12 n/cm 2 , respectively. The mean dark signal (K D ), dark signal spike, dark signal non-uniformity (DSNU), noise (V N ), saturation output signal voltage (V S ), and dynamic range (DR) versus neutron fluence are investigated. The degradation mechanisms of CMOS APS image sensors are analyzed. The mean dark signal increase due to neutron displacement damage appears to be proportional to displacement damage dose. The dark images from CMOS APS image sensors irradiated by neutrons are presented to investigate the generation of dark signal spike

  8. Comparing neutron and X-ray images from NIF implosions

    Directory of Open Access Journals (Sweden)

    Wilson D.C.

    2013-11-01

    Full Text Available Directly laser driven and X-radiation driven DT filled capsules differ in the relationship between neutron and X-ray images. Shot N110217, a directly driven DT-filled glass micro-balloon provided the first neutron images at the National Ignition Facility. As seen in implosions on the Omega laser, the neutron image can be enclosed inside time integrated X-ray images. HYDRA simulations show the X-ray image is dominated by emission from the hot glass shell while the neutron image arises from the DT fuel it encloses. In the absence of mix or jetting, X-ray images of a cryogenically layered THD fuel capsule should be dominated by emission from the hydrogen rather than the cooler plastic shell that is separated from the hot core by cold DT fuel. This cool, dense DT, invisible in X-ray emission, shows itself by scattering hot core neutrons. Germanium X-ray emission spectra and Ross pair filtered X-ray energy resolved images suggest that germanium doped plastic emits in the torus shaped hot spot, probably reducing the neutron yield.

  9. Collimator design for neutron imaging of laser-fusion targets

    International Nuclear Information System (INIS)

    Sommargren, G.E.; Lerche, R.A.

    1981-01-01

    Several pinhole collimator geometries for use in neutron imaging experiments have been modeled and compared. Point spread functions are shown for a cylinder, hyperbola, intersecting cones, and a five-zone approximation to the intersecting cones. Of the geometries studied, the intersecting cones appear the most promising with respect to neutron efficiency, field of view, and isoplanatism

  10. Neutron detection using soft errors in dynamic random access memories

    International Nuclear Information System (INIS)

    Darambara, D.G.; Spyrou, N.M.

    1992-01-01

    The fact that energetic alpha particles have been observed to be capable of inducing single-event upsets in integrated circuit memories has become a topic of considerable interest in the past few years. One recognized difficulty with dynamic random access memory devices (dRAMs) is that the alpha-particle 'contamination' present within the dRAM encapsulating material interact sufficiently as to corrupt stored data. The authors essentially utilized the fact that these corruptions may be induced in dRAMs by the interaction of charged particles with the chip of the dRAM itself as a basis of a hardware system for neutron detection with a view to applications in neutron imaging and elemental analysis. The design incorporates a bank of dRAMs on which the particles are incident. Initially, these particles were alpha particles from an appropriate alpha-emitting source employed to assess system parameters. The sensitivity of the device to logic state upsets by ionizing radiation is a function of design and technology parameters, inducing storage node area, node capacitance, operating voltage, minority carrier lifetime, electric fields pattern in the bulk silicon, and specific device geometry. The soft error rate of the device in a given package depends on the flux of alphas, the energy spectrum, the distribution of incident angles, the target area, the total stored charge, the collection efficiency, the cell geometry, the supply voltage, the cycle and refreshing time, and the noise margin

  11. A novel dual mode neutron-gamma imager

    International Nuclear Information System (INIS)

    Cooper, Robert Lee; Gerling, Mark; Brennan, James S.; Mascarenhas, Nicholas; Mrowka, Stanley; Marleau, Peter

    2010-01-01

    The Neutron Scatter Camera (NSC) can image fission sources and determine their energy spectra at distances of tens of meters and through significant thicknesses of intervening materials in relatively short times (1). We recently completed a 32 element scatter camera and will present recent advances made with this instrument. A novel capability for the scatter camera is dual mode imaging. In normal neutron imaging mode we identify and image neutron events using pulse shape discrimination (PSD) and time of flight in liquid scintillator. Similarly gamma rays are identified from Compton scatter in the front and rear planes for our segmented detector. Rather than reject these events, we show it is possible to construct a gamma-ray image by running the analysis in a 'Compton mode'. Instead of calculating the scattering angle by the kinematics of elastic scatters as is appropriate for neutron events, it can be found by the kinematics of Compton scatters. Our scatter camera has not been optimized as a Compton gamma-ray imager but is found to work reasonably. We studied imaging performance using a Cs137 source. We find that we are able to image the gamma source with reasonable fidelity. We are able to determine gamma energy after some reasonable assumptions. We will detail the various algorithms we have developed for gamma image reconstruction. We will outline areas for improvement, include additional results and compare neutron and gamma mode imaging.

  12. Implementation of neutron phase contrast imaging at FRM-II

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, Klaus

    2008-11-12

    At ANTARES, the beam line for neutron imaging at the Forschungsneutronenquelle Heinz Maier-Leibnitz (FRM-II) in Garching, the option to do phase contrast imaging besides conventional absorption based neutron imaging was implemented and successfully used for the non-destructive testing of various types of objects. The used propagation-based technique is based on the interference of neutron waves in the detector plane that were differently strong diffracted by the sample. A comparison with other phase-sensitive neutron imaging techniques highlights assets and drawbacks of the different methods. In preliminary measurements at ANTARES and the spallation source SINQ at PSI in Villigen, the influence of the beam geometry, the neutron spectrum and the detector on the quality of the phase contrast measurements were investigated systematically. It was demonstrated that gamma radiation and epithermal neutrons in the beam contribute severely to background noise in measurements, which motivated the installation of a remotely controlled filter wheel for a quick and precise positioning of different crystal filters in the beam. By the installation of a similar aperture wheel, a quick change between eight different beam geometries was made possible. Besides pinhole and slit apertures, coded apertures based on non redundant arrays were investigated. The possibilities, which arise by the exploitation of the real part of the refractive index in neutron imaging, were demonstrated in experiments with especially designed test samples and in measurements with ordinary, industrial components. (orig.)

  13. Implementation of neutron phase contrast imaging at FRM-II

    International Nuclear Information System (INIS)

    Lorenz, Klaus

    2008-01-01

    At ANTARES, the beam line for neutron imaging at the Forschungsneutronenquelle Heinz Maier-Leibnitz (FRM-II) in Garching, the option to do phase contrast imaging besides conventional absorption based neutron imaging was implemented and successfully used for the non-destructive testing of various types of objects. The used propagation-based technique is based on the interference of neutron waves in the detector plane that were differently strong diffracted by the sample. A comparison with other phase-sensitive neutron imaging techniques highlights assets and drawbacks of the different methods. In preliminary measurements at ANTARES and the spallation source SINQ at PSI in Villigen, the influence of the beam geometry, the neutron spectrum and the detector on the quality of the phase contrast measurements were investigated systematically. It was demonstrated that gamma radiation and epithermal neutrons in the beam contribute severely to background noise in measurements, which motivated the installation of a remotely controlled filter wheel for a quick and precise positioning of different crystal filters in the beam. By the installation of a similar aperture wheel, a quick change between eight different beam geometries was made possible. Besides pinhole and slit apertures, coded apertures based on non redundant arrays were investigated. The possibilities, which arise by the exploitation of the real part of the refractive index in neutron imaging, were demonstrated in experiments with especially designed test samples and in measurements with ordinary, industrial components. (orig.)

  14. Dynamically polarized samples for neutron protein crystallography at the Spallation Neutron Source

    International Nuclear Information System (INIS)

    Zhao, Jinkui; Pierce, Josh; Robertson, J. L.; Herwig, Kenneth W.; Myles, Dean; Cuneo, Matt; Li, Le; Meilleur, Flora; Standaert, Bob

    2016-01-01

    To prepare for the next generation neutron scattering instruments for the planned second target station at the Spallation Neutron Source (SNS) and to broaden the scientific impact of neutron protein crystallography at the Oak Ridge National Laboratory, we have recently ramped up our efforts to develop a dynamically polarized target for neutron protein crystallography at the SNS. Proteins contain a large amount of hydrogen which contributes to incoherent diffraction background and limits the sensitivity of neutron protein crystallography. This incoherent background can be suppressed by using polarized neutron diffraction, which in the same time also improves the coherent diffraction signal. Our plan is to develop a custom Dynamic Nuclear Polarization (DNP) setup tailored to neutron protein diffraction instruments. Protein crystals will be polarized at a magnetic field of 5 T and temperatures of below 1 K. After the dynamic polarization process, the sample will be brought to a frozen-spin mode in a 0.5 T holding field and at temperatures below 100 mK. In a parallel effort, we are also investigating various ways of incorporating polarization agents needed for DNP, such as site specific spin labels, into protein crystals. (paper)

  15. Assessment of Electromagnetic Stirrer Agitated Liquid Metal Flows by Dynamic Neutron Radiography

    Science.gov (United States)

    Ščepanskis, Mihails; Sarma, Mārtiņš; Vontobel, Peter; Trtik, Pavel; Thomsen, Knud; Jakovičs, Andris; Beinerts, Toms

    2017-04-01

    This paper presents qualitative and quantitative characterization of two-phase liquid metal flows agitated by the stirrer on rotating permanent magnets. The stirrer was designed to fulfill various eddy flows, which may have different rates of solid particle entrapment from the liquid surface and their homogenization. The flow was characterized by visualization of the tailored tracer particles by means of dynamic neutron radiography, an experimental method well suited for liquid metal flows due to low opacity of some metals for neutrons. The rather high temporal resolution of the image acquisition (32 Hz image acquisition rate) allows for the quantitative investigation of the flows up to 30 cm/s using neutron particle image velocimetry. In situ visualization of the two-phase liquid metal flow is also demonstrated.

  16. Spin dynamics in polarized neutron interferometry

    International Nuclear Information System (INIS)

    Buchelt, R.J.

    2000-05-01

    Since its first implementation in 1974, perfect crystal neutron interferometry has become an extremely successful method applicable to a variety of research fields. Moreover, it proved as an illustrative and didactically valuable experiment for the demonstration of the fundamental principles of quantum mechanics, the neutron being an almost ideal probe for the detection of various effects, as it interacts by all four forces of nature. For instance, the first experimental verification of the 4-pi-periodicity of spinor wave functions was performed with perfect crystal neutron interferometry, and it remains the only method known which demonstrates the quantum mechanical wave-particle-duality of massive particles at a macroscopic separation of the coherent matter waves of several centimeters. A particular position is taken herein by polarized neutron interferometry, which as a collective term comprises all techniques and experiments which not only aim at the coherent splitting and macroscopic separation of neutron beams in the interferometer with the purpose of their separate treatment, but which aim to do so with explicit employment of the spin-magnetic properties of the neutron as a fermion. Remarkable aspects may arise, for example, if nuclear and magnetic potentials are concurrently applied to a partial beam of the interferometer: among other results, it is found that - in perfect agreement to the theoretical predictions - the neutron beam leaving the interferometer features non-zero polarization, even if the incident neutron beam, and hence either of the partial beams, is unpolarized. The main emphasis of the present work lies on the development of an appropriate formalism that describes the effect of simultaneous occurrence of nuclear and magnetic interaction on the emerging intensity and polarization for an arbitrary number of sequential magnetic regions, so-called domains. The confrontation with subtle theoretical problems was inevitable during the experimental

  17. Neutron penumbral imaging of laser-fusion targets

    International Nuclear Information System (INIS)

    Lerche, R.A.; Ress, D.B.

    1988-01-01

    Using a new technique, penumbral coded-aperture imaging, the first neutron images of laser-driven, inertial-confinement fusion targets were obtained. With these images the deuterium-tritium burn region within a compressed target can be measured directly. 4 references, 11 figures

  18. Transportable, Low-Dose Active Fast-Neutron Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Mihalczo, John T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wright, Michael C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); McConchie, Seth M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Archer, Daniel E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Palles, Blake A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-08-01

    This document contains a description of the method of transportable, low-dose active fast-neutron imaging as developed by ORNL. The discussion begins with the technique and instrumentation and continues with the image reconstruction and analysis. The analysis discussion includes an example of how a gap smaller than the neutron production spot size and detector size can be detected and characterized depending upon the measurement time.

  19. Neutron diffractometer for bio-crystallography (BIX) with an imaging plate neutron detector

    Energy Technology Data Exchange (ETDEWEB)

    Niimura, Nobuo [Japan Atomic Energy Research Inst., Ibaraki-ken (Japan)

    1994-12-31

    We have constructed a dedicated diffractometer for neutron crystallography in biology (BIX) on the JRR-3M reactor at JAERI (Japan Atomic Energy Research Institute). The diffraction intensity from a protein crystal is weaker than that from most inorganic materials. In order to overcome the intensity problem, an elastically bent silicon monochromator and a large area detector system were specially designed. A preliminary result of diffraction experiment using BIX has been reported. An imaging plate neutron detector has been developed and a feasibility experiment was carried out on BIX. Results are reported. An imaging plate neutron detector has been developed and a feasibility test was carried out using BIX.

  20. First downscattered neutron images from Inertial Confinement Fusion experiments at the National Ignition Facility

    Directory of Open Access Journals (Sweden)

    Guler Nevzat

    2013-11-01

    Full Text Available Inertial Confinement Fusion experiments at the National Ignition Facility (NIF are designed to understand and test the basic principles of self-sustaining fusion reactions by laser driven compression of deuterium-tritium (DT filled cryogenic plastic (CH capsules. The experimental campaign is ongoing to tune the implosions and characterize the burning plasma conditions. Nuclear diagnostics play an important role in measuring the characteristics of these burning plasmas, providing feedback to improve the implosion dynamics. The Neutron Imaging (NI diagnostic provides information on the distribution of the central fusion reaction region and the surrounding DT fuel by collecting images at two different energy bands for primary (13–15 MeV and downscattered (10–12 MeV neutrons. From these distributions, the final shape and size of the compressed capsule can be estimated and the symmetry of the compression can be inferred. The first downscattered neutron images from imploding ICF capsules are shown in this paper.

  1. First downscattered neutron images from Inertial Confinement Fusion experiments at the National Ignition Facility

    Science.gov (United States)

    Guler, Nevzat; Aragonez, Robert J.; Archuleta, Thomas N.; Batha, Steven H.; Clark, David D.; Clark, Deborah J.; Danly, Chris R.; Day, Robert D.; Fatherley, Valerie E.; Finch, Joshua P.; Gallegos, Robert A.; Garcia, Felix P.; Grim, Gary; Hsu, Albert H.; Jaramillo, Steven A.; Loomis, Eric N.; Mares, Danielle; Martinson, Drew D.; Merrill, Frank E.; Morgan, George L.; Munson, Carter; Murphy, Thomas J.; Oertel, John A.; Polk, Paul J.; Schmidt, Derek W.; Tregillis, Ian L.; Valdez, Adelaida C.; Volegov, Petr L.; Wang, Tai-Sen F.; Wilde, Carl H.; Wilke, Mark D.; Wilson, Douglas C.; Atkinson, Dennis P.; Bower, Dan E.; Drury, Owen B.; Dzenitis, John M.; Felker, Brian; Fittinghoff, David N.; Frank, Matthias; Liddick, Sean N.; Moran, Michael J.; Roberson, George P.; Weiss, Paul; Buckles, Robert A.; Cradick, Jerry R.; Kaufman, Morris I.; Lutz, Steve S.; Malone, Robert M.; Traille, Albert

    2013-11-01

    Inertial Confinement Fusion experiments at the National Ignition Facility (NIF) are designed to understand and test the basic principles of self-sustaining fusion reactions by laser driven compression of deuterium-tritium (DT) filled cryogenic plastic (CH) capsules. The experimental campaign is ongoing to tune the implosions and characterize the burning plasma conditions. Nuclear diagnostics play an important role in measuring the characteristics of these burning plasmas, providing feedback to improve the implosion dynamics. The Neutron Imaging (NI) diagnostic provides information on the distribution of the central fusion reaction region and the surrounding DT fuel by collecting images at two different energy bands for primary (13-15 MeV) and downscattered (10-12 MeV) neutrons. From these distributions, the final shape and size of the compressed capsule can be estimated and the symmetry of the compression can be inferred. The first downscattered neutron images from imploding ICF capsules are shown in this paper.

  2. Moisture imaging of a camphor tree by neutron beam

    International Nuclear Information System (INIS)

    Nakanishi, Tomoko M.; Karakama, Isamu; Sakura, Tsuguo; Matsubayashi, Masashi

    1998-01-01

    Moisture distribution of a camphor tree was presented. A 23 year old camphor tree was downed at university forest and a wood disk, about 1 cm in width, was lumbered out from the breast height of the tree. The wood disk as well as a newly developing branch of the tree were irradiated with thermal neutrons at an atomic reactor installed at Japan Atomic Energy Research Institute. The total flux of thermal neutron was 3.0 x 10 9 n/cm 2 . Water specific images of the disk and a branch were presented with high resolution, which was estimated to be about 16 μm. In the case of wood disk, moisture decreasing manner while drying was also shown through neutron image. Neutron images showed that the moisture decreasing rate in sapwood was similar to that of heartwood. (author)

  3. The dynamics of physisorbed layers studied by neutron scattering

    International Nuclear Information System (INIS)

    Nielsen, M.; McTague, J.P.

    1978-01-01

    We discuss the neutron scattering technique applied to the study of adsorbed thin films. Despite the fact that neutrons are scattered very weakly by surfaces, recent studies have shown that both structural and dynamical information can be obtained even for submonolayer coverages. Results will be shown for films of Ar, D 2 , H 2 , and O 2 adsorbed on (001) surfaces of graphite and for H 2 molecules adsorbed on activated alumina. (orig.) [de

  4. Dynamical neutron diffraction by curved crystals in the Laue geometry

    International Nuclear Information System (INIS)

    Albertini, G.; Melone, S.; Lagomarsino, S.; Mazkedian, S.; Puliti, P.; Rustichelli, F.

    1977-01-01

    The Taupin dynamical theory of X-ray diffraction by deformed crystals which was previously extended to the neutron diffraction by curved crystals in the Bragg geometry, is applied to calculate neutron diffraction patterns in the Laue geometry. The theoretical results are compared with experimental data on curved silicon crystals. The agreement is quite satisfactory. In the second part a simple model recently presented to describe neutron diffraction properties in the Bragg case is extended to the Laue case. The predictions of such a model are in satisfactory agreement with the rigorous theory and the experimental results. (author)

  5. High speed motion neutron radiography of dynamic events

    International Nuclear Information System (INIS)

    Robinson, A.H.; Barton, J.P.

    1983-01-01

    The development of a technique that permits neutron radiographic analysis of dynamic processes over a period lasting from one to ten milliseconds is described. The key to the technique is the use of a neutron pulse broad enough to span the duration of a brief event and intense enough to allow recording of the results on a high-speed movie film at frame rates of 10,000 frames/sec. Some typical application results in ballistic studies and two-phase flow are shown and discussed. The use of scintillator screens in the high-speed motion neutron radiography system is summarized and the statistical limitations of the technique are discussed

  6. A neutron dynamic therapy with a boron tracedrug UTX-51 using a compact neutron generator.

    Science.gov (United States)

    Hori, Hitoshi; Tada, Ryu; Uto, Yoshihiro; Nakata, Eiji; Morii, Takashi; Masuda, Kai

    2014-08-01

    We are developing a neutron dynamic therapy (NDT) with boron tracedrugs for a new mechanical-clearance treatment of pathotoxic misfolded, aggregated, and self-propagating prion-associated disease proteins. We present a compact neutron generator-based NDT using a boron tracedrug UTX-51. Our NDT is based on the weak thermal neutron-bombarded destructive action of UTX-51 on bovine serum albumin (BSA) using the neutron beams produced from a compact inertial electrostatic confinement fusion (IECF) neutron generator. BSA as an NDT molecular target was subjected to thermal neutron irradiation for eight hours using a compact neutron generator. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis pattern showed no protein band when 2 nmoles of BSA were irradiated with more than 100 nmoles of UTX-51, while BSA was not affected when irradiated without UTX-51. For the first time, we have succeeded in the molecular destruction of a prion-disease model protein, BSA, by NDT with a boron tracedrug, UTX-51, using a compact neutron generator. Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  7. DIANE stationary neutron radiography system image quality and industrial applications

    International Nuclear Information System (INIS)

    Cluzeau, S.; Huet, J.; Tourneur, P. le

    1994-01-01

    The SODERN neutron radiography laboratory has operated since February 1993 using a sealed tube generator (GENIE 46). An experimental programme of characterization (dosimetry, spectroscopy) has confirmed the expected performances concerning: neutron flux intensity, neutron energy range, residual gamma flux. Results are given in a specific report [2]. This paper is devoted to the image performance reporting. ASTM and specific indicators have been used to test the image quality with various converters and films. The corresponding modulation transfer functions are to be determined from image processing. Some industrial applications have demonstrated the capabilities of the system: corrosion detection in aircraft parts, ammunitions filling testing, detection of polymer lacks in sandwich steel sheets, detection of moisture in a probe for geophysics, residual ceramic cores imaging in turbine blades. Various computerized electronic imaging systems will be tested to improve the industrial capabilities. (orig.)

  8. The analysis and correction of neutron scattering effects in neutron imaging

    International Nuclear Information System (INIS)

    Raine, D.A.; Brenizer, J.S.

    1997-01-01

    A method of correcting for the scattering effects present in neutron radiographic and computed tomographic imaging has been developed. Prior work has shown that beam, object, and imaging system geometry factors, such as the L/D ratio and angular divergence, are the primary sources contributing to the degradation of neutron images. With objects smaller than 20--40 mm in width, a parallel beam approximation can be made where the effects from geometry are negligible. Factors which remain important in the image formation process are the pixel size of the imaging system, neutron scattering, the size of the object, the conversion material, and the beam energy spectrum. The Monte Carlo N-Particle transport code, version 4A (MCNP4A), was used to separate and evaluate the effect that each of these parameters has on neutron image data. The simulations were used to develop a correction algorithm which is easy to implement and requires no a priori knowledge of the object. The correction algorithm is based on the determination of the object scatter function (OSF) using available data outside the object to estimate the shape and magnitude of the OSF based on a Gaussian functional form. For objects smaller than 1 mm (0.04 in.) in width, the correction function can be well approximated by a constant function. Errors in the determination and correction of the MCNP simulated neutron scattering component were under 5% and larger errors were only noted in objects which were at the extreme high end of the range of object sizes simulated. The Monte Carlo data also indicated that scattering does not play a significant role in the blurring of neutron radiographic and tomographic images. The effect of neutron scattering on computed tomography is shown to be minimal at best, with the most serious effect resulting when the basic backprojection method is used

  9. Three-dimensional visualization and measurement of water distributions in PEFC by dynamic CT method on neutron radiography

    International Nuclear Information System (INIS)

    Hashimoto, Michinori; Murakawa, Hideki; Sugimoto, Katsumi; Asano, Hitoshi; Takenaka, Nobuyuki; Mochiki, Koh-ichi

    2011-01-01

    Visualization of dynamic three-dimensional water behavior in a PEFC stack was carried out by neutron CT for clarifying water effects on performances of a Polymer Electrolyte Fuel Cell (PEFC) stack. Neutron radiography system at JRR-3 in Japan Atomic Energy Agency was used. An operating stack with three cells based on Japan Automobile Research Institute standard was visualized. A consecutive CT reconstruction method by rotating the fuel stack continuously was developed by using a neutron image intensifier and a C-MOS high speed video camera. The dynamic water behavior in channels in the operating PEFC stack was clearly visualized 15 sec in interval by the developed dynamic neutron CT system. From the CT reconstructed images, evaluation of water amount in each cell was carried out. It was shown that the water distribution in each cell was correlated well with power generation characteristics in each cell. (author)

  10. MINER - A Mobile Imager of Neutrons for Emergency Responders

    Energy Technology Data Exchange (ETDEWEB)

    Goldsmith, John E. M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brennan, James S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gerling, Mark D [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kiff, Scott D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Mascarenhas, Nicholas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Van De Vreugde, James L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-10-01

    We have developed a mobile fast neutron imaging platform to enhance the capabilities of emergency responders in the localization and characterization of special nuclear material. This mobile imager of neutrons for emergency responders (MINER) is based on the Neutron Scatter Camera, a large segmented imaging system that was optimized for large-area search applications. Due to the reduced size and power requirements of a man-portable system, MINER has been engineered to fit a much smaller form factor, and to be operated from either a battery or AC power. We chose a design that enabled omnidirectional (4π) imaging, with only a ~twofold decrease in sensitivity compared to the much larger neutron scatter cameras. The system was designed to optimize its performance for neutron imaging and spectroscopy, but it does also function as a Compton camera for gamma imaging. This document outlines the project activities, broadly characterized as system development, laboratory measurements, and deployments, and presents sample results in these areas. Additional information can be found in the documents that reside in WebPMIS.

  11. Neutron tomography at IPEN-CNEN/SP: images and applications

    Energy Technology Data Exchange (ETDEWEB)

    Pugliesi, Reynaldo; Pereira, Marco Antonio Stanojev; Andrade, Marcos Leandro Garcia, E-mail: pugliesi@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2016-07-01

    Full text: The neutron tomography is a non destructive testing technique used to inspect the internal structure of a sample by means of tridimensional digital images. Because of the neutron-matter interaction characteristics this technique can be used to inspect hydrogen-rich substances like ceramics, oil, grease, water, rubber, blood and others, even wrapped by thick metal layers. In this way, the information provided by neutrons are complementary to the ones provided by X-rays. The Brazilian Institute for Nuclear Technology IPEN-CNEN/SP has an equipment for neutron tomography which since Nov/2011 is operational and installed at the IEA-R1 Nuclear Research Reactor. This equipment is able to provide high quality tomographs and some important results obtained for Proton Exchange Membranes (PEM) cell, for an archaeological sample and for pottery, will be presented. Furthermore, details of its construction and its versatility, in the sense that by means of small adjustments is possible to obtain images by other neutron imaging techniques, will be also presented. Is very important enhance that the high quality of the obtained images is due to the excellence of the IEA-R1 reactor which is able to furnish neutron beams with adequate intensity for such purpose. (author)

  12. Neutron CSI: Integrated platform for non-destructive composition and stress imaging with neutrons

    International Nuclear Information System (INIS)

    Materna, T.; Pirling, T.

    2011-01-01

    We propose to build an interdisciplinary platform for non-destructive analysis and imaging with neutrons. The project regroups an instrument already available at ILL (Laue-Langevin Institute), SALSA, with a new one for Neutron Tomography coupled to Prompt-Gamma Neutron Activation (PGNA) as well as partial usage of another proposed instrument, FIPPS. The focus of the proposition is the versatility of high spatial resolution and energy-selective neutron tomography to provide a rapid and precise 3D morphological map of an object as well as indirect information on its 3D elemental and structural composition through the scan of Bragg-edges in transmission. Coupled to PGNA imaging and the strain analysis power of SALSA, the aim of the platform is to answer key questions occurring in geological, metallurgical, engineering and medical fields, material research and cultural heritage. (authors)

  13. Imaging of Rabbit VX-2 Hepatic Cancer by Cold and Thermal Neutron Radiography

    Science.gov (United States)

    Tsuchiya, Yoshinori; Matsubayashi, Masahito; Takeda, Tohoru; Lwin, Thet Thet; Wu, Jin; Yoneyama, Akio; Matsumura, Akira; Hori, Tomiei; Itai, Yuji

    2003-11-01

    Neutron radiography is based on differences in neutron mass attenuation coefficients among the elements and is a non-destructive imaging method. To investigate biomedical applications of neutron radiography, imaging of rabbit VX-2 liver cancer was performed using thermal and cold neutron radiography with a neutron imaging plate. Hepatic vessels and VX-2 tumor were clearly observed by neutron radiography, especially by cold neutron imaging. The image contrast of this modality was better than that of absorption-contrast X-ray radiography.

  14. Neutron Imaging with Timepix Coupled Lithium Indium Diselenide

    Directory of Open Access Journals (Sweden)

    Elan Herrera

    2017-12-01

    Full Text Available The material lithium indium diselenide, a single crystal neutron sensitive semiconductor, has demonstrated its capabilities as a high resolution imaging device. The sensor was prepared with a 55 μ m pitch array of gold contacts, designed to couple with the Timepix imaging ASIC. The resulting device was tested at the High Flux Isotope Reactor, demonstrating a response to cold neutrons when enriched in 95% 6 Li. The imaging system performed a series of experiments resulting in a <200 μ m resolution limit with the Paul Scherrer Institute (PSI Siemens star mask and a feature resolution of 34 μ m with a knife-edge test. Furthermore, the system was able to resolve the University of Tennessee logo inscribed into a 3D printed 1 cm 3 plastic block. This technology marks the application of high resolution neutron imaging using a direct readout semiconductor.

  15. Pion condensation and neutron star dynamics

    International Nuclear Information System (INIS)

    Kaempfer, B.

    1983-01-01

    The question of formation of pion condensate via a phase transition in nuclear matter, especially in the core of neutron stars is reviewed. The possible mechanisms and the theoretical restrictions of pion condensation are summarized. The effects of ultradense equation of state and density jumps on the possible condensation phase transition are investigated. The possibilities of observation of condensation process are described. (D.Gy.)

  16. Exploiting Fission Chain Reaction Dynamics to Image Fissile Materials

    Science.gov (United States)

    Chapman, Peter Henry

    Radiation imaging is one potential method to verify nuclear weapons dismantlement. The neutron coded aperture imager (NCAI), jointly developed by Oak Ridge National Laboratory (ORNL) and Sandia National Laboratories (SNL), is capable of imaging sources of fast (e.g., fission spectrum) neutrons using an array of organic scintillators. This work presents a method developed to discriminate between non-multiplying (i.e., non-fissile) neutron sources and multiplying (i.e., fissile) neutron sources using the NCAI. This method exploits the dynamics of fission chain-reactions; it applies time-correlated pulse-height (TCPH) analysis to identify neutrons in fission chain reactions. TCPH analyzes the neutron energy deposited in the organic scintillator vs. the apparent neutron time-of-flight. Energy deposition is estimated from light output, and time-of-flight is estimated from the time between the neutron interaction and the immediately preceding gamma interaction. Neutrons that deposit more energy than can be accounted for by their apparent time-of-flight are identified as fission chain-reaction neutrons, and the image is reconstructed using only these neutron detection events. This analysis was applied to measurements of weapons-grade plutonium (WGPu) metal and 252Cf performed at the Nevada National Security Site (NNSS) Device Assembly Facility (DAF) in July 2015. The results demonstrate it is possible to eliminate the non-fissile 252Cf source from the image while preserving the fissileWGPu source. TCPH analysis was also applied to additional scenes in which theWGPu and 252Cf sources were measured individually. The results of these separate measurements further demonstrate the ability to remove the non-fissile 252Cf source and retain the fissileWGPu source. Simulations performed using MCNPX-PoliMi indicate that in a one hour measurement, solid spheres ofWGPu are retained at a 1sigma level for neutron multiplications M -˜ 3.0 and above, while hollowWGPu spheres are

  17. Neutron Imaging Control Report: FY 2016

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, D. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-11-30

    During the 2016 fiscal year, work began on the supervision and control systems for the neutron source currently under construction in the B194 accelerator caves. This source relies on a deuteron beam colliding with a high-speed stream of deuterium gas to create neutrons, which poses significant technical challenges. To help overcome those challenges, an integrated, operator-focused control architecture is required to collect and assimilate disparate data from a variety of measurement points, as well as provide the means to remotely control the system hardware.

  18. Random mask optimization for fast neutron coded aperture imaging

    Energy Technology Data Exchange (ETDEWEB)

    McMillan, Kyle [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Univ. of California, Los Angeles, CA (United States); Marleau, Peter [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Brubaker, Erik [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2015-05-01

    In coded aperture imaging, one of the most important factors determining the quality of reconstructed images is the choice of mask/aperture pattern. In many applications, uniformly redundant arrays (URAs) are widely accepted as the optimal mask pattern. Under ideal conditions, thin and highly opaque masks, URA patterns are mathematically constructed to provide artifact-free reconstruction however, the number of URAs for a chosen number of mask elements is limited and when highly penetrating particles such as fast neutrons and high-energy gamma-rays are being imaged, the optimum is seldom achieved. In this case more robust mask patterns that provide better reconstructed image quality may exist. Through the use of heuristic optimization methods and maximum likelihood expectation maximization (MLEM) image reconstruction, we show that for both point and extended neutron sources a random mask pattern can be optimized to provide better image quality than that of a URA.

  19. Feasibility study on using imaging plates to estimate thermal neutron fluence in neutron-gamma mixed fields

    International Nuclear Information System (INIS)

    Fujibuchi, T.; Tanabe, Y.; Sakae, T.; Terunuma, T.; Isobe, T.; Kawamura, H.; Yasuoka, K.; Matsumoto, T.; Harano, H.; Nishiyama, J.; Masuda, A.; Nohtomi, A.

    2011-01-01

    In current radiotherapy, neutrons are produced in a photonuclear reaction when incident photon energy is higher than the threshold. In the present study, a method of discriminating the neutron component was investigated using an imaging plate (IP) in the neutron-gamma-ray mixed field. Two types of IP were used: a conventional IP for beta- and gamma rays, and an IP doped with Gd for detecting neutrons. IPs were irradiated in the mixed field, and the photo-stimulated luminescence (PSL) intensity of the thermal neutron component was discriminated using an expression proposed herein. The PSL intensity of the thermal neutron component was proportional to thermal neutron fluence. When additional irradiation of photons was added to constant neutron irradiation, the PSL intensity of the thermal neutron component was not affected. The uncertainty of PSL intensities was approximately 11.4 %. This method provides a simple and effective means of discriminating the neutron component in a mixed field. (authors)

  20. Molecular dynamics of TBP and DBP studied by neutron transmission

    International Nuclear Information System (INIS)

    Salles Filho, J.B.V.; Refinetti, M.E.; Fulfaro, R.; Vinhas, L.A.

    1984-04-01

    Differences between the properties of TBP and DBP, concerning the uranium extraction processes, may be related to certain characteristics of the molecular dynamics of each compound. In order to investigate the dynamical behaviour of hydrogen in these molecules, neutron transmission of TBP and DBP has been measured as a function of neutron wavelenght in the range 4.0 - 6.0 A, at room temperature. Scattering cross sections per hydrogen atom have been obtained. From the comparison with results previously obtained for n-butanol, similar dynamical behaviour of butyl radicals in these compounds could be observed. This similarity indicates that the presence of two or three butyl radicals in butylphosphate molecules does not exert influence in the hydrogen motion of methyl and methylene groups. This suggests that the different chemical behaviour between TBP and DBP is related to the dynamics of the hydrogen directly bound to the DBP phosphate group.(Author) [pt

  1. Improve the efficiency of PEMFC using neutron imaging

    International Nuclear Information System (INIS)

    Kim, Tae Joo; Shim, Chulmuu

    2010-01-01

    The water management is one of the most critical issues for PEMFC commercialization. In order to make a proper scheme for water management, the information of water distribution and behavior is very important. But the visualization is difficult due to metallic coverage. Recently, neutron imaging has joined the canon of diagnostic methods for fuel cell research and is applied worldwide with qualitative and quantitative results. In this investigation, we prepared 3-parallel serpentine single PEMFC. The active area is 250 mm 2 and channel size is 1 Χ 1 mm, respectively. Distribution and transport of water in an operating PEMFC were observed as functions of flow directions and differential pressures between anode and cathodes. This investigation was performed at BST-2, Nest. The collimation ratio is 600 and neutron fluence of BST-2 is 7.2 Χ 10 6 n/s, respectively. Neutron image was captured by A-Si detector with 1 sec expsosure time. The PEMFC has different performances for each differential pressure and flow directions. When the neutron images are compared with operating conditions, the distribution and behavior of water are different. Total water fraction is increased and then decreases as the current density increases. This situation is similar trend for the flow directions. It is shown that neutron imaging technique is powerful tool to visualize the PEMFC and the water distribution and behavior of an operating PEMFC helps improve the efficiency of PEMFC

  2. Dynamics of liquid N2 studied by neutron inelastic scattering

    DEFF Research Database (Denmark)

    Pedersen, Karen Schou; Carneiro, Kim; Hansen, Flemming Yssing

    1982-01-01

    Neutron inelastic-scattering data from liquid N2 at wave-vector transfer κ between 0.18 and 2.1 Å-1 and temperatures ranging from T=65-77 K are presented. The data are corrected for the contribution from multiple scattering and incoherent scattering. The resulting dynamic structure factor S (κ,ω)...

  3. Molecular dynamics using quasielastic neutron scattering

    CERN Document Server

    Mitra, S

    2003-01-01

    Quasielastic neutron scattering (QENS) technique is well suited to study the molecular motions (rotations and translations) in solids or liquids. It offers a unique possibility of analysing spatial dimensions of atomic or molecular processes in their development over time. We describe here some of the systems studied using the QENS spectrometer, designed, developed and commissioned at Dhruva reactor in Trombay. We have studied a variety of systems to investigate the molecular motion, for example, simple molecular solids, molecules adsorbed in confined medium like porous systems or zeolites, monolayer-protected nano-sized metal clusters, water in Portland cement as it cures with time, etc. (author)

  4. Development of a neutron imager based on superconducting detectors

    Energy Technology Data Exchange (ETDEWEB)

    Miyajima, Shigeyuki, E-mail: miyajima@nict.go.jp [Department of Physics and Engineering, Osaka Prefecture University (Japan); Institute for Nanofabrication Research, Osaka Prefecture University (Japan); Yamaguchi, Hiroyuki; Nakayama, Hirotaka; Shishido, Hiroaki [Department of Physics and Engineering, Osaka Prefecture University (Japan); Institute for Nanofabrication Research, Osaka Prefecture University (Japan); Fujimaki, Akira [Department of Quantum Engineering, Nagoya University (Japan); Hidaka, Mutsuo [National Institute of Advanced Industrial Science and Technology (Japan); Harada, Masahide; Oikawa, Kenichi; Oku, Takayuki; Arai, Masatoshi [J-PARC Center, Japan Atomic Energy Agency (Japan); Ishida, Takekazu [Department of Physics and Engineering, Osaka Prefecture University (Japan); Institute for Nanofabrication Research, Osaka Prefecture University (Japan)

    2016-11-15

    Highlights: • A neutron detector based on superconducting meander line is demonstrated. • Fast response time of a few tens ns is obtained. • Spatial resolution is 1 μm and can be improved to sub-μm scale. • The proposed neutron detector can operate under the γ-ray fields. - Abstract: We succeeded in demonstrating a neutron detector based on a Nb superconducting meander line with a {sup 10}B conversion layer for a neutron imager based on superconductor devices. We use a current-biased kinetic inductance detector (CB-KID), which is composed of a meander line, for detection of a neutron with high spatial resolution and fast response time. The thickness of Nb meander lines is 40 nm and the line width is narrower than 3 mu m. The area of 8 mm × 8 mm is covered by CB-KIDs, which are assembled at the center of the Si chip of the size 22 mm × 22 mm. The Nb CB-KIDs with a {sup 10}B conversion layer output the voltage by irradiating pulsed neutrons. We have investigated γ/n discrimination of a Nb-based CB-KID with {sup 10}B conversion layer using a Cd plate, which indicates that a CB-KID can operate as a neutron detector under the strong γ-ray fields.

  5. Development of a neutron imager based on superconducting detectors

    International Nuclear Information System (INIS)

    Miyajima, Shigeyuki; Yamaguchi, Hiroyuki; Nakayama, Hirotaka; Shishido, Hiroaki; Fujimaki, Akira; Hidaka, Mutsuo; Harada, Masahide; Oikawa, Kenichi; Oku, Takayuki; Arai, Masatoshi; Ishida, Takekazu

    2016-01-01

    Highlights: • A neutron detector based on superconducting meander line is demonstrated. • Fast response time of a few tens ns is obtained. • Spatial resolution is 1 μm and can be improved to sub-μm scale. • The proposed neutron detector can operate under the γ-ray fields. - Abstract: We succeeded in demonstrating a neutron detector based on a Nb superconducting meander line with a "1"0B conversion layer for a neutron imager based on superconductor devices. We use a current-biased kinetic inductance detector (CB-KID), which is composed of a meander line, for detection of a neutron with high spatial resolution and fast response time. The thickness of Nb meander lines is 40 nm and the line width is narrower than 3 mu m. The area of 8 mm × 8 mm is covered by CB-KIDs, which are assembled at the center of the Si chip of the size 22 mm × 22 mm. The Nb CB-KIDs with a "1"0B conversion layer output the voltage by irradiating pulsed neutrons. We have investigated γ/n discrimination of a Nb-based CB-KID with "1"0B conversion layer using a Cd plate, which indicates that a CB-KID can operate as a neutron detector under the strong γ-ray fields.

  6. Methods and applications in high flux neutron imaging

    International Nuclear Information System (INIS)

    Ballhausen, H.

    2007-01-01

    This treatise develops new methods for high flux neutron radiography and high flux neutron tomography and describes some of their applications in actual experiments. Instead of single images, time series can be acquired with short exposure times due to the available high intensity. To best use the increased amount of information, new estimators are proposed, which extract accurate results from the recorded ensembles, even if the individual piece of data is very noisy and in addition severely affected by systematic errors such as an influence of gamma background radiation. The spatial resolution of neutron radiographies, usually limited by beam divergence and inherent resolution of the scintillator, can be significantly increased by scanning the sample with a pinhole-micro-collimator. This technique circumvents any limitations in present detector design and, due to the available high intensity, could be successfully tested. Imaging with scattered neutrons as opposed to conventional total attenuation based imaging determines separately the absorption and scattering cross sections within the sample. For the first time even coherent angle dependent scattering could be visualized space-resolved. New applications of high flux neutron imaging are presented, such as materials engineering experiments on innovative metal joints, time-resolved tomography on multilayer stacks of fuel cells under operation, and others. A new implementation of an algorithm for the algebraic reconstruction of tomography data executes even in case of missing information, such as limited angle tomography, and returns quantitative reconstructions. The setup of the world-leading high flux radiography and tomography facility at the Institut Laue-Langevin is presented. A comprehensive appendix covers the physical and technical foundations of neutron imaging. (orig.)

  7. Application of flexible model in neutron dynamics equations

    International Nuclear Information System (INIS)

    Liu Cheng; Zhao Fuyu; Fu Xiangang

    2009-01-01

    Big errors will occur in the modeling by multimode methodology when the available core physical parameter sets are insufficient. In this paper, the fuzzy logic membership function is introduced to figure out the values of these parameters on any point of lifetime through limited several sets of values, and thus to obtain the neutron dynamics equations on any point of lifetime. In order to overcome the effect of subjectivity in the membership function selection on the parameter calculation, quadratic optimization is carried out to the membership function by genetic algorithm, to result in a more accurate neutron kinetics equation on any point of lifetime. (authors)

  8. Liquid dynamics and inelastic scattering of neutrons

    Energy Technology Data Exchange (ETDEWEB)

    De Gennes, P. G. [Commissariat a l' energie atomique et aux energies alternatives - CEA, CEN de Saclay, Gif sur Yvette (France)

    1960-07-01

    The energy transfers in one collision between a neutron and a liquid are computed by a method of moments. It is shown that for large momentum transfers a perfect gas model is correct. For small momentum transfers a macroscopic description of the density fluctuations in the liquid is applicable. It is in the intermediate region (where diffraction peaks are observed) that the method of moments is most useful. These different experimental situations are discussed for liquids where recoil and quantum effects are negligible, and numerical results are given for argon. An approximation for the so called autocorrelation function, valid for both long and short time scales and all distances, is also presented. Reprint of a paper published in Physica 25, 1959, p. 825-839.

  9. Evolution of Neutron Imaging at TRIGA PUSPATI Reactor: A Promising Digital Real-Time Imaging

    International Nuclear Information System (INIS)

    Khairiah Yazid; Muhammad Rawi Mohamed Zin; Rafhayudi Jamro; Azraf Azman

    2016-01-01

    Neutron radiography is a powerful tool for non-destructive testing of materials and finds numerous applications in industry and in material research as well. The basic principle is similar to that of X-ray radiography. A beam of neutrons falls on the sample and after passing through the sample, leaves the sample image on a photographic plate or on a detector. The neutrons interact with the nuclei of the atoms that compose the sample and the absorption and scattering properties of the contained elements make it possible to produce images of components containing light elements, like hydrogen beneath a matrix of metallic elements, (lead or bismuth), which cannot be easily done with conventional X ray radiography. Exploiting this property, neutron radiography has been used in applications requiring the identification of (light) materials inside solid samples. This article gives an overview of utilization of the CCD camera system in neutron imaging system for real time radiography/ tomography investigations. (author)

  10. Dynamic modeling of the advanced neutron source reactor

    International Nuclear Information System (INIS)

    March-Leuba, J.; Ibn-Khayat, M.

    1990-01-01

    The purpose of this paper is to provide a summary description and some applications of a computer model that has been developed to simulate the dynamic behavior of the advanced neutron source (ANS) reactor. The ANS dynamic model is coded in the advanced continuous simulation language (ACSL), and it represents the reactor core, vessel, primary cooling system, and secondary cooling systems. The use of a simple dynamic model in the early stages of the reactor design has proven very valuable not only in the development of the control and plant protection system but also of components such as pumps and heat exchangers that are usually sized based on steady-state calculations

  11. A local dynamic correlation function from inelastic neutron scattering

    International Nuclear Information System (INIS)

    McQueeney, R.J.

    1997-01-01

    Information about local and dynamic atomic correlations can be obtained from inelastic neutron scattering measurements by Fourier transform of the Q-dependent intensity oscillations at a particular frequency. A local dynamic structure function, S(r,ω), is defined from the dynamic scattering function, S(Q,ω), such that the elastic and frequency-integrated limits correspond to the average and instantaneous pair-distribution functions, respectively. As an example, S(r,ω) is calculated for polycrystalline aluminum in a model where atomic motions are entirely due to harmonic phonons

  12. Alignment effects on a neutron imaging system using coded apertures

    International Nuclear Information System (INIS)

    Thfoin, Isabelle; Landoas, Olivier; Caillaud, Tony; Vincent, Maxime; Bourgade, Jean-Luc; Rosse, Bertrand; Disdier, Laurent; Sangster, Thomas C.; Glebov, Vladimir Yu.; Pien, Greg; Armstrong, William

    2010-01-01

    A high resolution neutron imaging system is being developed and tested on the OMEGA laser facility for inertial confinement fusion experiments. This diagnostic uses a coded imaging technique with a penumbral or an annular aperture. The sensitiveness of these techniques to misalignment was pointed out with both experiments and simulations. Results obtained during OMEGA shots are in good agreement with calculations performed with the Monte Carlo code GEANT4. Both techniques are sensitive to the relative position of the source in the field of view. The penumbral imaging technique then demonstrates to be less sensitive to misalignment compared to the ring. These results show the necessity to develop a neutron imaging diagnostic for megajoule class lasers taking into account our alignment capabilities on such facilities.

  13. A new compact, high sensitivity neutron imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Caillaud, T.; Landoas, O.; Briat, M.; Rosse, B.; Thfoin, I.; Philippe, F.; Casner, A.; Bourgade, J. L.; Disdier, L. [CEA, DAM, DIF,F-91297 Arpajon (France); Glebov, V. Yu.; Marshall, F. J.; Sangster, T. C. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Park, H. S.; Robey, H. F.; Amendt, P. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2012-10-15

    We have developed a new small neutron imaging system (SNIS) diagnostic for the OMEGA laser facility. The SNIS uses a penumbral coded aperture and has been designed to record images from low yield (10{sup 9}-10{sup 10} neutrons) implosions such as those using deuterium as the fuel. This camera was tested at OMEGA in 2009 on a rugby hohlraum energetics experiment where it recorded an image at a yield of 1.4 Multiplication-Sign 10{sup 10}. The resolution of this image was 54 {mu}m and the camera was located only 4 meters from target chamber centre. We recently improved the instrument by adding a cooled CCD camera. The sensitivity of the new camera has been fully characterized using a linear accelerator and a {sup 60}Co {gamma}-ray source. The calibration showed that the signal-to-noise ratio could be improved by using raw binning detection.

  14. A new compact, high sensitivity neutron imaging system

    International Nuclear Information System (INIS)

    Caillaud, T.; Landoas, O.; Briat, M.; Rossé, B.; Thfoin, I.; Philippe, F.; Casner, A.; Bourgade, J. L.; Disdier, L.; Glebov, V. Yu.; Marshall, F. J.; Sangster, T. C.; Park, H. S.; Robey, H. F.; Amendt, P.

    2012-01-01

    We have developed a new small neutron imaging system (SNIS) diagnostic for the OMEGA laser facility. The SNIS uses a penumbral coded aperture and has been designed to record images from low yield (10 9 –10 10 neutrons) implosions such as those using deuterium as the fuel. This camera was tested at OMEGA in 2009 on a rugby hohlraum energetics experiment where it recorded an image at a yield of 1.4 × 10 10 . The resolution of this image was 54 μm and the camera was located only 4 meters from target chamber centre. We recently improved the instrument by adding a cooled CCD camera. The sensitivity of the new camera has been fully characterized using a linear accelerator and a 60 Co γ-ray source. The calibration showed that the signal-to-noise ratio could be improved by using raw binning detection.

  15. Dehydration process of fish analyzed by neutron beam imaging

    International Nuclear Information System (INIS)

    Tanoi, K.; Hamada, Y.; Seyama, S.; Saito, T.; Iikura, H.; Nakanishi, T.M.

    2009-01-01

    Since regulation of water content of the dried fish is an important factor for the quality of the fish, water-losing process during drying (squid and Japanese horse mackerel) was analyzed through neutron beam imaging. The neutron image showed that around the shoulder of mackerel, there was a part where water content was liable to maintain high during drying. To analyze water-losing process more in detail, spatial image was produced. From the images, it was clearly indicated that the decrease of water content was regulated around the shoulder part. It was suggested that to prevent deterioration around the shoulder part of the dried fish is an important factor to keep quality of the dried fish in the storage.

  16. Neutron radiography activity in the european program cost 524: Neutron imaging techniques

    International Nuclear Information System (INIS)

    Chirco, P.; Bach, P.; Lehmann, E.; Balasko, M.

    2001-01-01

    COST is a framework for scientific and technical cooperation, allowing the coordination of national research on a European level, including 32 member countries. Participation of institutes from non-COST countries is possible. From an initial 7 Actions in 1971, COST has grown to 200 Actions at the beginning of 2000. COST Action 524 is under materials domain, the title of which being 'Neutron Imaging Techniques for the Detection of Defects in Materials', under the Chairmanship of Dr. P. Chirco (I.N.F.N.). The following countries are represented in the Management Committee of Action 524: Italy, France, Austria, Germany, United Kingdom, Hungary, Switzerland, Spain, Czech Republic, Slovenia, and Russia. The six working groups of this Action are working respectively on standardization of neutron radiography techniques, on aerospace application, on civil engineering applications, on comparison and integration of neutron imaging techniques with other NDT, on neutron tomography, and on non radiographic techniques such as neutron scattering techniques. A specific effort is devoted to standardization issues, with respect to other non European standards. Results of work performed in the COST frame are published or will be published in the review INSIGHT, edited by the British Institute of Non Destructive Testing

  17. Applying thermal neutron radiography to non-destructive assays of dynamic systems

    International Nuclear Information System (INIS)

    Silvani, Maria I.; Almeida, Gevaldo L. de; Goncalves, Marcelo J.; Lopes, Ricardo T.

    2008-01-01

    Dynamic processes or systems frequently can not have their behavior directly analyzed due to safety reasons or because they require destructive assays, which can not be always afforded when high-cost equipment, devices and components are involved. Under these circumstances, some kind of non-destructive technique should be applied to preserve the safety of the personnel performing the assay, as well as the integrity of the piece being inspected. Thermal neutrons are specially suited as a tool for this purpose, thanks to their capability to pass through metallic materials, which could be utterly opaque to X-rays. This paper describes the accomplishments achieved at the Instituto de Engenharia Nuclear / CNEN, Brazil, aiming at the development of an Image Acquisition System capable to perform non-destructive assays using thermal neutrons. It is comprised of a thermal neutron source provided by the Argonauta research reactor, a converter-scintillating screen, and a CCD-based video camera optically coupled to the screen through a dark chamber equipped with a mirror. The developed system has been used to acquire 2D neutron radiographic images of static devices to reveal their inner structure, as well as movies of running systems and working devices to verify its functioning and soundness. Radiographic images of objects taken at different angles would be later on used as projections to retrieve - through a proper unfolding software - their 3D images expressed as attenuation coefficients for thermal neutrons. A quantitative performance of the system has been assessed through its Modulation Transfer Function - MTF. In order to determine this curve, unique collimators designed to simulate different spatial frequencies have been manufactured. Besides that, images of some objects have been acquired with the system being developed as well as using the conventional radiographic film, allowing thus a qualitative comparison between them. (author)

  18. Fundamentals and applications of neutron imaging. Application part 3. Application of neutron imaging in aircraft, space rocket, car and gunpowder industries

    International Nuclear Information System (INIS)

    Ikeda, Yasushi

    2007-01-01

    Neutron imaging is applied to nondestructive test. Four neutron imaging facilities are used in Japan. The application examples of industries are listed in the table: space rocket, aircraft, car, liquid metal, and works of art. Neutron imaging of transportation equipments are illustrated as an application to industry. X-ray radiography testing (XRT) image and neutron radiography testing (NRT) image of turbine blade of aircraft engine, honeycomb structure of aircraft, helicopter rotor blade, trigger tube, separation nut of space rocket, carburetor of car, BMW engine, fireworks and ammunitions are illustrated. (S.Y.)

  19. Image reconstruction technique using projection data from neutron tomography system

    Directory of Open Access Journals (Sweden)

    Waleed Abd el Bar

    2015-12-01

    Full Text Available Neutron tomography is a very powerful technique for nondestructive evaluation of heavy industrial components as well as for soft hydrogenous materials enclosed in heavy metals which are usually difficult to image using X-rays. Due to the properties of the image acquisition system, the projection images are distorted by several artifacts, and these reduce the quality of the reconstruction. In order to eliminate these harmful effects the projection images should be corrected before reconstruction. This paper gives a description of a filter back projection (FBP technique, which is used for reconstruction of projected data obtained from transmission measurements by neutron tomography system We demonstrated the use of spatial Discrete Fourier Transform (DFT and the 2D Inverse DFT in the formulation of the method, and outlined the theory of reconstruction of a 2D neutron image from a sequence of 1D projections taken at different angles between 0 and π in MATLAB environment. Projections are generated by applying the Radon transform to the original image at different angles.

  20. Characterization of Crystallographic Structures Using Bragg-Edge Neutron Imaging at the Spallation Neutron Source

    Directory of Open Access Journals (Sweden)

    Gian Song

    2017-12-01

    Full Text Available Over the past decade, wavelength-dependent neutron radiography, also known as Bragg-edge imaging, has been employed as a non-destructive bulk characterization method due to its sensitivity to coherent elastic neutron scattering that is associated with crystalline structures. Several analysis approaches have been developed to quantitatively determine crystalline orientation, lattice strain, and phase distribution. In this study, we report a systematic investigation of the crystal structures of metallic materials (such as selected textureless powder samples and additively manufactured (AM Inconel 718 samples, using Bragg-edge imaging at the Oak Ridge National Laboratory (ORNL Spallation Neutron Source (SNS. Firstly, we have implemented a phenomenological Gaussian-based fitting in a Python-based computer called iBeatles. Secondly, we have developed a model-based approach to analyze Bragg-edge transmission spectra, which allows quantitative determination of the crystallographic attributes. Moreover, neutron diffraction measurements were carried out to validate the Bragg-edge analytical methods. These results demonstrate that the microstructural complexity (in this case, texture plays a key role in determining the crystallographic parameters (lattice constant or interplanar spacing, which implies that the Bragg-edge image analysis methods must be carefully selected based on the material structures.

  1. An Evaluation of Grazing-Incidence Optics for Neutron Imaging

    Science.gov (United States)

    Gubarev, M. V.

    2007-01-01

    The refractive index for most materials is slightly less than unity, which opens an opportunity to develop the grazing incidence neutron imaging optics. The ideal material for the optics would be natural nickel and its isotopes. Marshall Space Flight Center (MSFC) has active development program on the nickel replicated optics for use in x-ray astronomy. Brief status report on the program is presented. The results of the neutron focusing optic test carried by the MSFC team at National Institute of Standards and Technology (NIST) are also presented. Possible applications of the optics are briefly discussed.

  2. Neutrons probing the structure and dynamics of liquids

    International Nuclear Information System (INIS)

    Leclercq-Hugeux, F.; Coulet, M.V.; Gaspard, J.P.; Pouget, St.; Zanotti, J.M.

    2007-01-01

    This article illustrates the benefits of neutron techniques to the understanding of the liquid state. As opposed to the nearly complete order of crystals or the nearly complete disorder of gas, the disorder of a liquid is partial and results from dynamical events acting on a broad range of space and time scales. Consequently, no single, simple parameter can encompass the concept of order or disorder in the liquid state. The wide variety of neutron techniques (diffraction, quasi-elastic and inelastic scattering) is a key asset to solve the issue. Selected studies ranging over typical interactions and conditions relevant to liquids (metallic, covalent, molecular, liquids near a phase transition and confined fluids) are presented. In each case, both structural and dynamical aspects, along with the connections to complementary techniques (computer simulation, X-ray absorption and/or scattering) are highlighted. (authors)

  3. Dynamic theory of neutron diffraction from a moving grating

    Energy Technology Data Exchange (ETDEWEB)

    Bushuev, V. A., E-mail: vabushuev@yandex.ru [Moscow State University (Russian Federation); Frank, A. I.; Kulin, G. V. [Joint Institute for Nuclear Research (Russian Federation)

    2016-01-15

    A multiwave dynamic theory of diffraction of ultracold neutrons from a moving phase grating has been developed in the approximation of coupled slowly varying amplitudes of wavefunctions. The effect of the velocity, period, and height of grooves of the grating, as well as the spectral angular distribution of the intensity of incident neurons, on the discrete energy spectrum and the intensity of diffraction reflections of various orders has been analyzed.

  4. Study of archaeological objects by neutron imaging, xrd and xrf

    International Nuclear Information System (INIS)

    Dinca, M.; Dinu, A. D.; Stanciulescu, M. G.; Mandescu, D.

    2015-01-01

    Archaeological objects were borrowed from Arges County History Museum (ACHM) and investigated at the Institute for Nuclear Research (INR). Metallic objects made in iron, copper alloys and silver discovered in southern part of Romania, mostly Dacian and Roman origin, were investigated. For imaging was used the neutron and gamma imaging facility from tangential channel of the TRIGA ACPR to put in evidence the internal structure of the objects. For elemental and chemical composition, concentration levels in objects were performed investigations by X-ray fluorescence (XRF) and X-ray diffraction (XRD). These investigations offer valuable information in archaeological research about composition, structure of the bulk, presence of alteration, inclusions, typology of the location of material extraction, manufacturing techniques etc. This work is an example of application of neutron imaging and other radiation-based analytical methods for cultural heritage research that had the aim to involve some of the non-destructive investigation methods available at INR. (authors)

  5. Fertilizer application and root development analyzed by neutron imaging

    International Nuclear Information System (INIS)

    Nihei, Naoto; Tanoi, Keitaro; Nakanishi, Tomoko M.

    2013-01-01

    We studied the development of the soybean root system under different application of fertilizer applying neutron imaging technique. When neutron beam was irradiated, the root image as well as fertilizer imbedded in a thin aluminum container was clearly projected, since water amount in roots are higher than that in soil. Through image analysis, the development of root system was studied under different application of the fertilizer. The development of a main root with lateral roots was observed without applying fertilizer. When the fertilizer was homogeneously supplied to the soil, the morphological development of the root showed the similar pattern to that grown without fertilizer, in different to the amount of the fertilizer. In the case of local application of the fertilizer, lateral position or downward to the main root, the inhibition of the root growth was observed, suggesting that the localization of the fertilizer is responsible for reduction of the soybean yield. (author)

  6. Preliminary examination of the applicability of imaging plates to fast neutron radiography

    International Nuclear Information System (INIS)

    Matsubayashi, Masahito; Hibiki, Takashi; Mishima, Kaichiro; Yoshii, Koji; Okamoto, Koji

    2001-01-01

    Fast neutron radiography is an attractive non-destructive inspection technique because of the excellent penetration characteristics of fast neutrons in matter. However, the difficulty of detecting fast neutrons reduces this attractive feature. As an experiment to overcome the difficulty, imaging plates were applied to fast neutron radiography. A simple combination of two sheets of imaging plates and a sheet of polyethylene as a proton emitter was examined with the (fast neutron, thermal neutron and gamma ray) FTG discriminator proposed by Yoneda et al. . The experimental results showed that the method could be applicable to fast neutron radiography with effective discrimination of γ-rays

  7. Characterization of two Japanese ancient swords through neutron imaging

    International Nuclear Information System (INIS)

    Grazzi, Francesco; Zoppi, Marco; Salvemini, Filomena; Kaestner, Anders; Lehmann, Eberhard; Civita, Francesco

    2015-01-01

    Japanese blades are culturally interesting objects both from the stylistic point of view and because of their fantastic performances. In this work, we present new results, using a non-invasive approach, concerning these peculiar artefacts. Two integer Japanese swords, pertaining to Kyoto (987-1596) and Shinto (1596-1781) periods have been analysed through neutron-imaging techniques. The experiments have been performed at the ICON beam line, operating at the spallation neutron source SINQ, Paul Scherrer Institut in Switzerland. The reconstruction of projection data into neutron tomographic slices or volumes, allowed us to identify some very peculiar characteristics, related to the forging methods and to the different thermal treatments applied to produce the cutting edge and its unique feature. (author)

  8. Imaging of fast-neutron sources using solid-state track-recorder pinhole radiography

    International Nuclear Information System (INIS)

    Ruddy, F.H.; Gold, R.; Roberts, J.H.; Kaiser, B.J.; Preston, C.C.

    1983-08-01

    Pinhole imaging methods are being developed and tested for potential future use in imaging the intense neutron source of the Fusion Materials Irradiation Test (FMIT) Facility. Previously reported, extensive calibration measurements of the proton, neutron, and alpha particle response characteristics of CR-39 polymer solid state track recorders (SSTRs) are being used to interpret the results of imaging experiments using both charged particle and neutron pinhole collimators. High resolution, neutron pinhole images of a 252 Cf source have been obtained in the form of neutron induced proton recoil tracks in CR-39 polymer SSTR. These imaging experiments are described as well as their potential future applications to FMIT

  9. The performance of an amorphous silicon flat panel for neutron imaging at the PSI NEUTRA facility

    International Nuclear Information System (INIS)

    Estermann, Mirko; Frei, Gabriel; Lehmann, Eberhard; Vontobel, Peter

    2005-01-01

    Commonly applied imaging methods in neutron radiography use a CCD camera in conjunction with a scintillator or imaging plates. CCDs and imaging plates have desirable properties concerning resolution, linearity, dynamic range and signal-to-noise ratio (S/N) but both techniques have the disadvantage of a slow read out and for the CCD camera, an additional disadvantage is the loss of light through the optical system. Amorphous silicon detectors, originally developed for medical and industrial X-ray imaging, generally do not have the above-mentioned disadvantages. These detectors have a much faster readout and, in comparison to the generally used crystalline silicon, can be put directly in the X-ray or neutron beam without being damaged. This type of detector also does not require any optical interface, minimizing possible light loss. The detector is operated at room temperature, which has some influence on the noise. Using the whole dynamic range with a low gain, results in a S/N of up to 30, for normal applications, however, a S/N of about 15-20 is typical. The main drawback of this imaging device is the dynamic range of only 12 bits and the relatively complicated operating system in which different operation modes can be chosen. In 2003, successful experiments were performed with this new device, but it is still in its fledgling stages and improvements from the manufacturer as well as the experience from the NEUTRA team will help to advance this technique for neutron imaging in a most efficient way

  10. Neutron detection using soft errors in dynamic Random Access Memories

    International Nuclear Information System (INIS)

    Darambara, D.G.; Spyrou, N.M.

    1994-01-01

    The purpose of this paper is to present results from experiments that have been performed to show the memory cycle time dependence of the soft errors produced by the interaction of alpha particles with dynamic random access memory devices, with a view to using these as position sensitive detectors. Furthermore, a preliminary feasibility study being carried out indicates the use of dynamic RAMs as neutron detectors by the utilization of (n, α) capture reactions in a Li converter placed on the top of the active area of the memory chip. ((orig.))

  11. Characterization of the new neutron imaging and materials science facility IMAT

    Science.gov (United States)

    Minniti, Triestino; Watanabe, Kenichi; Burca, Genoveva; Pooley, Daniel E.; Kockelmann, Winfried

    2018-04-01

    IMAT is a new cold neutron imaging and diffraction instrument located at the second target station of the pulsed neutron spallation source ISIS, UK. A broad range of materials science and materials testing areas will be covered by IMAT. We present the characterization of the imaging part, including the energy-selective and energy-dispersive imaging options, and provide the basic parameters of the radiography and tomography instrument. In particular, detailed studies on mono and bi-dimensional neutron beam flux profiles, neutron flux as a function of the neutron wavelength, spatial and energy dependent neutron beam uniformities, guide artifacts, divergence and spatial resolution, and neutron pulse widths are provided. An accurate characterization of the neutron beam at the sample position, located 56 m from the source, is required to optimize collection of radiographic and tomographic data sets and for performing energy-dispersive neutron imaging via time-of-flight methods in particular.

  12. Investigation of static and dynamic properties of condensed matter by using neutron scattering

    International Nuclear Information System (INIS)

    Davidovic, M.

    1997-01-01

    Possibilities of using neutron scattering for investigating microscopic properties of materials are analyzed. Basic neutron scattering theory is presented and its use in structure and dynamics analyses of condense systems. (author)

  13. Control of the neutron detector count rate by optical imaging

    International Nuclear Information System (INIS)

    Roquemore, A.L.; Johnson, L.C.

    1992-01-01

    The signal processing electronics used for the NE451 detectors on the TFTR multichannel neutron collimator are presently showing saturation effects at high counting rates equivalent to neutron yields of ∼10 16 n/s. While nonlinearity due to pulse pileup can be corrected for in most present TFTR experiments, additional steps are required for neutron source strengths above ∼3x10 16 n/s. These pulse pileup effects could be reduced by inserting sleeves in the collimator shielding to reduce the neutron flux in the vicinity of the detectors or by reducing the volume of detector exposed to the flux. We describe a novel method of avoiding saturation by optically controlling the number neutron events processed by the detector electronics. Because of the optical opacity of the ZnS-plastic detectors such as NE451, photons from a proton-recoil scintillation arise from a spatially localized area of the detector. By imaging a selected portion of the detector onto a photomultiplier, we reduce the effective volume of the detector in a controllable, reversible way. A prototype system, consisting of a focusing lens, a field lens, and a variable aperture, has been constructed. Results of laboratory feasibility tests are presented

  14. Probing the potential of neutron imaging for biomedical and biological applications

    International Nuclear Information System (INIS)

    Watkin, Kenneth L.; Bilheux, Hassina Z.; Ankner, John Francis

    2009-01-01

    Neutron imaging of biological specimens began soon after the discovery of the neutron by Chadwick in 1932. The first samples included tumors in tissues, internal organs in rats, and bones. These studies mainly employed thermal neutrons and were often compared with X-ray images of the same or equivalent samples. Although neutron scattering is widely used in biological studies, neutron imaging has yet to be exploited to its full capability in this area. This chapter summarizes past and current research efforts to apply neutron radiography to the study of biological specimens, in the expectation that clinical and medical research, as well as forensic science, may benefit from it.

  15. Bubble masks for time-encoded imaging of fast neutrons.

    Energy Technology Data Exchange (ETDEWEB)

    Brubaker, Erik; Brennan, James S.; Marleau, Peter; Nowack, Aaron B.; Steele, John T.; Sweany, Melinda; Throckmorton, Daniel J.

    2013-09-01

    Time-encoded imaging is an approach to directional radiation detection that is being developed at SNL with a focus on fast neutron directional detection. In this technique, a time modulation of a detected neutron signal is inducedtypically, a moving mask that attenuates neutrons with a time structure that depends on the source position. An important challenge in time-encoded imaging is to develop high-resolution two-dimensional imaging capabilities; building a mechanically moving high-resolution mask presents challenges both theoretical and technical. We have investigated an alternative to mechanical masks that replaces the solid mask with a liquid such as mineral oil. Instead of fixed blocks of solid material that move in pre-defined patterns, the oil is contained in tubing structures, and carefully introduced air gapsbubblespropagate through the tubing, generating moving patterns of oil mask elements and air apertures. Compared to current moving-mask techniques, the bubble mask is simple, since mechanical motion is replaced by gravity-driven bubble propagation; it is flexible, since arbitrary bubble patterns can be generated by a software-controlled valve actuator; and it is potentially high performance, since the tubing and bubble size can be tuned for high-resolution imaging requirements. We have built and tested various single-tube mask elements, and will present results on bubble introduction and propagation as a function of tubing size and cross-sectional shape; real-time bubble position tracking; neutron source imaging tests; and reconstruction techniques demonstrated on simple test data as well as a simulated full detector system.

  16. System of image package input and output for neutron radiography based on PC IBM XT/AT; Sistema paketnogo vvoda i vyvoda izobrazhenij dlya nejtronnoj radiografii na baze PEhVM IBM PC XCT/AT

    Energy Technology Data Exchange (ETDEWEB)

    Avarzad, O; Rikhvitskij, V S

    1996-12-31

    System of acquisition and analysis of both statistic and dynamic images of neutron radiography includes NM IBM PC XT/AT, super vidicon, telecamera based video detector, color monitor and interface board of image input-output. 2 refs.

  17. Dynamic neutron scattering from conformational dynamics. II. Application using molecular dynamics simulation and Markov modeling.

    Science.gov (United States)

    Yi, Zheng; Lindner, Benjamin; Prinz, Jan-Hendrik; Noé, Frank; Smith, Jeremy C

    2013-11-07

    Neutron scattering experiments directly probe the dynamics of complex molecules on the sub pico- to microsecond time scales. However, the assignment of the relaxations seen experimentally to specific structural rearrangements is difficult, since many of the underlying dynamical processes may exist on similar timescales. In an accompanying article, we present a theoretical approach to the analysis of molecular dynamics simulations with a Markov State Model (MSM) that permits the direct identification of structural transitions leading to each contributing relaxation process. Here, we demonstrate the use of the method by applying it to the configurational dynamics of the well-characterized alanine dipeptide. A practical procedure for deriving the MSM from an MD is introduced. The result is a 9-state MSM in the space of the backbone dihedral angles and the side-chain methyl group. The agreement between the quasielastic spectrum calculated directly from the atomic trajectories and that derived from the Markov state model is excellent. The dependence on the wavevector of the individual Markov processes is described. The procedure means that it is now practicable to interpret quasielastic scattering spectra in terms of well-defined intramolecular transitions with minimal a priori assumptions as to the nature of the dynamics taking place.

  18. High resolution neutron spectroscopy - a tool for the investigation of dynamics of polymers and soft matter

    International Nuclear Information System (INIS)

    Monkenbusch, M.; Richter, D.

    2007-01-01

    Neutron scattering, with the ability to vary the contrast of molecular items by hydrogen/deuterium exchanges, is an invaluable tool for soft matter research. Besides the structural information on the mesoscopic scale that is obtained by diffraction methods like small angle neutron scattering, the slow dynamics of molecular motion on mesoscopic scale is accessible by high resolution neutron spectroscopy. The basic features of neutron backscattering spectroscopy, and in particular neutron spin-echo spectroscopy, are presented, in combination with illustrations of results from polymer melt dynamics to protein dynamics which are obtained by these techniques. (authors)

  19. A Time of Flight Fast Neutron Imaging System Design Study

    Science.gov (United States)

    Canion, Bonnie; Glenn, Andrew; Sheets, Steven; Wurtz, Ron; Nakae, Les; Hausladen, Paul; McConchie, Seth; Blackston, Matthew; Fabris, Lorenzo; Newby, Jason

    2017-09-01

    LLNL and ORNL are designing an active/passive fast neutron imaging system that is flexible to non-ideal detector positioning. It is often not possible to move an inspection object in fieldable imager applications such as safeguards, arms control treaty verification, and emergency response. Particularly, we are interested in scenarios which inspectors do not have access to all sides of an inspection object, due to interfering objects or walls. This paper will present the results of a simulation-based design parameter study, that will determine the optimum system design parameters for a fieldable system to perform time-of-flight based imaging analysis. The imaging analysis is based on the use of an associated particle imaging deuterium-tritium (API DT) neutron generator to get the time-of-flight of radiation induced within an inspection object. This design study will investigate the optimum design parameters for such a system (e.g. detector size, ideal placement, etc.), as well as the upper and lower feasible design parameters that the system can expect to provide results within a reasonable amount of time (e.g. minimum/maximum detector efficiency, detector standoff, etc.). Ideally the final prototype from this project will be capable of using full-access techniques, such as transmission imaging, when the measurement circumstances allow, but with the additional capability of producing results at reduced accessibility.

  20. Neutron imaging options at the BOA beamline at Paul Scherrer Institut

    International Nuclear Information System (INIS)

    Morgano, M.; Peetermans, S.; Lehmann, E.H.; Panzner, T.; Filges, U.

    2014-01-01

    The BOA beamline at the Swiss spallation neutron source SINQ at Paul Scherrer Institut is a flexible instrument used mainly for testing novel techniques and devices for neutron scattering and optics, but, due to the large and relatively homogeneous field of view, it can be successfully used for experiments in the field of neutron imaging. The beamline allows also for the exploitation of advanced imaging concepts such as polarized neutron imaging and diffractive neutron imaging. In this paper we present the characterization of the BOA beamline in the light of its neutron imaging capabilities. We show also the different techniques that can be employed there as user-friendly plugins for non-standard neutron imaging experiments

  1. UF6 Cylinder Imaging by Fast Neutron Transmission Tomography

    International Nuclear Information System (INIS)

    McElroy, R.; Hausladen, P.; Blackston, M.; Croft, S.

    2015-01-01

    The common use Non-Destructive Assay techniques for the determination of 235 U enrichment and mass of UF6 cylinders used in the production of nuclear reactor fuel require prior knowledge of the physical distribution of the UF6 within the cylinder. The measurement performance for these techniques is typically evaluated based on assumed bounding case distributions of the material. However, little direct data such as radiographic or tomographic images, regarding the distribution of the UF6 within the cylinder is available against which to judge these assumptions. We have developed and tested a prototype active neutron tomographic imaging system employing an Associated Particle Imaging (API) neutron generator and an array of pixelated neutron scintillation counters. This system has been successfully used to obtain the 3-dimensional map of the distribution of UF6 within a type 12B storage cylinder. Results from these measurements are presented and the potential performance and utility of this technique with larger 30B and 48Y cylinders is discussed. (author)

  2. Geocoronal imaging with Dynamics Explorer

    Science.gov (United States)

    Rairden, R. L.; Frank, L. A.; Craven, J. D.

    1986-01-01

    The ultraviolet photometer of the University of Iowa spin-scan auroral imaging instrumentation on board Dynamics Explorer-1 has returned numerous hydrogen Lyman alpha images of the geocorona from altitudes of 570 km to 23,300 km (1.09 R sub E to 4.66 R sub E geocentric radial distance). The hydrogen density gradient is shown by a plot of the zenith intensities throughout this range, which decrease to near celestial background values as the spacecraft approaches apogee. Characterizing the upper geocorona as optically thin (single-scattering), the zenith intensity is converted directly to vertical column density. This approximation loses its validity deeper in the geocorona, where the hydrogen is demonstrated to be optically thick in that there is no Lyman alpha limb brightening. Further study of the geocoronal hydrogen distribution will require computer modeling of the radiative transfer.

  3. Comparison of polystyrene scintillator fiber array and monolithic polystyrene for neutron imaging and radiography

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, R., E-mail: raspberry@lanl.gov; Cutler, T. E.; Danly, C. R.; Espy, M. A.; Goglio, J. H.; Hunter, J. F.; Madden, A. C.; Mayo, D. R.; Merrill, F. E.; Nelson, R. O.; Swift, A. L.; Wilde, C. H.; Zocco, T. G. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2016-11-15

    The neutron imaging diagnostic at the National Ignition Facility has been operating since 2011 generating neutron images of deuterium-tritium (DT) implosions at peak compression. The current design features a scintillating fiber array, which allows for high imaging resolution to discern small-scale structure within the implosion. In recent years, it has become clear that additional neutron imaging systems need to be constructed in order to provide 3D reconstructions of the DT source and these additional views need to be on a shorter line of sight. As a result, there has been increased effort to identify new image collection techniques that improve upon imaging resolution for these next generation neutron imaging systems, such as monolithic deuterated scintillators. This work details measurements performed at the Weapons Neutron Research Facility at Los Alamos National Laboratory that compares the radiographic abilities of the fiber scintillator with a monolithic scintillator, which may be featured in a future short line of sight neutron imaging systems.

  4. Fundamentals and applications of neutron imaging. Application part 9. Application of neutron imaging to biological research

    International Nuclear Information System (INIS)

    Kawabata, Yuji

    2007-01-01

    For radiography, the use of neutrons as a complement to X-rays is especially suitable for biological research such as plant, wood, and medical application due to the enhanced sensitivity to light elements such as hydrogen, carbon, and nitrogen. The present paper introduces applications of neutron CT to the humidity (water) distribution and its variation in the flowering plant as cut carnation, observation of water movement in refrigerated chrysanthemum leaves using very cold neutron and in cut leaves using deuterium oxide and ordinary water, measurement of water movement in sprouting cone and soy bean and growing ginseng in the soil, and other applications as to archaeological wood immersed in a restoration solution and to medical purposes. (S. Ohno)

  5. Neutron Reflectivity Measurement for Polymer Dynamics near Graphene Oxide Monolayers

    Science.gov (United States)

    Koo, Jaseung

    We investigated the diffusion dynamics of polymer chains confined between graphene oxide layers using neutron reflectivity (NR). The bilayers of polymethylmetacrylate (PMMA)/ deuterated PMMA (d-PMMA) films and polystyrene (PS)/d-PS films with various film thickness sandwiched between Langmuir-Blodgett (LB) monolayers of graphene oxide (GO) were prepared. From the NR results, we found that PMMA diffusion dynamics was reduced near the GO surface while the PS diffusion was not significantly changed. This is due to the different strength of GO-polymer interaction. In this talk, these diffusion results will be compared with dewetting dynamics of polymer thin films on the GO monolayers. This has given us the basis for development of graphene-based nanoelectronics with high efficiency, such as heterojunction devices for polymer photovoltaic (OPV) applications.

  6. Neutron radiography imaging with 2-dimensional photon counting method and its problems

    International Nuclear Information System (INIS)

    Ikeda, Y.; Kobayashi, H.; Niwa, T.; Kataoka, T.

    1988-01-01

    A ultra sensitive neutron imaging system has been deviced with a 2-dimensional photon counting camara (ARGUS 100). The imaging system is composed by a 2-dimensional single photon counting tube and a low background vidicon followed with an image processing unit and frame memories. By using the imaging system, electronic neutron radiography (NTV) has been possible under the neutron flux less than 3 x 10 4 n/cm 2 ·s. (author)

  7. Quantitative assessment of dynamic PET imaging data in cancer imaging.

    Science.gov (United States)

    Muzi, Mark; O'Sullivan, Finbarr; Mankoff, David A; Doot, Robert K; Pierce, Larry A; Kurland, Brenda F; Linden, Hannah M; Kinahan, Paul E

    2012-11-01

    Clinical imaging in positron emission tomography (PET) is often performed using single-time-point estimates of tracer uptake or static imaging that provides a spatial map of regional tracer concentration. However, dynamic tracer imaging can provide considerably more information about in vivo biology by delineating both the temporal and spatial pattern of tracer uptake. In addition, several potential sources of error that occur in static imaging can be mitigated. This review focuses on the application of dynamic PET imaging to measuring regional cancer biologic features and especially in using dynamic PET imaging for quantitative therapeutic response monitoring for cancer clinical trials. Dynamic PET imaging output parameters, particularly transport (flow) and overall metabolic rate, have provided imaging end points for clinical trials at single-center institutions for years. However, dynamic imaging poses many challenges for multicenter clinical trial implementations from cross-center calibration to the inadequacy of a common informatics infrastructure. Underlying principles and methodology of PET dynamic imaging are first reviewed, followed by an examination of current approaches to dynamic PET image analysis with a specific case example of dynamic fluorothymidine imaging to illustrate the approach. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Stereographic images acquired with gamma rays and thermal neutron radiography

    International Nuclear Information System (INIS)

    Souza, Maria Ines Silvani; Almeida, Gevaldo L. de; Furieri, Rosanne C.; Lopes, Ricardo T.

    2011-01-01

    Full text: The inner structure of an object, which should not be submitted to an invasive assay, can only be perceived by using a suitable technique in order to render it transparent. A widely employed technique for this purpose involves the using of a radiation capable to pass through the object, collecting the transmitted radiation by a proper device, which furnishes a radiographic attenuation map of the object. This map, however, does not display the spatial distribution of the inner components of the object, but a convoluted view for each specific attitude of the object with regard to the set beam-detector. A 3D tomographic approach would show that distribution but it would demand a large number of projections requiring special equipment and software, not always available or affordable. In some circumstances however, a 3D tomography can be replaced by a stereographic view of the object under inspection, as done in this work, where instead of tens of radiographic projections, only two of them taken at suitable object attitudes are employed. Once acquired, these projections are properly processed and observed through a red and green eyeglass. For monochromatic images, this methodology requires the transformation of the black and white radiographs into red and white and green and white ones, which are afterwards merged to yield a single image. All the process is carried out with the software Image J . In this work, the Argonauta reactor at the Instituto de Engenharia Nuclear in Rio de Janeiro has been used as a source of thermal neutrons to acquire the neutron radiographic images, as well as to produce 198 Au sources employed in the acquisition of gamma-ray radiographic ones. X-ray or neutron-sensitive imaging plates have been used as detector, which after exposure were developed by a reader using a 0.5μm-diameter laser beam. (author)

  9. Noise characteristics of neutron images obtained by cooled CCD device

    International Nuclear Information System (INIS)

    Taniguchi, Ryoichi; Sasaki, Ryoya; Okuda, Shuichi; Okamoto, Ken-Ichi; Ogawa, Yoshihiro; Tsujimoto, Tadashi

    2009-01-01

    The noise characteristics of a cooled CCD device induced by neutron and gamma ray irradiation have been investigated. In the cooled CCD images, characteristic white spot noises (CCD noise) frequently appeared, which have a shape like a pixel in most cases and their brightness is extremely high compared with that of the image pattern. They could be divided into the two groups, fixed pattern noise (FPN) and random noise. The former always appeared in the same position in the image and the latter appeared at any position. In the background image, nearly all of the CCD noises were found to be the FPN, while many of them were the random noise during the irradiation. The random CCD noises increased with irradiation and decreased soon after the irradiation. In the case of large irradiation, a part of the CCD noise remained as the FPN. These facts suggest that the CCD noise is a phenomenon strongly relating to radiation damage of the CCD device.

  10. Measurement of Liquid-Metal Two-Phase Flow with a Dynamic Neutron Radiography

    International Nuclear Information System (INIS)

    Cha, J. E.; Lim, I. C.; Kim, H. R.; Kim, C. M.; Nam, H. Y.; Saito, Y.

    2005-01-01

    The dynamic neutron radiography(DNR) has complementary characteristics to X-ray radiography and is suitable to visualization and measurement of a multi-phase flow research in a metallic duct and liquid metal flow. The flow-field information of liquid metal system is very important for the safety analysis of fast breeder reactor and the design of the spallation target of accelerator driven system. A DNR technique was applied to visualize the flow field in the gas-liquid metal two-phase flow with the HANARO-beam facility. The lead bismuth eutectic and the nitrogen gas were used to construct the two-phase flow field in the natural circulation U-channel. The two-phase flow images in the riser were taken at various combinations of the liquid flow and gas flow with high frame-rate neutron radiography at 1000 fps

  11. A dynamic range upgrade for neutron backscattering spectroscopy

    International Nuclear Information System (INIS)

    Cook, J.C.; Petry, W.; Heidemann, A.; Barthelemy, J.F.

    1992-01-01

    We report on an instrumental development of the cold neutron backscattering spectrometer IN10 at the Institut Laue-Langevin which has led to a significant increase in its dynamic range. Thermal expansion of a variety of neutron monochromator crystals is used instead of a mechanical oscillation of the monochromator, yielding an increase in the energy transfer range by nearly two orders of magnitude in an elastic wave vector transfer range of 0.07≤Q (A -1 )≤2.0. Using this new configuration, first inelastic measurements have been performed using the (200) reflections from KCl and NaCl monochromators with crystal temperatures between 80 K and 700 K. The thermal expansion of these crystals in this temperature range gives rise to energy transfer ranges (neutron energy gain) of -16<ℎω(μeV)<+83 for KCl and -530<ℎω(μeV)<-420 for NaCl with energy resolution (FWHM) of around 0.6 and 1.4 μeV for KCl and NaCl respectively. These figures represent the highest energy resolution currently available at these energy and wave vector transfers. (orig.)

  12. Molecular dynamics of tert-butanol studied by neutron transmission

    International Nuclear Information System (INIS)

    Amaral, L.Q.; Fulfaro, R.; Vinhas, L.A.

    1974-01-01

    Neutron transmission of the globular compound tert-butanol (CH 3 ) 3 COH have been measured in the temperature interval O 0 C to 40 0 C for 6.13 A neutrons and in the neutron wavelength range 4A to 7.5A in the liquid and solid states. Results show that the cross-section difference at the state transition in 24 0 C is 13%, while it is only approximately 1% at the first order phase transition in 14 0 C. Evidence of existence of third crystalline phase with the lowest cross-section has been found. The barrier to interval methyl rotation in the solid states is estimated as (3.=+ - 0.5) Kcal/mol and does change much over the phase and state transitions. The observed dynamical changes must be due to movements of the whole molecule and evidence that tert-butanol is not in the strict sense a plastic crystal. Correlation with heat capacity results is discussed

  13. Dynamic radial distribution function from inelastic neutron scattering

    International Nuclear Information System (INIS)

    McQueeney, R.J.

    1998-01-01

    A real-space, local dynamic structure function g(r,ω) is defined from the dynamic structure function S(Q,ω), which can be measured using inelastic neutron scattering. At any particular frequency ω, S(Q,ω) contains Q-dependent intensity oscillations which reflect the spatial distribution and relative displacement directions for the atoms vibrating at that frequency. Information about local and dynamic atomic correlations is obtained from the Fourier transform of these oscillations g(r,ω) at the particular frequency. g(r,ω) can be formulated such that the elastic and frequency-summed limits correspond to the average and instantaneous radial distribution function, respectively, and is thus called the dynamic radial distribution function. As an example, the dynamic radial distribution function is calculated for fcc nickel in a model which considers only the harmonic atomic displacements due to phonons. The results of these calculations demonstrate that the magnitude of the atomic correlations can be quantified and g(r,ω) is a well-defined correlation function. This leads to a simple prescription for investigating local lattice dynamics. copyright 1998 The American Physical Society

  14. Dynamics of polymers in the bulk state by neutron scattering

    International Nuclear Information System (INIS)

    Kanaya, Toshiji; Kaji, Keisuke; Kawaguchi, Tatsuya; Inoue, Kazuhiko.

    1992-01-01

    Dynamics of polymers in the bulk state was studied by quasi- and inelastic neutron scattering techniques in the time range of 10 -13 to 10 -10 s. The present work can be classified into three parts: (i) dynamics in the glassy, state, (ii) dynamics near the glass transition and (iii) dynamics in the molten state. In the first section, we discuss the low energy excitation in glassy polymers, which is an origin of anomalous thermal properties of amorphous materials at low temperatures. In the next section, we study dynamics of amorphous polymers near the glass transition which is one of the current topics of solid state physics as well as polymer physics. It was found that two modes of motion appear near the glass transition in the energy ranges near 1 meV and of 10-30μeV. These fast and slow modes arising ca. 50K below T g and just above T g , respectively, are discussed from viewpoints of molecular basis. In the last section, dynamics in the molten state is investigated by focusing on the mechanism of local conformational transition of polymer chains. The results are analyzed in terms of jump diffusion model with damped vibrational motions and compared with the Kramers' rate theory. (author)

  15. Characterization of European sword blades through neutron imaging techniques

    Science.gov (United States)

    Salvemini, F.; Grazzi, F.; Peetermans, S.; Gener, M.; Lehmann, E. H.; Zoppi, M.

    2014-09-01

    In the present work, we have studied two European rapier blades, dating back to the period ranging from the Late Renaissance to the Early Modern Age (about 17th to 18th century). In order to determine variation in quality and differences in technology, a study was undertaken with the purpose to observe variations in the blade microstructure (and consequently in the construction processes). The samples, which in the present case were expendable, have been investigated, preliminarily, through standard metallography and then by means of white beam and energy-selective neutron imaging. The comparison of the results, using the two techniques, turned out to be satisfactory, with a substantial quantitative agreement of the results obtained with the two techniques, and show the complementarity of the two methods. Metallography has been considered up to now the method of choice for metal material characterization. The correspondence between the two methods, as well as the non-invasive character of the neutron-based techniques and its possibility to obtain 3D reconstruction, candidate neutron imaging as an important and quantitatively reliable technique for metal characterization.

  16. Sparse image representation for jet neutron and gamma tomography

    Energy Technology Data Exchange (ETDEWEB)

    Craciunescu, T. [EURATOM-MEdC Association, Institute for Laser, Plasma and Radiation Physics, Bucharest (Romania); Kiptily, V. [EURATOM/CCFE Association, Culham Science Centre, Abingdon (United Kingdom); Murari, A. [Consorzio RFX, Associazione EURATOM-ENEA per la Fusione, Padova (Italy); Tiseanu, I.; Zoita, V. [EURATOM-MEdC Association, Institute for Laser, Plasma and Radiation Physics, Bucharest (Romania)

    2013-10-15

    Highlights: •A new tomographic method for the reconstruction of the 2-D neutron and gamma emissivity on JET. •The method is based on the sparse representation of the reconstructed image in an over-complete dictionary. •Several techniques, based on a priori information are used to regularize this highly limited data set tomographic problem. •The proposed method provides good reconstructions in terms of shapes and resolution. -- Abstract: The JET gamma/neutron profile monitor plasma coverage of the emissive region enables tomographic reconstruction. However, due to the availability of only two projection angles and to the coarse sampling, tomography is a highly limited data set problem. A new reconstruction method, based on the sparse representation of the reconstructed image in an over-complete dictionary, has been developed and applied to JET neutron/gamma tomography. The method has been tested on JET experimental data and significant results are presented. The proposed method provides good reconstructions in terms of shapes and resolution.

  17. Neutrons and music: Imaging investigation of ancient wind musical instruments

    Energy Technology Data Exchange (ETDEWEB)

    Festa, G., E-mail: giulia.festa@roma2.infn.it [Università degli Studi di Roma Tor Vergata (Italy); Università degli Studi di Milano-Bicocca (Italy); Consiglio Nazionale delle Ricerche-IPCF, Messina (Italy); Tardino, G. [BauArt Basel, Basel (Switzerland); Pontecorvo, L. [Conservatorio di Cosenza – Cosenza Conservatory (Italy); Mannes, D.C. [Paul Scherrer Institut, Villigen (Switzerland); Senesi, R. [Università degli Studi di Roma Tor Vergata (Italy); Consiglio Nazionale delle Ricerche-IPCF, Messina (Italy); Gorini, G. [Università degli Studi di Milano-Bicocca (Italy); Andreani, C. [Università degli Studi di Roma Tor Vergata (Italy); Consiglio Nazionale delle Ricerche-IPCF, Messina (Italy)

    2014-10-01

    A set of seven musical instruments and two instruments cares from the ‘Fondo Antico della Biblioteca del Sacro Convento’ in Assisi, Italy, were investigated through neutron and X-ray imaging techniques. Historical and scientific interests around ancient musical instruments motivate an intense research effort for their characterization using non-destructive and non-invasive techniques. X-ray and neutron tomography/radiography were applied to the study of composite material samples containing wood, hide and metals. The study was carried out at the NEUTRA beamline, PSI (Paul Scherrer Institute, Switzerland). Results of the measurements provided new information on the composite and multi-scale structure, such as: the internal structure of the samples, position of added materials like metals, wood fiber displays, deformations, presence of adhesives and their spatial distribution and novel insight about construction methods to guide the instruments’ restoration process.

  18. Neutrons and music: Imaging investigation of ancient wind musical instruments

    International Nuclear Information System (INIS)

    Festa, G.; Tardino, G.; Pontecorvo, L.; Mannes, D.C.; Senesi, R.; Gorini, G.; Andreani, C.

    2014-01-01

    A set of seven musical instruments and two instruments cares from the ‘Fondo Antico della Biblioteca del Sacro Convento’ in Assisi, Italy, were investigated through neutron and X-ray imaging techniques. Historical and scientific interests around ancient musical instruments motivate an intense research effort for their characterization using non-destructive and non-invasive techniques. X-ray and neutron tomography/radiography were applied to the study of composite material samples containing wood, hide and metals. The study was carried out at the NEUTRA beamline, PSI (Paul Scherrer Institute, Switzerland). Results of the measurements provided new information on the composite and multi-scale structure, such as: the internal structure of the samples, position of added materials like metals, wood fiber displays, deformations, presence of adhesives and their spatial distribution and novel insight about construction methods to guide the instruments’ restoration process

  19. Neutrons and music: Imaging investigation of ancient wind musical instruments

    Science.gov (United States)

    Festa, G.; Tardino, G.; Pontecorvo, L.; Mannes, D. C.; Senesi, R.; Gorini, G.; Andreani, C.

    2014-10-01

    A set of seven musical instruments and two instruments cares from the 'Fondo Antico della Biblioteca del Sacro Convento' in Assisi, Italy, were investigated through neutron and X-ray imaging techniques. Historical and scientific interests around ancient musical instruments motivate an intense research effort for their characterization using non-destructive and non-invasive techniques. X-ray and neutron tomography/radiography were applied to the study of composite material samples containing wood, hide and metals. The study was carried out at the NEUTRA beamline, PSI (Paul Scherrer Institute, Switzerland). Results of the measurements provided new information on the composite and multi-scale structure, such as: the internal structure of the samples, position of added materials like metals, wood fiber displays, deformations, presence of adhesives and their spatial distribution and novel insight about construction methods to guide the instruments' restoration process.

  20. Neutron and Gamma Imaging for National Security Applications

    Science.gov (United States)

    Hornback, Donald

    2017-09-01

    The Department of Energy, National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation Research and Development (DNN R&D/NA-22) possesses, in part, the mission to develop technologies in support of nuclear security efforts in coordination with other U.S. government entities, such as the Department of Defense and the Department of Homeland Security. DNN R&D has long supported research in nuclear detection at national labs, universities, and through the small business innovation research (SBIR) program. Research topics supported include advanced detector materials and electronics, detection algorithm development, and advanced gamma/neutron detection systems. Neutron and gamma imaging, defined as the directional detection of radiation as opposed to radiography, provides advanced detection capabilities for the NNSA mission in areas of emergency response, international safeguards, and nuclear arms control treaty monitoring and verification. A technical and programmatic overview of efforts in this field of research will be summarized.

  1. Preliminary experiment of fast neutron imaging with direct-film method

    International Nuclear Information System (INIS)

    Pei Yuyang; Tang Guoyou; Guo Zhiyu; Zhang Guohui

    2005-01-01

    A preliminary experiment is conducted with direct-film method under the condition that fast neutron is generated by the reaction of 9 Be(d, n) on the Beijing University 4.5 MV Van de Graaff, whose energy is lower than 7 MeV. Basic characteristics of direct-film neutron radiography system are investigated with the help of samples in different materials, different thickness and holes of different diameter. The fast neutron converter, which is vital for fast neutron imaging, is produced with the materials made in China. The result indicates that fast neutron converter can meet the requirement of fast neutron imaging; further research of fast neutron imaging can be conducted on the accelerator and neutron-generator in China. (authors)

  2. Lithium indium diselenide: A new scintillator for neutron imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lukosi, Eric, E-mail: elukosi@utk.edu [University of Tennessee, Knoxville, TN (United States); Herrera, Elan; Hamm, Daniel; Lee, Kyung-Min [University of Tennessee, Knoxville, TN (United States); Wiggins, Brenden [Y-12 National Security Complex, Oak Ridge, TN (United States); Trtik, Pavel [Paul Scherrer Institut, Villigen CH-5232 (Switzerland); Penumadu, Dayakar; Young, Stephen [University of Tennessee, Knoxville, TN (United States); Santodonato, Louis; Bilheux, Hassina [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Burger, Arnold; Matei, Liviu [Fisk University, Nashville, TN (United States); Stowe, Ashley C. [University of Tennessee, Knoxville, TN (United States); Y-12 National Security Complex, Oak Ridge, TN (United States)

    2016-09-11

    Lithium indium diselenide, {sup 6}LiInSe{sub 2} or LISe, is a newly developed neutron detection material that shows both semiconducting and scintillating properties. This paper reports on the performance of scintillating LISe crystals for its potential use as a converter screen for cold neutron imaging. The spatial resolution of LISe, determined using a 10% threshold of the Modulation Transfer Function (MTF), was found to not scale linearly with thickness. Crystals having a thickness of 450 µm or larger resulted in an average spatial resolution of 67 µm, and the thinner crystals exhibited an increase in spatial resolution down to the Nyquist frequency of the CCD. The highest measured spatial resolution of 198 µm thick LISe (27 µm) outperforms a commercial 50 µm thick ZnS(Cu):{sup 6}LiF scintillation screen by more than a factor of three. For the LISe dimensions considered in this study, it was found that the light yield of LISe did not scale with its thickness. However, absorption measurements indicate that the {sup 6}Li concentration is uniform and the neutron absorption efficiency of LISe as a function of thickness follows general nuclear theory. This suggests that the differences in apparent brightness observed for the LISe samples investigated may be due to a combination of secondary charged particle escape, scintillation light transport in the bulk and across the LISe-air interface, and variations in the activation of the scintillation mechanism. Finally, it was found that the presence of {sup 115}In and its long-lived {sup 116}In activation product did not result in ghosting (memory of past neutron exposure), demonstrating potential of LISe for imaging transient systems.

  3. High dynamic range coding imaging system

    Science.gov (United States)

    Wu, Renfan; Huang, Yifan; Hou, Guangqi

    2014-10-01

    We present a high dynamic range (HDR) imaging system design scheme based on coded aperture technique. This scheme can help us obtain HDR images which have extended depth of field. We adopt Sparse coding algorithm to design coded patterns. Then we utilize the sensor unit to acquire coded images under different exposure settings. With the guide of the multiple exposure parameters, a series of low dynamic range (LDR) coded images are reconstructed. We use some existing algorithms to fuse and display a HDR image by those LDR images. We build an optical simulation model and get some simulation images to verify the novel system.

  4. Dynamic CT myocardial perfusion imaging

    International Nuclear Information System (INIS)

    Caruso, Damiano; Eid, Marwen; Schoepf, U. Joseph; Jin, Kwang Nam; Varga-Szemes, Akos; Tesche, Christian; Mangold, Stefanie

    2016-01-01

    Highlights: • CT myocardial perfusion provides functional assessment of the myocardium. • CCTA is limited in determining the hemodynamic significance of coronary stenosis. • CT-MPI can accurately detect hemodynamically significant coronary artery stenosis. - Abstract: Non-invasive cardiac imaging has rapidly evolved during the last decade due to advancements in CT based technologies. Coronary CT angiography has been shown to reliably assess coronary anatomy and detect high risk coronary artery disease. However, this technique is limited to anatomical assessment, thus non-invasive techniques for functional assessment of the heart are necessary. CT myocardial perfusion is a new CT based technique that provides functional assessment of the myocardium and allows for a comprehensive assessment of coronary artery disease with a single modality when combined with CTA. This review aims to discuss dynamic CT myocardial perfusion as a new technique in the assessment of CAD.

  5. Dynamic CT myocardial perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Caruso, Damiano [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiological Sciences, Oncological and Pathological Sciences, University of Rome “Sapienza”, Latina (Italy); Eid, Marwen [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (United States); Jin, Kwang Nam [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiology, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul (Korea, Republic of); Varga-Szemes, Akos [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Tesche, Christian [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich (Germany); Mangold, Stefanie [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen (Germany); and others

    2016-10-15

    Highlights: • CT myocardial perfusion provides functional assessment of the myocardium. • CCTA is limited in determining the hemodynamic significance of coronary stenosis. • CT-MPI can accurately detect hemodynamically significant coronary artery stenosis. - Abstract: Non-invasive cardiac imaging has rapidly evolved during the last decade due to advancements in CT based technologies. Coronary CT angiography has been shown to reliably assess coronary anatomy and detect high risk coronary artery disease. However, this technique is limited to anatomical assessment, thus non-invasive techniques for functional assessment of the heart are necessary. CT myocardial perfusion is a new CT based technique that provides functional assessment of the myocardium and allows for a comprehensive assessment of coronary artery disease with a single modality when combined with CTA. This review aims to discuss dynamic CT myocardial perfusion as a new technique in the assessment of CAD.

  6. High-resolution investigations of edge effects in neutron imaging

    International Nuclear Information System (INIS)

    Strobl, M.; Kardjilov, N.; Hilger, A.; Kuehne, G.; Frei, G.; Manke, I.

    2009-01-01

    Edge enhancement is the main effect measured by the so-called inline or propagation-based neutron phase contrast imaging method. The effect has originally been explained by diffraction, and high spatial coherence has been claimed to be a necessary precondition. However, edge enhancement has also been found in conventional imaging with high resolution. In such cases the effects can produce artefacts and hinder quantification. In this letter the edge effects at cylindrical shaped samples and long straight edges have been studied in detail. The enhancement can be explained by refraction and total reflection. Using high-resolution imaging, where spatial resolutions better than 50 μm could be achieved, refraction and total reflection peaks - similar to diffraction patterns - could be separated and distinguished.

  7. Block-Based Compressed Sensing for Neutron Radiation Image Using WDFB

    Directory of Open Access Journals (Sweden)

    Wei Jin

    2015-01-01

    Full Text Available An ideal compression method for neutron radiation image should have high compression ratio while keeping more details of the original image. Compressed sensing (CS, which can break through the restrictions of sampling theorem, is likely to offer an efficient compression scheme for the neutron radiation image. Combining wavelet transform with directional filter banks, a novel nonredundant multiscale geometry analysis transform named Wavelet Directional Filter Banks (WDFB is constructed and applied to represent neutron radiation image sparsely. Then, the block-based CS technique is introduced and a high performance CS scheme for neutron radiation image is proposed. By performing two-step iterative shrinkage algorithm the problem of L1 norm minimization is solved to reconstruct neutron radiation image from random measurements. The experiment results demonstrate that the scheme not only improves the quality of reconstructed image obviously but also retains more details of original image.

  8. Image enhancement using MCNP5 code and MATLAB in neutron radiography.

    Science.gov (United States)

    Tharwat, Montaser; Mohamed, Nader; Mongy, T

    2014-07-01

    This work presents a method that can be used to enhance the neutron radiography (NR) image for objects with high scattering materials like hydrogen, carbon and other light materials. This method used Monte Carlo code, MCNP5, to simulate the NR process and get the flux distribution for each pixel of the image and determines the scattered neutron distribution that caused image blur, and then uses MATLAB to subtract this scattered neutron distribution from the initial image to improve its quality. This work was performed before the commissioning of digital NR system in Jan. 2013. The MATLAB enhancement method is quite a good technique in the case of static based film neutron radiography, while in neutron imaging (NI) technique, image enhancement and quantitative measurement were efficient by using ImageJ software. The enhanced image quality and quantitative measurements were presented in this work. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Dynamic MR imaging of pancreatic cancer

    International Nuclear Information System (INIS)

    Akaki, Shiro; Kohno, Yoshihiro; Gohbara, Hideo

    1994-01-01

    Dynamic MRI was performed on 21 patients with pancreatic duct cell carcinoma. Turbo-FLASH or FLASH3D was performed immediately following rapid bolus injection of gadopentetate dimeglumine, and these FLASH images and conventional spin echo images were evaluated about detectability of the lesion. All images were classified into three groups of detectability of the lesion ; good, fair, and poor. On T 1 weighted image, 23% of cases were 'good' and 48% were evaluated as 'fair'. On the other hand, on dynamic MRI, 62% of cases were 'good' and 33% of cases were evaluated as 'fair'. Both T 2 weighted image and enhanced T 1 weighted image were not useful for depiction of the lesion. Direct comparison between T 1 weighted image and dynamic MRI was also done. In 55% of cases, dynamic MRI was superior to T 1 weighted image and in 40% of cases, dynamic MRI was equal to T 1 weighted image. Thus, dynamic MRI was superior to conventional spin echo images for detection of duct cell carcinoma. In 17 patients of duct cell carcinoma who underwent FLASH3D, contrast/noise ratio (CNR) was calculated before and after injection of gadopentetate dimeglumine. The absolute value of CNR became significantly larger by injection of contrast material. In nine resectable pancreatic carcinomas, two cases of INF α and two cases of medullary type were well depicted. It was concluded that dynamic MRI was useful for evaluation of pancreatic carcinoma. (author)

  10. Dynamic MR imaging in the musculoskeletal system

    International Nuclear Information System (INIS)

    Hedlund, L.; Vogler, J.; Utz, J.A.; Herfkens, R.J.; Martinez, S.; Urbaniak, J.; Evans, A.

    1986-01-01

    Many joint disorders are related to movement, and lack of dynamic imaging has thus far been a limitation of MR imaging. A recently developed dynamic MR imaging technique utilizing a gradient refocused echo (TE = 12 msec, TR = 21 msec) coupled to a physiologic trigger allows dynamic images of the moving joint to be obtained. Controlled joint articulation is produced using an air-driven nonmagnetic device. Imaging of the wrist by this technique demonstrated the dynamic motion of the carpal rows. The method displays cartilage with more sensitivity than does conventional MR imaging; thus, ligamentous and triangular cartilage alignment could be evaluated during motion. In the wrist, potential applications include imaging of carpal instability syndromes, ligamentous interruption, and tears of the triangular cartilage

  11. Image enhancement using MCNP5 code and MATLAB in neutron radiography

    International Nuclear Information System (INIS)

    Tharwat, Montaser; Mohamed, Nader; Mongy, T.

    2014-01-01

    This work presents a method that can be used to enhance the neutron radiography (NR) image for objects with high scattering materials like hydrogen, carbon and other light materials. This method used Monte Carlo code, MCNP5, to simulate the NR process and get the flux distribution for each pixel of the image and determines the scattered neutron distribution that caused image blur, and then uses MATLAB to subtract this scattered neutron distribution from the initial image to improve its quality. This work was performed before the commissioning of digital NR system in Jan. 2013. The MATLAB enhancement method is quite a good technique in the case of static based film neutron radiography, while in neutron imaging (NI) technique, image enhancement and quantitative measurement were efficient by using ImageJ software. The enhanced image quality and quantitative measurements were presented in this work. - Highlights: • This work is applicable for static based film neutron radiography and digital neutron imaging. • MATLAB is a useful tool for imaging enhancement in radiographic film. • Advanced imaging processing is available in the ETRR-2 for imaging processing and data extraction. • The digital imaging system is suitable for complex shapes and sizes, while MATLAB technique is suitable for simple shapes and sizes. • Quantitative measurements are available

  12. Assessment of Radiographic Image Quality by Visual Examination of Neutron Radiographs of the Calibration Fuel Pin

    DEFF Research Database (Denmark)

    Domanus, Joseph Czeslaw

    1986-01-01

    Up till now no reliable radiographic image quality standards exist for neutron radiography of nuclear reactor fuel. Under the Euratoro Neutron Radiography Working Group (NRWG) Test Program neutron radiographs were produced at different neutron radiography facilities within the European Community...... of a calibration fuel pin. The radiographs were made by the direct, transfer and tracketch methods using different film recording materials. These neutron radiographs of the calibration fuel pin were used for the assessement of radiographic image quality. This was done by visual examination of the radiographs...

  13. Monte Carlo modeling of neutron imaging at the SINQ spallation source

    International Nuclear Information System (INIS)

    Lebenhaft, J.R.; Lehmann, E.H.; Pitcher, E.J.; McKinney, G.W.

    2003-01-01

    Modeling of the Swiss Spallation Neutron Source (SINQ) has been used to demonstrate the neutron radiography capability of the newly released MPI-version of the MCNPX Monte Carlo code. A detailed MCNPX model was developed of SINQ and its associated neutron transmission radiography (NEUTRA) facility. Preliminary validation of the model was performed by comparing the calculated and measured neutron fluxes in the NEUTRA beam line, and a simulated radiography image was generated for a sample consisting of steel tubes containing different materials. This paper describes the SINQ facility, provides details of the MCNPX model, and presents preliminary results of the neutron imaging. (authors)

  14. A new position-sensitive transmission detector for epithermal neutron imaging

    International Nuclear Information System (INIS)

    Schooneveld, E M; Kockelmann, W; Rhodes, N; Tardocchi, M; Gorini, G; Perelli Cippo, E; Nakamura, T; Postma, H; Schillebeeckx, P

    2009-01-01

    A new neutron resonant transmission (NRT) detector for epithermal neutron imaging has been designed and built for the ANCIENT CHARM project, which is developing a set of complementary neutron imaging methods for analysis of cultural heritage objects. One of the techniques being exploited is NRT with the aim of performing bulk elemental analysis. The 16-pixel prototype NRT detector consists of independent crystals of 2 x 2 mm pixel size, which allow for 2D position-sensitive transmission measurements with epithermal neutrons. First results obtained at the ISIS pulsed spallation neutron source are presented. (fast track communication)

  15. Dynamic neutron scattering from conformational dynamics. I. Theory and Markov models.

    Science.gov (United States)

    Lindner, Benjamin; Yi, Zheng; Prinz, Jan-Hendrik; Smith, Jeremy C; Noé, Frank

    2013-11-07

    The dynamics of complex molecules can be directly probed by inelastic neutron scattering experiments. However, many of the underlying dynamical processes may exist on similar timescales, which makes it difficult to assign processes seen experimentally to specific structural rearrangements. Here, we show how Markov models can be used to connect structural changes observed in molecular dynamics simulation directly to the relaxation processes probed by scattering experiments. For this, a conformational dynamics theory of dynamical neutron and X-ray scattering is developed, following our previous approach for computing dynamical fingerprints of time-correlation functions [F. Noé, S. Doose, I. Daidone, M. Löllmann, J. Chodera, M. Sauer, and J. Smith, Proc. Natl. Acad. Sci. U.S.A. 108, 4822 (2011)]. Markov modeling is used to approximate the relaxation processes and timescales of the molecule via the eigenvectors and eigenvalues of a transition matrix between conformational substates. This procedure allows the establishment of a complete set of exponential decay functions and a full decomposition into the individual contributions, i.e., the contribution of every atom and dynamical process to each experimental relaxation process.

  16. Protein dynamics by neutron scattering: The protein dynamical transition and the fragile-to-strong dynamical crossover in hydrated lysozyme

    International Nuclear Information System (INIS)

    Magazù, Salvatore; Migliardo, Federica; Benedetto, Antonio; Vertessy, Beata

    2013-01-01

    Highlights: • The role played by the instrumental energy resolution in neutron scattering is presented. • The effect of natural bioprotectants on protein dynamics is shown. • A connection between the protein dynamical transition and the fragile-to-strong dynamical crossover is formulated. - Abstract: In this work Elastic Incoherent Neutron Scattering (EINS) results on lysozyme water mixtures in absence and in presence of bioprotectant systems are presented. The EINS data have been collected by using the IN13 and the IN10 spectrometers at the Institut Laue-Langevin (ILL, Grenoble, France) allowing to evaluate the temperature behaviour of the mean square displacement and of the relaxation time for the investigated systems. The obtained experimental findings together with theoretical calculations allow to put into evidence the role played by the spectrometer resolution and to clarify the connexion between the registered protein dynamical transition, the system relaxation time, and the instrumental energy resolution

  17. Dynamic MR imaging of the musculoskeletal system

    International Nuclear Information System (INIS)

    Shah, A.S.; Hylton, H.; Hentz, V.R.; Schattner, P.

    1991-01-01

    This paper reports on dynamic MR imaging which is an MR technique that allows imaging of the musculoskeletal system in motion. Current methods for observing the articulation of muscles and joints are limited to acquisition of stationary images at different spatial orientations. These images are then replayed from computer memory to simulate motion. Unlike stationary acquisition, dynamic MR imaging allows the volume of interest to be subjected to motion and dynamic stress, which is important for detecting stress-induced pathology. To demonstrate the utility of dynamic MR imaging, a system for imaging a moving wrist has been developed. The system consists of apparatus capable of providing simultaneous radialulnar deviation and flexion-extension, and hardware for system control and acquisition gating. The apparatus is mounted on the patient bed and is transferable to a variety of standard clinical MR imaging systems. Images were obtained during motion, and the ability of dynamic MR imaging to accurately image the moving wrist with very little motion artifact was demonstrated

  18. Scintillating-fiber imaging detector for 14-MeV neutrons

    International Nuclear Information System (INIS)

    Ress, D.; Lerche, R.A.; Ellis, R.J.; Heaton, G.W.; Nelson, M.B.; Mant, G.; Lehr, D.E.

    1994-01-01

    The authors have created a detector to image the neutrons emitted by imploded inertial-confinement fusion targets. The 14-MeV neutrons, which are produced by deuterium-tritium fusion events in the target, pass through an aperture to create an image on the detector. The neutron radiation is converted to blue light (430 nm) with a 20-cm-square array of plastic scintillating fibers. Each fiber is 10-cm long with a 1-mm-square cross section; approximately 35-thousand fibers make up the array. The resulting blue-light image is reduced and amplified by a sequence of fiber-optic tapers and image intensifiers, then acquired by a CCD camera. The fiber-optic readout system was tested optically for overall throughput the resolution. The authors plan to characterize the scintillator array reusing an ion-beam neutron source as well as DT-fusion neutrons emitted by inertial confinement targets. Characterization experiments will measure the light-production efficiency, spatial resolution, and neutron scattering within the detector. Several neutron images of laser-fusion targets have been obtained with the detector. Several neutron images of laser-fusion targets have been obtained with the detector. They describe the detector and their characterization methods, present characterization results, and give examples of the neutron images

  19. Image reconstruction of dynamic infrared single-pixel imaging system

    Science.gov (United States)

    Tong, Qi; Jiang, Yilin; Wang, Haiyan; Guo, Limin

    2018-03-01

    Single-pixel imaging technique has recently received much attention. Most of the current single-pixel imaging is aimed at relatively static targets or the imaging system is fixed, which is limited by the number of measurements received through the single detector. In this paper, we proposed a novel dynamic compressive imaging method to solve the imaging problem, where exists imaging system motion behavior, for the infrared (IR) rosette scanning system. The relationship between adjacent target images and scene is analyzed under different system movement scenarios. These relationships are used to build dynamic compressive imaging models. Simulation results demonstrate that the proposed method can improve the reconstruction quality of IR image and enhance the contrast between the target and the background in the presence of system movement.

  20. Structure and dynamics of photosynthetic proteins studied by neutron scattering and molecular dynamic simulation

    International Nuclear Information System (INIS)

    Dellerue, Serge

    2000-01-01

    Understand the structure-dynamics-function relation in the case of proteins is essential. But few experimental techniques allow to have access to knowledge of fast internal movements of biological macromolecules. With the neutron scattering method, it has been possible to study the reorientation dynamics of side chains and of polypeptide skeleton for two proteins in terms of water or detergent and of temperature. With the use of the molecular dynamics method, essential for completing and interpreting the experimental data, it has been possible to assess the different contributions of the whole structure of proteins to the overall dynamics. It has been shown that the polypeptide skeleton presents an energy relaxation comparable to those of the side chains. Moreover, it has been explained that the protein dynamics can only be understood in terms of relaxation time distribution. (author) [fr

  1. A SrBPO5: Eu2+ phosphor for neutron imaging

    International Nuclear Information System (INIS)

    Sakasai, K.; Katagiri, M.; Toh, K.; Nakamura, T.

    2001-01-01

    A SrBPO 5 : Eu 2+ phosphor material has been investigated for neutron imaging. This phosphor showed photostimulated luminescence (PSL) by illumination of 635 nm laser light after X-ray irradiation. The spectral characteristics of the phosphor were similar to those of BaFBr: Eu 2+ , which is a commonly used phosphor of imaging plates. In addition, we found that this phosphor also showed PSL for neutron irradiation. It comes from the fact that it contains atomic boron in base matrix. Therefore, this phosphor can be used for neutron imaging without adding neutron sensitive materials such as Gd in commercially available neutron imaging plates. The PSL intensity and the neutron detection will be increased by using enriched boron instead of natural boron. (author)

  2. Dynamical response of the nuclear 'pasta' in neutron star crusts

    International Nuclear Information System (INIS)

    Horowitz, C.J.; Perez-Garcia, M.A.; Berry, D.K.; Piekarewicz, J.

    2005-01-01

    The nuclear pasta - a novel state of matter having nucleons arranged in a variety of complex shapes - is expected to be found in the crust of neutron stars and in core-collapse supernovae at subnuclear densities of about 10 14 g/cm 3 . Owing to frustration, a phenomenon that emerges from the competition between short-range nuclear attraction and long-range Coulomb repulsion, the nuclear pasta displays a preponderance of unique low-energy excitations. These excitations could have a strong impact on many transport properties, such as neutrino propagation through stellar environments. The excitation spectrum of the nuclear pasta is computed via a molecular-dynamics simulation involving up to 100,000 nucleons. The dynamic response of the pasta displays a classical plasma oscillation in the 1- to 2-MeV region. In addition, substantial strength is found at low energies. Yet this low-energy strength is missing from a simple ion model containing a single-representative heavy nucleus. The low-energy strength observed in the dynamic response of the pasta is likely to be a density wave involving the internal degrees of freedom of the clusters

  3. Malaysia: Overview of activities on Neutron Imaging (NI) and Cultural Heritage (CH) studies

    International Nuclear Information System (INIS)

    Muhammad Rawi Mohamed Zin

    2012-01-01

    Inspection of cultural heritage artifact by neutron imaging becoming interesting and important research area since its able to sees internal structure non-destructively. Therefore advanced neutron imaging capability to conduct this kind of inspection is needed. Associated with this needs, TRIGA MARK II PUSPATI reactor has neutron imaging facility, NUR-2 which capable for radiography and tomography usage. Details parameters of current set up is given. Neutron radiography capability at this facility has been relied on direct method technique by the usage of SR-45 KODAK film technology. Current set-up has been used by university student through-out the country to conduct their research in various levels of educations

  4. New neutron imaging techniques to close the gap to scattering applications

    International Nuclear Information System (INIS)

    Lehmann, Eberhard H.; Peetermans, S.; Trtik, P.; Betz, B.; Grünzweig, C.

    2017-01-01

    Neutron scattering and neutron imaging are activities at the strong neutron sources which have been developed rather independently. However, there are similarities and overlaps in the research topics to which both methods can contribute and thus useful synergies can be found. In particular, the spatial resolution of neutron imaging has improved recently, which - together with the enhancement of the efficiency in data acquisition- can be exploited to narrow the energy band and to implement more sophisticated methods like neutron grating interferometry. This paper provides a report about the current options in neutron imaging and describes how the gap to neutron scattering data can be closed in the future, e.g. by diffractive imaging, the use of polarized neutrons and the dark-field imagining of relevant materials. This overview is focused onto the interaction between neutron imaging and neutron scattering with the aim of synergy. It reflects mainly the authors’ experiences at their PSI facilities without ignoring the activities at the different other labs world-wide. (paper)

  5. New neutron imaging techniques to close the gap to scattering applications

    Science.gov (United States)

    Lehmann, Eberhard H.; Peetermans, S.; Trtik, P.; Betz, B.; Grünzweig, C.

    2017-01-01

    Neutron scattering and neutron imaging are activities at the strong neutron sources which have been developed rather independently. However, there are similarities and overlaps in the research topics to which both methods can contribute and thus useful synergies can be found. In particular, the spatial resolution of neutron imaging has improved recently, which - together with the enhancement of the efficiency in data acquisition- can be exploited to narrow the energy band and to implement more sophisticated methods like neutron grating interferometry. This paper provides a report about the current options in neutron imaging and describes how the gap to neutron scattering data can be closed in the future, e.g. by diffractive imaging, the use of polarized neutrons and the dark-field imagining of relevant materials. This overview is focused onto the interaction between neutron imaging and neutron scattering with the aim of synergy. It reflects mainly the authors’ experiences at their PSI facilities without ignoring the activities at the different other labs world-wide.

  6. Comparison of dynamic compensation methods for delayed self-powered neutron detector

    International Nuclear Information System (INIS)

    In, Wang Kee; Kim, Joon Sung; Auh, Geun Sun; Yoon, Tae Young

    1993-01-01

    Dynamic compensation methods for rhodium self-powered neutron detector have been developed by Banda and Hoppe to compensate for the time delay associated with detector signals. The time delay is due to the decay of the neutron-activated rhodium and results in delayed detector response. Two digital dynamic compensation methods, were compared for step change of neutron flux in this paper. The inverse kinetics method gave slightly better response time and noise gain. However, the inverse kinetics method also showed overshooting of neutron flux for the step change. (Author)

  7. Preliminary energy-filtering neutron imaging with time-of-flight method on PKUNIFTY: A compact accelerator based neutron imaging facility at Peking University

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hu; Zou, Yubin, E-mail: zouyubin@pku.edu.cn; Wen, Weiwei; Lu, Yuanrong; Guo, Zhiyu

    2016-07-01

    Peking University Neutron Imaging Facility (PKUNIFTY) works on an accelerator–based neutron source with a repetition period of 10 ms and pulse duration of 0.4 ms, which has a rather low Cd ratio. To improve the effective Cd ratio and thus improve the detection capability of the facility, energy-filtering neutron imaging was realized with the intensified CCD camera and time-of-flight (TOF) method. Time structure of the pulsed neutron source was firstly simulated with Geant4, and the simulation result was evaluated with experiment. Both simulation and experiment results indicated that fast neutrons and epithermal neutrons were concentrated in the first 0.8 ms of each pulse period; meanwhile in the period of 0.8–2.0 ms only thermal neutrons existed. Based on this result, neutron images with and without energy filtering were acquired respectively, and it showed that detection capability of PKUNIFTY was improved with setting the exposure interval as 0.8–2.0 ms, especially for materials with strong moderating capability.

  8. Dynamic MR imaging of pituitary adenoma

    International Nuclear Information System (INIS)

    Miki, Yukio; Nishizawa, Sadahiko; Kuroda, Yasumasa; Keyaki, Atsushi; Nabeshima, Sachio; Kawamura, Junichiro; Matsuo, Michimasa

    1990-01-01

    The authors performed serial dynamic MR imaging in patients with 10 normal pituitary and 21 pituitary adenoma utilizing spin-echo sequence with a very short repetition time (SE 100/15) every minute immediately after a bolus injection of Gd-DTPA. Usual T 1 -weighted images (SE 600/15) were also obtained before and after the dynamic study. Pituitary adenomas included 10 adenomas confirmed by surgery, 4 adenomas confirmed by biologic data, and 7 postoperative adenomas. Out of 10 patients who underwent surgery after dynamic MRI, 9 patients underwent postoperative dynamic MRI. In normal patients, the pituitary gland was markedly enhanced on the early-phase images of the dynamic study, followed by gradual decrease of intensity throughout the dynamic study. In cases of microadenomas, the contrast between the normal pituitary gland and adenoma is better than that on the usual T 1 -weighted images by marked enhancement of the normal pituitary gland. Dynamic images clearly showed the residual normal pituitary glands in all cases of macroadenoma larger than 15 mm in diameter, whereas usual contrast-enhanced images showed the normal pituitary gland only in one case. In all patients who underwent both preoperative and postoperative dynamic MRI, postoperative dynamic MRI showed the normal pituitary glands which are markedly enhanced on the early-phase images in the sites which correspond to the preoperative dynamic study. The normal residual anterior gland was also visualized in four out of 7 patients who received only postoperative dynamic MRI. Dynamic MRI is a strong diagnostic modality for visualizing microadenoma and for visualizing the normal pituitary gland in cases of preoperative and postoperative macroadenoma. (author)

  9. Distribution of root exudates and mucilage in the rhizosphere: combining 14C imaging with neutron radiography

    Science.gov (United States)

    Holz, Maire; Carminati, Andrea; Kuzyakov, Yakov

    2015-04-01

    exudates. We found that mucilage and 14C concentrations were higher around the young root segments. Mucilage concentration was particularly high in the most apical 3-5 cm of the roots. Drought stress increased 14C exudation relative to C fixation and led to higher mucilage concentrations around roots. However, it remains unclear, whether the lower mucilage concentration around roots grown at higher soil moisture was caused by the faster diffusion of mucilage in wet soils. Therefore, a second experiment was focused on diffusion of mucilage in soil at varying water contents. The diffusion of mucilage in soil was not very sensitive to soil water content. We conclude that mucilage release was higher for plants exposed to drought stress. In summary, the combination of neutron radiography and 14C imaging can successfully be used to visualize and to quantify the distribution of mucilage and root exudates in the rhizosphere of plants grown in soil. References Kroener, E., Zarebanadkouki, M., Kaestner, A., & Carmintati, A. (2014). Nonequilibrium water dynamics in the rhizosphere: How mucilage affects water flow in soils. Water Resources Research, 37. Pausch, J., & Kuzyakov, Y. (2011). Photoassimilate allocation and dynamics of hotspots in roots visualized by 14C phosphor imaging. Journal of Plant Nutrition and Soil Science, 174(1), 12-19.

  10. Digital image processing for real-time neutron radiography and its applications

    International Nuclear Information System (INIS)

    Fujine, Shigenori

    1989-01-01

    The present paper describes several digital image processing approaches for the real-time neutron radiography (neutron television-NTV), such as image integration, adaptive smoothing and image enhancement, which have beneficial effects on image improvements, and also describes how to use these techniques for applications. Details invisible in direct images of NTV are able to be revealed by digital image processing, such as reversed image, gray level correction, gray scale transformation, contoured image, subtraction technique, pseudo color display and so on. For real-time application a contouring operation and an averaging approach can also be utilized effectively. (author)

  11. Applications and characteristics of imaging plates as detector in neutron radiography at SINQ

    CERN Document Server

    Kolbe, H; Gunia, W; Körner, S

    1999-01-01

    Imaging plate technique is a commonly accepted method in many fields as in medicine, biology and physics for detection of the distribution of beta- and gamma-radiation or X-rays on large areas. Recently a new type of imaging plate sensitive to neutrons has been developed. The storage layer is doped with gadolinium, which, after absorption of neutrons, produces radiation detectable by the same sensitive crystals used in conventional imaging plates. At the spallation neutron source, SINQ, at the Paul Scherrer Institut (CH) some of the characteristics of the neutron radiography station in combination with the imaging plate technique were investigated. The intensity distribution of the source was measured to check the accuracy for quantification of the image data. Also, the reproducibility of results obtained by this detection system was stated. For a test object, the high selectivity for different neutron absorption is demonstrated at details with low contrast. The obtainable spatial resolution was determined re...

  12. Visualization and measurement by image processing of thermal hydraulic phenomena by neutron radiography

    International Nuclear Information System (INIS)

    Takenaka, Nobuyuki

    1996-01-01

    Neutron Radiography was applied to visualization of thermal hydraulic phenomena and measurement was carried out by image processing the visualized images. Since attenuation of thermal neutron rays is high in ordinary liquids like water and organic fluid while it is low in most of metals, liquid flow behaviors can be visualized through a metallic wall by neutron radiography. Measurement of void fraction and flow vector field which is important to study thermal hydraulic phenomena can be carried out by image processing the images obtained by the visualization. Various two-phase and liquid metal flows were visualized by a JRR-3M thermal neutron radiography system in the present study. Multi-dimensional void fraction distributions in two-phase flows and flow vector fields in liquid metals, which are difficult to measure by the other methods, were successfully measured by image processing. It was shown that neutron radiography was efficiently applicable to study thermal hydraulic phenomena. (author)

  13. Non-Destructive Spent Fuel Characterization with Semiconducting Gallium Arsinde Neutron Imaging Arrays

    International Nuclear Information System (INIS)

    McGregor, Douglas S.; Gersch, Holly K.; Sanders, Jeffrey D.; Lee, John C.; Hammig, Mark D.; Hartman, Michael R.; Yong Hong Yang; Klann, Raymond T.; Elzen, Brian Van Der; Lindsay, John T.; Simpson, Philip A.

    2002-01-01

    High resistivity bulk grown GaAs has been used to produce thermal neutron imaging devices for use in neutron radiography and characterizing burnup in spent fuel. The basic scheme utilizes a portable Sb/Be source for monoenergetic (24 keV) neutron radiation source coupled to an Fe filter with a radiation hard B-coated pixellated GaAs detector array as the primary neutron detector. The coated neutron detectors have been tested for efficiency and radiation hardness in order to determine their fitness for the harsh environments imposed by spent fuel. Theoretical and experimental results are presented, showing detector radiation hardness, expected detection efficiency and the spatial resolution from such a scheme. A variety of advanced neutron detector designs have been explored, with experimental results achieving 13% thermal neutron detection efficiency while projecting the possibility of over 30% thermal neutron detection efficiency

  14. Detector for imaging and dosimetry of laser-driven epithermal neutrons by alpha conversion

    Science.gov (United States)

    Mirfayzi, S. R.; Alejo, A.; Ahmed, H.; Wilson, L. A.; Ansell, S.; Armstrong, C.; Butler, N. M. H.; Clarke, R. J.; Higginson, A.; Notley, M.; Raspino, D.; Rusby, D. R.; Borghesi, M.; Rhodes, N. J.; McKenna, P.; Neely, D.; Brenner, C. M.; Kar, S.

    2016-10-01

    An epithermal neutron imager based on detecting alpha particles created via boron neutron capture mechanism is discussed. The diagnostic mainly consists of a mm thick Boron Nitride (BN) sheet (as an alpha converter) in contact with a non-borated cellulose nitride film (LR115 type-II) detector. While the BN absorbs the neutrons in the thermal and epithermal ranges, the fast neutrons register insignificantly on the detector due to their low neutron capture and recoil cross-sections. The use of solid-state nuclear track detectors (SSNTD), unlike image plates, micro-channel plates and scintillators, provide safeguard from the x-rays, gamma-rays and electrons. The diagnostic was tested on a proof-of-principle basis, in front of a laser driven source of moderated neutrons, which suggests the potential of using this diagnostic (BN+SSNTD) for dosimetry and imaging applications.

  15. Development of neutron imaging beamline for NDT applications at Dhruva reactor, India

    Science.gov (United States)

    Shukla, Mayank; Roy, Tushar; Kashyap, Yogesh; Shukla, Shefali; Singh, Prashant; Ravi, Baribaddala; Patel, Tarun; Gadkari, S. C.

    2018-05-01

    Thermal neutron imaging techniques such as radiography or tomography are very useful tool for various scientific investigations and industrial applications. Neutron radiography is complementary to X-ray radiography, as neutrons interact with nucleus as compared to X-ray interaction with orbital electrons. We present here design and development of a neutron imaging beamline at 100 MW Dhruva research reactor for neutron imaging applications such as radiography, tomography and phase contrast imaging. Combinations of sapphire and bismuth single crystals have been used as thermal neutron filter/gamma absorber at the input of a specially designed collimator to maximize thermal neutron to gamma ratio. The maximum beam size of neutrons has been restricted to ∼120 mm diameter at the sample position. A cadmium ratio of ∼250 with L / D ratio of 160 and thermal neutron flux of ∼ 4 × 107 n/cm2 s at the sample position has been measured. In this paper, different aspects of the beamline design such as collimator, shielding, sample manipulator, digital imaging system are described. Nondestructive radiography/tomography experiments on hydrogen concentration in Zr-alloy, aluminium foam, ceramic metal seals etc. are also presented.

  16. Microstructured boron foil scintillating G-GEM detector for neutron imaging

    Energy Technology Data Exchange (ETDEWEB)

    Fujiwara, Takeshi, E-mail: fujiwara-t@aist.go.jp [Research Institute for Measurement and Analytical Instrumentation, Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki (Japan); Center for Advanced Photonics, Neutron Beam Technology Team, RIKEN, Saitama (Japan); Bautista, Unico [Department of Nuclear Engineering and Management, The University of Tokyo, Tokyo (Japan); Philippine Nuclear Research Institute-Department of Science and Technology (PNRI-DOST), Commonwealth Avenue, Diliman, Quezon City (Philippines); Mitsuya, Yuki [Nuclear Professional School, The University of Tokyo, Tokai-mura, Naka-gun, Ibaraki (Japan); Takahashi, Hiroyuki [Department of Nuclear Engineering and Management, The University of Tokyo, Tokyo (Japan); Yamada, Norifumi L. [Neutron Science Laboratory, Institute of Material Structure Science, High Energy Accelerator Research Organization (KEK) (Japan); Otake, Yoshie; Taketani, Atsushi [Center for Advanced Photonics, Neutron Beam Technology Team, RIKEN, Saitama (Japan); Uesaka, Mitsuru [Nuclear Professional School, The University of Tokyo, Tokai-mura, Naka-gun, Ibaraki (Japan); Toyokawa, Hiroyuki [Research Institute for Measurement and Analytical Instrumentation, Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki (Japan)

    2016-12-01

    In this study, a new simple neutron imaging gaseous detector was successfully developed by combining a micro-structured {sup 10}B foil, a glass gas electron multiplier (G-GEM), and a mirror–lens–charge-coupled device (CCD)–camera system. The neutron imaging system consists of a chamber filled with Ar/CF{sub 4} scintillating gas mixture. Inside this system, the G-GEM is mounted for gas multiplication. The neutron detection in this system is based on the reaction between {sup 10}B and neutrons. A micro-structured {sup 10}B is developed to overcome the issue of low detection efficiency. Secondary electrons excite Ar/CF{sub 4} gas molecules, and high-yield visible photons are emitted from those excited gas molecules during the gas electron multiplication process in the G-GEM holes. These photons are easily detected by a mirror–lens–CCD–camera system. A neutron radiograph is then simply formed. We obtain the neutron images of different materials with a compact accelerator-driven neutron source. We confirm that the new scintillating G-GEM-based neutron imager works properly with low gamma ray sensitivity and exhibits a good performance as a new simple digital neutron imaging device.

  17. Understanding dynamic changes in live cell adhesion with neutron reflectometry

    Science.gov (United States)

    Junghans, Ann

    Understanding the structure and functionality of biological systems on a nanometer-resolution and short temporal scales is important for solving complex biological problems, developing innovative treatment, and advancing the design of highly functionalized biomimetic materials. For example, adhesion of cells to an underlying substrate plays a crucial role in physiology and disease development, and has been investigated with great interest for several decades. In the talk, we would like to highlight recent advances in utilizing neutron scattering to study bio-related structures in dynamic conditions (e . g . under the shear flow) including in-situ investigations of the interfacial properties of living cells. The strength of neutron reflectometry is its non-pertubative nature, the ability to probe buried interfaces with nanometer resolution and its sensitivity to light elements like hydrogen and carbon. That allows us to study details of cell - substrate interfaces that are not accessible with any other standard techniques. We studied the adhesion of human brain tumor cells (U251) to quartz substrates and their responses to the external mechanical forces. Such cells are isolated within the central nervous system which makes them difficult to reach with conventional therapies and therefore making them highly invasive. Our results reveal changes in the thickness and composition of the adhesion layer (a layer between the cell lipid membrane and the quartz substrate), largely composed of hyaluronic acid and associated proteoglycans, when the cells were subjected to shear stress. Further studies will allow us to determine more conditions triggering changes in the composition of the bio-material in the adhesion layer. This, in turn, can help to identify changes that correlate with tumor invasiveness, which can have significant medical impact for the development of targeted anti-invasive therapies.

  18. Overview of the Conceptual Design of the Future VENUS Neutron Imaging Beam Line at the Spallation Neutron Source

    Science.gov (United States)

    Bilheux, Hassina; Herwig, Ken; Keener, Scott; Davis, Larry

    VENUS (Versatile Neutron Imaging Beam line at the Spallation Neutron Source) will be a world-class neutron-imaging instrument that will uniquely utilize the Spallation Neutron Source (SNS) time-of-flight (TOF) capabilities to measure and characterize objects across several length scales (mm to μm). When completed, VENUS will provide academia, industry and government laboratories with the opportunity to advance scientific research in areas such as energy, materials, additive manufacturing, geosciences, transportation, engineering, plant physiology, biology, etc. It is anticipated that a good portion of the VENUS user community will have a strong engineering/industrial research focus. Installed at Beam line 10 (BL10), VENUS will be a 25-m neutron imaging facility with the capability to fully illuminate (i.e., umbra illumination) a 20 cm x 20 cm detector area. The design allows for a 28 cm x 28 cm field of view when using the penumbra to 80% of the full illumination flux. A sample position at 20 m will be implemented for magnification measurements. The optical components are comprised of a series of selected apertures, T0 and bandwidth choppers, beam scrapers, a fast shutter to limit sample activation, and flight tubes filled with Helium. Techniques such as energy selective, Bragg edge and epithermal imaging will be available at VENUS.

  19. Studies of molecular dynamics with neutron scattering techniques. Part of a coordinated programme on neutron scattering techniques

    International Nuclear Information System (INIS)

    Vinhas, L.A.

    1980-05-01

    Molecular dynamics was studied in samples of tert-butanol, cyclohexanol and methanol, using neutron inelastic and quasi-elastic techniques. The frequency spectra of cyclohexanol in crystalline phase were interpreted by assigning individual energy peaks to hindered rotation of molecules, lattice vibration, hydrogen bond stretching and ring bending modes. Neutron quasi-elastic scattering measurements permitted the testing of models for molecular diffusion as a function of temperature. The interpretation of neutron incoherent inelastic scattering on methanol indicated the different modes of molecular dynamics in this material; individual inelastic peaks in the spectra could be assigned to vibrations of crystalline lattice, stretching of hydrogen bond and vibrational and torsional modes of CH 3 OH molecule. The results of the experimental work on tertbutanol indicate two distinct modes of motion in this material: individual molecular librations are superposed to a cooperative rotation diffusion which occurs both in solid and in liquid state

  20. Passive and Active Fast-Neutron Imaging in Support of Advanced Fuel Cycle Initiative Safeguards Campaign

    International Nuclear Information System (INIS)

    Blackston, Matthew A.; Hausladen, Paul

    2010-01-01

    Results from safeguards-related passive and active coded-aperture fast-neutron imaging measurements of plutonium and highly enriched uranium (HEU) material configurations performed at Idaho National Laboratory s Zero Power Physics Reactor facility are presented. The imaging measurements indicate that it is feasible to use fast neutron imaging in a variety of safeguards-related tasks, such as monitoring storage, evaluating holdup deposits in situ, or identifying individual leached hulls still containing fuel. The present work also presents the first demonstration of imaging of differential die away fast neutrons.

  1. Progress toward the development and testing of source reconstruction methods for NIF neutron imaging.

    Science.gov (United States)

    Loomis, E N; Grim, G P; Wilde, C; Wilson, D C; Morgan, G; Wilke, M; Tregillis, I; Merrill, F; Clark, D; Finch, J; Fittinghoff, D; Bower, D

    2010-10-01

    Development of analysis techniques for neutron imaging at the National Ignition Facility is an important and difficult task for the detailed understanding of high-neutron yield inertial confinement fusion implosions. Once developed, these methods must provide accurate images of the hot and cold fuels so that information about the implosion, such as symmetry and areal density, can be extracted. One method under development involves the numerical inversion of the pinhole image using knowledge of neutron transport through the pinhole aperture from Monte Carlo simulations. In this article we present results of source reconstructions based on simulated images that test the methods effectiveness with regard to pinhole misalignment.

  2. Geant4 Analysis of a Thermal Neutron Real-Time Imaging System

    Science.gov (United States)

    Datta, Arka; Hawari, Ayman I.

    2017-07-01

    Thermal neutron imaging is a technique for nondestructive testing providing complementary information to X-ray imaging for a wide range of applications in science and engineering. Advancement of electronic imaging systems makes it possible to obtain neutron radiographs in real time. This method requires a scintillator to convert neutrons to optical photons and a charge-coupled device (CCD) camera to detect those photons. Alongside, a well collimated beam which reduces geometrical blurriness, the use of a thin scintillator can improve the spatial resolution significantly. A representative scintillator that has been applied widely for thermal neutron imaging is 6LiF:ZnS (Ag). In this paper, a multiphysics simulation approach for designing thermal neutron imaging system is investigated. The Geant4 code is used to investigate the performance of a thermal neutron imaging system starting with a neutron source and including the production of charged particles and optical photons in the scintillator and their transport for image formation in the detector. The simulation geometry includes the neutron beam collimator and sapphire filter. The 6LiF:ZnS (Ag) scintillator is modeled along with a pixelated detector for image recording. The spatial resolution of the system was obtained as the thickness of the scintillator screen was varied between 50 and 400 μm. The results of the simulation were compared to experimental results, including measurements performed using the PULSTAR nuclear reactor imaging beam, showing good agreement. Using the established model, further examination showed that the resolution contribution of the scintillator screen is correlated with its thickness and the range of the neutron absorption reaction products (i.e., the alpha and triton particles). Consequently, thinner screens exhibit improved spatial resolution. However, this will compromise detection efficiency due to the reduced probability of neutron absorption.

  3. Charge-dependent conformations and dynamics of pamam dendrimers revealed by neutron scattering and molecular dynamics

    Science.gov (United States)

    Wu, Bin

    Neutron scattering and fully atomistic molecular dynamics (MD) are employed to investigate the structural and dynamical properties of polyamidoamine (PAMAM) dendrimers with ethylenediamine (EDA) core under various charge conditions. Regarding to the conformational characteristics, we focus on scrutinizing density profile evolution of PAMAM dendrimers as the molecular charge of dendrimer increases from neutral state to highly charged condition. It should be noted that within the context of small angle neutron scattering (SANS), the dendrimers are composed of hydrocarbon component (dry part) and the penetrating water molecules. Though there have been SANS experiments that studied the charge-dependent structural change of PAMAM dendrimers, their results were limited to the collective behavior of the aforementioned two parts. This study is devoted to deepen the understanding towards the structural responsiveness of intra-molecular polymeric and hydration parts separately through advanced contrast variation SANS data analysis scheme available recently and unravel the governing principles through coupling with MD simulations. Two kinds of acids, namely hydrochloric and sulfuric acids, are utilized to tune the pH condition and hence the molecular charge. As far as the dynamical properties, we target at understanding the underlying mechanism that leads to segmental dynamic enhancement observed from quasielstic neutron scattering (QENS) experiment previously. PAMAM dendrimers have a wealth of potential applications, such as drug delivery agency, energy harvesting medium, and light emitting diodes. More importantly, it is regarded as an ideal system to test many theoretical predictions since dendrimers conjugate both colloid-like globular shape and polymer-like flexible chains. This Ph.D. research addresses two main challenges in studying PAMAM dendrimers. Even though neutron scattering is an ideal tool to study this PAMAM dendrimer solution due to its matching temporal and

  4. ICF ignition capsule neutron, gamma ray, and high energy x-ray images

    Science.gov (United States)

    Bradley, P. A.; Wilson, D. C.; Swenson, F. J.; Morgan, G. L.

    2003-03-01

    Post-processed total neutron, RIF neutron, gamma-ray, and x-ray images from 2D LASNEX calculations of burning ignition capsules are presented. The capsules have yields ranging from tens of kilojoules (failures) to over 16 MJ (ignition), and their implosion symmetry ranges from prolate (flattest at the hohlraum equator) to oblate (flattest towards the laser entrance hole). The simulated total neutron images emphasize regions of high DT density and temperature; the reaction-in-flight neutrons emphasize regions of high DT density; the gamma rays emphasize regions of high shell density; and the high energy x rays (>10 keV) emphasize regions of high temperature.

  5. Magnetic Resonance Imaging (MRI): Dynamic Pelvic Floor

    Science.gov (United States)

    ... to a CD or uploaded to a digital cloud server. Dynamic pelvic floor MRI provides detailed pictures ... with you. top of page What are the benefits vs. risks? Benefits MRI is a noninvasive imaging ...

  6. High Dynamic Range Imaging Using Multiple Exposures

    Science.gov (United States)

    Hou, Xinglin; Luo, Haibo; Zhou, Peipei; Zhou, Wei

    2017-06-01

    It is challenging to capture a high-dynamic range (HDR) scene using a low-dynamic range (LDR) camera. This paper presents an approach for improving the dynamic range of cameras by using multiple exposure images of same scene taken under different exposure times. First, the camera response function (CRF) is recovered by solving a high-order polynomial in which only the ratios of the exposures are used. Then, the HDR radiance image is reconstructed by weighted summation of the each radiance maps. After that, a novel local tone mapping (TM) operator is proposed for the display of the HDR radiance image. By solving the high-order polynomial, the CRF can be recovered quickly and easily. Taken the local image feature and characteristic of histogram statics into consideration, the proposed TM operator could preserve the local details efficiently. Experimental result demonstrates the effectiveness of our method. By comparison, the method outperforms other methods in terms of imaging quality.

  7. National array of neutron detectors (NAND) a versatile setup for studies on reaction dynamics

    International Nuclear Information System (INIS)

    Golda, K.S.; Singh, R.P.; Zacharias, J.; Archunan, M.; Kothari, A.; Barua, P.; Gupta, Arti; Venkataramanan, S.; Suman, S.K.; Kumar, Rajesh; Kumar, Pankaj; Jhingan, A.; Sugathan, P.; Datta, S.K.; Chatterjee, Mihir; Bhowmik, R.K.; Singh, Hardev; Behera, B.; Kumar, A.; Singh, G.; Ranjit; Mandal, S.

    2006-01-01

    National Array of Neutron Detectors (NAND) is a large array of neutron detectors being setup at Inter University Accelerator Centre. The primary motive behind the development of this array, is the study of reaction dynamics in the energy domain near the Coulomb barrier

  8. Neutron μstiX. Micrometer structure investigation with real space and reciprocal space crossover using neutron imaging detectors

    Energy Technology Data Exchange (ETDEWEB)

    Muehlbauer, Martin Johann

    2013-07-19

    This work is concerned with the investigation of inhomogeneities in materials with length scales of the order of micrometers by means of neutrons. In real space this is done by neutron imaging methods measuring the transmitted signal while for Ultra Small Angle Neutron Scattering (USANS) the signal of the scattered neutrons is assigned to a spatial frequency distribution in reciprocal space. The part about neutron imaging is focused on time-resolved neutron radiography on an injection nozzle similar to the ones used for modern diesel truck engines. The associated experiments have been carried out at the neutron imaging facility ANTARES at the Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II) of the Technische Universitaet Muenchen in Garching near Munich. Especially the demands on the detector system were high. Therefore different detection methods and detector configurations have been tested. On the one hand the detector should allow for a time resolution high enough to record the injection process lasting about 900 μs. On the other hand it needed to offer a spatial resolution sufficient to resolve the test oil inside the spray hole of a maximum diameter of less than 200 μm. An advanced aim of this work is the visualization of cavitation phenomena which may occur during the injection process inside of the spray hole. In order to operate the injector at conditions as close to reality as possible a high pressure pump supplying the injector with test oil at a pressure of 1600 bar was needed in addition to the specially developed control electronics, the recuperation tank and the exhaust gas equipment for the escaping atomized spray. A second part of the work describes USANS experiments based on the idea of Dr. Roland Gaehler and carried out at the instrument D11 at the Institut Laue-Langevin in Grenoble. For this purpose a specific multi-beam geometry was applied, where a multi-slit aperture replaced the standard source aperture and the sample aperture was

  9. Neutron μstiX. Micrometer structure investigation with real space and reciprocal space crossover using neutron imaging detectors

    International Nuclear Information System (INIS)

    Muehlbauer, Martin Johann

    2013-01-01

    This work is concerned with the investigation of inhomogeneities in materials with length scales of the order of micrometers by means of neutrons. In real space this is done by neutron imaging methods measuring the transmitted signal while for Ultra Small Angle Neutron Scattering (USANS) the signal of the scattered neutrons is assigned to a spatial frequency distribution in reciprocal space. The part about neutron imaging is focused on time-resolved neutron radiography on an injection nozzle similar to the ones used for modern diesel truck engines. The associated experiments have been carried out at the neutron imaging facility ANTARES at the Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II) of the Technische Universitaet Muenchen in Garching near Munich. Especially the demands on the detector system were high. Therefore different detection methods and detector configurations have been tested. On the one hand the detector should allow for a time resolution high enough to record the injection process lasting about 900 μs. On the other hand it needed to offer a spatial resolution sufficient to resolve the test oil inside the spray hole of a maximum diameter of less than 200 μm. An advanced aim of this work is the visualization of cavitation phenomena which may occur during the injection process inside of the spray hole. In order to operate the injector at conditions as close to reality as possible a high pressure pump supplying the injector with test oil at a pressure of 1600 bar was needed in addition to the specially developed control electronics, the recuperation tank and the exhaust gas equipment for the escaping atomized spray. A second part of the work describes USANS experiments based on the idea of Dr. Roland Gaehler and carried out at the instrument D11 at the Institut Laue-Langevin in Grenoble. For this purpose a specific multi-beam geometry was applied, where a multi-slit aperture replaced the standard source aperture and the sample aperture was

  10. A portable neutron spectroscope (NSPECT) for detection, imaging and identification of nuclear material

    Science.gov (United States)

    Ryan, James M.; Bancroft, Christopher; Bloser, Peter; Bravar, Ulisse; Fourguette, Dominique; Frost, Colin; Larocque, Liane; McConnell, Mark L.; Legere, Jason; Pavlich, Jane; Ritter, Greg; Wassick, Greg; Wood, Joshua; Woolf, Richard

    2010-08-01

    We have developed, fabricated and tested a prototype imaging neutron spectrometer designed for real-time neutron source location and identification. Real-time detection and identification is important for locating materials. These materials, specifically uranium and transuranics, emit neutrons via spontaneous or induced fission. Unlike other forms of radiation (e.g. gamma rays), penetrating neutron emission is very uncommon. The instrument detects these neutrons, constructs images of the emission pattern, and reports the neutron spectrum. The device will be useful for security and proliferation deterrence, as well as for nuclear waste characterization and monitoring. The instrument is optimized for imaging and spectroscopy in the 1-20 MeV range. The detection principle is based upon multiple elastic neutron-proton scatters in organic scintillator. Two detector panel layers are utilized. By measuring the recoil proton and scattered neutron locations and energies, the direction and energy spectrum of the incident neutrons can be determined and discrete and extended sources identified. Event reconstruction yields an image of the source and its location. The hardware is low power, low mass, and rugged. Its modular design allows the user to combine multiple units for increased sensitivity. We will report the results of laboratory testing of the instrument, including exposure to a calibrated Cf-252 source. Instrument parameters include energy and angular resolution, gamma rejection, minimum source identification distances and times, and projected effective area for a fully populated instrument.

  11. Conversion from film to image plates for transfer method neutron radiography of nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Craft, Aaron E.; Papaioannou, Glen C.; Chichester, David L.; Williams, Walter J.

    2017-02-01

    This paper summarizes efforts to characterize and qualify a computed radiography (CR) system for neutron radiography of irradiated nuclear fuel at Idaho National Laboratory (INL). INL has multiple programs that are actively developing, testing, and evaluating new nuclear fuels. Irradiated fuel experiments are subjected to a number of sequential post-irradiation examination techniques that provide insight into the overall behavior and performance of the fuel. One of the first and most important of these exams is neutron radiography, which provides more comprehensive information about the internal condition of irradiated nuclear fuel than any other non-destructive technique to date. Results from neutron radiography are often the driver for subsequent examinations of the PIE program. Features of interest that can be evaluated using neutron radiography include irradiation-induced swelling, isotopic and fuel-fragment redistribution, plate deformations, and fuel fracturing. The NRAD currently uses the foil-film transfer technique with film for imaging fuel. INL is pursuing multiple efforts to advance its neutron imaging capabilities for evaluating irradiated fuel and other applications, including conversion from film to CR image plates. Neutron CR is the current state-of-the-art for neutron imaging of highly-radioactive objects. Initial neutron radiographs of various types of nuclear fuel indicate that radiographs can be obtained of comparable image quality currently obtained using film. This paper provides neutron radiographs of representative irradiated fuel pins along with neutron radiographs of standards that informed the qualification of the neutron CR system for routine use. Additionally, this paper includes evaluations of some of the CR scanner parameters and their effects on image quality.

  12. Argentina: Overview of activities on Neutron Imaging (NI) and Cultural Heritage (CH) studies

    International Nuclear Information System (INIS)

    Sánchez, Fernando

    2012-01-01

    In Argentina there exists a community of researchers of national institutions involved in CH studies and also periodic congresses about the topic since 2007. A new group on neutron imaging is beginning at Bariloche Atomic Center (CNEA). The plan of this group is: - Characterize the facility: flux, doses, collimation, etc;. - Establish contact with CH researchers for offering neutron imaging; - Demonstrate capabilities of the technique with 2D imaging; - In the future, a 3D tomography improvement will be developed

  13. Dynamical theory of neutron diffraction. [One-body Schroedinger equation, review

    Energy Technology Data Exchange (ETDEWEB)

    Sears, V F [Atomic Energy of Canada Ltd., Chalk River, Ontario. Chalk River Nuclear Labs.

    1978-10-01

    We present a review of the dynamical theory of neutron diffraction by macroscopic bodies which provides the theoretical basis for the study of neutron optics. We consider both the theory of dispersion, in which it is shown that the coherent wave in the medium satisfies a macroscopic one-body Schroedinger equation, and the theory of reflection, refraction, and diffraction in which the above equation is solved for a number of special cases of interest. The theory is illustrated with the help of experimental results obtained over the past 10 years by a number of new techniques such as neutron gravity refractometry. Pendelloesung interference, and neutron interferometry.

  14. Optimisation of the neutron source based on gas dynamic trap for transmutation of radioactive wastes

    Science.gov (United States)

    Anikeev, Andrey V.

    2012-06-01

    The Budker Institute of Nuclear Physics in collaboration with the Russian and foreign organizations develop the project of 14 MeV neutron source, which can be used for fusion material studies and for other application. The projected neutron source of plasma type is based on the plasma Gas Dynamic Trap (GDT), which is a special magnetic mirror system for plasma confinement. Presented work continues the subject of development the GDT-based neutron source (GDT-NS) for hybrid fusion-fission reactors. The paper presents the results of recent numerical optimization of such neutron source for transmutation of the long-lives radioactive wastes in spent nuclear fuel.

  15. Neutron imaging of Zr-1%Nb fuel cladding material containing hydrogen

    International Nuclear Information System (INIS)

    Svab, E.; Meszaros, Gy.; Somogyvari, Z.; Balasko, M.; Koeroesi, F.

    2004-01-01

    Hydrogen distribution and hydride phases were analyzed in reactor fuel cladding pressure tube Zr-1%Nb material up to 13,300 ppm. From neutron diffraction measurements, formation of cubic δ-ZrH 2 and a small amount of tetragonal γ-ZrH was established. Texture effects were analyzed by imaging plate technique. From neutron radiography images a linear model was set up that adequately described the relationship between gray levels and nominal H-concentrations. The H-distribution was unveiled by 3D intensity histograms and fractal analysis of multilevel-segmented neutron radiography images

  16. A tilted fiber-optic plate coupled CCD detector for high resolution neutron imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jongyul; Cho, Gyuseong [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Kim, Jongyul; Hwy, Limchang; Kim, Taejoo; Lee, Kyehong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, Seungwook [Pusan National Univ., Pusan (Korea, Republic of)

    2013-05-15

    One of these efforts is that a tilted scintillator geometry and lens coupled CCD detector for neutron imaging system were used to improve spatial resolution in one dimension. The increased spatial resolution in one dimension was applied to fuel cell study. However, a lens coupled CCD detector has lower sensitivity than a fiber-optic plate coupled CCD detector due to light loss. In this research, a tilted detector using fiber-optic plate coupled CCD detector was developed to improve resolution and sensitivity. In addition, a tilted detector can prevent an image sensor from direct radiation damage. Neutron imaging has been used for fuel cell study, lithium ion battery study, and many scientific applications. High quality neutron imaging is demanded for more detailed studies of applications, and spatial resolution should be considered to get high quality neutron imaging. Therefore, there were many efforts to improve spatial resolution.

  17. Dynamic imaging of oropharyngeal swallowing

    International Nuclear Information System (INIS)

    Fanucci, A.; Cerro, P.; Diotallevi, P.; Metastasio, F.; Fanucci, E.

    1991-01-01

    Oropharyngeal swallowing is too fast and complex a motion for the human eye to seize its various phases and subsequently evaluate morphology and function of the anatomical structures involved. A chronological subdivision of the swallowing act is needed for e step-by-step analysis. Dinamic evaluation of oropharyngeal swallowing by means of fluoroscopic and US videorecording proved to be a reliable method. Echovideorecording allowed tongue movements to be depicted, together with bolus formation and propulsion. Fluorovideorecording (U-Matic Sony unit, 25-30 images/sec) demonstrated pharyngeal and esophageal phases. A series of chronological and morphological reference points, which characterize oropharyngeal swallowing, were employed to analyze videorecorded images. Slowmotion mode, 'freezed' images, and rewinding allowed an easy and accurate evaluation of swallowing details. Combined chronological and morphological pieces of information allow a comprehensive evaluation of the swallowing act

  18. Timing and position response of a block detector for fast neutron time-of-flight imaging

    Energy Technology Data Exchange (ETDEWEB)

    Laubach, M.A., E-mail: mlaubach@utk.edu [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Hayward, J.P., E-mail: jhayward@utk.edu [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Oak Ridge National Laboratory, 1 Bethel Valley Rd., Oak Ridge, TN 37831 (United States); Zhang, X., E-mail: xzhang39@utk.edu [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Cates, J.W., E-mail: jcates7@vols.utk.edu [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996 (United States)

    2014-11-01

    Our research effort seeks to improve the spatial and timing performance of a block detector made of a pixilated plastic scintillator (EJ-200), first demonstrated as part of Oak Ridge National Laboratory's Advanced Portable Neutron Imaging System. Improvement of the position and time response is necessary to achieve better resolution and contrast in the images of shielded special nuclear material. Time-of-flight is used to differentiate between gamma and different sources of neutrons (e.g., transmission and fission neutrons). Factors limiting the timing and position performance of the neutron detector have been revealed through simulations and measurements. Simulations have suggested that the degradation in the ability to resolve pixels in the neutron detector is due to those interactions occurring near the light guide. The energy deposition within the neutron detector is shown to affect position performance and imaging efficiency. This examination details how energy cuts improve the position performance and degrade the imaging efficiency. Measurements have shown the neutron detector to have a timing resolution of σ=238 ps. The majority of this timing uncertainty is from the depth-of-interaction (DOI) of the neutron which is confirmed by simulations and analytical calculations.

  19. Gamma–neutron imaging system utilizing pulse shape discrimination with CLYC

    International Nuclear Information System (INIS)

    Whitney, Chad M.; Soundara-Pandian, Lakshmi; Johnson, Erik B.; Vogel, Sam; Vinci, Bob; Squillante, Michael; Glodo, Jarek; Christian, James F.

    2015-01-01

    Recently, RMD has investigated the use of CLYC (Cs 2 LiYCl 6 :Ce), a new and emerging scintillation material, in a gamma–neutron coded aperture imaging system based on RMD's commercial RadCam TM instrument. CLYC offers efficient thermal neutron detection, fast neutron detection capabilities, excellent pulse shape discrimination (PSD), and gamma-ray energy resolution as good as 4% at 662 keV. PSD improves the isolation of higher energy gammas from thermal neutron interactions (>3 MeV electron equivalent peak), compared to conventional pulse height techniques. The scintillation emission time in CLYC provides the basis for PSD; where neutron interactions result in a slower emission rise and decay components while gamma interactions result in a faster emission components. By creating a population plot based on the ratio of the decay tail compared to the total integral amplitude (PSD ratio), discrimination of gammas, thermal neutrons, and fast neutrons is possible. Previously, we characterized the CLYC-based RadCam system for imaging gammas and neutrons using a layered W-Cd coded aperture mask and employing only pulse height discrimination. In this paper, we present the latest results which investigate gamma-neutron imaging capabilities using PSD. An FPGA system is used to acquire the CLYC–PSPMT last dynode signals, determine a PSD ratio for each event, and compare it to a calibrated PSD cutoff. Each event is assigned either a gamma (low) or neutron (high) flag signal which is then correlated with the imaging information for each event. - Highlights: • The latest results are presented for our CLYC RadCam-2 system which investigate gamma–neutron imaging using pulse shape discrimination. • CLYC RadCam-2 system successfully discriminates gammas, thermal neutrons, and fast neutrons by employing a fully integrated, FPGA-based PSD system. • Imaging of our 252 Cf source was possible using both pulse height and pulse shape discrimination with CLYC. • Imaging

  20. A Detector for 2-D Neutron Imaging for the Spallation Neutron Source

    International Nuclear Information System (INIS)

    Britton, Charles L. Jr.; Bryan, W.L.; Wintenberg, Alan Lee; Clonts, Lloyd G.; Warmack, Robert J. Bruce; McKnight, Timothy E.; Frank, Steven Shane; Cooper, Ronald G.; Dudney, Nancy J.; Veith, Gabriel M.

    2006-01-01

    We have designed, built, and tested a 2-D pixellated thermal neutron detector. The detector is modeled after the MicroMegas-type structure previously published for collider-type experiments. The detector consists of a 4X4 square array of 1 cm 2 pixels each of which is connected to an individual preamplifier-shaper-data acquisition system. The neutron converter is a 10B film on an aluminum substrate. We describe the construction of the detector and the test results utilizing 252Cf sources in Lucite to thermalize the neutrons. Drift electrode (Aluminum) Converter (10B) 3 mm Conversion gap neutron (-900 V)

  1. Development of a dynamic CT system for neutron radiography and consecutive visualization of three-dimensional water behavior in a PEFC stack

    International Nuclear Information System (INIS)

    Murakawa, Hideki; Hashimoto, Michinori; Sugimoto, Katsumi; Asano, Hitoshi; Takenaka, Nobuyuki; Mochiki, Koh-ichi; Yasuda, Ryo

    2011-01-01

    A dynamic CT system was developed for visualization of consecutive three-dimensional water behavior in a PEFC stack for neutron radiography. The system is composed of a neutron image intensifier and a C-MOS high speed video camera. An operating stack with three cells based on the Japan Automobile Research Institute standard was visualized using the neutron radiography system at a research reactor JRR-3 in Japan Atomic Energy Agency. The dynamic water behavior in channels in the operating PEFC stack was clearly visualized every 15 seconds by using the system. The water amount in each cell was evaluated by the CT reconstructed images. It was shown that a cell voltage decreased gradually when the water increased and increased rapidly when the water was evacuated. It was estimated that the power generation stopped when the channel of a cell was partly filled with the water because the air supply was blocked to a cell in the stack. (author)

  2. Neutron imaging with the short-pulse laser driven neutron source at the Trident laser facility

    Czech Academy of Sciences Publication Activity Database

    Guler, N.; Volegov, P.; Favalli, A.; Merrill, F.E.; Falk, Kateřina; Jung, D.; Tybo, J.L.; Wilde, C.H.; Croft, S.; Danly, C.; Deppert, O.; Devlin, M.; Fernandez, J.; Gautier, D.C.; Geissel, M.; Haight, R.; Hamilton, C.E.; Hegelich, B.M.; Henzlova, D.; Johnson, R. P.; Schaumann, G.; Schoenberg, K.; Schollmeier, M.; Shimada, T.; Swinhoe, M.T.; Taddeucci, T.; Wender, S.A.; Wurden, G.A.; Roth, M.

    2016-01-01

    Roč. 120, č. 15 (2016), s. 1-12, č. článku 154901. ISSN 0021-8979 R&D Projects: GA MŠk EF15_008/0000162 Grant - others:ELI Beamlines(XE) CZ.02.1.01/0.0/0.0/15_008/0000162 Institutional support: RVO:68378271 Keywords : inertial confinement fusion * ion-beams * plasma interactions * reconstruction * acceleration * dynamics * targets * images Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.068, year: 2016

  3. Neutron Imaging study of bubble behaviors in Nanofluid Through Engineered Orifices

    International Nuclear Information System (INIS)

    Seo, Seok Bin; Bang, In Cheol; Kim, Tae Joo

    2014-01-01

    Most studies focused on the change of surface parameters through deposited nanoparticles, while Vafaei and Wen firstly discussed modification of bubble dynamics by dispersed nanoparticles in fluid as well as deposited ones. The boiling mechanism, as an effective heat transfer mode, includes bubble generation, growth, departure, and coalescence. Therefore the change of bubble dynamics can lead to the change of boiling heat transfer condition. That is, not only surface characteristics but the dispersed nanoparticles would be the essential parameters of boiling mechanism in terms of bubble dynamics. For advanced visualization of opaque fluids, the neutron imaging technique is introduced. In the present study, the bubble dynamics in nanofluid through engineered orifices was studied. The main parameters of engineered orifices are size and geometry. Photographic analysis of bubble departure frequency and averaged bubble departure volume provides as follows: With increasing orifice diameter, averaged bubble departure volume increases, while bubble departure frequency decreases. The results are attributed to enhanced capillary force by increasing contact perimeter. Averaged bubble departure volume and bubble departure frequency remain similar for three different types of orifices. But edges of the triangle and square orifice produce small bubbles which interrupts bubble generation. The converged triple contact line due to the edge may be a reason for the emerged baby bubbles. Nanofluid shows less averaged bubble departure volume and higher bubble departure frequency. Considering little change in physical properties of the fluid, interaction between bubble interface and nanoparticles may be in charge of the results

  4. Structure and dynamics of nonaqueous electrolyte solutions by small angle neutron scattering, brownian dynamics and primitive model theories

    International Nuclear Information System (INIS)

    Kunz, W.; Turq, P.

    1990-01-01

    The study of electrolyte solutions by small angle neutron scattering (static) of quasi-elastic neutron scattering (dynamics) gives new perspectives to the primitive model of electrolytes, for both static and dynamic properties of those systems. Whereas all properties can be interpreted by brownian dynamics, integral equations cannot be used at the present time to get transport coefficients in all cases. As regards the choice of the potentials at the McMillan Mayer level, specific Gurney terms for solvation are not needed for tetraalkylammonium salts. (orig.)

  5. Monte Carlo simulation of grating-based neutron phase contrast imaging at CPHS

    International Nuclear Information System (INIS)

    Zhang Ran; Chen Zhiqiang; Huang Zhifeng; Xiao Yongshun; Wang Xuewu; Wie Jie; Loong, C.-K.

    2011-01-01

    Since the launching of the Compact Pulsed Hadron Source (CPHS) project of Tsinghua University in 2009, works have begun on the design and engineering of an imaging/radiography instrument for the neutron source provided by CPHS. The instrument will perform basic tasks such as transmission imaging and computerized tomography. Additionally, we include in the design the utilization of coded-aperture and grating-based phase contrast methodology, as well as the options of prompt gamma-ray analysis and neutron-energy selective imaging. Previously, we had implemented the hardware and data-analysis software for grating-based X-ray phase contrast imaging. Here, we investigate Geant4-based Monte Carlo simulations of neutron refraction phenomena and then model the grating-based neutron phase contrast imaging system according to the classic-optics-based method. The simulated experimental results of the retrieving phase shift gradient information by five-step phase-stepping approach indicate the feasibility of grating-based neutron phase contrast imaging as an option for the cold neutron imaging instrument at the CPHS.

  6. Active neutron and gamma-ray imaging of highly enriched uranium for treaty verification.

    Science.gov (United States)

    Hamel, Michael C; Polack, J Kyle; Ruch, Marc L; Marcath, Matthew J; Clarke, Shaun D; Pozzi, Sara A

    2017-08-11

    The detection and characterization of highly enriched uranium (HEU) presents a large challenge in the non-proliferation field. HEU has a low neutron emission rate and most gamma rays are low energy and easily shielded. To address this challenge, an instrument known as the dual-particle imager (DPI) was used with a portable deuterium-tritium (DT) neutron generator to detect neutrons and gamma rays from induced fission in HEU. We evaluated system response using a 13.7-kg HEU sphere in several configurations with no moderation, high-density polyethylene (HDPE) moderation, and tungsten moderation. A hollow tungsten sphere was interrogated to evaluate the response to a possible hoax item. First, localization capabilities were demonstrated by reconstructing neutron and gamma-ray images. Once localized, additional properties such as fast neutron energy spectra and time-dependent neutron count rates were attributed to the items. For the interrogated configurations containing HEU, the reconstructed neutron spectra resembled Watt spectra, which gave confidence that the interrogated items were undergoing induced fission. The time-dependent neutron count rate was also compared for each configuration and shown to be dependent on the neutron multiplication of the item. This result showed that the DPI is a viable tool for localizing and confirming fissile mass and multiplication.

  7. Bulk magnetic domain structures visualized by neutron dark-field imaging

    International Nuclear Information System (INIS)

    Gruenzweig, C.; David, C.; Bunk, O.; Dierolf, M.; Frei, G.; Kuehne, G.; Schaefer, R.; Pofahl, S.; Roennow, H. M. R.; Pfeiffer, F.

    2008-01-01

    We report on how a neutron grating interferometer can yield projection images of the internal domain structure in bulk ferromagnetic samples. The image contrast relies on the ultrasmall angle scattering of unpolarized neutrons at domain wall structures in the specimen. The results show the basic domains of (110)-oriented sheets in an FeSi test sample. The obtained domain structures could be correlated with surface sensitive magneto-optical Kerr effect micrographs

  8. Bulk magnetic domain structures visualized by neutron dark-field imaging

    Science.gov (United States)

    Grünzweig, C.; David, C.; Bunk, O.; Dierolf, M.; Frei, G.; Kühne, G.; Schäfer, R.; Pofahl, S.; Rønnow, H. M. R.; Pfeiffer, F.

    2008-09-01

    We report on how a neutron grating interferometer can yield projection images of the internal domain structure in bulk ferromagnetic samples. The image contrast relies on the ultrasmall angle scattering of unpolarized neutrons at domain wall structures in the specimen. The results show the basic domains of (110)-oriented sheets in an FeSi test sample. The obtained domain structures could be correlated with surface sensitive magneto-optical Kerr effect micrographs.

  9. Russia: Overview of activities on Neutron Imaging (NI) and Cultural Heritage (CH) studies

    International Nuclear Information System (INIS)

    Kozlenko, Denis

    2012-01-01

    The development of neutron imaging techniques as a tool for non-destructive analysis of the internal structure, defects and processes in industrial products, functional materials, objects of cultural heritage attracts considerable attention at the present time. The dedicated instruments are available at the many neutron sources. The IBR-2M high flux pulsed reactor is one of the most powerful pulsed neutron sources in the world with the average power 2 MW, power per neutron pulse 1850 MW and neutron flux in pulse of 5·10 15 n/cm 2 /s. During the period December 2006 – December 2010 the reactor was on modernization for replacement of the reactor vessel and fuel elements. During 2011, the successful physical and power start-up of IBR-2M were performed. Now reactor is operational and can be used for research and development activities using neutron scattering techniques in next 25 years prospective. However, no instruments dedicated for neutron imaging is installed at IBR-2M so far. Moreover, in Russian Federation there is no dedicated neutron imaging facility for cultural heritage research at the moment

  10. Neutron radiography, techniques and applications

    International Nuclear Information System (INIS)

    Domanus, J.C.

    1987-10-01

    After describing the principles of the ''in pool'' and ''dry'' installations, techniques used in neutron radiography are reviewed. Use of converter foils with silver halide films for the direct and transfer methods is described. Advantages of the use of nitrocellulose film for radiographying radioactive objects are discussed. Dynamic imaging is shortly reviewed. Standardization in the field of neutron radiography (ASTM and Euratom Neutron Radiography Working Group) is described. The paper reviews main fields of use of neutron radiography. Possibilities of use of neutron radiography at research reactors in various scientific, industrial and other fields are mentioned. Examples are given of application of neutron radiography in industry and the nuclear field. (author)

  11. Understanding synthesis imaging dynamic range

    Science.gov (United States)

    Braun, R.

    2013-03-01

    We develop a general framework for quantifying the many different contributions to the noise budget of an image made with an array of dishes or aperture array stations. Each noise contribution to the visibility data is associated with a relevant correlation timescale and frequency bandwidth so that the net impact on a complete observation can be assessed when a particular effect is not captured in the instrumental calibration. All quantities are parameterised as function of observing frequency and the visibility baseline length. We apply the resulting noise budget analysis to a wide range of existing and planned telescope systems that will operate between about 100 MHz and 5 GHz to ascertain the magnitude of the calibration challenges that they must overcome to achieve thermal noise limited performance. We conclude that calibration challenges are increased in several respects by small dimensions of the dishes or aperture array stations. It will be more challenging to achieve thermal noise limited performance using 15 m class dishes rather than the 25 m dishes of current arrays. Some of the performance risks are mitigated by the deployment of phased array feeds and more with the choice of an (alt,az,pol) mount, although a larger dish diameter offers the best prospects for risk mitigation. Many improvements to imaging performance can be anticipated at the expense of greater complexity in calibration algorithms. However, a fundamental limitation is ultimately imposed by an insufficient number of data constraints relative to calibration variables. The upcoming aperture array systems will be operating in a regime that has never previously been addressed, where a wide range of effects are expected to exceed the thermal noise by two to three orders of magnitude. Achieving routine thermal noise limited imaging performance with these systems presents an extreme challenge. The magnitude of that challenge is inversely related to the aperture array station diameter.

  12. Quantum dynamic imaging theoretical and numerical methods

    CERN Document Server

    Ivanov, Misha

    2011-01-01

    Studying and using light or "photons" to image and then to control and transmit molecular information is among the most challenging and significant research fields to emerge in recent years. One of the fastest growing areas involves research in the temporal imaging of quantum phenomena, ranging from molecular dynamics in the femto (10-15s) time regime for atomic motion to the atto (10-18s) time scale of electron motion. In fact, the attosecond "revolution" is now recognized as one of the most important recent breakthroughs and innovations in the science of the 21st century. A major participant in the development of ultrafast femto and attosecond temporal imaging of molecular quantum phenomena has been theory and numerical simulation of the nonlinear, non-perturbative response of atoms and molecules to ultrashort laser pulses. Therefore, imaging quantum dynamics is a new frontier of science requiring advanced mathematical approaches for analyzing and solving spatial and temporal multidimensional partial differ...

  13. Characterization of the Annular Core Research Reactor (ACRR Neutron Radiography System Imaging Plane

    Directory of Open Access Journals (Sweden)

    Kaiser Krista

    2016-01-01

    Full Text Available The Annular Core Research Reactor (ACRR at Sandia National Laboratories (SNL is an epithermal pool-type research reactor licensed up to a thermal power of 2.4 MW. The ACRR facility has a neutron radiography facility that is used for imaging a wide range of items including reactor fuel and neutron generators. The ACRR neutron radiography system has four apertures (65:1, 125:1, 250:1, and 500:1 available to experimenters. The neutron flux and spectrum as well as the gamma dose rate were characterized at the imaging plane for the ACRR's neutron radiography system for the 65:1, 125:1 and 250:1 apertures.

  14. Spin dynamics above the Curie temperature studied by neutron scattering

    International Nuclear Information System (INIS)

    Steinsvoll, O.; Riste, T.

    1986-01-01

    Neutron scattering can in principle give information about magnetic fluctuations over the entire atomic space and time domain. The weakness of the neutron-matter interaction renders this information undistorted by the neutron probe, but at the same time puts intensity limitations on the method. A considerable number of studies on the magnetism of 3d metals have been performed at some of the larger reactor laboratories. In the regions of overlap the experimental results from the different laboratories are consistent, but the interpretations are along different lines. Among the controversial issues are itinerancy versus localization, the degree of order above T C . In our talk we shall give an introduction to the neutron scattering method, including some of the sophisticated polarized beam methods. In the rest of the talk we shall review recent experimental results and some of the theoretical models used in their interpretation. (orig.)

  15. Dynamic properties of electrons in solids by neutron scattering

    International Nuclear Information System (INIS)

    Lovesey, S.W.

    1980-12-01

    Illustrative cases of the use of neutron scattering in the study of the electronic properties of materials discussed here include scattering by localised electrons, narrow band materials and electron plasmas. (U.K.)

  16. A new method by steering kernel-based Richardson–Lucy algorithm for neutron imaging restoration

    International Nuclear Information System (INIS)

    Qiao, Shuang; Wang, Qiao; Sun, Jia-ning; Huang, Ji-peng

    2014-01-01

    Motivated by industrial applications, neutron radiography has become a powerful tool for non-destructive investigation techniques. However, resulted from a combined effect of neutron flux, collimated beam, limited spatial resolution of detector and scattering, etc., the images made with neutrons are degraded severely by blur and noise. For dealing with it, by integrating steering kernel regression into Richardson–Lucy approach, we present a novel restoration method in this paper, which is capable of suppressing noise while restoring details of the blurred imaging result efficiently. Experimental results show that compared with the other methods, the proposed method can improve the restoration quality both visually and quantitatively

  17. Dynamic metamaterial aperture for microwave imaging

    International Nuclear Information System (INIS)

    Sleasman, Timothy; Imani, Mohammadreza F.; Gollub, Jonah N.; Smith, David R.

    2015-01-01

    We present a dynamic metamaterial aperture for use in computational imaging schemes at microwave frequencies. The aperture consists of an array of complementary, resonant metamaterial elements patterned into the upper conductor of a microstrip line. Each metamaterial element contains two diodes connected to an external control circuit such that the resonance of the metamaterial element can be damped by application of a bias voltage. Through applying different voltages to the control circuit, select subsets of the elements can be switched on to create unique radiation patterns that illuminate the scene. Spatial information of an imaging domain can thus be encoded onto this set of radiation patterns, or measurements, which can be processed to reconstruct the targets in the scene using compressive sensing algorithms. We discuss the design and operation of a metamaterial imaging system and demonstrate reconstructed images with a 10:1 compression ratio. Dynamic metamaterial apertures can potentially be of benefit in microwave or millimeter wave systems such as those used in security screening and through-wall imaging. In addition, feature-specific or adaptive imaging can be facilitated through the use of the dynamic aperture

  18. Dynamic metamaterial aperture for microwave imaging

    Energy Technology Data Exchange (ETDEWEB)

    Sleasman, Timothy; Imani, Mohammadreza F.; Gollub, Jonah N.; Smith, David R. [Center for Metamaterials and Integrated Plasmonics, Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina, 27708 (United States)

    2015-11-16

    We present a dynamic metamaterial aperture for use in computational imaging schemes at microwave frequencies. The aperture consists of an array of complementary, resonant metamaterial elements patterned into the upper conductor of a microstrip line. Each metamaterial element contains two diodes connected to an external control circuit such that the resonance of the metamaterial element can be damped by application of a bias voltage. Through applying different voltages to the control circuit, select subsets of the elements can be switched on to create unique radiation patterns that illuminate the scene. Spatial information of an imaging domain can thus be encoded onto this set of radiation patterns, or measurements, which can be processed to reconstruct the targets in the scene using compressive sensing algorithms. We discuss the design and operation of a metamaterial imaging system and demonstrate reconstructed images with a 10:1 compression ratio. Dynamic metamaterial apertures can potentially be of benefit in microwave or millimeter wave systems such as those used in security screening and through-wall imaging. In addition, feature-specific or adaptive imaging can be facilitated through the use of the dynamic aperture.

  19. Super-resolution processing for pulsed neutron imaging system using a high-speed camera

    International Nuclear Information System (INIS)

    Ishizuka, Ken; Kai, Tetsuya; Shinohara, Takenao; Segawa, Mariko; Mochiki, Koichi

    2015-01-01

    Super-resolution and center-of-gravity processing improve the resolution of neutron-transmitted images. These processing methods calculate the center-of-gravity pixel or sub-pixel of the neutron point converted into light by a scintillator. The conventional neutron-transmitted image is acquired using a high-speed camera by integrating many frames when a transmitted image with one frame is not provided. It succeeds in acquiring the transmitted image and calculating a spectrum by integrating frames of the same energy. However, because a high frame rate is required for neutron resonance absorption imaging, the number of pixels of the transmitted image decreases, and the resolution decreases to the limit of the camera performance. Therefore, we attempt to improve the resolution by integrating the frames after applying super-resolution or center-of-gravity processing. The processed results indicate that center-of-gravity processing can be effective in pulsed-neutron imaging with a high-speed camera. In addition, the results show that super-resolution processing is effective indirectly. A project to develop a real-time image data processing system has begun, and this system will be used at J-PARC in JAEA. (author)

  20. Non destructive testing and neutron radiography in 1994

    International Nuclear Information System (INIS)

    Bayon, G.

    1994-01-01

    Neutron radiography has been considered for a long time as a promising technique; however it plays a minor part in the world of non destructive testing today, due to the lack of suitable neutron sources and lack of new industrial applications. This paper reviews the present status of neutron sources, neutron radiography activities, especially in France (such as the neutron-capture-issued secondary radiation spectrometry), in nuclear, aerospace, aeronautical and metallurgical sectors, and the last applications of neutron dynamic imaging. 9 refs

  1. Cf-252 based neutron radiography using real-time image processing system

    International Nuclear Information System (INIS)

    Mochiki, Koh-ichi; Koiso, Manabu; Yamaji, Akihiro; Iwata, Hideki; Kihara, Yoshitaka; Sano, Shigeru; Murata, Yutaka

    2001-01-01

    For compact Cf-252 based neutron radiography, a real-time image processing system by particle counting technique has been developed. The electronic imaging system consists of a supersensitive imaging camera, a real-time corrector, a real-time binary converter, a real-time calculator for centroid, a display monitor and a computer. Three types of accumulated NR image; ordinary, binary and centroid images, can be observed during a measurement. Accumulated NR images were taken by the centroid mode, the binary mode and ordinary mode using of Cf-252 neutron source and those images were compared. The centroid mode presented the sharpest image and its statistical characteristics followed the Poisson distribution, while the ordinary mode showed the smoothest image as the averaging effect by particle bright spots with distributed brightness was most dominant. (author)

  2. Trends in X-, gamma and neutron radiographic imaging at IGCAR Kalpakkam

    International Nuclear Information System (INIS)

    Venkatraman, B.; Raghu, N.; Menaka, M.; Anandraj, R.

    2015-01-01

    In the nuclear fuel cycle, right from raw material stage through fabrication and in service inspection upto the retirement of the component, NDE is an indispensable tool. While X- and gamma radiography is quite common, neutron radiography is a very efficient and complementary tool which can enhance investigations in the field of non-destructive testing as well as in many fundamental research applications. The main advantage of neutrons compared to X-rays is its ability to penetrate heavy elements and also image light elements (i.e. with low atomic numbers) such as hydrogen, water, carbon etc. This is because, neutrons interact with the nucleus rather than with the outer electron in the shell. This also makes it possible to distinguish between different isotopes of the same element by neutron radiography. The KAMINI reactor at IGCAR is a versatile and unique facility wherein extensive work has been undertaken on neutron radiography and activation analysis. Apart from conventional neutron radiography using transfer technique, real time neutron imaging of fuel pins and other objects have also been carried out. Using Beam purity indicator and sensitivity indicator, the neutron beam from KAMINI has also been characterized. This paper focuses on the developments and applications of digital imaging NDE using X-, gamma and neutrons at IGCAR. Both 2-dimensional imaging and -D tomography has been undertaken. Case studies undertaken for strategic and core industries including societal applications such as in cultural heritage is also highlighted. Advanced image processing and analysis has also been applied for enhancing the sensitivity and better defect quantification

  3. Gd-DTPA-enhanced dynamic MR imaging

    International Nuclear Information System (INIS)

    Frank, J.A.; Choyke, P.L.; Carvlin, M.; Inscoe, S.; Austin, H.; Dwyer, A.J.; Girton, M.; Black, J.

    1988-01-01

    This paper describes dynamic enhanced renal MR imaging, a new method of identifying specific derangements in renal function. Various diuretics were employed in 45 animal experiments to demonstrate the effects on the normal renal enhancement pattern (EP) after Gd-DTPA. Since different diuretics, osmotic (O), carbonic anhydrase (CA), and loop (L), are active at different sites, specific EP alterations are observed. Imaging was performed with 32 5.1-second sequential gradient recalled acquisition in a steady state images following a bolus of Gd-DTPA

  4. Women's preferences of dynamic spectral imaging colposcopy

    NARCIS (Netherlands)

    Louwers, J.A.; Zaal, Afra; Kocken, M.; Papagiannakis, E.; Meijer, C.J.; Verheijen, RHM

    2015-01-01

    Background: The focus of testing the dynamic spectral imaging (DSI) colposcope has been on the technical characteristics and clinical performance. However, aspects from a patient’s perspective are just as important. Methods: This study was designed as a substudy of the DSI validation study, a

  5. Neutron imaging development for megajoule scale inertial confinement fusion experiments{sup 1}

    Energy Technology Data Exchange (ETDEWEB)

    Grim, G P; Bradley, P A; Day, R D; Clark, D D; Fatherley, V E; Finch, J P; Garcia, F P; Jaramillo, S A; Montoya, A J; Morgan, G L; Oertel, J A; Ortiz, T A; Payton, J R; Pazuchanics, P; Schmidt, D W; Valdez, A C; Wilde, C H; Wilke, M D; Wilson, D C [Los Alamos National Laboratory, PO Box 1663, Los Alamos, NM 87545 (United States)], E-mail: gpgrim@lanl.gov

    2008-05-15

    Neutron imaging of Inertial Confinement Fusion (ICF) targets is useful for understanding the implosion conditions of deuterium and tritium filled targets at Mega-Joule/Tera-Watt scale laser facilities. The primary task for imaging ICF targets at the National Ignition Facility, Lawrence Livermore National Laboratory, Livermore CA, is to determine the asymmetry of the imploded target. The image data, along with other nuclear information, are to be used to provide insight into target drive conditions. The diagnostic goal at the National Ignition Facility is to provide neutron images with 10 {mu}m resolution and peak signal-to-background values greater than 20 for neutron yields of {approx} 10{sup 15}. To achieve this requires signal multiplexing apertures with good resolution. In this paper we present results from imaging system development efforts aimed at achieving these requirements using neutron pinholes. The data were collected using directly driven ICF targets at the Omega Laser, University of Rochester, Rochester, NY., and include images collected from a 3 x 3 array of 15.5 {mu}m pinholes. Combined images have peak signal-to-background values greater than 30 at neutron yields of {approx} 10{sup 13}.

  6. A novel approach to correct the coded aperture misalignment for fast neutron imaging

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, F. N.; Hu, H. S., E-mail: huasi-hu@mail.xjtu.edu.cn; Wang, D. M.; Jia, J. [School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Zhang, T. K. [Laser Fusion Research Center, CAEP, Mianyang, 621900 Sichuan (China); Jia, Q. G. [Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China)

    2015-12-15

    Aperture alignment is crucial for the diagnosis of neutron imaging because it has significant impact on the coding imaging and the understanding of the neutron source. In our previous studies on the neutron imaging system with coded aperture for large field of view, “residual watermark,” certain extra information that overlies reconstructed image and has nothing to do with the source is discovered if the peak normalization is employed in genetic algorithms (GA) to reconstruct the source image. Some studies on basic properties of residual watermark indicate that the residual watermark can characterize coded aperture and can thus be used to determine the location of coded aperture relative to the system axis. In this paper, we have further analyzed the essential conditions for the existence of residual watermark and the requirements of the reconstruction algorithm for the emergence of residual watermark. A gamma coded imaging experiment has been performed to verify the existence of residual watermark. Based on the residual watermark, a correction method for the aperture misalignment has been studied. A multiple linear regression model of the position of coded aperture axis, the position of residual watermark center, and the gray barycenter of neutron source with twenty training samples has been set up. Using the regression model and verification samples, we have found the position of the coded aperture axis relative to the system axis with an accuracy of approximately 20 μm. Conclusively, a novel approach has been established to correct the coded aperture misalignment for fast neutron coded imaging.

  7. Deriving Quantitative Crystallographic Information from the Wavelength-Resolved Neutron Transmission Analysis Performed in Imaging Mode

    Directory of Open Access Journals (Sweden)

    Hirotaka Sato

    2017-12-01

    Full Text Available Current status of Bragg-edge/dip neutron transmission analysis/imaging methods is presented. The method can visualize real-space distributions of bulk crystallographic information in a crystalline material over a large area (~10 cm with high spatial resolution (~100 μm. Furthermore, by using suitable spectrum analysis methods for wavelength-dependent neutron transmission data, quantitative visualization of the crystallographic information can be achieved. For example, crystallographic texture imaging, crystallite size imaging and crystalline phase imaging with texture/extinction corrections are carried out by the Rietveld-type (wide wavelength bandwidth profile fitting analysis code, RITS (Rietveld Imaging of Transmission Spectra. By using the single Bragg-edge analysis mode of RITS, evaluations of crystal lattice plane spacing (d-spacing relating to macro-strain and d-spacing distribution’s FWHM (full width at half maximum relating to micro-strain can be achieved. Macro-strain tomography is performed by a new conceptual CT (computed tomography image reconstruction algorithm, the tensor CT method. Crystalline grains and their orientations are visualized by a fast determination method of grain orientation for Bragg-dip neutron transmission spectrum. In this paper, these imaging examples with the spectrum analysis methods and the reliabilities evaluated by optical/electron microscope and X-ray/neutron diffraction, are presented. In addition, the status at compact accelerator driven pulsed neutron sources is also presented.

  8. Demonstration of Focusing Wolter Mirrors for Neutron Phase and Magnetic Imaging

    Directory of Open Access Journals (Sweden)

    Daniel S. Hussey

    2018-03-01

    Full Text Available Image-forming focusing mirrors were employed to demonstrate their applicability to two different modalities of neutron imaging, phase imaging with a far-field interferometer, and magnetic-field imaging through the manipulation of the neutron beam polarization. For the magnetic imaging, the rotation of the neutron polarization in the magnetic field was measured by placing a solenoid at the focus of the mirrors. The beam was polarized upstream of the solenoid, while the spin analyzer was situated between the solenoid and the mirrors. Such a polarized neutron microscope provides a path toward considerably improved spatial resolution in neutron imaging of magnetic materials. For the phase imaging, we show that the focusing mirrors preserve the beam coherence and the path-length differences that give rise to the far-field moiré pattern. We demonstrated that the visibility of the moiré pattern is modified by small angle scattering from a highly porous foam. This experiment demonstrates the feasibility of using Wolter optics to significantly improve the spatial resolution of the far-field interferometer.

  9. Phenylene ring dynamics in bisphenol-A-polysulfone by neutron scattering

    International Nuclear Information System (INIS)

    Arrese-Igor, S.; Arbe, A.; Alegria, A.; Colmenero, J.; Frick, B.

    2004-01-01

    We have investigated the dynamics of phenylene rings in a glassy polysulfone (bisphenol-A-polysulfone) by means of quasielastic neutron scattering. Nowadays it is well known that these molecular motions are directly connected with the mechanical properties of engineering thermoplastics in general. The particular system investigated by us has the advantage that by selective deuteration of the methyl groups, the neutron scattering measured is dominated by the incoherent contribution from the protons in the phenylene rings. In this way, the dynamics of such molecular groups can be experimentally isolated. Two different types of neutron spectrometers: time of flight and backscattering, were used in order to cover a wide dynamic range, which extends from microscopic (10 -13 s) to mesoscopic (10 -9 s) times. Moreover, neutron diffraction experiments with polarization analysis were also carried out in order to characterize the structural features of the sample investigated. Fast oscillations of increasing amplitude with temperature and π-flips are identified for phenylene rings motions. Due to the structural disorder characteristic of the amorphous state, both molecular motions display a broad distribution of relaxation times, which spreads over several orders of magnitude. Based on the results obtained, we propose a model for phenylene rings dynamics, which combines the two kinds of molecular motions identified. This model nicely describes the neutron scattering results in the whole dynamic range investigated

  10. Dynamic high resolution imaging of rats

    International Nuclear Information System (INIS)

    Miyaoka, R.S.; Lewellen, T.K.; Bice, A.N.

    1990-01-01

    A positron emission tomography with the sensitivity and resolution to do dynamic imaging of rats would be an invaluable tool for biological researchers. In this paper, the authors determine the biological criteria for dynamic positron emission imaging of rats. To be useful, 3 mm isotropic resolution and 2-3 second time binning were necessary characteristics for such a dedicated tomograph. A single plane in which two objects of interest could be imaged simultaneously was considered acceptable. Multi-layered detector designs were evaluated as a possible solution to the dynamic imaging and high resolution imaging requirements. The University of Washington photon history generator was used to generate data to investigate a tomograph's sensitivity to true, scattered and random coincidences for varying detector ring diameters. Intrinsic spatial uniformity advantages of multi-layered detector designs over conventional detector designs were investigated using a Monte Carlo program. As a result, a modular three layered detector prototype is being developed. A module will consist of a layer of five 3.5 mm wide crystals and two layers of six 2.5 mm wide crystals. The authors believe adequate sampling can be achieved with a stationary detector system using these modules. Economical crystal decoding strategies have been investigated and simulations have been run to investigate optimum light channeling methods for block decoding strategies. An analog block decoding method has been proposed and will be experimentally evaluated to determine whether it can provide the desired performance

  11. On determination of the dynamics of hydrocarbon molecules on catalyst's surfaces by means of neutron scattering

    International Nuclear Information System (INIS)

    Stockmeyer, R.

    1976-01-01

    The intensity distribution of slow neutrons scattered by adsorbed hydrocarbon molecules contains information on the dynamics of the molecules. In this paper the scattering law for incoherently scattering molecules is derived taking into account the very different mobility perpendicular and parallel to the surface. In contrast to the well known scattering law of threedimensionally diffusing particles the scattering law for twodimensional diffusion diverges logarithmically at zero energy transfer. Conclusions relevant to the interpretation of neutron scattering data are discussed. (orig.) [de

  12. Dynamic MR imaging of the sellar region

    International Nuclear Information System (INIS)

    Takahashi, M.; Sakamoto, Y.; Korogi, Y.; Nishimura, R.; Yoshizumi, K.; Ushio, Y.

    1990-01-01

    This paper reports on sequential and differential enhancement of the normal and abnormal structures of the sellar regions were evaluated with dynamic MR imaging for the diagnosis of sellar and parasellar tumors. Dynamic MR imaging was performed on a 1.5-T superconductive unit, with rapid injection of Gd-DTPA (0.1 mmol/kg body weight) followed by serial spin-echo (TR 220/TE 15 msec) images of the sellar region for 3-5 minutes. The first structures visualized were the cavernous sinus, infundibulum, and posterior pituitary lobe within 30 seconds, followed by enhancement of the anterior pituitary lobe near the infundibulum in 50 seconds and the peripheral portion of the anterior pituitary lobe in 80 seconds

  13. Dynamic Image Stitching for Panoramic Video

    Directory of Open Access Journals (Sweden)

    Jen-Yu Shieh

    2014-10-01

    Full Text Available The design of this paper is based on the Dynamic image titching for panoramic video. By utilizing OpenCV visual function data library and SIFT algorithm as the basis for presentation, this article brings forward Gaussian second differenced MoG which is processed basing on DoG Gaussian Difference Map to reduce order in synthesizing dynamic images and simplify the algorithm of the Gaussian pyramid structure. MSIFT matches with overlapping segmentation method to simplify the scope of feature extraction in order to enhance speed. And through this method traditional image synthesis can be improved without having to take lots of time in calculation and being limited by space and angle. This research uses four normal Webcams and two IPCAM coupled with several-wide angle lenses. By using wide-angle lenses to monitor over a wide range of an area and then by using image stitching panoramic effect is achieved. In terms of overall image application and control interface, Microsoft Visual Studio C# is adopted to a construct software interface. On a personal computer with 2.4-GHz CPU and 2-GB RAM and with the cameras fixed to it, the execution speed is three images per second, which reduces calculation time of the traditional algorithm.

  14. Thailand: Overview of activities on Neutron Imaging (NI) and Cultural Heritage (CH) studies

    International Nuclear Information System (INIS)

    Khaweerat, Sasiphan

    2012-01-01

    Undoubtedly, neutron imaging is one of the best investigation techniques for cultural heritage researches. Cultural heritage is what we obtain from the past and pass on to future generation. It contains unique and irreplaceable record that is important to fulfill our understanding about the past. Recently, many cultural heritages remain untouched and historical records are ambiguous because scientific method of proof is difficult to make without destruction. Fortunately, the neutron imaging technique allows property of neutron that can penetrate through object providing non-invasive characterization. The intensity of transmitting neutron varies upon neutron flux at exposing position and elemental composition in particular objects. Consequently, the object’s provenance, manufacturing technology, authentication, and hidden structure can be determined. To achieve a high quality image and further service for cultural heritage research, good facility and practice are of significant concerns.This CRP provides great opportunity to develop neutron facility and to standardize methodology in Thailand. After official meeting between Thailand Institute of Nuclear Technology (TINT) and Office of National Museum (ONM), Fine Arts Department on 24th January 2011, we are agreed to collaborate in CRP- F11018. With supporting from IAEA, the neutron imaging technology will be sustainable developed and the strengthen collaboration between TINT and ONM will be established. TINT scientists will work in an appropriate channel to meet the state-of-the-art end user’s requirements. Since the hidden historical records will be revealed, we strongly believe that the adapted neutron imaging technique will help answer questions regarding ancient Thais

  15. Switzerland: Overview of activities on Neutron Imaging (NI) and Cultural Heritage (CH) studies - Paul Scherrer Institut

    International Nuclear Information System (INIS)

    Mannes, David

    2012-01-01

    Historical bronze objects play an important rule in cultural heritage research as this material was used for a broad variety of different purposes (tools, weapons, jewellery, cult objects,…) since more than 5000 years in most parts of the world (Africa, Asia, Europe). Furthermore this group of copper alloys shows high durability and has low susceptibility for corrosion, which explains the large number of objects, which have stand the test of time and wait to be studied. For the study of cultural heritage objects non-destructive testing methods are in many cases required and generally preferred. Neutron imaging provides a unique opportunity to thoroughly characterize bronze objects and to provide information on the inner structure also from larger objects while other conventional methods such as X-ray methods are restricted to surface regions of such metal objects. In the scope of this CRP we propose an interdisciplinary platform for non-destructive investigations of historical bronze objects using neutrons. The platform will provide a forum and link users from the cultural heritage area with partners from the neutron imaging community. As outcome we anticipate a document listing the possibilities and limitations of neutron imaging (such as neutron-radiography, -tomography, energy selective imaging,…) and other neutron based techniques (e.g. diffraction, PGAA,...) to investigate certain questions and problems from the cultural heritage area regarding bronze objects. The document should also contain possible methodical approaches (i.e. how to perform certain investigations) and list partners from the neutron imaging community, which could help in the planning and realization of investigations. The platform will intensify the collaboration and strengthen the connections between the involved research institutes from both areas neutron physics and cultural heritage and result in a long-lasting synergetic effect

  16. Thermal neutron imaging through XRQA2 GAFCHROMIC films coupled with a cadmium radiator

    Energy Technology Data Exchange (ETDEWEB)

    Sacco, D. [INFN – LNF, Via E. Fermi n.40, Frascati, 00044 Roma (Italy); INAIL – DIT, Via di Fontana Candida n.1, 00040 Monteporzio Catone (Italy); Bedogni, R., E-mail: roberto.bedogni@lnf.infn.it [INFN – LNF, Via E. Fermi n.40, Frascati, 00044 Roma (Italy); Bortot, D. [Politecnico di Milano, Dipartimento di Energia, Via La Masa 34, 20156 Milano (Italy); INFN – Milano, Via Celoria16, 20133 Milano (Italy); Palomba, M. [ENEA Casaccia, Via Anguillarese, 301, S. Maria di Galeria, 00123 Roma (Italy); Pola, A. [Politecnico di Milano, Dipartimento di Energia, Via La Masa 34, 20156 Milano (Italy); INFN – Milano, Via Celoria16, 20133 Milano (Italy); Introini, M.V.; Lorenzoli, M. [Politecnico di Milano, Dipartimento di Energia, Via La Masa 34, 20156 Milano (Italy); Gentile, A. [INFN – LNF, Via E. Fermi n.40, Frascati, 00044 Roma (Italy); Strigari, L. [Laboratory of Medical Physics, Regina Elena National Cancer Institute, Via E. Chianesi 53, 00144 Roma (Italy); Pressello, C. [Department of Medical Physics, Azienda Ospedaliera San Camillo Forlanini, Circonvallazione Gianicolense 87, 00152 Roma (Italy); Soriani, A. [Laboratory of Medical Physics, Regina Elena National Cancer Institute, Via E. Chianesi 53, 00144 Roma (Italy); Gómez-Ros, J.M. [INFN – LNF, Via E. Fermi n.40, Frascati, 00044 Roma (Italy); CIEMAT, Av. Complutense 40, 28040 Madrid (Spain)

    2015-10-21

    A simple and inexpensive method to perform passive thermal neutron imaging on large areas was developed on the basis of XRQA2 GAFCHROMIC films, commonly employed for quality assurance in radiology. To enhance their thermal neutron response, the sensitive face of film was coupled with a 1 mm thick cadmium radiator, forming a sandwich. By exchanging the order of Cd filter and sensitive film with respect to the incident neutron beam direction, two different configurations (beam-Cd-film and beam-film-Cd) were identified. These configurations were tested at thermal neutrons fluence values in the range 10{sup 9}–10{sup 10} cm{sup −2}, using the ex-core radial thermal neutron column of the ENEA Casaccia – TRIGA reactor. The results are presented in this work.

  17. Lattice dynamics of solid deuterium by inelastic neutron scattering

    DEFF Research Database (Denmark)

    Nielsen, Mourits; Bjerrum Møller, Hans

    1971-01-01

    The dispersion relations for phonons in solid ortho-deuterium have been measured at 5 °K by inelastic neutron scattering. The results are in good agreement with recent calculations in which quantum effects are taken into account. The data have been fitted to a third-neighbor general force model...

  18. Dynamics of Magnetic Nanoparticles Studied by Neutron Scattering

    DEFF Research Database (Denmark)

    Hansen, Mikkel Fougt; Bødker, Franz; Mørup, Steen

    1997-01-01

    We present the first triple-axis neutron scattering measurements of magnetic fluctuations in nanoparticles using an antiferromagnetic reflection. Both the superparamagnetic relaxation and precession modes in similar to 15 nm hematite particles are: observed. The results have been consistently...... analyzed on the basis of a simple model with uniaxial anisotropy and the Neel-Brown theory for the relaxation....

  19. Spin dynamics in Tb studied by critical neutron scattering

    DEFF Research Database (Denmark)

    Dietrich, O. W.; Als-Nielsen, Jens Aage

    1971-01-01

    The inelasticity of the critical neutron scattering in Tb was measured at and above the Neel temperature. In the hydrodynamic region the line width Gamma (q=0, kappa 1)=C kappa z1, with z=1.4+or-0.1 and c=4.3+or-0.3 meVAAz. This result deviates from the conventional theory, which predicts...

  20. Image fusion for dynamic contrast enhanced magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Leach Martin O

    2004-10-01

    Full Text Available Abstract Background Multivariate imaging techniques such as dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI have been shown to provide valuable information for medical diagnosis. Even though these techniques provide new information, integrating and evaluating the much wider range of information is a challenging task for the human observer. This task may be assisted with the use of image fusion algorithms. Methods In this paper, image fusion based on Kernel Principal Component Analysis (KPCA is proposed for the first time. It is demonstrated that a priori knowledge about the data domain can be easily incorporated into the parametrisation of the KPCA, leading to task-oriented visualisations of the multivariate data. The results of the fusion process are compared with those of the well-known and established standard linear Principal Component Analysis (PCA by means of temporal sequences of 3D MRI volumes from six patients who took part in a breast cancer screening study. Results The PCA and KPCA algorithms are able to integrate information from a sequence of MRI volumes into informative gray value or colour images. By incorporating a priori knowledge, the fusion process can be automated and optimised in order to visualise suspicious lesions with high contrast to normal tissue. Conclusion Our machine learning based image fusion approach maps the full signal space of a temporal DCE-MRI sequence to a single meaningful visualisation with good tissue/lesion contrast and thus supports the radiologist during manual image evaluation.

  1. Bulgaria: Overview of activities on Neutron Imaging (NI) and Cultural Heritage (CH) studies

    International Nuclear Information System (INIS)

    Djingova, Rumyana

    2012-01-01

    Neutron tomography has recently found new applications in many different fields like for example in Biology, Medicine, Geology, Archaeology and Cultural Heritage. One of the reasons is the fast development in digital image recording and processing, which enables the computation of tomographic reconstructions from high-resolution images at a reasonable timescale. The development of new detectors with better signal-to-noise characteristics and faster read-out electronics has allowed the overcoming of some of the spatial and time resolution limitations of conventional neutron radiography and tomography. Nevertheless the quantification of neutron tomographic data is a challenging task in many cases. The diverse experimental conditions at different facilities (beam spectrum, collimation, background, etc.) hinder the distinct relation between attenuation coefficient and single material. In this case complementary methods should be used for determination of the chemical composition in multicomponent samples which can be related later to the obtained matrix of attenuation coefficients from the neutron tomographic measurement

  2. A concept to collect neutron and x-ray images on the same line of sight at NIF

    Energy Technology Data Exchange (ETDEWEB)

    Merrill, F. E., E-mail: fmerrill@lanl.gov; Danly, C. R.; Grim, G. P.; Volegov, P. L.; Wilde, C. H. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Izumi, N.; Jedlovec, D.; Fittinghoff, D. N.; Pak, A.; Park, H.-S. [Livermore National Laboratory, Livermore, California 94551 (United States)

    2014-11-15

    Neutron and x-ray images are collected at the National Ignition Facility (NIF) to measure the size and shape of inertial confinement fusion implosions. The x-ray images provide a measure of the size and shape of the hot region of the deuterium-tritium fuel while the neutron images provide a measure of the size and shape of the burning plasma. Although these two types of images are collected simultaneously, they are not collected along the same line of sight (LOS). One 14 MeV neutron image is collected on the NIF equator, and two x-ray images are collected along the polar axis and nearly perpendicular to the neutron imaging line of sight on the equator. Both measurements use pinhole apertures to form the images, but existing x-ray imaging provides time-resolved measurements while the neutron images are time-integrated. Detailed comparisons of the x-ray and neutron images can provide information on the fuel assembly, but these studies have been limited because the implosions are not azimuthally symmetric and the images are collected along different LOS. We have developed a conceptual design of a time-integrated x-ray imaging system that could be added to the existing neutron imaging LOS. This new system would allow these detailed studies, providing important information on the fuel assembly of future implosions. Here we present this conceptual design and the expected performance characteristics.

  3. A concept to collect neutron and x-ray images on the same line of sight at NIF.

    Science.gov (United States)

    Merrill, F E; Danly, C R; Izumi, N; Jedlovec, D; Fittinghoff, D N; Grim, G P; Pak, A; Park, H-S; Volegov, P L; Wilde, C H

    2014-11-01

    Neutron and x-ray images are collected at the National Ignition Facility (NIF) to measure the size and shape of inertial confinement fusion implosions. The x-ray images provide a measure of the size and shape of the hot region of the deuterium-tritium fuel while the neutron images provide a measure of the size and shape of the burning plasma. Although these two types of images are collected simultaneously, they are not collected along the same line of sight (LOS). One 14 MeV neutron image is collected on the NIF equator, and two x-ray images are collected along the polar axis and nearly perpendicular to the neutron imaging line of sight on the equator. Both measurements use pinhole apertures to form the images, but existing x-ray imaging provides time-resolved measurements while the neutron images are time-integrated. Detailed comparisons of the x-ray and neutron images can provide information on the fuel assembly, but these studies have been limited because the implosions are not azimuthally symmetric and the images are collected along different LOS. We have developed a conceptual design of a time-integrated x-ray imaging system that could be added to the existing neutron imaging LOS. This new system would allow these detailed studies, providing important information on the fuel assembly of future implosions. Here we present this conceptual design and the expected performance characteristics.

  4. Dynamics of polymers in elongational flow studied by the neutron spin-echo technique

    International Nuclear Information System (INIS)

    Rheinstaedter, Maikel C.; Sattler, Rainer; Haeussler, Wolfgang; Wagner, Christian

    2010-01-01

    The nanoscale fluctuation dynamics of semidilute high molecular weight polymer solutions of polyethylenoxide (PEO) in D 2 O under non-equilibrium flow conditions were studied by the neutron spin-echo technique. The sample cell was in contraction flow geometry and provided a pressure driven flow with a high elongational component that stretched the polymers most efficiently. Neutron scattering experiments in dilute polymer solutions are challenging because of the low polymer concentration and corresponding small quasi-elastic signals. A relaxation process with relaxation times of about 10 ps was observed, which shows anisotropic dynamics with applied flow.

  5. High dynamic range imaging sensors and architectures

    CERN Document Server

    Darmont, Arnaud

    2013-01-01

    Illumination is a crucial element in many applications, matching the luminance of the scene with the operational range of a camera. When luminance cannot be adequately controlled, a high dynamic range (HDR) imaging system may be necessary. These systems are being increasingly used in automotive on-board systems, road traffic monitoring, and other industrial, security, and military applications. This book provides readers with an intermediate discussion of HDR image sensors and techniques for industrial and non-industrial applications. It describes various sensor and pixel architectures capable

  6. HIGH SPATIAL RESOLUTION IMAGING OF INERTIAL FUSION TARGET PLASMAS USING BUBBLE NEUTRON DETECTORS

    International Nuclear Information System (INIS)

    FISHER, R.K.

    2003-01-01

    OAK B202 HIGH SPATIAL RESOLUTION IMAGING OF INERTIAL FUSION TARGET PLASMAS USING BUBBLE NEUTRON DETECTORS. Bubble detectors, which can detect neutrons with a spatial 5 to 30 (micro), are the most promising approach to imaging NIF target plasmas with the desired 5 (micro) spatial resolution in the target plane. Gel bubble detectors are being tested to record neutron images of ICF implosions in OMEGA experiments. By improving the noise reduction techniques used in analyzing the data taken in June 2000, we have been able to image the neutron emission from 6 · 10 13 yield DT target plasmas with a target plane spatial resolution of ∼ 140 (micro). As expected, the spatial resolution was limited by counting statistics as a result of the low neutron detection efficiency of the easy-to-use gel bubble detectors. The results have been submitted for publication and will be the subject of an invited talk at the October 2001 Meeting of the Division of Plasma Physics of the American Physical Society. To improve the counting statistics, data was taken in May 2001 using a stack of four gel detectors and integrated over a series of up to seven high-yield DT shots. Analysis of the 2001 data is still in its early stages. Gel detectors were chosen for these initial tests since the bubbles can be photographed several hours after the neutron exposure. They consist of ∼ 5000 drops (∼ 100 (micro) in diameter) of bubble detector liquid/cm 3 suspended in an inactive support gel that occupies ∼ 99% of the detector volume. Using a liquid bubble chamber detector and a light scattering system to record the bubble locations a few microseconds after the neutron exposure when the bubbles are ∼ 10 (micro) in diameter, should result in ∼ 1000 times higher neutron detection efficiency and a target plane resolution on OMEGA of ∼ 10 to 50 (micro)

  7. South Africa: Overview of activities on Neutron Imaging (NI) and Cultural Heritage (CH) studies

    International Nuclear Information System (INIS)

    De Beer, Frikkie

    2012-01-01

    South Africa has a rich cultural history with ample opportunities for Neutron Imaging to be applied in Archaeological and Palaeontological studies as depicted in the references. Through this collaboration the NI and CH communities are united to introduce neutron induced Autoradiography of paintings as new analytical technique to South Africa. The outcome is foreseen to be a database on NI techniques and applications in CH as well as and exhibition at a museum to showcase the scientific collaborations

  8. Brazil: Overview of activities on Neutron Imaging (NI) and Cultural Heritage (CH) studies

    International Nuclear Information System (INIS)

    Pugliesi, Reynaldo

    2012-01-01

    The neutron imaging is a set of non - destructive testing techniques commonly employed to inspect the internal structure of objects. Because of the neutron - matter interaction characteristics, these techniques are largely employed to inspect hydrogenous substances (water, organic fibers, adhesives, etc) even wrapped by thick metal layers. The Brazilian culture is surrounded by a rich cultural heritage, mainly left by Indians and slaves. Many of the old objects and tools they have used, were manufactured by using clay, wood, organic fibers as well as bones. These materials and the ones used for their restoration are manufactured of several types of hydrogenous substances and hence the use of neutron imaging techniques are very adequate to study such objects. The neutron imaging activities at IPEN - CNEN/SP began in 1988 and the primary objective of the working group was to design and to construct an operational facility for neutron imaging, to be installed in the beam-hole - 08 of the 5MW IEA-R1 Nuclear Research Reactor. From 1992 to 1997, the group has developed several 2D imaging techniques

  9. Cardiac fluid dynamics meets deformation imaging.

    Science.gov (United States)

    Dal Ferro, Matteo; Stolfo, Davide; De Paris, Valerio; Lesizza, Pierluigi; Korcova, Renata; Collia, Dario; Tonti, Giovanni; Sinagra, Gianfranco; Pedrizzetti, Gianni

    2018-02-20

    Cardiac function is about creating and sustaining blood in motion. This is achieved through a proper sequence of myocardial deformation whose final goal is that of creating flow. Deformation imaging provided valuable contributions to understanding cardiac mechanics; more recently, several studies evidenced the existence of an intimate relationship between cardiac function and intra-ventricular fluid dynamics. This paper summarizes the recent advances in cardiac flow evaluations, highlighting its relationship with heart wall mechanics assessed through the newest techniques of deformation imaging and finally providing an opinion of the most promising clinical perspectives of this emerging field. It will be shown how fluid dynamics can integrate volumetric and deformation assessments to provide a further level of knowledge of cardiac mechanics.

  10. Advanced neutron imaging methods with a potential to benefit from pulsed sources

    International Nuclear Information System (INIS)

    Strobl, M.; Kardjilov, N.; Hilger, A.; Penumadu, D.; Manke, I.

    2011-01-01

    During the last decade neutron imaging has seen significant improvements in instrumentation, detection and spatial resolution. Additionally, a variety of new applications and methods have been explored. As a consequence of an outstanding development nowadays various techniques of neutron imaging go far beyond a two- and three-dimensional mapping of the attenuation coefficients for a broad range of samples. Neutron imaging has become sensitive to neutron scattering in the small angle scattering range as well as with respect to Bragg scattering. Corresponding methods potentially provide spatially resolved and volumetric data revealing microstructural inhomogeneities, texture variations, crystalline phase distributions and even strains in bulk samples. Other techniques allow for the detection of refractive index distribution through phase sensitive measurements and the utilization of polarized neutrons enables radiographic and tomographic investigations of magnetic fields and properties as well as electrical currents within massive samples. All these advanced methods utilize or depend on wavelength dependent signals, and are hence suited to profit significantly from pulsed neutron sources as will be discussed.

  11. Measurement of neutron importance by a dynamic method

    International Nuclear Information System (INIS)

    Dmitriev, V.M.; Matusevich, E.S.; Regushevskij, V.I.; Sazonov, S.P.; Usikov, D.A.

    1977-01-01

    A procedure is proposed for measuring neutron importance spatial distribution in a critical reactor by determining the parameters of its run-up with a constant neutron source. 252 Cf quasiisotropic point source was used. The measurements were performed at a critical assembly with a highly enriched uranium core and beryllium reflector. Importance distributions in critical and subsritical assemblies were compared for various degrees of subcriticality. Absolute normalization for the importance was obtained, and some new integral reactor characteristics were determined experimentally on its basis. An experimental data acquisition and processing system was developed on the basis of the ELECTRONIKA-100 computer. An algorithm was also developed for statistical treatment of the data. The importance distributions in critical and subcritical assemblies proved to coincide up to a rather deep subcriticality

  12. Dynamics of crystalline acetanilide: Analysis using neutron scattering and computer simulation

    Science.gov (United States)

    Hayward, R. L.; Middendorf, H. D.; Wanderlingh, U.; Smith, J. C.

    1995-04-01

    The unusual temperature dependence of several optical spectroscopic vibrational bands in crystalline acetanilide has been interpreted as providing evidence for dynamic localization. Here we examine the vibrational dynamics of crystalline acetanilide over a spectral range of ˜20-4000 cm-1 using incoherent neutron scattering experiments, phonon normal mode calculations and molecular dynamics simulations. A molecular mechanics energy function is parametrized and used to perform the normal mode analyses in the full configurational space of the crystal i.e., including the intramolecular and intermolecular degrees of freedom. One- and multiphonon incoherent inelastic neutron scattering intensities are calculated from harmonic analyses in the first Brillouin zone and compared with the experimental data presented here. Phonon dispersion relations and mean-square atomic displacements are derived from the harmonic model and compared with data derived from coherent inelastic neutron scattering and neutron and x-ray diffraction. To examine the temperature effects on the vibrations the full, anharmonic potential function is used in molecular dynamics simulations of the crystal at 80, 140, and 300 K. Several, but not all, of the spectral features calculated from the molecular dynamics simulations exhibit temperature-dependent behavior in agreement with experiment. The significance of the results for the interpretation of the optical spectroscopic results and possible improvements to the model are discussed.

  13. Incoherent imaging using dynamically scattered coherent electrons

    International Nuclear Information System (INIS)

    Nellist, P.D.; Pennycook, S.J.

    1999-01-01

    We use a Bloch wave approach to show that, even for coherent dynamical scattering from a stationary lattice with no absorption, annular dark-field imaging in a scanning transmission electron microscope gives a direct incoherent structure image of the atomic-column positions of a zone-axis-aligned crystal. Although many Bloch waves may be excited by the probe, the detector provides a filtering effect so that the 1s-type bound states are found to dominate the image contrast for typical experimental conditions. We also find that the column intensity is related to the transverse kinetic energy of the 1s states, which gives atomic number, Z, contrast. The additional effects of phonon scattering are discussed, in particular the reasons why phonon scattering is not a prerequisite for transverse incoherence. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  14. Fundamentals and applications of neutron imaging. Applications part 5. Application of neutron imaging to fluid engineering-1

    International Nuclear Information System (INIS)

    Takenaka, Nobuyuki; Asano, Hitoshi; Umekawa, Hisashi; Matsubayashi, Masahito

    2007-01-01

    Characteristics of the neutron beam attenuation vary with elements constituting the object and it attenuates with hydrogen and a specific element greatly and penetrates most metal well. Normal liquid such as water, oil, the organic liquid includes a lot of hydrogen, and a neutron beam attenuates, but attenuation characteristics of the metal well used industrially such as iron, copper, aluminum are smaller than normal liquid. Because most machines are made of metal, and liquid behavior of the machine inside can be seen through neutron radiography, it is possible to be used as the X-rays of the machine. As an application of neutron radiography to the fluid engineering, fluid behavior in the metal pipe and container, especially two phase flow mingled with each phase of gas/liquid/solid, has been visible and measurable which is difficult to be performed by other methods, and in late years the industry use of neutron radiography attracts attention particularly. This serial course describes overviews of two-phase flow visualization and measurement and freezing/cooling machinery as the first example of recent application to the machinery. (T. Tanaka)

  15. Neutron Imaging of Lithium Concentration in Battery Pouch Cells

    Science.gov (United States)

    2011-06-01

    water distribution and removal phenomena in an operating pemfc via neutron radiography,” J. Electrochem. Soc., vol. 155, no. 3, pp. B294–B302, 2008...12] J. B. Siegel, D. A. McKay, A. G. Stefanopoulou, D. S. Hussey, and D. L. Jacobson, “Measurement of liquid water accumulation in a pemfc with dead

  16. Time-of-flight neutron Bragg-edge transmission imaging of microstructures in bent steel plates

    Energy Technology Data Exchange (ETDEWEB)

    Su, Yuhua, E-mail: yuhua.su@j-parc.jp [J-PARC Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai, Ibaraki 319-1195 (Japan); Oikawa, Kenichi; Harjo, Stefanus; Shinohara, Takenao; Kai, Tetsuya; Harada, Masahide; Hiroi, Kosuke [J-PARC Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai, Ibaraki 319-1195 (Japan); Zhang, Shuoyuan; Parker, Joseph Don [Neutron R& D Division, CROSS-Tokai, 162-1 Shirakata, Tokai, Ibaraki 319-1106 (Japan); Sato, Hirotaka [Faculty of Engineering, Hokkaido University, Sapporo 060-8628 (Japan); Shiota, Yoshinori; Kiyanagi, Yoshiaki [Graduate School of Engineering, Nagoya University, Nagoya, Aichi 464-8603 (Japan); Tomota, Yo [Research Center for Strategic Materials, National Institute for Materials Science, Tsukuba 305-0047 (Japan)

    2016-10-15

    Neutron Bragg-edge transmission imaging makes it possible to quantitatively visualize the two-dimensional distribution of microstructure within a sample. In order to examine its application to engineering products, time-of-flight Bragg-edge transmission imaging experiments using a pulsed neutron source were performed for plastically bent plates composed of a ferritic steel and a duplex stainless steel. The non-homogeneous microstructure distributions, such as texture, crystalline size, phase volume fraction and residual elastic strain, were evaluated for the cross sections of the bent plates. The obtained results were compared with those by neutron diffraction and electron back scatter diffraction, showing that the Bragg-edge transmission imaging is powerful for engineering use.

  17. Dynamics of proteins and of their hydration layer studied by neutron scattering and additional biophysical methods

    International Nuclear Information System (INIS)

    Gallat, Francois-Xavier

    2011-01-01

    This thesis work focused on the dynamics of proteins, surrounded by their hydration layer, a water shell around the protein vital for its biological function. Each of these components is accompanied by a specific dynamics which union reforms the complex energy landscape of the system. The joint implementation of selective deuteration, incoherent neutron scattering and tera-hertz spectroscopy allowed to explore the dynamics of proteins and that of the hydration shell. The influence of the folding state of protein on its dynamics has been studied by elastic neutron scattering. Globular proteins were less dynamic than its intrinsically disordered analogues. Themselves appear to be stiffer than non-physiological unfolded proteins. The oligomerization state and the consequences on the dynamics were investigated. Aggregates of a globular protein proved to be more flexible than the soluble form. In contrast, aggregates of a disordered protein showed lower average dynamics compared to the soluble form. These observations demonstrate the wide range of dynamics among the proteome. Incoherent neutron scattering experiences on the hydration layer of globular and disordered proteins have yielded information on the nature of water motion around these proteins. The measurements revealed the presence of translational motions concomitant with the onset of the transition dynamics of hydration layers, at 220 K. Measurements have also shown a stronger coupling between a disordered protein and its hydration water, compared to a globular protein and its hydration shell. The nature of the hydration layer and its influence on its dynamics has been explored with the use of polymers that mimic the water behavior and that act as a source of flexibility for the protein. Eventually, the dynamics of methyl groups involved in the dynamical changes observed at 150 and 220 K, was investigated. (author) [fr

  18. Research of the system response of neutron double scatter imaging for MLEM reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, M., E-mail: wyj2013@163.com [Northwest Institute of Nuclear Technology, Xi’an 710024 (China); State Key Laboratory of Intense Pulsed Radiation-Simulation and Effect, Xi’an 710024 (China); Peng, B.D.; Sheng, L.; Li, K.N.; Zhang, X.P.; Li, Y.; Li, B.K.; Yuan, Y.; Wang, P.W.; Zhang, X.D.; Li, C.H. [Northwest Institute of Nuclear Technology, Xi’an 710024 (China); State Key Laboratory of Intense Pulsed Radiation-Simulation and Effect, Xi’an 710024 (China)

    2015-03-01

    A Maximum Likelihood image reconstruction technique has been applied to neutron scatter imaging. The response function of the imaging system can be obtained by Monte Carlo simulation, which is very time-consuming if the number of image pixels and particles is large. In this work, to improve time efficiency, an analytical approach based on the probability of neutron interaction and transport in the detector is developed to calculate the system response function. The response function was applied to calculate the relative efficiency of the neutron scatter imaging system as a function of the incident neutron energy. The calculated results agreed with simulations by the MCNP5 software. Then the maximum likelihood expectation maximization (MLEM) reconstruction method with the system response function was used to reconstruct data simulated by Monte Carlo method. The results showed that there was good consistency between the reconstruction position and true position. Compared with back-projection reconstruction, the improvement in image quality was obvious, and the locations could be discerned easily for multiple radiation point sources.

  19. Fundamentals and applications of neutron imaging. Applications part 8. Application of neutron imaging to inspection of art objects and ancient artifacts

    International Nuclear Information System (INIS)

    Matsubayashi, Masahito; Masuzawa, Fumitake

    2007-01-01

    Neutron radiography is an imaging technique which provides images similar to X-ray radiography and is often used to study ancient artifacts and art objects because the measurements are non-destructive. While metallic elements contained in ancient artifacts, namely gold, silver, mercury, copper, tin, lead, or iron, have X-ray mass attenuation coefficient much higher than light elements composing organic substances, for neutron attenuation the coefficient values are entirely opposite. The method is particularly useful for examination of the internal structure and composition of cultural object made of organic materials inside the metallic vessel. Here some of the research results using JAEA-JRR3M facility are presented: sutras in a cylindrical copper tube, the interior structure of Buddha statues, bone materials in metallic bottles, bronze mirrors, ancient jars and textiles. (S. Ohno)

  20. Robust filtering for dynamic compensation of self-powered neutron detectors

    International Nuclear Information System (INIS)

    Peng, Xingjie; Li, Qing; Zhao, Wenbo; Gong, Helin; Wang, Kan

    2014-01-01

    Highlights: • Three dynamic compensation methods based on robust filtering theory are proposed. • Filter design problems are converted into linear matrix inequality problems. • Rhodium and Vanadium self-powered neutron detectors are used to validate the use of these three dynamic compensation methods. • The numerical simulation results show that all three methods can provide a reasonable balance between response speed and noise suppression. - Abstract: Self-powered neutron detectors (SPNDs), which are widely used in nuclear reactors to obtain core neutron flux distribution, are accurate at steady state but respond slowly to changes in neutron flux. Dynamic compensation methods are required to improve the response speed of the SPNDs and make it possible to apply the SPNDs for core monitoring and surveillance. In this paper, three digital dynamic compensation methods are proposed. All the three methods are based on the convex optimization framework using linear matrix inequalities (LMIs). The simulation results show that all three methods can provide a reasonable balance between response speed and noise suppression

  1. Hydration of Hydroxyl and Amino Groups Examined by Molecular Dynamics and Neutron Scattering

    Czech Academy of Sciences Publication Activity Database

    Hladílková, Jana; Fischer, H. E.; Jungwirth, Pavel; Mason, Philip E.

    2015-01-01

    Roč. 119, č. 21 (2015), s. 6357-6365 ISSN 1520-6106 R&D Projects: GA ČR GBP208/12/G016 Institutional support: RVO:61388963 Keywords : neutron scattering * molecular dynamics * isopropyl alcohol * isopropylamine Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.187, year: 2015

  2. Accounting for Electronic Polarization Effects in Aqueous Sodium Chloride via Molecular Dynamics Aided by Neutron Scattering

    Czech Academy of Sciences Publication Activity Database

    Kohagen, Miriam; Mason, Philip E.; Jungwirth, Pavel

    2016-01-01

    Roč. 120, č. 8 (2016), s. 1454-1460 ISSN 1520-6106 R&D Projects: GA ČR GBP208/12/G016 Institutional support: RVO:61388963 Keywords : molecular dynamics * neutron scattering * agueous sodium chloride Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.177, year: 2016

  3. Germany: Overview of activities on Neutron Imaging (NI) and Cultural Heritage (CH) studies - Technische Universitaet Muenchen

    International Nuclear Information System (INIS)

    Schillinger, Burkhard

    2012-01-01

    The ANTARES facility for neutron imaging is currently completely refurbished and will restart operation in summer 2012. ANTARES will again provide the combination of highest flux and highest resolution worldwide in neutron imaging. Additional methods include energy-dependent measurements (Bragg edges) for the identification of different elements and phases as well as (soon) phase gratings for linear phase contrast. With the collaboration partners The University of Queens (Canada), The Archäologisches Landesamt für Denkmalpflege in Esslingen, Germany, and Archäologische Staatssammlung of Bavaria, Germany, research at ANTARES will focus on the examination of organic materials in combination with metal artefacts

  4. Low frequency enzyme dynamics as a function of temperature and hydration: A neutron scattering study

    Energy Technology Data Exchange (ETDEWEB)

    Kurkal, V. [Interdisciplinary Center for Scientific Computing (IWR), University of Heidelberg, Im Neuenheimer Feld 368, D-69120 Heidelberg (Germany); Daniel, R.M. [Department of Biological Sciences, University of Waikato, Private Bag 3105, Hamilton (New Zealand); Finney, John L. [Department of Physics and Astronomy, University college, London, Gower Street, London WC1E 6BT, England (United Kingdom); Tehei, M. [Department of Biological Sciences, University of Waikato, Private Bag 3105, Hamilton (New Zealand); Dunn, R.V. [Department of Biological Sciences, University of Waikato, Private Bag 3105, Hamilton (New Zealand); Smith, Jeremy C. [Interdisciplinary Center for Scientific Computing (IWR), University of Heidelberg, Im Neuenheimer Feld 368, D-69120 Heidelberg (Germany)], E-mail: biocomputing@iwr.uni-heidelberg.de

    2005-10-31

    The effect of hydration and temperature on the low-frequency dynamics of the enzyme Pig liver esterase has been investigated with incoherent neutron scattering experiments. The results suggest that at low temperature, increasing hydration results in lower flexibility of the protein. At higher temperatures, systems containing sufficient number of water molecules interacting with the protein exhibit increased flexibility. The environmental force constants indicate that the environment of the protein is more rigid below than it is above the dynamical transition temperature.

  5. Dual-Particle Imaging System with Neutron Spectroscopy for Safeguard Applications

    Energy Technology Data Exchange (ETDEWEB)

    Hamel, Michael C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Weber, Thomas M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-11-01

    A dual-particle imager (DPI) has been designed that is capable of detecting gamma-ray and neutron signatures from shielded SNM. The system combines liquid organic and NaI(Tl) scintillators to form a combined Compton and neutron scatter camera. Effective image reconstruction of detected particles is a crucial component for maximizing the performance of the system; however, a key deficiency exists in the widely used iterative list-mode maximum-likelihood estimation-maximization (MLEM) image reconstruction technique. For MLEM a stopping condition is required to achieve a good quality solution but these conditions fail to achieve maximum image quality. Stochastic origin ensembles (SOE) imaging is a good candidate to address this problem as it uses Markov chain Monte Carlo to reach a stochastic steady-state solution. The application of SOE to the DPI is presented in this work.

  6. Dynamic MR imaging of mandibular osteoradionecrosis

    International Nuclear Information System (INIS)

    Store, G.; Smith, H.J.; Larheim, T.A.

    2000-01-01

    Osteoradionecrotic bone has been characterised as hypovascular and metabolically inactive tissue with impaired perfusion. The present study was conducted to determine if dynamic contrast-enhanced MR imaging could provide additional information about the vascularity of radionecrotic mandibular bone. Dynamic contrast-enhanced MR imaging was performed on 10 patients with mandibular osteoradionecrosis (ORN), and on 6 patients, irradiated for oropharyngeal tumours, without symptoms or signs of ORN. Nine patients in the ORN group received a series of 20 hyperbaric oxygen (HBO) treatments, after which the dynamic MR investigation was repeated. Radiation per se did not lead to increased contrast enhancement, whereas all patients with ORN showed marked contrast enhancement of the osteoradionecrotic bone marrow. After HBO treatment, pathological contrast enhancement of the abnormal bone marrow could still be seen, but the rate of enhancement was less than before in 7 of 9 patients. Two patients had an increase in the enhancement rate. The findings suggest the existence of an increased and patent microvasculature

  7. Development of instrumentation for imaging scattered cold neutrons. Phase 1 report

    International Nuclear Information System (INIS)

    Walter, J.

    1988-01-01

    The project involves the development of a cold neutron imaging array consisting of a neutron to charged particle convertor and an array of Si detector pixels. Each detector pixel has its own preamplifier/signal conditioning chain and its own data storage registers. The parallel processing capability will be contained on WSI-ASIC sub-array wafers with 196 channels per wafer. Such sub-arrays can be assembled into large focal plane arrays. The high speed of the silicon detectors and signal conditioning chains makes 100,000 cps per pixel a realistic goal. Calculations and experimental measurements of neutron detection efficiency as a function of neutron wavelength are very encouraging. Preliminary design studies of the preamplifier/signal conditioning chain appear to present no insurmountable technical problems

  8. Observed diurnal variations in Mars Science Laboratory Dynamic Albedo of Neutrons passive mode data

    Science.gov (United States)

    Tate, C. G.; Moersch, J.; Jun, I.; Mitrofanov, I.; Litvak, M.; Boynton, W. V.; Drake, D.; Fedosov, F.; Golovin, D.; Hardgrove, C.; Harshman, K.; Kozyrev, A. S.; Kuzmin, R.; Lisov, D.; Maclennan, E.; Malakhov, A.; Mischna, M.; Mokrousov, M.; Nikiforov, S.; Sanin, A. B.; Starr, R.; Vostrukhin, A.

    2018-06-01

    The Mars Science Laboratory Dynamic Albedo of Neutrons (DAN) experiment measures the martian neutron leakage flux in order to estimate the amount of water equivalent hydrogen present in the shallow regolith. When DAN is operating in passive mode, it is sensitive to neutrons produced through the interactions of galactic cosmic rays (GCR) with the regolith and atmosphere and neutrons produced by the rover's Multi-Mission Radioisotope Thermoelectric Generator (MMRTG). During the mission, DAN passive mode data were collected over the full diurnal cycle at the locations known as Rocknest (sols 60-100) and John Klein (sols 166-272). A weak, but unexpected, diurnal variation was observed in the neutron count rates reported at these locations. We investigate different hypotheses that could be causing these observed variations. These hypotheses are variations in subsurface temperature, atmospheric pressure, the exchange of water vapor between the atmosphere and regolith, and instrumental effects on the neutron count rates. Our investigation suggests the most likely factors contributing to the observed diurnal variations in DAN passive data are instrumental effects and time-variable preferential shielding of alpha particles, with other environmental effects only having small contributions.

  9. Modified TOV in gravity’s rainbow: properties of neutron stars and dynamical stability conditions

    Energy Technology Data Exchange (ETDEWEB)

    Hendi, S.H. [Physics Department and Biruni Observatory, College of Sciences, Shiraz University,Shiraz 71454 (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha (RIAAM),P.O. Box 55134-441, Maragha (Iran, Islamic Republic of); Bordbar, G.H. [Physics Department and Biruni Observatory, College of Sciences, Shiraz University,Shiraz 71454 (Iran, Islamic Republic of); Center for Excellence in Astronomy and Astrophysics (CEAA-RIAAM)-Maragha,P.O. Box 55134-441, Maragha 55177-36698 (Iran, Islamic Republic of); Panah, B. Eslam [Physics Department and Biruni Observatory, College of Sciences, Shiraz University,Shiraz 71454 (Iran, Islamic Republic of); Panahiyan, S. [Physics Department and Biruni Observatory, College of Sciences, Shiraz University,Shiraz 71454 (Iran, Islamic Republic of); Physics Department, Shahid Beheshti University,Tehran 19839 (Iran, Islamic Republic of)

    2016-09-09

    In this paper, we consider a spherical symmetric metric to extract the hydrostatic equilibrium equation of stars in (3+1)-dimensional gravity’s rainbow in the presence of cosmological constant. Then, we generalize the hydrostatic equilibrium equation to d-dimensions and obtain the hydrostatic equilibrium equation for this gravity. Also, we obtain the maximum mass of neutron star using the modern equations of state of neutron star matter derived from the microscopic calculations. It is notable that, in this paper, we consider the effects of rainbow functions on the diagrams related to the mass-central mass density (M-ρ{sub c}) relation and also the mass-radius (M-R) relation of neutron star. We also study the effects of rainbow functions on the other properties of neutron star such as the Schwarzschild radius, average density, strength of gravity and gravitational redshift. Then, we apply the cosmological constant to this theory to obtain the diagrams of M-ρ{sub c} (or M-R) and other properties of these stars. Next, we investigate the dynamical stability condition for these stars in gravity’s rainbow and show that these stars have dynamical stability. We also obtain a relation between mass of neutron stars and Planck mass. In addition, we compare obtained results of this theory with the observational data.

  10. Dynamically polarized hydrogen target as a broadband, wavelength-independent thermal neutron spin polarizer

    International Nuclear Information System (INIS)

    Zhao Jinkui; Garamus, Vasil M.; Mueller, Wilhelm; Willumeit, Regine

    2005-01-01

    A hydrogen-rich sample with dynamically polarized hydrogen nuclei was tested as a wavelength-independent neutron transmission spin polarizer. The experiment used a modified setup of the dynamic nuclear polarization target station at the GKSS research center. The standard solvent sample at the GKSS DNP station was used. It is 2.8mm thick and consists of 43.4wt% water, 54.6wt% glycerol, and 2wt% of EHBA-Cr(v) complex. The wavelength of the incident neutrons for the transmission experiment was λ=8.1A with Δλ/λ=10%. The polarization of neutron beam after the target sample was analyzed with a supermirror analyzer. A neutron polarization of -52% was achieved at the hydrogen polarization of -69%. Further experiments will test the feasibility of other hydrogen-rich materials, such as methane, as the polarizer. A theoretical calculation shows that a polarized methane target would allow over 95% neutron polarizations with more than 30% transmission

  11. Neutron imaging of water penetration into cracked steel reinforced concrete

    International Nuclear Information System (INIS)

    Zhang, P.; Wittmann, F.H.; Zhao, T.; Lehmann, E.H.

    2010-01-01

    Service life and durability of reinforced concrete structures have become a crucial issue because of the economical and ecological implications. Service life of reinforced concrete structures is often limited by penetration of water and chemical compounds dissolved in water into the porous cement-based material. By now it is well-known that cracks in reinforced concrete are preferential paths for ingress of aggressive substances. Neutron radiography was successfully applied to study the process of water penetration into cracked steel reinforced concrete. In addition, the effectiveness of integral water repellent concrete to prevent ingress of water and salt solutions was investigated. Results are described in detail in this contribution. It will be shown that neutron radiography is a powerful method to visualize the process of water penetration into cracked and uncracked cement-based materials. On the basis of the obtained experimental data, it is possible to quantify the time-dependent water distributions in concrete with high accuracy and spatial resolution. It is of particular interest that penetration of water and salt solutions into damaged interfaces between concrete and steel can be visualized by means of neutron radiography. Deteriorating processes in cracked reinforced concrete structures can be studied in a completely new way. This advanced technology will help and find adequate ways to improve durability and service life of reinforced concrete structures. This will mean at the same time an essential contribution to improved sustainability.

  12. An information-theoretical approach to image resolution applied to neutron imaging detectors based upon individual discriminator signals

    International Nuclear Information System (INIS)

    Clergeau, Jean-Francois; Ferraton, Matthieu; Guerard, Bruno; Khaplanov, Anton; Piscitelli, Francesco; Platz, Martin; Rigal, Jean-Marie; Van Esch, Patrick; Daulle, Thibault

    2013-06-01

    1D or 2D neutron imaging detectors with individual wire or strip readout using discriminators have the advantage of being able to treat several neutron impacts partially overlapping in time, hence reducing global dead time. A single neutron impact usually gives rise to several discriminator signals. In this paper, we introduce an information-theoretical definition of image resolution. Two point-like spots of neutron impacts with a given distance between them act as a source of information (each neutron hit belongs to one spot or the other), and the detector plus signal treatment is regarded as an imperfect communication channel that transmits this information. The maximal mutual information obtained from this channel as a function of the distance between the spots allows to define a calibration-independent measure of resolution. We then apply this measure to quantify the power of resolution of different algorithms treating these individual discriminator signals which can be implemented in firmware. The method is then applied to different detectors existing at the ILL. Center-of-gravity methods usually improve the resolution over best-wire algorithms which are the standard way of treating these signals. (authors)

  13. An information-theoretical approach to image resolution applied to neutron imaging detectors based upon individual discriminator signals

    Energy Technology Data Exchange (ETDEWEB)

    Clergeau, Jean-Francois; Ferraton, Matthieu; Guerard, Bruno; Khaplanov, Anton; Piscitelli, Francesco; Platz, Martin; Rigal, Jean-Marie; Van Esch, Patrick [Institut Laue Langevin, Neutron Detector Service, Grenoble (France); Daulle, Thibault [PHELMA Grenoble - INP Grenoble (France)

    2013-06-15

    1D or 2D neutron imaging detectors with individual wire or strip readout using discriminators have the advantage of being able to treat several neutron impacts partially overlapping in time, hence reducing global dead time. A single neutron impact usually gives rise to several discriminator signals. In this paper, we introduce an information-theoretical definition of image resolution. Two point-like spots of neutron impacts with a given distance between them act as a source of information (each neutron hit belongs to one spot or the other), and the detector plus signal treatment is regarded as an imperfect communication channel that transmits this information. The maximal mutual information obtained from this channel as a function of the distance between the spots allows to define a calibration-independent measure of resolution. We then apply this measure to quantify the power of resolution of different algorithms treating these individual discriminator signals which can be implemented in firmware. The method is then applied to different detectors existing at the ILL. Center-of-gravity methods usually improve the resolution over best-wire algorithms which are the standard way of treating these signals. (authors)

  14. Time-of-Flight Neutron Imaging on IMAT@ISIS: A New User Facility for Materials Science

    Directory of Open Access Journals (Sweden)

    Winfried Kockelmann

    2018-02-01

    Full Text Available The cold neutron imaging and diffraction instrument IMAT at the second target station of the pulsed neutron source ISIS is currently being commissioned and prepared for user operation. IMAT will enable white-beam neutron radiography and tomography. One of the benefits of operating on a pulsed source is to determine the neutron energy via a time of flight measurement, thus enabling energy-selective and energy-dispersive neutron imaging, for maximizing image contrasts between given materials and for mapping structure and microstructure properties. We survey the hardware and software components for data collection and image analysis on IMAT, and provide a step-by-step procedure for operating the instrument for energy-dispersive imaging using a two-phase metal test object as an example.

  15. Neutron scattering studies of the dynamics of biopolymer-water systems using pulsed-source spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Middendorf, H.D. [Univ. of Oxford (United Kingdom); Miller, A. [Stirling Univ., Stirling (United Kingdom)

    1994-12-31

    Energy-resolving neutron scattering techniques provide spatiotemporal data suitable for testing and refining analytical models or computer simulations of a variety of dynamical processes in biomolecular systems. This paper reviews experimental work on hydrated biopolymers at ISIS, the UK Pulsed Neutron Facility. Following an outline of basic concepts and a summary of the new instrumental capabilities, the progress made is illustrated by results from recent experiments in two areas: quasi- elastic scattering from highly hydrated polysaccharide gels (agarose and hyaluronate), and inelastic scattering from vibrational modes of slightly hydrated collagen fibers.

  16. Effects of loading reactivity at dynamic state on wave of neutrons in burst reactor

    International Nuclear Information System (INIS)

    Gao Hui; Liu Xiaobo; Fan Xiaoqiang

    2013-01-01

    Based on the point reactor model, the program for simulating the burst of reactors, including delay neutron, thermal feedback and reactivity of rod, was developed. The program proves to be suitable to burst reactor by experimental data. The program can describe the process of neutron-intensity change in burst reactors. With the program, the parameters of burst (wave of burst, power of peak and reactivity of reactor) under the condition of dynamic reactivity can be calculated. The calculated result demonstrates that the later the burst is initiated, the greater its power of peak and yield are and that the maximum yield coordinates with the yield under static state. (authors)

  17. Neutron scattering studies of the dynamics of biopolymer-water systems using pulsed-source spectrometers

    International Nuclear Information System (INIS)

    Middendorf, H.D.; Miller, A.

    1994-01-01

    Energy-resolving neutron scattering techniques provide spatiotemporal data suitable for testing and refining analytical models or computer simulations of a variety of dynamical processes in biomolecular systems. This paper reviews experimental work on hydrated biopolymers at ISIS, the UK Pulsed Neutron Facility. Following an outline of basic concepts and a summary of the new instrumental capabilities, the progress made is illustrated by results from recent experiments in two areas: quasi- elastic scattering from highly hydrated polysaccharide gels (agarose and hyaluronate), and inelastic scattering from vibrational modes of slightly hydrated collagen fibers

  18. Polarized-neutron study of spin dynamics in the Kondo insulator YbB12.

    Science.gov (United States)

    Nemkovski, K S; Mignot, J-M; Alekseev, P A; Ivanov, A S; Nefeodova, E V; Rybina, A V; Regnault, L-P; Iga, F; Takabatake, T

    2007-09-28

    Inelastic neutron scattering experiments have been performed on the archetype compound YbB(12), using neutron polarization analysis to separate the magnetic signal from the phonon background. With decreasing temperature, components characteristic for a single-site spin-fluctuation dynamics are suppressed, giving place to specific, strongly Q-dependent, low-energy excitations near the spin-gap edge. This crossover is discussed in terms of a simple crystal-field description of the incoherent high-temperature state and a predominantly local mechanism for the formation of the low-temperature singlet ground state.

  19. Solar Flare Dynamic Microwave Imaging with EOVSA

    Science.gov (United States)

    Gary, D. E.; Chen, B.; Nita, G. M.; Fleishman, G. D.; Yu, S.; White, S. M.; Hurford, G. J.; McTiernan, J. M.

    2017-12-01

    The Expanded Owens Valley Solar Array (EOVSA) is both an expansion of our existing solar array and serves as a prototype for a much larger future project, the Frequency Agile Solar Radiotelescope (FASR). EOVSA is now complete, and is producing daily imaging of the full solar disk, including active regions and solar radio bursts at hundreds of frequencies in the range 2.8-18 GHz. We present highlights of the 1-s-cadence dynamic imaging spectroscropy of radio bursts we have obtained to date, along with deeper analysis of multi-wavelength observations and modeling of a well-observed burst. These observations are revealing the full life-cycle of the trapped population of high-energy electrons, from their initial acceleration and subsequent energy-evolution to their eventual decay through escape and thermalization. All of our data are being made available for download in both quick-look image form and in the form of the community-standard CASA measurement sets for subsequent imaging and analysis.

  20. Quasielastic neutron scattering and microscopic dynamics of liquid ethylene glycol

    Energy Technology Data Exchange (ETDEWEB)

    Sobolev, O. [Laboratoire de Geophysique Interne et Tectonophysique, BP 53, Maison des Geosciences - Domaine Universitaire, 38041 Grenoble, Cedex 9 (France)], E-mail: Oleg.Sobolev@ujf-grenoble.fr; Novikov, A. [Institute for Physics and Power Engineering, Bondarenko Sq. 1, Obninsk, Kaluga Reg. 249033 (Russian Federation); Pieper, J. [Technische Universitaet Berlin, Strasse des 17, Juni 135, D-10623 Berlin (Germany)

    2007-04-20

    Quasielastic neutron scattering (QENS) by liquid ethylene glycol was analyzed using different model approaches. It was found that approximation of the QENS spectra by a set of Lorentzian functions corresponding to the translational and rotational motions produce physically unrealistic results. At the same time, the Fourier transform of the stretched-exponential function exp(-(t/{tau}){sup {beta}}) fits the experimental data well, and results of the fit are in good agreement with those obtained earlier for other systems. The stretching parameter {beta} was found Q independent and shows weak temperature dependence. The mean relaxation time as a function of Q departs strongly from the simple diffusion low and can be approximated by a power law <{tau}{sub w}> = {tau}{sub 0}Q{sup -{gamma}} with the exponent parameter {gamma} = 2.4.

  1. Neutron spin-echo investigation of the microemulsion dynamics. in bicontinuous lamellar and droplet phases

    CERN Document Server

    Mihailescu, M; Endo, H; Allgaier, J; Gompper, G; Stellbrink, J; Richter, D; Jakobs, B; Sottmann, T; Faragó, B

    2002-01-01

    Using neutron spin-echo (NSE) spectroscopy in combination with dynamic light scattering (DLS), we performed an extensive investigation of the bicontinuous phase in ternary water-surfactant-oil microemulsions, with extension to lamellar and droplet phases. The dynamical behavior of surfactant monolayers of decyl-polyglycol-ether (C sub 1 sub 0 E sub 4) molecules, or mixtures of surfactant with long amphiphilic block-copolymers of type poly-ethylene propylene/poly-ethylene oxide (PEP-PEO) was studied, under comparable conditions. The investigation techniques provide access to different length scales relative to the characteristic periodicity length of the microemulsion structure. Information on the elastic bending modulus is obtained from the local scale dynamics in view of existing theoretical descriptions and is found to be in accordance with small angle neutron scattering (SANS) studies. Evidence for the modified elastic properties and additional interaction of the amphiphilic layers due to the polymer is mo...

  2. High dynamic range image acquisition based on multiplex cameras

    Science.gov (United States)

    Zeng, Hairui; Sun, Huayan; Zhang, Tinghua

    2018-03-01

    High dynamic image is an important technology of photoelectric information acquisition, providing higher dynamic range and more image details, and it can better reflect the real environment, light and color information. Currently, the method of high dynamic range image synthesis based on different exposure image sequences cannot adapt to the dynamic scene. It fails to overcome the effects of moving targets, resulting in the phenomenon of ghost. Therefore, a new high dynamic range image acquisition method based on multiplex cameras system was proposed. Firstly, different exposure images sequences were captured with the camera array, using the method of derivative optical flow based on color gradient to get the deviation between images, and aligned the images. Then, the high dynamic range image fusion weighting function was established by combination of inverse camera response function and deviation between images, and was applied to generated a high dynamic range image. The experiments show that the proposed method can effectively obtain high dynamic images in dynamic scene, and achieves good results.

  3. Visualization and quantification of weathering effects on capillary water uptake of natural building stones by using neutron imaging

    International Nuclear Information System (INIS)

    Raneri, Simona; Barone, Germana; Mazzoleni, Paolo; Rabot, Eva

    2016-01-01

    Building stones are frequently subjected to very intense degradation due to salt crystallization, often responsible for strong modifications of their pore network. These effects have a great influence on the mechanical properties and durability of the materials, and on the penetration of water. Therefore, the quantification and visualization of water absorption into the pore network of degraded stones could provide useful information to better understand the weathering process. In this study, neutron radiography has been used (1) to monitor and visualize in two dimensions the capillary water uptake in a Sicilian calcarenite widely used as building and replace stone (namely Sabucina stone) and (2) to quantify the water content distribution, as a function of time and weathering degree. Additionally, traditional experiments based on gravimetric methods have been performed, following the standard recommendations. Results demonstrated a change in the physical properties of Sabucina stones with the intensification of the degradation process, with severe effects on the capillary imbibition dynamics. The water penetration depth at the end of the experiment was substantially higher in the fresh than in the weathered stones. The water absorption kinetics was faster in the weathered samples, and the amount of water absorbed increased with the number of weathering cycles. Good agreement between classical and neutron imaging data has also been evidenced. However, neutron radiography has allowed retrieving additional spatial information on the water absorption process, and to better understand how salt weathering affects the petrophysical properties of the studied stone and how it influences then the stone response against water. (orig.)

  4. Visualization and quantification of weathering effects on capillary water uptake of natural building stones by using neutron imaging

    Energy Technology Data Exchange (ETDEWEB)

    Raneri, Simona; Barone, Germana; Mazzoleni, Paolo [University of Catania, Department of Biological, Geological and Environment Sciences, Catania (Italy); Rabot, Eva [Laboratoire Leon Brillouin (CNRS/CEA), Gif-Sur-Yvette (France)

    2016-11-15

    Building stones are frequently subjected to very intense degradation due to salt crystallization, often responsible for strong modifications of their pore network. These effects have a great influence on the mechanical properties and durability of the materials, and on the penetration of water. Therefore, the quantification and visualization of water absorption into the pore network of degraded stones could provide useful information to better understand the weathering process. In this study, neutron radiography has been used (1) to monitor and visualize in two dimensions the capillary water uptake in a Sicilian calcarenite widely used as building and replace stone (namely Sabucina stone) and (2) to quantify the water content distribution, as a function of time and weathering degree. Additionally, traditional experiments based on gravimetric methods have been performed, following the standard recommendations. Results demonstrated a change in the physical properties of Sabucina stones with the intensification of the degradation process, with severe effects on the capillary imbibition dynamics. The water penetration depth at the end of the experiment was substantially higher in the fresh than in the weathered stones. The water absorption kinetics was faster in the weathered samples, and the amount of water absorbed increased with the number of weathering cycles. Good agreement between classical and neutron imaging data has also been evidenced. However, neutron radiography has allowed retrieving additional spatial information on the water absorption process, and to better understand how salt weathering affects the petrophysical properties of the studied stone and how it influences then the stone response against water. (orig.)

  5. Large area imaging of hydrogenous materials using fast neutrons from a DD fusion generator

    Energy Technology Data Exchange (ETDEWEB)

    Cremer, J.T., E-mail: ted@adelphitech.com [Adelphi Technology Inc., 2003 East Bayshore Road, Redwood City, California 94063 (United States); Williams, D.L.; Gary, C.K.; Piestrup, M.A.; Faber, D.R.; Fuller, M.J.; Vainionpaa, J.H.; Apodaca, M. [Adelphi Technology Inc., 2003 East Bayshore Road, Redwood City, California 94063 (United States); Pantell, R.H.; Feinstein, J. [Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States)

    2012-05-21

    A small-laboratory fast-neutron generator and a large area detector were used to image hydrogen-bearing materials. The overall image resolution of 2.5 mm was determined by a knife-edge measurement. Contact images of objects were obtained in 5-50 min exposures by placing them close to a plastic scintillator at distances of 1.5 to 3.2 m from the neutron source. The generator produces 10{sup 9} n/s from the DD fusion reaction at a small target. The combination of the DD-fusion generator and electronic camera permits both small laboratory and field-portable imaging of hydrogen-rich materials embedded in high density materials.

  6. Notes on LCW Activation Calculation for Neutron Imaging Operations in the North Cave of Building 194

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, S. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-09-20

    This note estimates the amount of activation that could be produced in the Facilities-provided Low Conductivity Water (LCW) that is proposed to be used for cooling of electromagnets and beam stops in the Neutron Imaging (NI) accelerator project in the North Cave of Building 194.

  7. Interaction of Water with Cement Based Repository Materials - Application of Neutron Imaging

    International Nuclear Information System (INIS)

    Mcglinn, P.J.; Brew, D.R.M.; Beer, F.C. De; Radebe, M.J.; Nshimirimana, R.

    2013-01-01

    Cementitious materials are conventionally used in conditioning intermediate and low level radioactive waste. In this study, a candidate cement-based wasteform and a series of barrier materials have been investigated using neutron imaging to: 1) characterise the wasteform for disposal in a repository for radioactive materials, and 2) characterise the compositon of the barrier materials in assessing their potential to transmit water. Imaging showed both the pore size distribution and the extent of the cracking that had occurred in the wasteform samples. The rate of the water penetration measured both by conventional sorptivity measurements and neutron imaging was greater than in pastes made from Ordinary Portland Cement. The ability of the cracks to distribute the water through the sample in a very short time was also evident. Macro-pore volume distributions of barrier samples, also acquired using neutron tomography, are shown to relate to water/cement ratio, composition and sorptivity data. The study highlights the significant potential of neutron imaging in the investigation of cementitious materials. The technique has the advantage of visualising and measuring, non-destructively, material distribution within macroscopic samples and is particularly useful in defining movement of water through the cementitious materials. (author)

  8. The use of neutron activation to detect a photographic image under a painting

    International Nuclear Information System (INIS)

    Wall, T.; Bird, R.

    1980-01-01

    Neutron activation followed by autoradiography has been used in a number of studies of oil paintings to reveal brush technique, overpainting, pigment types and other information. The facilities of the Australian Atomic Energy Commission Research Establishment have been used to investigate whether there is a photographic image underlying a painting by the Swedish born artist Carl Magnus Oscar Fristrom (1856-1919)

  9. Imaging and focussing of neutrons by a zone plate

    International Nuclear Information System (INIS)

    Kearney, P.D.; Klein, A.G.; Opat, G.I.

    1980-01-01

    The use of refractive lenses for long wavelength neutrons, though possible, is severely limited by the fact that the refractive index differs only very slightly from unity. However, only a relatively thin layer of material is needed to produce an optical path difference of half a wavelength. This fact led the authors in 1978 to propose focussing by diffraction from a phase grating of variable spacing which is, in fact, a type of zone plate. They have been shown to work satisfactorily over a wide range of the electromagnetic spectrum, from microwaves, through visible light, and more recently soft X-rays. Their use in focussing matter waves has not heretofore been demonstrated

  10. Dynamics of biopolymers on nanomaterials studied by quasielastic neutron scattering and MD simulations

    Science.gov (United States)

    Dhindsa, Gurpreet K.

    Neutron scattering has been proved to be a powerful tool to study the dynamics of biological systems under various conditions. This thesis intends to utilize neutron scattering techniques, combining with MD simulations, to develop fundamental understanding of several biologically interesting systems. Our systems include a drug delivery system containing Nanodiamonds with nucleic acid (RNA), and two specific model proteins, beta-Casein and Inorganic Pyrophosphatase (IPPase). RNA and nanodiamond (ND) both are suitable for drug-delivery applications in nano-biotechnology. The architecturally flexible RNA with catalytic functionality forms nanocomposites that can treat life-threatening diseases. The non-toxic ND has excellent mechanical and optical properties and functionalizable high surface area, and thus actively considered for biomedical applications. In this thesis, we utilized two tools, quasielastic neutron scattering (QENS) and Molecular Dynamics Simulations to probe the effect of ND on RNA dynamics. Our work provides fundamental understanding of how hydrated RNA motions are affected in the RNA-ND nanocomposites. From the experimental and Molecular Dynamics Simulation (MD), we found that hydrated RNA motion is faster on ND surface than a freestanding one. MD Simulation results showed that the failure of Stokes Einstein relation results the presence of dynamic heterogeneities in the biomacromolecules. Radial pair distribution function from MD Simulation confirmed that the hydrophilic nature of ND attracts more water than RNA results the de-confinement of RNA on ND. Therefore, RNA exhibits faster motion in the presence of ND than freestanding RNA. In the second project, we studied the dynamics of a natively disordered protein beta-Casein which lacks secondary structures. In this study, the temperature and hydration effects on the dynamics of beta-Casein are explored by Quasielastic Neutron Scattering (QENS). We investigated the mean square displacement (MSD) of

  11. Spin filtering neutrons with a proton target dynamically polarized using photo-excited triplet states

    International Nuclear Information System (INIS)

    Haag, M.; Brandt, B. van den; Eichhorn, T.R.; Hautle, P.; Wenckebach, W.Th.

    2012-01-01

    In a test of principle a neutron spin filter has been built, which is based on dynamic nuclear polarization (DNP) using photo-excited triplet states. This DNP method has advantages over classical concepts as the requirements for cryogenic equipment and magnets are much relaxed: the spin filter is operated in a field of 0.3 T at a temperature of about 100 K and has performed reliably over periods of several weeks. The neutron beam was also used to analyze the polarization of the target employed as a spin filter. We obtained an independent measurement of the proton spin polarization of ∼0.13 in good agreement with the value determined with NMR. Moreover, the neutron beam was used to measure the proton spin polarization as a function of position in the naphthalene sample. The polarization was found to be homogeneous, even at low laser power, in contradiction to existing models describing the photo-excitation process.

  12. Proton dynamics in oxides: insight into the mechanics of proton conduction from quasielastic neutron scattering.

    Science.gov (United States)

    Karlsson, Maths

    2015-01-07

    This article is concerned with the use of quasielastic neutron scattering as a technique for investigation of the dynamical properties of proton conducting oxides. Currently, the main interest in these materials comes from their promise as electrolytes in future electrochemical devices and particularly through their use as electrolytes in next-generation, intermediate-temperature, fuel cells. However, the realization of such devices depends critically on the development of new, more highly proton conducting oxides. Such a development depends on increasing the current understanding of proton conduction in oxides and for this purpose quasielastic neutron scattering is an important mean. The aim of this article is to introduce the non-specialist reader to the basic principles of quasielastic neutron scattering, its advantages and disadvantages, to summarize the work that has been done on proton conducting oxides using this technique, as well as to discuss future opportunities within this field of research.

  13. Molecular dynamical and structural studies for the bakelite by neutron cross section measurements

    International Nuclear Information System (INIS)

    Voi, D.L.

    1992-05-01

    Neutron reaction cross sections were determined by transmission and scattering measurements, to study the dynamics and molecular structure of calcined bakelites. Total cross sections were determined, with a deviation smaller than 5%, from the literature values, by neutron transmission method and a specially devised approximation. These cross sections were then correlated with data obtained with infra-red spectroscopy, elemental analysis and other techniques to get the probable molecular formulae of bakelite. Double differential scattering cross sections, scattering law values and frequency distributions were determined with 15% error using the neutron inelastic scattering method. The frequency distributions as well as the overall results from all experimental techniques used in this work allowed to suggest a structural model like polycyclic hydrocarbons, for calcined bakelite at 800 0 C. (author)

  14. Collective dynamics of protein hydration water by brillouin neutron spectroscopy.

    Science.gov (United States)

    Orecchini, Andrea; Paciaroni, Alessandro; De Francesco, Alessio; Petrillo, Caterina; Sacchetti, Francesco

    2009-04-08

    By a detailed experimental study of THz dynamics in the ribonuclease protein, we could detect the propagation of coherent collective density fluctuations within the protein hydration shell. The emerging picture indicates the presence of both a dispersing mode, traveling with a speed greater than 3000 m/s, and a nondispersing one, characterized by an almost constant energy of 6-7 meV. In agreement with molecular dynamics simulations [Phys. Rev. Lett. 2002, 89, 275501], the features of the dispersion curves closely resemble those observed in pure liquid water [Phys. Rev. E: Stat. Phys., Plasmas, Fluids, Relat. Interdiscip. Top. 2004, 69, 061203]. On the contrary, the observed damping factors are much larger than in bulk water, with the dispersing mode becoming overdamped at Q = 0.6 A(-1) already. Such novel experimental findings are discussed as a dynamic signature of the disordering effect induced by the protein surface on the local structure of water.

  15. Dynamic subcriticality measurements using the CF neutron noise method: Videotape

    Energy Technology Data Exchange (ETDEWEB)

    Mihalczo, J.T.; Blakeman, E.D.; Ragan, G.E.; Johnson, E.B.

    1987-01-01

    The capability to measure the subcriticality for a multiplying system with k-effective values as low as 0.3 was demonstrated for measurement times of approximately 10 s; the measured k-effective values obtained do not depend on the speed with which the solution height is changed or on whether the tank is filling or draining. As in previous experiments, the low-frequency ratios of spectral densities are all that are needed to obtain the k-effective value. This method's effectiveness for systems where conditions are changing with time as demonstrated, probably exceeds the dynamic requirements for most nuclear fuel plant processing applications. The calculated k-effective values using the KENO code and Hansen-Roach cross-sections compare well with the experimental values. Before the dynamic capability of the method can be considered fully explored, additional dynamic experiments are required for other geometries and fuel concentrations.

  16. Development and investigation of a neutron radiography imaging system with a low-pressure multistep chamber

    International Nuclear Information System (INIS)

    Anisimov, Yu.S.; Chernenko, S.P.; Ivanov, A.B.; Netusil, T.; Peshekhonov, V.D.; Smykov, L.P.; Zanevsky, Yu.V.; Cisar, M.; Horacek, J.; Knourek, J.; Moucka, L.; Nezmar, L.; Pellar, L.; Pochman, J.; Schneider, Z.; Sidak, Z.; Vrba, I.; Bizek, V.; Zavadil, Z.; Beran, P.; Cerny, K.

    1988-01-01

    An imaging system of thermal neutrons for an investigation of digital neutron radiography has been developed and tested. Some characteristics obtained on a neutron radiography beam of an experimental reactor are reported. The coordinates of each event are determined in this system. After processing in a LSI 11/23 computer, a radiograph, accumulated in a histogramming memory of 64 K 16-bit words, is presented on a colour display. A 230x180 mm 2 low-pressure multistep chamber is used as a detector. Neutron conversion takes place in a 6 μm boron layer enriched to 86% in 10 B. The detection efficiency of thermal neutrons is no less than 3%. The count rate of the system reaches up to 2x10 5 events per second. A radiograph can be obtained within 10 minutes. The sensitivity of this system to gamma-background is low. One event/s is detected for a background of 1 R/h. The spatial resolution is found to be 0.7 mm (FWHM) using a cadmium knife edge. The integral nonlinearity is less than 0.4%. The possibility of using a hydrogeneous converter in this system for neutron radiography is discussed. (orig.)

  17. Kinetics, dynamics and neutron noise in Molten Salt Reactors

    International Nuclear Information System (INIS)

    Pazsit, Imre

    2013-01-01

    Reactor kinetic and dynamic properties of Molten Salt Reactors (MSR) are investigated in a simple model, which allows closed compact analytical solutions to be obtained. The goal is to gain insight, rather than to produce high-quality quantitative data. Through an interpretation of the different terms in the basic equations, and by means of analytical solutions, various approximations are introduced and their validity discussed. The dynamical behaviour of MSRs and their response to small stationary perturbations is described and discussed in comparison with traditional systems. (author)

  18. Time gating for energy selection and scatter rejection: High-energy pulsed neutron imaging at LANSCE

    Science.gov (United States)

    Swift, Alicia; Schirato, Richard; McKigney, Edward; Hunter, James; Temple, Brian

    2015-09-01

    The Los Alamos Neutron Science Center (LANSCE) is a linear accelerator in Los Alamos, New Mexico that accelerates a proton beam to 800 MeV, which then produces spallation neutron beams. Flight path FP15R uses a tungsten target to generate neutrons of energy ranging from several hundred keV to ~600 MeV. The beam structure has micropulses of sub-ns width and period of 1.784 ns, and macropulses of 625 μs width and frequency of either 50 Hz or 100 Hz. This corresponds to 347 micropulses per macropulse, or 1.74 x 104 micropulses per second when operating at 50 Hz. Using a very fast, cooled ICCD camera (Princeton Instruments PI-Max 4), gated images of various objects were obtained on FP15R in January 2015. Objects imaged included blocks of lead and borated polyethylene; a tungsten sphere; and a tungsten, polyethylene, and steel cylinder. Images were obtained in 36 min or less, with some in as little as 6 min. This is novel because the gate widths (some as narrow as 10 ns) were selected to reject scatter and other signal not of interest (e.g. the gamma flash that precedes the neutron pulse), which has not been demonstrated at energies above 14 MeV. This proof-of-principle experiment shows that time gating is possible above 14MeV and is useful for selecting neutron energy and reducing scatter, thus forming clearer images. Future work (simulation and experimental) is being undertaken to improve camera shielding and system design and to precisely determine optical properties of the imaging system.

  19. Beam dynamics simulation of the Spallation Neutron Source linear accelerator

    International Nuclear Information System (INIS)

    Takeda, H.; Billen, J.H.; Bhatia, T.S.

    1998-01-01

    The accelerating structure for Spallation Neutron Source (SNS) consists of a radio-frequency-quadrupole-linac (RFQ), a drift-tube-linac (DTL), a coupled-cavity-drift-tube-linac (CCDTL), and a coupled-cavity-linac (CCL). The linac is operated at room temperature. The authors discuss the detailed design of linac which accelerates an H - pulsed beam coming out from RFQ at 2.5 MeV to 1000 MeV. They show a detailed transition from 402.5 MHz DTL with a 4 βλ structure to a CCDTL operated at 805 MHz with a 12 βλ structure. After a discussion of overall feature of the linac, they present an end-to-end particle simulation using the new version of the PARMILA code for a beam starting from the RFQ entrance through the rest of the linac. At 1000 MeV, the beam is transported to a storage ring. The storage ring requires a large (±500-keV) energy spread. This is accomplished by operating the rf-phase in the last section of the linac so the particles are at the unstable fixed point of the separatrix. They present zero-current phase advance, beam size, and beam emittance along the entire linac

  20. Use and imaging performance of CMOS flat panel imager with LiF/ZnS(Ag) and Gadox scintillation screens for neutron radiography

    Science.gov (United States)

    Cha, B. K.; kim, J. Y.; Kim, T. J.; Sim, C.; Cho, G.; Lee, D. H.; Seo, C.-W.; Jeon, S.; Huh, Y.

    2011-01-01

    In digital neutron radiography system, a thermal neutron imaging detector based on neutron-sensitive scintillating screens with CMOS(complementary metal oxide semiconductor) flat panel imager is introduced for non-destructive testing (NDT) application. Recently, large area CMOS APS (active-pixel sensor) in conjunction with scintillation films has been widely used in many digital X-ray imaging applications. Instead of typical imaging detectors such as image plates, cooled-CCD cameras and amorphous silicon flat panel detectors in combination with scintillation screens, we tried to apply a scintillator-based CMOS APS to neutron imaging detection systems for high resolution neutron radiography. In this work, two major Gd2O2S:Tb and 6LiF/ZnS:Ag scintillation screens with various thickness were fabricated by a screen printing method. These neutron converter screens consist of a dispersion of Gd2O2S:Tb and 6LiF/ZnS:Ag scintillating particles in acrylic binder. These scintillating screens coupled-CMOS flat panel imager with 25x50mm2 active area and 48μm pixel pitch was used for neutron radiography. Thermal neutron flux with 6x106n/cm2/s was utilized at the NRF facility of HANARO in KAERI. The neutron imaging characterization of the used detector was investigated in terms of relative light output, linearity and spatial resolution in detail. The experimental results of scintillating screen-based CMOS flat panel detectors demonstrate possibility of high sensitive and high spatial resolution imaging in neutron radiography system.

  1. A QUANTITATIVE EVALUATION OF THE WATER DISTRIBUTION IN A SOIL SAMPLE USING NEUTRON IMAGING

    Directory of Open Access Journals (Sweden)

    Jan Šácha

    2016-10-01

    Full Text Available This paper presents an empirical method by Kang et al. recently proposed for correcting two-dimensional neutron radiography for water quantification in soil. The method was tested on data from neutron imaging of the water infiltration in a soil sample. The raw data were affected by neutron scattering and by beam hardening artefacts. Two strategies for identifying the correction parameters are proposed in this paper. The method has been further developed for the case of three-dimensional neutron tomography. In a related experiment, neutron imaging is used to record ponded-infiltration experiments in two artificial soil samples. Radiograms, i.e., two-dimensional projections of the sample, were acquired during infiltration. A calculation was made of the amount of water and its distribution within the radiograms, in the form of two-dimensional water thickness maps. Tomograms were reconstructed from the corrected and uncorrected water thickness maps to obtain the 3D spatial distribution of the water content within the sample. Without the correction, the beam hardening and the scattering effects overestimated the water content values close to the perimeter of the sample, and at the same time underestimated the values close to the centre of the sample. The total water content of the entire sample was the same in both cases. The empirical correction method presented in this study is a relatively accurate, rapid and simple way to obtain the quantitatively determined water content from two-dimensional and three-dimensional neutron images. However, an independent method for measuring the total water volume in the sample is needed in order to identify the correction parameters.

  2. Usefulness of dynamic magnetic resonance imaging in pituitary microadenomas

    International Nuclear Information System (INIS)

    Rhee, Chang Soo; Lee, Eun Young; Joo, Yang Gu; Kim, Hong; Lee, Hee Jung; Sch, Soo Ji

    1996-01-01

    To investigate the usefulness of dynamic MR imaging in the diagnosis of pituitary microadenomas. Dynamic MR imaging was performed in 31 patients with suspicious pituitary microadinoma. The MR examination was performed on a 2.0T or 1.5T superconductive MR unit using spin echo(SE) technique with a repetition time of 200msec, echo time of 15 msec, 128X256 matrix and one excitation. Actual sampling time per image was 26 seconds. The field of view was 25cm and a section thickness if 3 mm with 2mm gap was chose. After a rapid hand injection(2-3ml/sec) of Gd-DTPA(0.1 mmol/kg of body weight), dynamic coronal plane MR images were obtained every 20-30 seconds for 3-5 minutes. Between never and ten serial images were usually obtained. After dynamic MR imaging, toutine SE T1-weighted images(T1W1) were obtained in the same plane as dynamic images, and detection rates of pituitary microadinoma using dynamic MR imaging and using routine enhanced T1W1, were retrospectively compared. On early dynamic images(30-90 seconds), 23 of 31 adenomas(74.2%) were well visualized at 30-second dynamic image. On late dynamic images(120-180 seconds), six microadeomas(19.4%) were well-visualized and ; two(6.5%) were well-visualized on toutine Gd-DTPA enhanced T1W1. dynamic MR imaging with Gd-DTPA bolus injection was the most useful technique for the detection of pituitary microadenoma, especially on early-phase dynamic images

  3. PREFACE: Structure and dynamics determined by neutron and x-ray scattering Structure and dynamics determined by neutron and x-ray scattering

    Science.gov (United States)

    Müller-Buschbaum, Peter

    2011-06-01

    Neutron and x-ray scattering have emerged as powerful methods for the determination of structure and dynamics. Driven by emerging new, powerful neutron and synchrotron radiation sources, the continuous development of new instrumentation and novel scattering techniques gives rise to exciting possibilities. For example, in situ observations become possible via a high neutron or x-ray flux at the sample and, as a consequence, morphological transitions with small time constants can be detected. This special issue covers a broad range of different materials from soft to hard condensed matter. Hence, different material classes such as colloids, polymers, alloys, oxides and metals are addressed. The issue is dedicated to the 60th birthday of Professor Winfried Petry, scientific director of the Research Neutron Source Heinz Maier-Leibnitz (FRM-II), Germany, advisor at the physics department for the Bayerische Elite-Akademie, chair person of the Arbeitsgemeinschaft Metall- und Materialphysik of the German Physical Society (DPG) and a member of the professional council of the German Science Foundation (Deutsche Forschungsgemeinschaft, DFG). We would like to acknowledge and thank all contributors for their submissions, which made this special issue possible in the first place. Moreover, we would like to thank the staff at IOP Publishing for helping us with the administrative aspects and for coordinating the refereeing process, and Valeria Lauter for the beautiful cover artwork. Finally, to the readers, we hope that you find this special issue a valuable resource that provides insights into the present possibilities of neutron and x-ray scattering as powerful tools for the investigation of structure and dynamics. Structure and dynamics determined by neutron and x-ray scattering contents In situ studies of mass transport in liquid alloys by means of neutron radiography F Kargl, M Engelhardt, F Yang, H Weis, P Schmakat, B Schillinger, A Griesche and A Meyer Magnetic spin

  4. ASIC Development for Three-Dimensional Silicon Imaging Array for Cold Neutrons

    International Nuclear Information System (INIS)

    Britton, C.L.; Jagadish, U.; Bryan, W.L.

    2004-01-01

    An Integrated Circuit (IC) readout chip with four channels arranged so as to receive input charge from the corners of the chip was designed for use with 5- to 7-mm pixel detectors. This Application Specific IC (ASIC) can be used for cold neutron imaging, for study of structural order in materials using cold neutron scattering or for particle physics experiments. The ASIC is fabricated in a 0.5-(micro)m n-well AMI process. The design of the ASIC and the test measurements made is reported. Noise measurements are also reported

  5. Image processing and resolution restoration of fast-neutron hodoscope data

    International Nuclear Information System (INIS)

    Rhodes, E.A.; DeVolpi, A.

    1982-01-01

    The fast-neutron hodoscope is a cineradiographic device that monitors fuel motion within thick opaque test capsules during radiation transients at the Transient Reactor Test Facility reactor which simulate accident conditions in power reactors. By means of a collimator and detector array, emissive neutron radiographic digital data is collected in time-resolved and static (scan) modes. Data is digitally reconstructed into raidographic images and used directly for quantitative analysis. Spatial resolution is adequate in most cases, but is marginal for a few experiments. Collimator repositioning, scan increment size-reduction, and deconvolution algorithms are being applied to improve resolution of existing collimators

  6. Inelastic neutron scattering experiments with the monochromatic imaging mode of the RITA-II spectrometer

    International Nuclear Information System (INIS)

    Bahl, C.R.H.; Lefmann, K.; Abrahamsen, A.B.; Ronnow, H.M.; Saxild, F.; Jensen, T.B.S.; Udby, L.; Andersen, N.H.; Christensen, N.B.; Jakobsen, H.S.; Larsen, T.; Haefliger, P.S.; Streule, S.; Niedermayer, Ch.

    2006-01-01

    Recently a monochromatic multiple data taking mode has been demonstrated for diffraction experiments using a RITA type cold neutron spectrometer with a multi-bladed analyser and a position-sensitive detector. Here, we show how this mode can be used in combination with a flexible radial collimator to perform real inelastic neutron scattering experiments. We present the results from inelastic powder, single crystal dispersion and single crystal constant energy mapping experiments. The advantages and complications of performing these experiments are discussed along with a comparison between the imaging mode and the traditional monochromatic focussing mode

  7. Inelastic neutron scattering experiments with the monochromatic imaging mode of the RITA-II spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Bahl, C.R.H. [Department of Materials Research, Riso National Laboratory, Building 227, Frederiksborgvej 399, DK-4000 Roskilde (Denmark) and Department of Physics, Technical University of Denmark, DK-2800 Lyngby (Denmark)]. E-mail: christian.bahl@risoe.dk; Lefmann, K. [Department of Materials Research, Riso National Laboratory, Building 227, Frederiksborgvej 399, DK-4000 Roskilde (Denmark)]. E-mail: kim.lefmann@risoe.dk; Abrahamsen, A.B. [Department of Materials Research, Riso National Laboratory, Building 227, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Ronnow, H.M. [Laboratory for Neutron Scattering, Paul Scherrer Institute, CH-5232 Villigen (Switzerland); Saxild, F. [Department of Materials Research, Riso National Laboratory, Building 227, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Jensen, T.B.S. [Department of Materials Research, Riso National Laboratory, Building 227, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Udby, L. [Department of Materials Research, Riso National Laboratory, Building 227, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Andersen, N.H. [Department of Materials Research, Riso National Laboratory, Building 227, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Christensen, N.B. [Department of Materials Research, Riso National Laboratory, Building 227, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Laboratory for Neutron Scattering, Paul Scherrer Institute, CH-5232 Villigen (Switzerland); Jakobsen, H.S. [Niels Bohr Institute for Astronomy, Physics and Geophysics, University of Copenhagen, DK-2100 Copenhagen (Denmark); Larsen, T. [Niels Bohr Institute for Astronomy, Physics and Geophysics, University of Copenhagen, DK-2100 Copenhagen (Denmark); Haefliger, P.S. [Laboratory for Neutron Scattering, Paul Scherrer Institute, CH-5232 Villigen (Switzerland); Streule, S.; Niedermayer, Ch. [Laboratory for Neutron Scattering, Paul Scherrer Institute, CH-5232 Villigen (Switzerland)

    2006-05-15

    Recently a monochromatic multiple data taking mode has been demonstrated for diffraction experiments using a RITA type cold neutron spectrometer with a multi-bladed analyser and a position-sensitive detector. Here, we show how this mode can be used in combination with a flexible radial collimator to perform real inelastic neutron scattering experiments. We present the results from inelastic powder, single crystal dispersion and single crystal constant energy mapping experiments. The advantages and complications of performing these experiments are discussed along with a comparison between the imaging mode and the traditional monochromatic focussing mode.

  8. How to observe water movement in plants using neutron imaging

    International Nuclear Information System (INIS)

    Matsushima, Uzuki

    2011-01-01

    Water in plants is one of the most important factors for life. Water availability, water distribution and water flow also regulate various plant physiological phenomena. However, non-destructive methods for the in-situ study of water transport are quite limited. Neutron Radiography (NR) seem to be appropriate methods to study water distribution in intact plants. Also the combination of NR with the low-contrast tracer D 2 O allows the direct visualization of water flow and the calculation of water flow rates in plants with a high resolution at the tissue level. This article gives general introduction into those two methods and report about most recent results of our experiments in this field. (author)

  9. Self characterization of a coded aperture array for neutron source imaging

    Energy Technology Data Exchange (ETDEWEB)

    Volegov, P. L., E-mail: volegov@lanl.gov; Danly, C. R.; Guler, N.; Merrill, F. E.; Wilde, C. H. [Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States); Fittinghoff, D. N. [Livermore National Laboratory, Livermore, California 94550 (United States)

    2014-12-15

    The neutron imaging system at the National Ignition Facility (NIF) is an important diagnostic tool for measuring the two-dimensional size and shape of the neutrons produced in the burning deuterium-tritium plasma during the stagnation stage of inertial confinement fusion implosions. Since the neutron source is small (∼100 μm) and neutrons are deeply penetrating (>3 cm) in all materials, the apertures used to achieve the desired 10-μm resolution are 20-cm long, triangular tapers machined in gold foils. These gold foils are stacked to form an array of 20 apertures for pinhole imaging and three apertures for penumbral imaging. These apertures must be precisely aligned to accurately place the field of view of each aperture at the design location, or the location of the field of view for each aperture must be measured. In this paper we present a new technique that has been developed for the measurement and characterization of the precise location of each aperture in the array. We present the detailed algorithms used for this characterization and the results of reconstructed sources from inertial confinement fusion implosion experiments at NIF.

  10. Spatial resolution limit study of a CCD camera and scintillator based neutron imaging system according to MTF determination and analysis

    International Nuclear Information System (INIS)

    Kharfi, F.; Denden, O.; Bourenane, A.; Bitam, T.; Ali, A.

    2012-01-01

    Spatial resolution limit is a very important parameter of an imaging system that should be taken into consideration before examination of any object. The objectives of this work are the determination of a neutron imaging system's response in terms of spatial resolution. The proposed procedure is based on establishment of the Modulation Transfer Function (MTF). The imaging system being studied is based on a high sensitivity CCD neutron camera (2×10 −5 lx at f1.4). The neutron beam used is from the horizontal beam port (H.6) of the Algerian Es-Salam research reactor. Our contribution is on the MTF determination by proposing an accurate edge identification method and a line spread function undersampling problem-resolving procedure. These methods and procedure are integrated into a MatLab code. The methods, procedures and approaches proposed in this work are available for any other neutron imaging system and allow for judging the ability of a neutron imaging system to produce spatial (internal details) properties of any object under examination. - Highlights: ► Determination of spatial response of a neutron imaging system. ► Ability of a neutron imaging system to reproduce spatial properties of any object. ► Spatial resolution limits measurement using MTF with the slanted edge method. ► Accurate edge identification and line spread function sampling improvement. ► Development of a MatLab code to compute automatically the MTF.

  11. Evaluations of the new LiF-scintillator and optional brightness enhancement films for neutron imaging

    Energy Technology Data Exchange (ETDEWEB)

    Iikura, H., E-mail: Iikura.hiroshi@jaea.go.jp [Japan Atomic Energy Agency, 2-4 Shirakata-shirane, Tokai-mura, Naka-gun, Ibaraki (Japan); Tsutsui, N. [Chichibu Fuji Co., Ltd., Ogano, Chichibu, Saitama 368-0193 (Japan); Nakamura, T.; Katagiri, M.; Kureta, M. [Japan Atomic Energy Agency, 2-4 Shirakata-shirane, Tokai-mura, Naka-gun, Ibaraki (Japan); Kubo, J. [Nissan Motor Co., Ltd., Atsugi, Kanagawa 243-0126 (Japan); Matsubayashi, M. [Japan Atomic Energy Agency, 2-4 Shirakata-shirane, Tokai-mura, Naka-gun, Ibaraki (Japan)

    2011-09-21

    Japan Atomic Energy Agency has developed the neutron scintillator jointly with Chichibu Fuji Co., Ltd. In this study, we evaluated the new ZnS(Ag):Al/{sup 6}Li scintillator developed for neutron imaging. It was confirmed that the brightness increased by about double while maintaining equal performance for the spatial resolution as compared with a conventional scintillator. High frame-rate imaging using a high-speed video camera system and this new scintillator made it possible to image beyond 10 000 frames per second while still having enough brightness. This technique allowed us to obtain a high-frame-rate visualization of oil flow in a running car engine. Furthermore, we devised a technique to increase the light intensity of reception for a camera by adding brightness enhancement films on the output surface of the scintillator. It was confirmed that the spatial resolution degraded more than double, but the brightness increased by about three times.

  12. Summary of the first neutron image data collected at the National Ignition Facility

    Directory of Open Access Journals (Sweden)

    Grim Gary P.

    2013-11-01

    Full Text Available A summary of data and results from the first neutron images produced by the National Ignition Facility (NIF, Lawrence Livermore National Laboratory, Livermore, CA, USA are presented. An overview of the neutron imaging technique is presented, as well as a synopsis of data and measurements made to date. Data from directly driven, DT filled microballoons, as well as indirectly driven, cryogenically layered ignition experiments are presented. The data show that the primary cores from directly driven implosions are approximately twice as large, 64 ± 3 μm, as indirectly driven cores, 25 ± 4 and 29 ± 4 μm and more asymmetric, P2/P0 = 47% vs. − 14% and 7%. Further, comparison with the size and shape of X-ray image data on the same implosions show good agreement, indicating X-ray emission is dominated by the hot regions of the implosion.

  13. Hydration-dependent dynamics of human telomeric oligonucleotides in the picosecond timescale: A neutron scattering study

    Energy Technology Data Exchange (ETDEWEB)

    Sebastiani, F.; Comez, L.; Sacchetti, F. [Dipartimento di Fisica e Geologia, Università degli Studi di Perugia, Via A. Pascoli, 06123 Perugia (Italy); CNR, Istituto Officina dei Materiali, Unità di Perugia, c/o Dipartimento di Fisica e Geologia, Università di Perugia, 06123 Perugia (Italy); Longo, M. [Dipartimento di Fisica e Geologia, Università degli Studi di Perugia, Via A. Pascoli, 06123 Perugia (Italy); Elettra—Sincrotrone Trieste, 34149 Basovizza, Trieste (Italy); Orecchini, A.; Petrillo, C.; Paciaroni, A., E-mail: alessandro.paciaroni@fisica.unipg.it [Dipartimento di Fisica e Geologia, Università degli Studi di Perugia, Via A. Pascoli, 06123 Perugia (Italy); De Francesco, A. [CNR-IOM OGG c/o Institut Laue-Langevin, 71 Avenue des Martyrs, CS20156, 38042 Grenoble Cedex 9 (France); Muthmann, M. [Jülich Centre for Neutron Science, Forschungszentrum Jülich GmbH, Outstation at Heinz Maier-Leibnitz Zentrum, Lichtenbergstrasse 1, 85747 Garching (Germany); Teixeira, S. C. M. [EPSAM, Keele University, Staffordshire ST5 5BG (United Kingdom); Institut Laue–Langevin, 71 Avenue des Martyrs, CS20156, 38042 Grenoble Cedex 9 (France)

    2015-07-07

    The dynamics of the human oligonucleotide AG{sub 3}(T{sub 2}AG{sub 3}){sub 3} has been investigated by incoherent neutron scattering in the sub-nanosecond timescale. A hydration-dependent dynamical activation of thermal fluctuations in weakly hydrated samples was found, similar to that of protein powders. The amplitudes of such thermal fluctuations were evaluated in two different exchanged wave-vector ranges, so as to single out the different contributions from intra- and inter-nucleotide dynamics. The activation energy was calculated from the temperature-dependent characteristic times of the corresponding dynamical processes. The trends of both amplitudes and activation energies support a picture where oligonucleotides possess a larger conformational flexibility than long DNA sequences. This additional flexibility, which likely results from a significant relative chain-end contribution to the average chain dynamics, could be related to the strong structural polymorphism of the investigated oligonucleotides.

  14. SU-F-J-196: A Prototype System for Portal Imaging for Intensity Modulated Neutron Therapy

    Energy Technology Data Exchange (ETDEWEB)

    St James, S; Argento, D; DeWitt, D; Miyaoka, R; Stewart, R [University of Washington, Seattle, WA (United States); Moffitt, G [University of Utah, Salt Lake City, UT (United States)

    2016-06-15

    Purpose: Fast neutron therapy is offered at the University of Washington Medical Center for treatment of selected cancers. The hardware and control systems of the UW Clinical Neutron Therapy System are undergoing upgrades to enable delivery of IMNT. To clinically implement IMNT, dose verification tools need to be developed. We propose a portal imaging system that relies on the creation of positron emitting isotopes ({sup 11}C and {sup 15}O) through (n, 2n) reactions with a PMMA plate placed below the patient. After field delivery, the plate is retrieved from the vault and imaged using a reader that detects the annihilation photons. The pattern of activity produced in the plate provides information to reconstruct the neutron fluence map that can be compared to fluence maps from Monte Carlo (MCNP) simulations to verify treatment delivery. We have previously performed Monte Carlo simulations of the portal imaging system (GATE simulations) and the beam line (MCNP simulations). In this work, initial measurements using a prototype system are presented. Methods: Custom electronics were developed for BGO detectors read out with photomultiplier tubes (previous generation PET detectors from a CTI ECAT 953 scanner). Two detectors were placed in coincidence, with a detector separation of 2 cm. Custom software was developed to create the crystal look up tables and perform a limited angle planar reconstruction with a stochastic normalization. To test the initial capabilities of the system, PMMA squares were irradiated with neutrons at a depth of 1.5 cm and read out using the prototype system. Doses ranging from 10–200 cGy were delivered. Results: Using the prototype system, dose differences in the therapeutic range could be determined. Conclusion: The prototype portal imaging system is capable of detecting neutron doses as low as 10–50 cGy and shows great promise as a patient QA tool for IMNT.

  15. Japan: Overview of activities on Neutron Imaging (NI) and Cultural Heritage (CH) studies

    International Nuclear Information System (INIS)

    Kiyanagi, Yoshiaki

    2012-01-01

    The pulsed neutron imaging using the time-of-flight method can give structural information on materials by using the characteristic features of the wavelength dependent neutron transmission. The crystal structure (lattice spacing), crystallite size, and preferred orientation in metal materials are investigated by analyzing the Bragg edge shapes and the elements by the resonance absorption peaks. Such information is important for characterizing the steels and other metal products, and only our group has the data analysis code for deducing such information. It is useful to apply the pulsed neutron imaging to the cultural heritages since the method helps to understand smithing and smelting processes of the specimens. The transmission method gives position dependent information and the diffraction gives complemental and more detailed data for the crystal structures and the textures. Therefore, the combined use of these methods is very useful for studying rigorously the crystal structure of cultural heritage samples. We have already collaborated with the Italian group for this direction, since the group has been performing the diffraction study. Therefore, we promote the research collaboratively for comprehensive and rigorous understanding of the crystallographic characteristics of the cultural heritages and archaeological specimens. The main object of this study is to obtain comprehensive crystallographic information of the cultural heritages and archaeological specimens. The main object of this study is to obtain comprehensive crystallographic information of the cultural heritages and the smithing and the smelting. To obtain such outcomes we are planning to perform mainly the pulsed neutron imaging using NOBORU at J-PARC, HUNS at Hokkaido University and INES at ISIS. We are the only group that can obtain the crystallographic images by using the pulsed neutron experiments coupled with the data analysis code we developed. In parallel we improve the Bragg edge analysis

  16. On the dynamics of polymers in dense systems - Results of neutron spin echo spectroscopy

    International Nuclear Information System (INIS)

    Richter, D.

    1997-01-01

    One of the basic problems in the dynamics of polymers concerns the importance of geometrical or topological interactions which are directly related to the large scale molecular structures. In the famous reptation model these constraints are pictured in terms of a tube of localization following the average chain profile and confining the chain motion to the curve-linear tube. Recently studying the dynamic structure factor of a single labeled chain in a polymer melt by means of neutron spin echo spectroscopy (NSE) led to a direct observation of these tube constraints. Here I shall summarize these neutron spin echo experiments. I shall address the NSE technique, present results on the entropy driven segmental chain dynamics, discuss the dynamics of single chains in the melt where the chain length is increased through the transition to 'reptation' dynamics and display NSE measurements on long chain systems which revealed the molecular existence of the entanglement distance. Their magnitudes agree very well with tube diameters derived from dynamical mechanical measurements on the basis of the reptation model proving thereby the basic assumption of this Nobel Price winning concept

  17. Summary of dynamic analyses of the advanced neutron source reactor inner control rods

    International Nuclear Information System (INIS)

    Hendrich, W.R.

    1995-08-01

    A summary of the structural dynamic analyses that were instrumental in providing design guidance to the Advanced Neutron source (ANS) inner control element system is presented in this report. The structural analyses and the functional constraints that required certain performance parameters were combined to shape and guide the design effort toward a prediction of successful and reliable control and scram operation to be provided by these inner control rods

  18. Dynamical scaling in polymer solutions investigated by the neutron spin echo technique

    International Nuclear Information System (INIS)

    Richter, D.; Ewen, B.

    1979-01-01

    Chain dynamics in polymer solutions was investigated by means of the recently developed neutron spin echo spectroscopy. - By this technique, it was possible for the first time to verify unambiguously the scaling predictions of the Zimm model in the case of single chain behaviour and to observe the cross over to many chain behaviour. The segmental diffusion of single chains exhibits deviations from a simple exponential law, indicating the importance of memory effects. (orig.) [de

  19. Analysis of critical neutron- scattering data from iron and dynamical scaling theory

    DEFF Research Database (Denmark)

    Als-Nielsen, Jens Aage

    1970-01-01

    Experimental three- axis spectrometer data of critical neutron- scattering data from Fe are reanalyzed and compared with the recent theoretical prediction by P. Resibois and C. Piette. The reason why the spin- diffusion parameter did not obey the prediction of dynamical scaling theory is indicated....... Double- axis spectrometer data have previously been interpreted in terms of a non- Lorentzian susceptibility. It is shown that with proper corrections for the inelasticity of the scattering the data are consistent with a Lorentzian form of susceptibility....

  20. Hydration of the chloride ion in concentrated aqueous solutions using neutron scattering and molecular dynamics

    Czech Academy of Sciences Publication Activity Database

    Pluhařová, Eva; Fischer, H. E.; Mason, Philip E.; Jungwirth, Pavel

    2014-01-01

    Roč. 112, 9/10 (2014), s. 1230-1240 ISSN 0026-8976 R&D Projects: GA ČR GBP208/12/G016; GA MŠk LH12001 Grant - others:GA MŠk(CZ) LM2010005 Institutional support: RVO:61388963 Keywords : lithium * solution * molecular dynamics * chloride * neutron scattering Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.720, year: 2014

  1. Effects of geochemical composition on neutron die-away measurements: Implications for Mars Science Laboratory's Dynamic Albedo of Neutrons experiment

    Energy Technology Data Exchange (ETDEWEB)

    Hardgrove, C., E-mail: craig.hardgrove@stonybrook.edu [Department of Earth and Planetary Science, University of Tennessee, Knoxville, TN (United States); Moersch, J.; Drake, D. [Techsource, Santa Fe, NM (United States)

    2011-12-11

    The Dynamic Albedo of Neutrons (DAN) experiment, part of the scientific payload of the Mars Science Laboratory (MSL) rover mission, will have the ability to assess both the abundance and the burial depth of subsurface hydrogen as the rover traverses the Martian surface. DAN will employ a method of measuring neutron fluxes called 'neutron die-away' that has not been used in previous planetary exploration missions. This method requires the use of a pulsed neutron generator that supplements neutrons produced via spallation in the subsurface by the cosmic ray background. It is well established in neutron remote sensing that low-energy (thermal) neutrons are sensitive not only to hydrogen content, but also to the macroscopic absorption cross-section of near-surface materials. To better understand the results that will be forthcoming from DAN, we model the effects of varying abundances of high absorption cross-section elements that are likely to be found on the Martian surface (Cl, Fe) on neutron die-away measurements made from a rover platform. Previously, the Mars Exploration Rovers (MER) Spirit and Opportunity found that elevated abundances of these two elements are commonly associated with locales that have experienced some form of aqueous activity in the past, even though hydrogen-rich materials are not necessarily still present. By modeling a suite of H and Cl compositions, we demonstrate that (for abundance ranges reasonable for Mars) both the elements will significantly affect DAN thermal neutron count rates. Additionally, we show that the timing of thermal neutron arrivals at the detector can be used together with the thermal neutron count rates to independently determine the abundances of hydrogen and high neutron absorption cross-section elements (the most important being Cl). Epithermal neutron die-away curves may also be used to separate these two components. We model neutron scattering in actual Martian compositions that were determined by the MER

  2. Neutron rich clusters and the dynamics of fission and fusion

    International Nuclear Information System (INIS)

    Armbruster, P.

    1988-07-01

    In this lecture I want to discuss experimental evidence for the appearance of cluster aspects in the dynamics of large rearrangement processes, as fusion and fission. Clusters in the sense as used in my lecture are the strongly bound doubly magic nuclei as 20 Ca 28 48 , 28 Ni 50 78 , 132 50 Sn 82 , and 208 82 Pb 126 and the superheavy nucleus 298 114 184 . Two of these nuclei, 78 Ni and 298 114 have not yet been identified. I discuss first the experimental findings from heavy element production. Then I cover the stability of cluster aspects to intrinsic excitation energy in fusion and fission. (orig./HSI)

  3. Sealed operation of a rf driven ion source for a compact neutron generator to be used for associated particle imaging.

    Science.gov (United States)

    Wu, Y; Hurley, J P; Ji, Q; Kwan, J W; Leung, K N

    2010-02-01

    We present the recent development of a prototype compact neutron generator to be used in conjunction with the method of associated particle imaging for the purpose of active neutron interrogation. In this paper, the performance and device specifications of these compact generators that employ rf driven ion sources will be discussed. Initial measurements of the generator performance include a beam spot size of 1 mm in diameter and a neutron yield of 2x10(5) n/s with air cooling.

  4. Image Alignment for Multiple Camera High Dynamic Range Microscopy

    OpenAIRE

    Eastwood, Brian S.; Childs, Elisabeth C.

    2012-01-01

    This paper investigates the problem of image alignment for multiple camera high dynamic range (HDR) imaging. HDR imaging combines information from images taken with different exposure settings. Combining information from multiple cameras requires an alignment process that is robust to the intensity differences in the images. HDR applications that use a limited number of component images require an alignment technique that is robust to large exposure differences. We evaluate the suitability fo...

  5. Evidence for Dynamically Driven Formation of the GW170817 Neutron Star Binary in NGC 4993

    Energy Technology Data Exchange (ETDEWEB)

    Palmese, A.; et al.

    2017-11-09

    We present a study of NGC 4993, the host galaxy of the GW170817 gravitational wave event, the GRB170817A short gamma-ray burst (sGRB) and the AT2017gfo kilonova. We use Dark Energy Camera imaging, AAT spectra and publicly available data, relating our findings to binary neutron star (BNS) formation scenarios and merger delay timescales. NGC4993 is a nearby (40 Mpc) early-type galaxy, with $i$-band S\\'ersic index $n=4.0$ and low asymmetry ($A=0.04\\pm 0.01$). These properties are unusual for sGRB hosts. However, NGC4993 presents shell-like structures and dust lanes indicative of a recent galaxy merger, with the optical transient located close to a shell. We constrain the star formation history (SFH) of the galaxy assuming that the galaxy merger produced a star formation burst, but find little to no on-going star formation in either spatially-resolved broadband SED or spectral fitting. We use the best-fit SFH to estimate the BNS merger rate in this type of galaxy, as $R_{NSM}^{gal}= 5.7^{+0.57}_{-3.3} \\times 10^{-6} {\\rm yr}^{-1}$. If star formation is the only considered BNS formation scenario, the expected number of BNS mergers from early-type galaxies detectable with LIGO during its first two observing seasons is $0.038^{+0.004}_{-0.022}$, as opposed to $\\sim 0.5$ from all galaxy types. Hypothesizing that the binary system formed due to dynamical interactions during the galaxy merger, the subsequent time elapsed can constrain the delay time of the BNS coalescence. By using velocity dispersion estimates and the position of the shells, we find that the galaxy merger occurred $t_{\\rm mer}\\lesssim 200~{\\rm Myr}$ prior to the BNS coalescence.

  6. Evidence for Dynamically Driven Formation of the GW170817 Neutron Star Binary in NGC 4993

    Science.gov (United States)

    Palmese, A.; Hartley, W.; Tarsitano, F.; Conselice, C.; Lahav, O.; Allam, S.; Annis, J.; Lin, H.; Soares-Santos, M.; Tucker, D.; Brout, D.; Banerji, M.; Bechtol, K.; Diehl, H. T.; Fruchter, A.; García-Bellido, J.; Herner, K.; Levan, A. J.; Li, T. S.; Lidman, C.; Misra, K.; Sako, M.; Scolnic, D.; Smith, M.; Abbott, T. M. C.; Abdalla, F. B.; Benoit-Lévy, A.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; Castander, F. J.; Cunha, C. E.; D'Andrea, C. B.; da Costa, L. N.; Davis, C.; DePoy, D. L.; Desai, S.; Dietrich, J. P.; Doel, P.; Drlica-Wagner, A.; Eifler, T. F.; Evrard, A. E.; Flaugher, B.; Fosalba, P.; Frieman, J.; Gaztanaga, E.; Gerdes, D. W.; Giannantonio, T.; Gruen, D.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; Honscheid, K.; Jain, B.; James, D. J.; Jeltema, T.; Johnson, M. W. G.; Johnson, M. D.; Krause, E.; Kron, R.; Kuehn, K.; Kuhlmann, S.; Kuropatkin, N.; Lima, M.; Maia, M. A. G.; March, M.; Marshall, J. L.; McMahon, R. G.; Menanteau, F.; Miller, C. J.; Miquel, R.; Neilsen, E.; Ogando, R. L. C.; Plazas, A. A.; Reil, K.; Romer, A. K.; Sanchez, E.; Schindler, R.; Smith, R. C.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Thomas, R. C.; Walker, A. R.; Weller, J.; Zhang, Y.; Zuntz, J.

    2017-11-01

    We present a study of NGC 4993, the host galaxy of the GW170817 gravitational-wave event, the GRB 170817A short gamma-ray burst (sGRB), and the AT 2017gfo kilonova. We use Dark Energy Camera imaging, AAT spectra, and publicly available data, relating our findings to binary neutron star (BNS) formation scenarios and merger delay timescales. NGC 4993 is a nearby early-type galaxy, with an I-band Sérsic index n = 4.0 and low asymmetry (A = 0.04 ± 0.01). These properties are unusual for sGRB hosts. However, NGC 4993 presents shell-like structures and dust lanes indicative of a recent galaxy merger, with the optical transient located close to a shell. We constrain the star formation history (SFH) of the galaxy assuming that the galaxy merger produced a star formation burst, but find little to no ongoing star formation in either spatially resolved broadband SED or spectral fitting. We use the best-fit SFH to estimate the BNS merger rate in this type of galaxy, as {R}{NSM}{gal}={5.7}-3.3+0.57× {10}-6{{yr}}-1. If star formation is the only considered BNS formation scenario, the expected number of BNS mergers from early-type galaxies detectable with LIGO during its first two observing seasons is {0.038}-0.022+0.004, as opposed to ˜0.5 from all galaxy types. Hypothesizing that the binary formed due to dynamical interactions during the galaxy merger, the subsequent time elapsed can constrain the delay time of the BNS coalescence. By using velocity dispersion estimates and the position of the shells, we find that the galaxy merger occurred t mer ≲ 200 Myr prior to the BNS coalescence.

  7. Optical imaging of tumor hypoxia dynamics

    Science.gov (United States)

    Palmer, Gregory M.; Fontanella, Andrew N.; Zhang, Guoqing; Hanna, Gabi; Fraser, Cassandra L.; Dewhirst, Mark W.

    2010-11-01

    The influence of the tumor microenvironment and hypoxia plays a significant role in determining cancer progression, treatment response, and treatment resistance. That the tumor microenvironment is highly heterogeneous with significant intratumor and intertumor variability presents a significant challenge in developing effective cancer therapies. Critical to understanding the role of the tumor microenvironment is the ability to dynamically quantify oxygen levels in the vasculature and tissue in order to elucidate the roles of oxygen supply and consumption, spatially and temporally. To this end, we describe the use of hyperspectral imaging to characterize hemoglobin absorption to quantify hemoglobin content and oxygen saturation, as well as dual emissive fluorescent/phosphorescent boron nanoparticles, which serve as ratiometric indicators of tissue oxygen tension. Applying these techniques to a window-chamber tumor model illustrates the role of fluctuations in hemoglobin saturation in driving changes in tissue oxygenation, the two being significantly correlated (r = 0.77). Finally, a green-fluorescence-protein reporter for hypoxia inducible factor-1 (HIF-1) provides an endpoint for hypoxic stress in the tumor, which is used to demonstrate a significant association between tumor hypoxia dynamics and HIF-1 activity in an in vivo demonstration of the technique.

  8. Dynamic imaging with coincidence gamma camera

    International Nuclear Information System (INIS)

    Elhmassi, Ahmed

    2008-01-01

    In this paper we develop a technique to calculate dynamic parameters from data acquired using gamma-camera PET (gc PET). Our method is based on an algorithm development for dynamic SPECT, which processes all decency projection data simultaneously instead of reconstructing a series of static images individually. The algorithm was modified to account for the extra data that is obtained with gc PET (compared with SPEC). The method was tested using simulated projection data for both a SPECT and a gc PET geometry. These studies showed the ability of the code to reconstruct simulated data with a varying range of half-lives. The accuracy of the algorithm was measured in terms of the reconstructed half-life and initial activity for the simulated object. The reconstruction of gc PET data showed improvement in half-life and activity compared to SPECT data of 23% and 20%, respectively (at 50 iterations). The gc PET algorithm was also tested using data from an experimental phantom and finally, applied to a clinical dataset, where the algorithm was further modified to deal with the situation where the activity in certain pixels decreases and then increases during the acquisition. (author)

  9. Neutron Imaging in Cultural Heritage Research at the FRM II Reactor of the Heinz Maier-Leibnitz Center

    Directory of Open Access Journals (Sweden)

    Burkhard Schillinger

    2018-01-01

    Full Text Available Neutron Imaging is ideally suited for applications in cultural heritage even at small reactors with moderate image resolution. However, recently, high resolution imaging is being increasingly used for advanced studies, especially in paleontology. The special contrast for hydrogen and between neighboring elements in the periodic system allows for new applications that are not accessible for X-rays, like organic material in enclosed containers made of ceramics or metals, fossilized bones in chalk rock or in ferrous “red” beds, and even for animal and hominid teeth. Fission neutrons permit the examination of large samples that otherwise show large attenuation for thermal neutrons.

  10. Neutron imaging: A non-destructive tool for materials testing. Report of a coordinated research project 2003-2006

    International Nuclear Information System (INIS)

    2008-09-01

    The enhancement of utilization of research reactors is one of the major objectives of the IAEA's project on Effective Utilization of Research Reactors. In particular, the improvement of existing installations for neutron imaging and the effective utilization of such facilities are intended. From the experience of Type A facilities, it is obvious that some investment is required to come from simple neutron imaging methods (film, track-etch foils) to the more enhanced ones. Related to the installation and operation of the whole reactor system, the volume of the investment for an imaging device is minor. Also compared to the installations for neutron scattering research, neutron imaging systems are relatively cheap, but very efficient in the use of the neutrons. Therefore, one of the aims of the CRP was to look for adapted solutions for the individual reactor installation and beam line. Specific Research Objectives: To optimize the neutron beams for imaging purpose using modern simulation techniques; To enhance the beam intensity using modern layout principles, neutron optics, like focusing and beam guides and filters; To develop a standardized, low cost, neutron image grabber and analyzer for efficient data collection that can be used with low intensity sources; To improve signal processing techniques used in neutron imaging applications. Expected Research Outputs: Neutron radiography is used at research reactor centres in many Member States, but the facilities are not optimized for attractive potential applications. This fact has been brought out at various discussion meetings. The CRP is aimed at improving the design of beam lines in terms of neutron collimation and intensity; Improvements in resolution are normally achieved at a cost in intensity. For an instrument exhibiting good resolution, one needs to employ a fast counting system. It is proposed to work along these lines to develop an optimised detection system. Many facilities, at present, have small CCD

  11. Germany: Overview of activities on Neutron Imaging (NI) and Cultural Heritage (CH) studies - Helmholtz-Zentrum Berlin

    International Nuclear Information System (INIS)

    Kardjilov, Nikolay

    2012-01-01

    Neutron imaging is a non-destructive investigation method with a fast growing application field in materials research and fundamental science. The method is used broadly in the cultural heritage research as complementary technique to x-ray imaging. The ability of neutron beam to transmit thick layers of metal and the sensitivity to light elements makes the technique unique for detection of organic substances in metal and stone matrices. The high penetration power of neutrons allows for investigation of samples with real dimensions of about 100 cm3. The neutron imaging in cultural heritage helps to provide information about manufacturing processes and material properties which is very important for further restoration and conservation of the objects. The development of new methods like energy selective imaging and grating interferometry and the application of autoradiography increase the potential of the method for characterization of cultural heritage samples. The neutron tomography instrument CONRAD has been in operation since 2005 at the Hahn-Meitner research reactor at Helmholtz-Zentrum Berlin (HZB). Over the last 5 years, significant development work has been performed to expand the radiographic and tomographic capabilities of the beamline. New techniques have been implemented, including imaging with polarized neutrons, Bragg-edge mapping, high-resolution neutron imaging and grating interferometry. These methods together with the autoradiography have been provided to the user community as tools to help address scientific problems particularly in the field of cultural heritage and palaeontology. Descriptions and parameters of the facilities are given

  12. Zaccai neutron resilience and site-specific hydration dynamics in a globular protein

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Yinglong [Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hong, Liang [Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Yi, Zheng [Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Smith, Jeremy C. [Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2013-07-16

    A discussion is presented of contributions of the Zaccai group to the understanding of flexibility in biological macromolecules using dynamic neutron scattering. The concept of resilience as introduced by Zaccai is discussed and investigated using molecular dynamics simulation on camphor-bound cytochrome P450. The resilience of hydrophilic residues is found to be more strongly affected by hydration than that of hydrophobic counterparts. The hydration-induced softening of protein propagates from the surface into the dry core. Furthermore, buried hydrophilic residues behave more like those exposed on the protein surface, and are different from their hydrophobic counterparts.

  13. Effects of Neutron-Star Dynamic Tides on Gravitational Waveforms within the Effective-One-Body Approach.

    Science.gov (United States)

    Hinderer, Tanja; Taracchini, Andrea; Foucart, Francois; Buonanno, Alessandra; Steinhoff, Jan; Duez, Matthew; Kidder, Lawrence E; Pfeiffer, Harald P; Scheel, Mark A; Szilagyi, Bela; Hotokezaka, Kenta; Kyutoku, Koutarou; Shibata, Masaru; Carpenter, Cory W

    2016-05-06

    Extracting the unique information on ultradense nuclear matter from the gravitational waves emitted by merging neutron-star binaries requires robust theoretical models of the signal. We develop a novel effective-one-body waveform model that includes, for the first time, dynamic (instead of only adiabatic) tides of the neutron star as well as the merger signal for neutron-star-black-hole binaries. We demonstrate the importance of the dynamic tides by comparing our model against new numerical-relativity simulations of nonspinning neutron-star-black-hole binaries spanning more than 24 gravitational-wave cycles, and to other existing numerical simulations for double neutron-star systems. Furthermore, we derive an effective description that makes explicit the dependence of matter effects on two key parameters: tidal deformability and fundamental oscillation frequency.

  14. Effects of Neutron-Star Dynamic Tides on Gravitational Waveforms within the Effective-One-Body Approach

    Science.gov (United States)

    Hinderer, Tanja; Taracchini, Andrea; Foucart, Francois; Buonanno, Alessandra; Steinhoff, Jan; Duez, Matthew; Kidder, Lawrence E.; Pfeiffer, Harald P.; Scheel, Mark A.; Szilagyi, Bela; Hotokezaka, Kenta; Kyutoku, Koutarou; Shibata, Masaru; Carpenter, Cory W.

    2016-05-01

    Extracting the unique information on ultradense nuclear matter from the gravitational waves emitted by merging neutron-star binaries requires robust theoretical models of the signal. We develop a novel effective-one-body waveform model that includes, for the first time, dynamic (instead of only adiabatic) tides of the neutron star as well as the merger signal for neutron-star-black-hole binaries. We demonstrate the importance of the dynamic tides by comparing our model against new numerical-relativity simulations of nonspinning neutron-star-black-hole binaries spanning more than 24 gravitational-wave cycles, and to other existing numerical simulations for double neutron-star systems. Furthermore, we derive an effective description that makes explicit the dependence of matter effects on two key parameters: tidal deformability and fundamental oscillation frequency.

  15. Australia: Overview of activities on Neutron Imaging (NI) and Cultural Heritage (CH) studies

    International Nuclear Information System (INIS)

    Garbe, Ulf

    2012-01-01

    With the ability to analyze and visualize local resolved texture by neutron imaging a great tool is created for better understanding of the history of the material (cultural heritage sample). It is important knowledge for any kind of manufactured material like jewelry, weapons, sculpture … as the texture shows the manufacturing history. In addition archeological samples embedded in rocks and stones will show the history of the environment in terms of deformation, sedimentation and metamorphosis conditions. All the texture information is available nondestructive and in combination with the real space 3D model. In order to establish texture imaging by neutron radiation, the method has to be developed and tested from simple basic textured material (single crystal and single phase) in small steps to more advanced systems like rolled or recrystallizes metal samples and finally geological samples with multiphase systems and large variation in grain size. A set of wavelength dependent neutron radiography images under certain orientations is needed to calculate the ODF and understand the texture. To determine the sufficient number of single images for ODF calculation several test materials with different known textures are required. This has to be developed in an iterative process from single crystal orientation to polycrystalline multiphase and multitexture material as especially geological samples represent the most complex textures. As an important outcome a user-friendly software package should be available which should be tested at different facilities with different type of samples. Consistent results from these facilities are strongly required to encourage the cultural heritage community in accepting the method. The typical end user has only basic knowledge of texture and neutron imaging and has to rely on the correctness of the measurement and analyses

  16. Dynamic imaging through turbid media based on digital holography.

    Science.gov (United States)

    Li, Shiping; Zhong, Jingang

    2014-03-01

    Imaging through turbid media using visible or IR light instead of harmful x ray is still a challenging problem, especially in dynamic imaging. A method of dynamic imaging through turbid media using digital holography is presented. In order to match the coherence length between the dynamic object wave and the reference wave, a cw laser is used. To solve the problem of difficult focusing in imaging through turbid media, an autofocus technology is applied. To further enhance the image contrast, a spatial filtering technique is used. A description of digital holography and experiments of imaging the objects hidden in turbid media are presented. The experimental result shows that dynamic images of the objects can be achieved by the use of digital holography.

  17. Detection of 10B distributions in histological samples by NCAR using thermal and cold neutrons and photoluminiscent imaging plates. New results

    International Nuclear Information System (INIS)

    Rant, J.; Skvarc, J.; Ilic, R.; Gabel, D.; Bayon, G.; Yanagie, H.; Kobayashi, H.; Lehmann, E.; Kuehne, G.

    1999-01-01

    The Neutron Capture Autoradiography (NCAR) using various Solid State Nuclear Track Detectors (SSNTDs) is a well established and accurate method to detect and measure the distributions of 10 B in the ppm range on macroscopic and microscopic level in biological samples, such as histological sections of tumours loaded with 10 B compounds used for BNCT (e.g. 1,2). recently a new technique of NCAR using sensitive photoluminescent Imaging Plates (IP) has been proposed to detect 10 B distributions in histological sections (3), exploiting excellent detection properties of IP systems such as very high detection sensitivity and quantum detection efficiency, broad linear response and dynamic range, very small image distortion, reusability of IP and possibilities of digital autoradiography. The advantage of IP-NCAR vs. NCAR with SSNTDs should be the much lower neutron fluence (10 7 10 9 vs. 10 10 10 13 n/cm 2 with SSNTDs), no intermediate chemical treatment (track etching) and direct and fast compuitational handling and evaluation of the digitized autoradiographic image. However, the spatial resolution of the present available IP detection systems is somewhat lower (∼ 0,04 mm) than with SSNTDs (∼ 0,01 mm). Another problem with IP NCAR is rather high sensitivity of IP to all types of ionizing radiations. Therefore the background of direct and induced gamma-rays as well as of epithermal and fast neutrons has to be filtered out of thermal neutron beam to be used for IP-NCAR. To improve the signal/background ratio and to increase the detectibility of 10 B we propose to use clean cold neutron beams for the IP-NCAR of 10 B distributions in histological samples in BNCT experiments (4,5). In the present work the recent results of experiments in IP-NCAR with cold neutrons from the neutron radiographic channel of the ORPHEE reactor in Saclay and with the rather clean thermal neutron beam of the NEUTRA neutron radiography facility of the PSI (Villingen) will be presented. For the

  18. Ab initio simulations and neutron scattering studies of structure and dynamics in PdH

    International Nuclear Information System (INIS)

    Totolici, I.E.

    2001-07-01

    The work presented in this PhD thesis is concerned with the interpretation of the neutron scattering measurements from the palladium hydrogen system by means of ab initio electronic structure calculations. The motivation of performing such calculations was due to recent neutron scattering studies on this system that showed a strong directional dependence to the dynamical structure factor together with a complex dependence on energy. Here we attempt to describe the origin of these features by ab initio simulations of the dynamical structure factor. The method assumes an adiabatic separation of the motion of the proton and palladium atoms. The proton wave functions are calculated by a direct solution of the associated single-particle Schroedinger equation using a plane wave basis set method and a mapping of the adiabatic surface. The Fourier components of the adiabatic potential are obtained from LDA pseudopotential calculations. Using Fermi's golden rule within the Born approximation we were then able to calculate the dynamical structure factor, S(Q,ω), for exciting the proton from its ground state to various excited states as a function of the magnitude and direction of the scattering wave vector. The results are in agreement with the inelastic neutron scattering spectra and allow us to identify the origin of previous inexplicable features, in particular the strong directional dependence to the experimental data. The method was extended to investigate the expansion of the equilibrium lattice constant as a function of the H isotope when the zero-point energy of the proton/deuterium is explicitly taken into account in the relaxation process. The results we obtained predicted a bigger lattice constant for the hydride, as expected. Furthermore, other complex ab initio calculations were carried out in order to describe the origin of the large optic dispersion, seen previously in the coherent neutron scattering data. Our calculated dispersion proved to be in good

  19. Neutron spin echo spectroscopy. Its application to the study of the dynamics of polymers in solution

    International Nuclear Information System (INIS)

    Papoular, Robert

    1992-06-01

    This work focuses on Neutron Spin Echo (NSE) spectroscopy and on the NSE spectrometer MESS, which we have built at the L.L.B. (CE Saclay). After analyzing in detail the classical and quantum principles of this type of instrument, and illustrated them with optical analogies, we expound a simple formalism for the interpretation of polarized neutron experiments of the most general type. In a second part, we describe the MESS spectrometer extensively; its characteristics and performances as well as the first results obtained with this instrument. In particular, we include two papers showing how the neutron depolarization, spin rotation and echoes can be used to investigate high-Tc superconductors. The last part deals with the dynamics of Polymer-Polymer-Solvent ternary solutions and demonstrates how the Neutron Spin Echo technique becomes a privileged tool for such physico-chemical studies thanks to the joint use of NSE and contrast variation methods, coupled with the adequate ranges of time and scattering vectors accessible. Finally, we describe the specific case of partially deuterated polydimethyl-siloxane (PDMS) in semi-dilute solution in Toluene. We have experimentally and separately evidenced the cooperative and inter-diffusive diffusion modes predicted by the theory of Akcasu, Benoit, Benmouna et al. These results, obtained at the L.L.B. (CE Saclay) are the subject matter of the last paper included in this work. (author) [fr

  20. In situ diagnostics of the crystal-growth process through neutron imaging

    DEFF Research Database (Denmark)

    Tremsin, Anton S.; Makowska, Malgorzata Grazyna; Perrodin, Didier

    2016-01-01

    Neutrons are known to be unique probes in situations where other types of radiation fail to penetrate samples and their surrounding structures. In this paper it is demonstrated how thermal and cold neutron radiography can provide time-resolved imaging of materials while they are being processed (e......, as limited by the resolution of the present experiments). It is also demonstrated that the dopant concentration can be quantified even for very low concentration levels (∼ 0.1%) in 10 mm thick samples. The interface between the solid and liquid phases can also be imaged, provided there is a sufficient change.......g. while growing single crystals). The processing equipment, in this case furnaces, and the scintillator materials are opaque to conventional X-ray interrogation techniques. The distribution of the europium activator within a BaBrCl:Eu scintillator (0.1 and 0.5% nominal doping concentrations per mole...

  1. Neutron stress measurement using image plate and the cos α method

    International Nuclear Information System (INIS)

    Sasaki, Toshihiko; Hirose, Yukio; Minakawa, Nobuaki; Morii, Yukio

    2004-01-01

    A new type of the neutron stress measurement method, in which the stress is determined by the cos α method, was studied. A neutron image plate was used in this study for detecting the diffraction image. Steel specimens of 5 mm thickness were used for the tensile stress test. The stresses obtain from the experiment showed one-to-one ratio with respect to the applied stresses, though the misfit stress of about 400 MPa was also observed in the result. A simple correction technique for calibrating raw data was proposed to obtain the true stress. A simulation study was carried out to check the experimental result on the peak positions in the diffraction ring and the stress calculation by the cos α method. (author)

  2. The monochromatic imaging mode of a RITA-type neutron spectrometer

    International Nuclear Information System (INIS)

    Bahl, C.R.H.; Andersen, P.; Klausen, S.N.; Lefmann, K.

    2004-01-01

    The imaging monochromatic mode of a neutron spectrometer with a multi-bladed RITA analyser system is so far unexplored. We present analytical calculations that define the mode. It is shown that the mode can be realised for PG (0 0 2) analyser crystals, from incident energies of about 3.2 meV and up, allowing the important cases of 3.7, 5.0 and 13.7 meV. Due to beam divergence, the neutron rays from neighbouring analyser blades are found to overlap slightly. Hence, the optimal use of the monochromatic imaging mode would be found by employing an adjustable radial collimator to limit the spread of the ray from each analyser blade

  3. The monochromatic imaging mode of a RITA-type neutron spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Bahl, C.R.H. [Department of Materials Research, Riso National Laboratory, Building 227, Frederiksborgvej 399, DK-4000 Roskilde (Denmark) and Department of Physics, Technical University of Denmark, DK-2800 Lyngby (Denmark)]. E-mail: christian.bahl@risoe.dk; Andersen, P. [Department of Materials Research, Riso National Laboratory, Building 227, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Niels Bohr Institute for Astronomy, Physics and Geophysics, University of Copenhagen, DK-2100 Copenhagen (Denmark); Klausen, S.N. [Department of Materials Research, Riso National Laboratory, Building 227, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Lefmann, K. [Department of Materials Research, Riso National Laboratory, Building 227, Frederiksborgvej 399, DK-4000 Roskilde (Denmark)

    2004-12-01

    The imaging monochromatic mode of a neutron spectrometer with a multi-bladed RITA analyser system is so far unexplored. We present analytical calculations that define the mode. It is shown that the mode can be realised for PG (0 0 2) analyser crystals, from incident energies of about 3.2 meV and up, allowing the important cases of 3.7, 5.0 and 13.7 meV. Due to beam divergence, the neutron rays from neighbouring analyser blades are found to overlap slightly. Hence, the optimal use of the monochromatic imaging mode would be found by employing an adjustable radial collimator to limit the spread of the ray from each analyser blade.

  4. Velocity determination of neutron-rich projectile fragments with a ring-imaging Cherenkov detector

    International Nuclear Information System (INIS)

    Zeitelhack, K.

    1992-11-01

    For the velocity determination of relativistic heavy ions (A>100) in the energy range 300A.MeV ≤ E kin ≤ 2A.GeV a highly resolving, compact ring-imaging Cherenkov counter with large dynamical measurement range was developed. The Cherenkov light cone emitted in the flight of a relativistic heavy ion by a liquid layer (C 6 F 14 ) is focused on the entrance window of a one-dimensional position-resolving VUV-sensitive photon detector. This gas detector is operated at atmospheric pressure with a mixture of 90% methane and 10% isobutane with 0.04% TMAE as photosensitive admixture. For 725A.MeV 129 Xe ions a velocity resolution Δβ/β=1.8.10 -3 and a nuclear charge-number resolution ΔZ/Z=5.1.10 -2 was reached. The over the photon energy range 5.4 eV ≤ E γ ≤ 7.2 eV averaged detection efficiency of the detector system was determined to ε tot =2.8%>. At the 0deg magnet spectrometer Fragmentseparator of the GSI Darmstadt the RICH detector was for the first time applied for the identification of nuclear charge number and mass of heavy relativistic projectile fragments. In the experiment the production cross sections of very neutron-rich nuclei by fragmentation of 136 Xe projectiles in the reaction 76A.MeV 136 Xe on 27 Al were determined. From the measured production erates for the production of the double-magic nucleus 132 Zn in this reaction a cross section of σ=(0.4± 0.3 0.6 ) μbarn can be extrapolated. (orig./HSI) [de

  5. On-line video image processing system for real-time neutron radiography

    Energy Technology Data Exchange (ETDEWEB)

    Fujine, S; Yoneda, K; Kanda, K [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.

    1983-09-15

    The neutron radiography system installed at the E-2 experimental hole of the KUR (Kyoto University Reactor) has been used for some NDT applications in the nuclear field. The on-line video image processing system of this facility is introduced in this paper. A 0.5 mm resolution in images was obtained by using a super high quality TV camera developed for X-radiography viewing a NE-426 neutron-sensitive scintillator. The image of the NE-426 on a CRT can be observed directly and visually, thus many test samples can be sequentially observed when necessary for industrial purposes. The video image signals from the TV camera are digitized, with a 33 ms delay, through a video A/D converter (ADC) and can be stored in the image buffer (32 KB DRAM) of a microcomputer (Z-80) system. The digitized pictures are taken with 16 levels of gray scale and resolved to 240 x 256 picture elements (pixels) on a monochrome CRT, with the capability also to display 16 distinct colors on a RGB video display. The direct image of this system could be satisfactory for penetrating the side plates to test MTR type reactor fuels and for the investigation of moving objects.

  6. High resolution neutron imaging of water in the polymer electrolyte fuel cell membrane

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, Partha P [Los Alamos National Laboratory; Makundan, Rangachary [Los Alamos National Laboratory; Spendelow, Jacob S [Los Alamos National Laboratory; Borup, Rodney L [Los Alamos National Laboratory; Hussey, D S [NIST; Jacobson, D L [NIST; Arif, M [NIST

    2009-01-01

    Water transport in the ionomeric membrane, typically Nafion{reg_sign}, has profound influence on the performance of the polymer electrolyte fuel cell, in terms of internal resistance and overall water balance. In this work, high resolution neutron imaging of the Nafion{reg_sign} membrane is presented in order to measure water content and through-plane gradients in situ under disparate temperature and humidification conditions.

  7. The measurement of the presampled MTF of a high spatial resolution neutron imaging system

    International Nuclear Information System (INIS)

    Cao, Raymond Lei; Biegalski, Steven R.

    2007-01-01

    A high spatial resolution neutron imaging device was developed at the Mark II TRIGA reactor at University of Texas at Austin. As the modulation transfer function (MTF) is recognized as a well-established parameter for evaluation of imaging system resolution, the aliasing associated with digital sampling adds complexity to its measurement. Aliasing is especially problematic when using a high spatial resolution micro-channel plate (MCP) neutron detector that has a pixel grid size similar to that of a CCD array. To compensate for the aliasing an angulated edge method was used to evaluate the neutron imaging facility, overcoming aliasing by obtaining an oversampled edge spread function (ESF). Baseline correction was applied to the ESF to remove the noticeable trends and the LSF was multiplied by Hann window to obtain a smoothed version of presampled MTF. The computing procedure is confirmed by visual inspection of a testing phantom; in addition, it is confirmed by comparison to the MTF measurement of a scintillation screen with a known MTF curve

  8. Stability Measurements for Alignment of the NIF Neutron Imaging System Pinhole Array

    International Nuclear Information System (INIS)

    Fittinghoff, D.N.; Bower, D.E.; Drury, O.B.; Dzenitis, J.M.; Frank, M.; Buckles, R.A.; Munson, C.; Wilde, C.H.

    2011-01-01

    The alignment system for the National Ignition Facility's neutron imaging system has been commissioned and measurements of the relative stability of the 90-315 DIM, the front and the back of the neutron imaging pinhole array and an exploding pusher target have been made using the 90-135 and the 90-258 opposite port alignment systems. Additionally, a laser beam shot from the neutron-imaging Annex and reflected from a mirror at the back of the pinhole array was used to monitor the pointing of the pinhole. Over a twelve hour period, the relative stability of these parts was found to be within ∼ ±18 (micro)m rms even when using manual methods for tracking the position of the objects. For highly visible features, use of basic particle tracking techniques found that the front of the pinhole array was stable relative to the 90-135 opposite port alignment camera to within ±3.4 (micro)m rms. Reregistration, however, of the opposite port alignment systems themselves using the target alignment sensor was found to change the expected position of target chamber center by up to 194 (micro)m.

  9. Non-destructive investigations of Swiss museums objects with neutron and x-ray imaging methods

    International Nuclear Information System (INIS)

    Lehmann, E.H.; Deschler, E.; Pernet, L.; Vontobel, P.

    2004-01-01

    Many objects of archaeological relevance found in Switzerland are from the Celtic and Roman era. Because of their uniqueness in most cases it is demanded to perform any investigation with such samples non-destructively. Depending on the structure and size of the objects a transmission experiment performed either with X-ray or neutron can alight inner structures, composition, defects or the principles of the manufacturing procedures. Furthermore, the treatment by conservators and restaurateurs becomes visible in many cases. This report describes some examples of such investigations. In the case of neutron investigations, beside the transmission imaging as a radiograph the three-dimensional structure was observed with a tomography technique. For X-ray radiography, the images were obtained in the same digital format because the similar experimental method (imaging plates) was applied. It becomes evident in the described examples that the combination and complementary use of both methods (neutrons and X-ray) brings insights in different aspects of the samples properties and treatment. This approach to study museums objects stored and exhibit in Switzerland can be extrapolated to other countries where these techniques are also simultaneously available in order to investigate other objects of relevance. The European network COST-G8 entitled 'Non-destructive analysis and testing of museum objects' can help to support initiatives in this direction. (author)

  10. How to organize a neutron imaging user lab? 13 years of experience at PSI, CH

    Energy Technology Data Exchange (ETDEWEB)

    Lehmann, E.H., E-mail: eberhard.lehmann@psi.ch [Spallation Neutron Source Division, Paul Scherrer Institute, CH-5232 Villigen (Switzerland); Vontobel, P.; Frei, G.; Kuehne, G.; Kaestner, A. [Spallation Neutron Source Division, Paul Scherrer Institute, CH-5232 Villigen (Switzerland)

    2011-09-21

    PSI has a relatively long tradition in neutron imaging since the first trials were done at its formerly existing research reactor SAPHIR with film methods. This reactor source was replaced after its shutdown in 1994 by the spallation neutron source SINQ in 1996, driven by the 590 MeV cyclotron for protons with presently up to 2.3 mA beam current. One of the first experimental devices at SINQ was the thermal neutron imaging facility NEUTRA, which was designed from scratch and has been the first device of its kind at a spallation source. Until now, NEUTRA has been successfully in use for many investigations in a wide range of studies covering fuel cell research, environmental behavior of plants, nuclear fuel inspection and the research on cultural heritage objects. It has been the host of PhD projects for students from all over Europe for years. In a previous meeting it has been offered as a European reference facility. Some of its features were really adapted to the layout of new installations. In 2004, it was possible to initiate the project of a second beam line at SINQ for imaging with cold neutrons. Previous studies have shown the potential of this option in order to broaden the user profile and to extend the scientific basis for neutron imaging. It was inaugurated with a workshop at PSI in 2005. The user service was started at the facility ICON in 2006. Beside the setup, installation and optimization of the facilities, the organization of the user program plays an important role. The two neutron imaging beam lines are equal installations at SINQ among the 14 scientific devices. Therefore, the user approach is organized via 'calls for proposals', which are sent out each half year via the 'Digital User Office (DUO)' (see (http://duo.web.psi.ch)). The evaluation of the proposals is done by the 'Advisory Committee for Neutron Imaging (ACNI)' consisting of 6 external and PSI internal members. Further requests are given by industrial

  11. How to organize a neutron imaging user lab? 13 years of experience at PSI, CH

    Science.gov (United States)

    Lehmann, E. H.; Vontobel, P.; Frei, G.; Kuehne, G.; Kaestner, A.

    2011-09-01

    PSI has a relatively long tradition in neutron imaging since the first trials were done at its formerly existing research reactor SAPHIR with film methods. This reactor source was replaced after its shutdown in 1994 by the spallation neutron source SINQ in 1996, driven by the 590 MeV cyclotron for protons with presently up to 2.3 mA beam current. One of the first experimental devices at SINQ was the thermal neutron imaging facility NEUTRA, which was designed from scratch and has been the first device of its kind at a spallation source. Until now, NEUTRA has been successfully in use for many investigations in a wide range of studies covering fuel cell research, environmental behavior of plants, nuclear fuel inspection and the research on cultural heritage objects. It has been the host of PhD projects for students from all over Europe for years. In a previous meeting it has been offered as a European reference facility. Some of its features were really adapted to the layout of new installations. In 2004, it was possible to initiate the project of a second beam line at SINQ for imaging with cold neutrons. Previous studies have shown the potential of this option in order to broaden the user profile and to extend the scientific basis for neutron imaging. It was inaugurated with a workshop at PSI in 2005. The user service was started at the facility ICON in 2006. Beside the setup, installation and optimization of the facilities, the organization of the user program plays an important role. The two neutron imaging beam lines are equal installations at SINQ among the 14 scientific devices. Therefore, the user approach is organized via "calls for proposals", which are sent out each half year via the "Digital User Office (DUO)" (see http://duo.web.psi.ch). The evaluation of the proposals is done by the "Advisory Committee for Neutron Imaging (ACNI)" consisting of 6 external and PSI internal members. Further requests are given by industrial collaborations. This beam time

  12. How to organize a neutron imaging user lab? 13 years of experience at PSI, CH

    International Nuclear Information System (INIS)

    Lehmann, E.H.; Vontobel, P.; Frei, G.; Kuehne, G.; Kaestner, A.

    2011-01-01

    PSI has a relatively long tradition in neutron imaging since the first trials were done at its formerly existing research reactor SAPHIR with film methods. This reactor source was replaced after its shutdown in 1994 by the spallation neutron source SINQ in 1996, driven by the 590 MeV cyclotron for protons with presently up to 2.3 mA beam current. One of the first experimental devices at SINQ was the thermal neutron imaging facility NEUTRA, which was designed from scratch and has been the first device of its kind at a spallation source. Until now, NEUTRA has been successfully in use for many investigations in a wide range of studies covering fuel cell research, environmental behavior of plants, nuclear fuel inspection and the research on cultural heritage objects. It has been the host of PhD projects for students from all over Europe for years. In a previous meeting it has been offered as a European reference facility. Some of its features were really adapted to the layout of new installations. In 2004, it was possible to initiate the project of a second beam line at SINQ for imaging with cold neutrons. Previous studies have shown the potential of this option in order to broaden the user profile and to extend the scientific basis for neutron imaging. It was inaugurated with a workshop at PSI in 2005. The user service was started at the facility ICON in 2006. Beside the setup, installation and optimization of the facilities, the organization of the user program plays an important role. The two neutron imaging beam lines are equal installations at SINQ among the 14 scientific devices. Therefore, the user approach is organized via 'calls for proposals', which are sent out each half year via the 'Digital User Office (DUO)' (see (http://duo.web.psi.ch)). The evaluation of the proposals is done by the 'Advisory Committee for Neutron Imaging (ACNI)' consisting of 6 external and PSI internal members. Further requests are given by industrial collaborations. This beam time

  13. Italy: Overview of activities on Neutron Imaging (NI) and Cultural Heritage (CH) studies

    International Nuclear Information System (INIS)

    Zoppi, Marco

    2012-01-01

    Materials characterization, through non-invasive techniques, represents an important strategic tool in the non-destructive quantitative analysis of artefacts of archaeological and historical interest. In fact, thanks to the high penetration power of thermal neutrons in dense matter, bulk analysis of massive findings, characteristic of archaeological activity, can be nowadays carried out in an almost straightforward way, especially on metal samples. By means of neutron diffraction, it is possible to obtain, without any need of sampling, the average bulk phase composition of the specimen and to reveal the hidden presence of mineralisation phases, which, in turn, gives a deep information on its preservation status. Moreover, a detailed analysis of the peak shape, can shed light on smelting and smithing methods, as well as on the amount of mechanical work that was originally carried out on the sample. Neutron imaging techniques, have developed to such an extent that, today, it is possible to reconstruct tomographic images down to ≅30 μm space resolution. In addition, thanks to the developing techniques of energy selective neutron imaging and tomography the scenario opens over a wealth of futuristic applications, thanks to the enhanced contrast inherent in this technique. At present, these energy selective techniques are only limited by the performances of the device needed to select the energy (and wavelength) of the incident neutron beam: i.e. a rotating disk velocity selector and double monochromator. The possibility of enhancing this technique by fully exploiting the Time of Flight technique could improve dramatically the energy resolution and consequently the range of possible “contrast enhancement” possibilities. What we propose is a research activity using energy selective neutron imaging, applied to cultural heritage metal artefacts, to study the historical evolution of iron production on a world basis, i.e. including European, middle-east, Indian, and

  14. Determination of neutron beam quality and evaluation of image quality (neutron radiography technique)

    International Nuclear Information System (INIS)

    Wan Muhammad Saridan Wan Hassan; Manan Munhamad Jaib; Ng Sook Kien; Lai Zhong Yuan; Azali Muhammad; Abd Aziz Mohamed; Mohd Rawi Abdullah

    2005-01-01

    The following topics were presented: beam purity Indicator (BPI) and sensitivity indicator (SI) test objects (ASTM E545-91); No Numbra (NU) test object (ASTM E803-91); MTF and Noise; parameters used in calculation; results of the experiments; summary of analysis. The resulting data consisted exposure contributors and sensitivity levels for films that were radiographed along with 0.25 and 0.5 mm Gd converters; visibility of holes and gaps on the image of the sensitivity indicator using both 0.25 and 0.5 mm Gd converters; qualitative data obtained from observation of the blurring effect on the lower boron nitride disc for both 0.25 and 0.5 mm Gd converters

  15. Non destructive testing and neutron radiography in 1994; Les controles non destructifs et la neutronographie en 1994

    Energy Technology Data Exchange (ETDEWEB)

    Bayon, G.

    1994-12-31

    Neutron radiography has been considered for a long time as a promising technique; however it plays a minor part in the world of non destructive testing today, due to the lack of suitable neutron sources and lack of new industrial applications. This paper reviews the present status of neutron sources, neutron radiography activities, especially in France (such as the neutron-capture-issued secondary radiation spectrometry), in nuclear, aerospace, aeronautical and metallurgical sectors, and the last applications of neutron dynamic imaging. 9 refs.

  16. Imaging complex nutrient dynamics in mycelial networks.

    Science.gov (United States)

    Fricker, M D; Lee, J A; Bebber, D P; Tlalka, M; Hynes, J; Darrah, P R; Watkinson, S C; Boddy, L

    2008-08-01

    Transport networks are vital components of multi-cellular organisms, distributing nutrients and removing waste products. Animal cardiovascular and respiratory systems, and plant vasculature, are branching trees whose architecture is thought to determine universal scaling laws in these organisms. In contrast, the transport systems of many multi-cellular fungi do not fit into this conceptual framework, as they have evolved to explore a patchy environment in search of new resources, rather than ramify through a three-dimensional organism. These fungi grow as a foraging mycelium, formed by the branching and fusion of threadlike hyphae, that gives rise to a complex network. To function efficiently, the mycelial network must both transport nutrients between spatially separated source and sink regions and also maintain its integrity in the face of continuous attack by mycophagous insects or random damage. Here we review the development of novel imaging approaches and software tools that we have used to characterise nutrient transport and network formation in foraging mycelia over a range of spatial scales. On a millimetre scale, we have used a combination of time-lapse confocal imaging and fluorescence recovery after photobleaching to quantify the rate of diffusive transport through the unique vacuole system in individual hyphae. These data then form the basis of a simulation model to predict the impact of such diffusion-based movement on a scale of several millimetres. On a centimetre scale, we have used novel photon-counting scintillation imaging techniques to visualize radiolabel movement in small microcosms. This approach has revealed novel N-transport phenomena, including rapid, preferential N-resource allocation to C-rich sinks, induction of simultaneous bi-directional transport, abrupt switching between different pre-existing transport routes, and a strong pulsatile component to transport in some species. Analysis of the pulsatile transport component using Fourier

  17. The new neutron radiography/tomography/imaging station DINGO at OPAL

    International Nuclear Information System (INIS)

    Garbe, U.; Randall, T.; Hughes, C.

    2011-01-01

    A new neutron imaging instrument will be built to support the area of neutron imaging research (neutron radiography/tomography) at ANSTO. The instrument will be designed for an international user community and for routine quality control for defence, industrial, mining, space and aircraft applications. It will also be a useful tool for assessing oil and water flow in sedimentary rock reservoirs (like the North West Shelf), assessing water damage in aircraft components, and the study of hydrogen distribution and cracking in steel. The instrument is planned to be completed by the end of June 2013 and is currently in the design stage. The usable neutron flux is mainly determined by the neutron source, but it also depends on the instrument position and the resolution. The designated instrument position for DINGO is the beam port HB-2 in the reactor hall. The estimated flux for an L/D of approximately 250 at HB-2 is calculated by Mcstas simulation in a range of 4.75x10 7 n/cm 2 s, which is in the same range of other facilities like ANSTARES (FRM II; Schillinger et al., 2004 ) or BT2 (NIST; Hussey et al., 2005 ). A special feature of DINGO is the in-pile collimator place in front of the main shutter at HB-2. The collimator offers two pinholes with a possible L/D of 250 and 1000. A secondary collimator will separate the two beams and block one. The whole instrument will operate in two different positions, one for high resolution and the other for high speed.

  18. The new neutron radiography/tomography/imaging station DINGO at OPAL

    Science.gov (United States)

    Garbe, U.; Randall, T.; Hughes, C.

    2011-09-01

    A new neutron imaging instrument will be built to support the area of neutron imaging research (neutron radiography/tomography) at ANSTO. The instrument will be designed for an international user community and for routine quality control for defence, industrial, mining, space and aircraft applications. It will also be a useful tool for assessing oil and water flow in sedimentary rock reservoirs (like the North West Shelf), assessing water damage in aircraft components, and the study of hydrogen distribution and cracking in steel. The instrument is planned to be completed by the end of June 2013 and is currently in the design stage. The usable neutron flux is mainly determined by the neutron source, but it also depends on the instrument position and the resolution. The designated instrument position for DINGO is the beam port HB-2 in the reactor hall. The estimated flux for an L/ D of approximately 250 at HB-2 is calculated by Mcstas simulation in a range of 4.75×10 7 n/cm 2 s, which is in the same range of other facilities like ANSTARES (FRM II; Schillinger et al., 2004 [1]) or BT2 (NIST; Hussey et al., 2005 [2]). A special feature of DINGO is the in-pile collimator place in front of the main shutter at HB-2. The collimator offers two pinholes with a possible L/ D of 250 and 1000. A secondary collimator will separate the two beams and block one. The whole instrument will operate in two different positions, one for high resolution and the other for high speed.

  19. Angular resolution study of a combined gamma-neutron coded aperture imager for standoff detection

    International Nuclear Information System (INIS)

    Ayaz-Maierhafer, Birsen; Hayward, Jason P.; Ziock, Klaus P.; Blackston, Matthew A.; Fabris, Lorenzo

    2013-01-01

    Nuclear threat source observables at standoff distances of tens of meters from mCi class sources include both gamma-rays and neutrons. This work uses simulations to investigate the effects of the angular resolution of a mobile gamma-ray and neutron coded aperture imaging system upon orphan source detection significance and specificity. The design requires maintaining high sensitivity and specificity while keeping the system size as compact as possible to reduce weight, footprint, and cost. A mixture of inorganic and organic scintillators was considered in the detector plane for high sensitivity to both gamma-rays and fast neutrons. For gamma-rays (100 to 2500 keV) and fission spectrum neutrons, angular resolutions of 1–9° and radiation angles of incidence appropriate for mobile search were evaluated. Detection significance for gamma-rays considers those events that contribute to the photopeak of the image pixel corresponding the orphan source location. For detection of fission spectrum neutrons, energy depositions above a set pulse shape discrimination threshold were tallied. The results show that the expected detection significance for the system at an angular resolution of 1° is significantly lower compared to its detection significance an angular resolution of ∼3–4°. An angular resolution of ∼3–4° is recommended both for better detection significance and improved false alarm rate, considering that finer angular resolution does not result in improved background rejection when the coded aperture method is used. Instead, over-pixelating the search space may result in an unacceptably high false alarm rate

  20. X-ray and neutron diffraction and molecular dynamics simulation of molten lithium and rubidium nitrates

    International Nuclear Information System (INIS)

    Yamaguchi, Toshio; Okada, Isao; Ohtaki, Hitoshi; Mikami, Masuhiro; Kawamura, Kazutaka

    1986-01-01

    Molecular dynamics simulations have been performed for lithium and rubidium nitrate melts at 550 and 600K, respectively, together with X-ray and neutron diffraction experiments. Simple Coulomb pair potentials with Born-type repulsions have been adopted in the simulations with a rigid body model for the nitrate ion. Structure functions derived from the X-ray and neutron experiments are well reproduced by the simulations, from which the three-dimensional cation distribution around the nitrate ion has been revealed. The self-diffusion coefficients, the velocity autocorrelation functions and the self-exchange velocities of lithium, rubidium and nitrate ions have been calculated. Anisotropic motion of nitrate ions has been found and is discussed on the basis of the structure of the melts. (author)

  1. Molecular Dynamics and Neutron Scattering Studies of Mixed Solutions of Caffeine and Pyridine in Water.

    Science.gov (United States)

    Tavagnacco, Letizia; Mason, Philip E; Neilson, George W; Saboungi, Marie-Louise; Cesàro, Attilio; Brady, John W

    2018-05-31

    Insight into the molecular interactions of homotactic and heterotactic association of caffeine and pyridine in aqueous solution is given on the basis of both experimental and simulation studies. Caffeine is about 5 times more soluble in a 3 m aqueous pyridine solution than it is in pure water (an increase from ∼0.1 m to 0.5 m). At this elevated concentration the system becomes suitable for neutron scattering study. Caffeine-pyridine interactions were studied by neutron scattering and molecular dynamics simulations, allowing a detailed characterization of the spatial and orientational structure of the solution. It was found that while pyridine-caffeine interactions are not as strong as caffeine-caffeine interactions, the pyridine-caffeine interactions still significantly disrupted caffeine-caffeine stacking. The alteration of the caffeine-caffeine stacking, occasioned by the presence of pyridine molecules in solution and the consequent formation of heterotactic interactions, leads to the experimentally detected increase in caffeine solubility.

  2. Aspects of molecular dynamic of cyclohexanol studied by scattering of slow neutrons

    International Nuclear Information System (INIS)

    Walder, Vilma Sidneia

    1978-01-01

    Molecular dynamics of cyclohexanol in three crystalline phases and in the liquid state was investigated by cold neutron scattering in the temperature interval 100 to 300 K. The measurements were performed using a Beryllium Filter Time-of-Flight Spectrometer. The neutron inelastic scattering spectra and the frequency spectra fitted by a sum of Gaussians show evidences for events around 36-44. 62-79, 120-148, 216-250 and 384-509 c m -1 interpreted respectively as hundred rotation of molecules, lattice vibrations, H bond stretching vibration, out-of-line and in-plane ring bending modes. Quasi-elastic broadening were analysed in terms of modules for molecular diffusion. The behaviour of the self-diffusion coefficient with temperature was studied and the activation energies for diffusion in the liquid and solid states were determined. (author)

  3. Mixing of alcohol and water molecules studied by neutron probe. Structure and dynamics

    International Nuclear Information System (INIS)

    Yoshida, Koji

    2001-01-01

    Structure of water/alcohol mixing solution was studied by three methods such as an isotope-exchanged neutron scattering method, RISM (Reference Interaction Site Model) integral equation and a neutron spin echo method. The principle of methods, experiments and results were reported. The results of experiments of water/tert-butyl alcohol (TBA) solution by the isotope-exchange neutron scattering method showed TBA molecule associated with each other through end methyl group. Especially this effect was the largest at x TBA = 0.06 and decreased with increasing the concentration of TBA. However, hydrogen bonding of TBA was very rare at x TBA = 0.06. By the partial radial distribution function obtained from RISM integral equation, it indicated that the structure of pure TBA became chain structure by hydrogen bond but changed to the structure contacted directly each hydrophobic group with increasing the concentration of water. Water/2-butoxyethanol (BE) mixing solution was measured by a neutron spin echo method. The activation energy of the diffusion coefficients obtained agreed to the energy of hydrogen bonding. The temperature response of diffusion coefficients showed the inverse of the experimental results obtained by the dynamic light scattering method. The difference between two measurement methods was different time scale and space scale. Namely, the object of the neutron scattering method is nano meter and nano second, but one of light scattering method many times over. It was proved from the above results that there was the cluster consisted of the same kind of molecule in the homogeneous two components solution, but the cluster was not stable and constantly exchanged with molecule, where the production and decay of the cluster is repeated at about nano sec. (S.Y.)

  4. Fluid-flow measurements in low permeability media with high pressure gradients using neutron imaging: Application to concrete

    Science.gov (United States)

    Yehya, Mohamad; Andò, Edward; Dufour, Frédéric; Tengattini, Alessandro

    2018-05-01

    This article focuses on a new experimental apparatus for investigating fluid flow under high pressure gradients within low-permeability porous media by means of neutron imaging. A titanium Hassler cell which optimises neutron transparency while allowing high pressure confinement (up to 50 MPa) and injection is designed for this purpose and presented here. This contribution focuses on the development of the proposed methodology thanks to some preliminary results obtained using a new neutron imaging facility named NeXT on the D50 beamline at the Institute Laue Langevin (Grenoble). The preliminary test was conducted by injecting normal water into concrete sample prepared and saturated with heavy water to take advantage of the isotope sensitivity of neutrons. The front between these two types of water is tracked in space and time with a combination of neutron radiography and tomography.

  5. Neutron emission as a probe of fusion-fission and quasi-fission dynamics

    International Nuclear Information System (INIS)

    Hinde, D.J.

    1991-01-01

    Pre- and post scission neutron yeilds have been measured as a function of projectile mass, compound nucleus fissility, and fission mass-split and total kinetic energy (TKE) for 27 fusion-fission and quasi-fission reactions induced by beams of 16,18 O, 40 Ar and 64 Ni. A new method of interpretation of experimental pre-scission neutron multiplicities ν-pre and mean kinetic energies ε ν allows the extraction of fission time scales with much less uncertainty than previously, all fusion-fission results being consistent with a dynamical time scale of (35±15) x 10 -21 s for symmetric fission. All reactions show that ν-pre falls quite rapidly with increasing mass-asymmetry; evidence is presented that for fusion-fission reactions this is partly due to a reduction of the dynamical fission time scale with mass-asymmetry. For quasi-fission, the data indicate that the pre-scission multiplicity and mean neutron kinetic energy are very sensitive to the final mass-asymmetry, but that the time scale is virtually independent of mass-asymmetry. It is concluded that for fusion-fission there is no dependence of ν-pre on TKE, whilst for 64 Ni-induced quasi-fission reactions, a strong increase of ν-pre with decreasing TKE is observed, probably largely caused by neutron emission during the acceleration time of the fission fragments in these fast reactions. Interpretation of post-scission multiplicities in terms of fragment excitation energies leads to deduced time scales consistent with those determined from the pre-scission data. 54 refs., 17 tabs., 25 figs

  6. Image Alignment for Multiple Camera High Dynamic Range Microscopy.

    Science.gov (United States)

    Eastwood, Brian S; Childs, Elisabeth C

    2012-01-09

    This paper investigates the problem of image alignment for multiple camera high dynamic range (HDR) imaging. HDR imaging combines information from images taken with different exposure settings. Combining information from multiple cameras requires an alignment process that is robust to the intensity differences in the images. HDR applications that use a limited number of component images require an alignment technique that is robust to large exposure differences. We evaluate the suitability for HDR alignment of three exposure-robust techniques. We conclude that image alignment based on matching feature descriptors extracted from radiant power images from calibrated cameras yields the most accurate and robust solution. We demonstrate the use of this alignment technique in a high dynamic range video microscope that enables live specimen imaging with a greater level of detail than can be captured with a single camera.

  7. A framework of region-based dynamic image fusion

    Institute of Scientific and Technical Information of China (English)

    WANG Zhong-hua; QIN Zheng; LIU Yu

    2007-01-01

    A new framework of region-based dynamic image fusion is proposed. First, the technique of target detection is applied to dynamic images (image sequences) to segment images into different targets and background regions. Then different fusion rules are employed in different regions so that the target information is preserved as much as possible. In addition, steerable non-separable wavelet frame transform is used in the process of multi-resolution analysis, so the system achieves favorable characters of orientation and invariant shift. Compared with other image fusion methods, experimental results showed that the proposed method has better capabilities of target recognition and preserves clear background information.

  8. Demonstration of a time-integrated short line of sight neutron imaging system for inertial confinement fusion

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, R., E-mail: raspberry@lanl.gov; Danly, C.; Fatherley, V. E.; Merrill, F. E.; Volegov, P.; Wilde, C. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Christensen, K.; Fittinghoff, D.; Grim, G. P.; Izumi, N.; Jedlovec, D.; Skulina, K. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2015-12-15

    The Neutron Imaging System (NIS) is an important diagnostic for understanding implosions of deuterium-tritium capsules at the National Ignition Facility. While the detectors for the existing system must be positioned 28 m from the source to produce sufficient imaging magnification and resolution, recent testing of a new short line of sight neutron imaging system has shown sufficient resolution to allow reconstruction of the source image with quality similar to that of the existing NIS on a 11.6 m line of sight. The new system used the existing pinhole aperture array and a stack of detectors composed of 2 mm thick high-density polyethylene converter material followed by an image plate. In these detectors, neutrons enter the converter material and interact with protons, which recoil and deposit energy within the thin active layer of the image plate through ionization losses. The described system produces time-integrated images for all neutron energies passing through the pinhole. We present details of the measurement scheme for this novel technique to produce energy-integrated neutron images as well as source reconstruction results from recent experiments at NIF.

  9. Analysis and solution of current spike occurred in dynamic compensation of self-powered neutron detectors

    International Nuclear Information System (INIS)

    Peng, Xingjie; Li, Qing; Wang, Kan

    2017-01-01

    Highlights: • The current spike problem is observed in the dynamic compensation process of SPNDs. • The current spike is caused by unphysical current change due to range switching. • Modification on the compensation algorithm is introduced to deal with current spike. - Abstract: Dynamic compensation methods are required to improve the response speed of the Self-Powered Neutron Detectors (SPNDs) and make it possible to apply the SPNDs for core monitoring and surveillance. During the experimental test of the compensation method based on linear matrix inequality (LMI), spikes are observed in the compensated SPND current. After analyzing the measurement data, the cause is fixed on the unphysical change of the uncompensated SPND current due to range switching. Then some modifications on the dynamic compensation algorithms are proposed to solve the current spike problem.

  10. The dynamics of water in hydrated white bread investigated using quasielastic neutron scattering

    International Nuclear Information System (INIS)

    Sjoestroem, J; Kargl, F; Fernandez-Alonso, F; Swenson, J

    2007-01-01

    The dynamics of water in fresh and in rehydrated white bread is studied using quasielastic neutron scattering (QENS). A diffusion constant for water in fresh bread, without temperature gradients and with the use of a non-destructive technique, is presented here for the first time. The self-diffusion constant for fresh bread is estimated to be D s = 3.8 x 10 -10 m 2 s -1 and the result agrees well with previous findings for similar systems. It is also suggested that water exhibits a faster dynamics than previously reported in the literature using equilibration of a hydration-level gradient monitored by vibrational spectroscopy. The temperature dependence of the dynamics of low hydration bread is also investigated for T = 280-350 K. The average relaxation time at constant momentum transfer (Q) shows an Arrhenius behavior in the temperature range investigated

  11. Determination of very low concentrations of hydrogen in zirconium alloys by neutron imaging

    Science.gov (United States)

    Buitrago, N. L.; Santisteban, J. R.; Tartaglione, A.; Marín, J.; Barrow, L.; Daymond, M. R.; Schulz, M.; Grosse, M.; Tremsin, A.; Lehmann, E.; Kaestner, A.; Kelleher, J.; Kabra, S.

    2018-05-01

    Zr-based alloys are used in nuclear power plants because of a unique combination of very low neutron absorption and excellent mechanical properties and corrosion resistance at operating conditions. However, Hydrogen (H) or Deuterium ingress due to waterside corrosion during operation can embrittle these materials. In particular, Zr alloys are affected by Delayed Hydride Cracking (DHC), a stress-corrosion cracking mechanism operating at very low H content (∼100-300 wt ppm), which involves the diffusion of H to the crack tip. H content in Zr alloys is commonly determined by destructive techniques such as inert gas fusion and vacuum extraction. In this work, we have used neutron imaging to non-destructively quantify the spatial distribution of H in Zr alloys specimens with a resolution of ∼5 wt ppm, an accuracy of ∼10 wt ppm and a spatial resolution of ∼25 μm × 5 mm x 10 mm. Non-destructive experiments performed on a comprehensive set of calibrated specimens of Zircaloy-2 and Zr2.5%Nb at four neutron facilities worldwide show the typical precision and repeatability of the technique. We have observed that the microstructure of the alloy plays an important role on the homogeneity of H across a specimen. We propose several strategies for performing H determinations without calibrated specimens, with the most precise results for neutrons having wavelengths longer than 5.7 Å.

  12. Dynamic flat panel detector versus image intensifier in cardiac imaging: dose and image quality

    Science.gov (United States)

    Vano, E.; Geiger, B.; Schreiner, A.; Back, C.; Beissel, J.

    2005-12-01

    The practical aspects of the dosimetric and imaging performance of a digital x-ray system for cardiology procedures were evaluated. The system was configured with an image intensifier (II) and later upgraded to a dynamic flat panel detector (FD). Entrance surface air kerma (ESAK) to phantoms of 16, 20, 24 and 28 cm of polymethyl methacrylate (PMMA) and the image quality of a test object were measured. Images were evaluated directly on the monitor and with numerical methods (noise and signal-to-noise ratio). Information contained in the DICOM header for dosimetry audit purposes was also tested. ESAK values per frame (or kerma rate) for the most commonly used cine and fluoroscopy modes for different PMMA thicknesses and for field sizes of 17 and 23 cm for II, and 20 and 25 cm for FD, produced similar results in the evaluated system with both technologies, ranging between 19 and 589 µGy/frame (cine) and 5 and 95 mGy min-1 (fluoroscopy). Image quality for these dose settings was better for the FD version. The 'study dosimetric report' is comprehensive, and its numerical content is sufficiently accurate. There is potential in the future to set those systems with dynamic FD to lower doses than are possible in the current II versions, especially for digital cine runs, or to benefit from improved image quality.

  13. Calcium ions in aqueous solutions: Accurate force field description aided by ab initio molecular dynamics and neutron scattering

    Science.gov (United States)

    Martinek, Tomas; Duboué-Dijon, Elise; Timr, Štěpán; Mason, Philip E.; Baxová, Katarina; Fischer, Henry E.; Schmidt, Burkhard; Pluhařová, Eva; Jungwirth, Pavel

    2018-06-01

    We present a combination of force field and ab initio molecular dynamics simulations together with neutron scattering experiments with isotopic substitution that aim at characterizing ion hydration and pairing in aqueous calcium chloride and formate/acetate solutions. Benchmarking against neutron scattering data on concentrated solutions together with ion pairing free energy profiles from ab initio molecular dynamics allows us to develop an accurate calcium force field which accounts in a mean-field way for electronic polarization effects via charge rescaling. This refined calcium parameterization is directly usable for standard molecular dynamics simulations of processes involving this key biological signaling ion.

  14. Dynamics of water and ions in clays of type montmorillonite by microscopic simulation and quasi-elastic neutron scattering

    International Nuclear Information System (INIS)

    Malikova, N.

    2005-09-01

    Montmorillonite clays in low hydration states, with Na + and Cs + compensating counter ions, are investigated by a combination of microscopic simulation and quasi-elastic neutron scattering to obtain information on the local structure and dynamics of water and ions in the interlayer. At first predictions of simulation into the dynamics of water and ions at elevate temperatures are shown (0 deg C 80 deg C, pertinent for the radioactive waste disposal scenario) Marked difference is observed between the modes of diffusion of the Na + and C + counter ions. In water dynamics, a significant step towards bulk water behaviour is seen on transition from the mono- to bilayer states. Secondly, a detailed comparison between simulation and quasi-elastic neutron scattering (Neutron Spin Echo and Time-of-Flight) regarding ambient temperature water dynamics is presented. Overall, the approaches are found to be in good agreement with each other and limitations of each of the methods are clearly shown. (author)

  15. Simultaneous usage of pinhole and penumbral apertures for imaging small scale neutron sources from inertial confinement fusion experiments.

    Science.gov (United States)

    Guler, N; Volegov, P; Danly, C R; Grim, G P; Merrill, F E; Wilde, C H

    2012-10-01

    Inertial confinement fusion experiments at the National Ignition Facility are designed to understand the basic principles of creating self-sustaining fusion reactions by laser driven compression of deuterium-tritium (DT) filled cryogenic plastic capsules. The neutron imaging diagnostic provides information on the distribution of the central fusion reaction region and the surrounding DT fuel by observing neutron images in two different energy bands for primary (13-17 MeV) and down-scattered (6-12 MeV) neutrons. From this, the final shape and size of the compressed capsule can be estimated and the symmetry of the compression can be inferred. These experiments provide small sources with high yield neutron flux. An aperture design that includes an array of pinholes and penumbral apertures has provided the opportunity to image the same source with two different techniques. This allows for an evaluation of these different aperture designs and reconstruction algorithms.

  16. High-frame rate imaging of two-phase flow in a thin rectangular channel using fast neutrons.

    Science.gov (United States)

    Zboray, R; Mor, I; Dangendorf, V; Stark, M; Tittelmeier, K; Cortesi, M; Adams, R

    2014-08-01

    We have demonstrated the feasibility of performing high-frame-rate, fast neutron radiography of air-water two-phase flows in a thin channel with rectangular cross section. The experiments have been carried out at the accelerator facility of the Physikalisch-Technische Bundesanstalt. A polychromatic, high-intensity fast neutron beam with average energy of 6 MeV was produced by 11.5 MeV deuterons hitting a thick Be target. Image sequences down to 10 ms exposure times were obtained using a fast-neutron imaging detector developed in the context of fast-neutron resonance imaging. Different two-phase flow regimes such as bubbly slug and churn flows have been examined. Two phase flow parameters like the volumetric gas fraction, bubble size and mean bubble velocities have been measured. The first results are promising, improvements for future experiments are also discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Neutron Imaging for Selective Laser Melting Inconel Hardware with Internal Passages

    Science.gov (United States)

    Tramel, Terri L.; Norwood, Joseph K.; Bilheux, Hassina

    2014-01-01

    Additive Manufacturing is showing great promise for the development of new innovative designs and large potential life cycle cost reduction for the Aerospace Industry. However, more development work is required to move this technology into space flight hardware production. With selective laser melting (SLM), hardware that once consisted of multiple, carefully machined and inspected pieces, joined together can be made in one part. However standard inspection techniques cannot be used to verify that the internal passages are within dimensional tolerances or surface finish requirements. NASA/MSFC traveled to Oak Ridge National Lab's (ORNL) Spallation Neutron Source to perform some non-destructive, proof of concept imaging measurements to assess the capabilities to understand internal dimensional tolerances and internal passages surface roughness. This presentation will describe 1) the goals of this proof of concept testing, 2) the lessons learned when designing and building these Inconel 718 test specimens to minimize beam time, 3) the neutron imaging test setup and test procedure to get the images, 4) the initial results in images, volume and a video, 4) the assessment of using this imaging technique to gather real data for designing internal flow passages in SLM manufacturing aerospace hardware, and lastly 5) how proper cleaning of the internal passages is critically important. In summary, the initial results are very promising and continued development of a technique to assist in SLM development for aerospace components is desired by both NASA and ORNL. A plan forward that benefits both ORNL and NASA will also be presented, based on the promising initial results. The initial images and volume reconstruction showed that clean, clear images of the internal passages geometry are obtainable. These clear images of the internal passages of simple geometries will be compared to the build model to determine any differences. One surprising result was that a new cleaning

  18. Imaging of heterogeneous materials by prompt gamma-ray neutron activation analysis

    International Nuclear Information System (INIS)

    Staples, Parrish; Prettyman, Tom; Lestone, John

    1999-01-01

    We have used a Tomographic Gamma Scanner (TGS) to produce tomographic Prompt Gamma-Ray Neutron Activation Imaging of heterogeneous matrices [T.H. Prettyman, R.J. Estep, G.A. Sheppard, Trans. Am. Nucl. Soc. 69 (1993) 183-184]. The TGS was modified by the addition of graphite reflectors that contain isotopic neutron sources for sample interrogation. We are in the process of developing the analysis methodology necessary for a quantitative assay of large containers of heterogeneous material. This nondestructive analysis technique can be used for material characterization and the determination of neutron assay correction factors. The most difficult question to be answered is the determination of the source to sample coupling term. To assist in the determination of the coupling term we have obtained images for a range of samples that are very well characterized; such as, homogenous pseudo one-dimensional samples to three-dimensional heterogeneous samples. We then compare the measurements to Monte Carlo N-particle calculations. For an accurate quantitative measurement it is also necessary to determine the sample gamma-ray self attenuation at higher gamma-ray energies, namely pair production should be incorporated into the analysis codes

  19. Imaging of heterogeneous materials by prompt gamma-ray neutron activation analysis

    International Nuclear Information System (INIS)

    Staples, P.; Prettyman, T.; Lestone, J.

    1998-01-01

    The authors have used a tomographic gamma scanner (TGS) to produce tomographic prompt gamma-ray neutron activation analysis imaging (PGNAA) of heterogeneous matrices. The TGS was modified by the addition of graphite reflectors that contain isotopic neutron sources for sample interrogation. The authors are in the process of developing the analysis methodology necessary for a quantitative assay of large containers of heterogeneous material. This nondestructive analysis (NDA) technique can be used for material characterization and the determination of neutron assay correction factors. The most difficult question to be answered is the determination of the source-to-sample coupling term. To assist in the determination of the coupling term, the authors have obtained images for a range of sample that are very well characterized, such as, homogenous pseudo one-dimensional samples to three-dimensional heterogeneous samples. They then compare the measurements to MCNP calculations. For an accurate quantitative measurement, it is also necessary to determine the sample gamma-ray self attenuation at higher gamma-ray energies, namely pair production should be incorporated into the analysis codes

  20. A wide dynamic range BF3 neutron monitor with front-end electronics based on a logarithmic amplifier

    International Nuclear Information System (INIS)

    Ferrarini, M.; Varoli, V.; Favalli, A.; Caresana, M.; Pedersen, B.

    2010-01-01

    This paper describes a wide dynamic range neutron monitor based on a BF 3 neutron detector. The detector is used in current mode, and front-end electronics based on a logarithmic amplifier are used in order to have a measurement capability ranging over many orders of magnitude. The system has been calibrated at the Polytechnic of Milan, CESNEF, with an AmBe neutron source, and has been tested in a pulsed field at the PUNITA facility at JRC, Ispra. The detector has achieved a dynamic range of over 6 orders of magnitude, being able to measure single neutron pulses and showing saturation-free response for a reaction rate up to 10 6 s -1 . It has also proved effective in measuring the PUNITA facility pulse integral fluence.

  1. A wide dynamic range BF{sub 3} neutron monitor with front-end electronics based on a logarithmic amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Ferrarini, M., E-mail: michele.ferrarini@polimi.i [Politecnico di Milano, Dipartimento Energia, via G. Ponzio 34/3, I-20133 Milano (Italy); Fondazione CNAO, via Caminadella 16, 20123 Milano (Italy); Varoli, V. [Politecnico di Milano, Dipartimento Energia, via G. Ponzio 34/3, I-20133 Milano (Italy); Favalli, A. [European Commission, Joint Research Centre, Institute for the Protection and Security of Citizen, TP 800, Via E. Fermi, 21027 Ispra (Vatican City State, Holy See) (Italy); Caresana, M. [Politecnico di Milano, Dipartimento Energia, via G. Ponzio 34/3, I-20133 Milano (Italy); Pedersen, B. [European Commission, Joint Research Centre, Institute for the Protection and Security of Citizen, TP 800, Via E. Fermi, 21027 Ispra (Italy)

    2010-02-01

    This paper describes a wide dynamic range neutron monitor based on a BF{sub 3} neutron detector. The detector is used in current mode, and front-end electronics based on a logarithmic amplifier are used in order to have a measurement capability ranging over many orders of magnitude. The system has been calibrated at the Polytechnic of Milan, CESNEF, with an AmBe neutron source, and has been tested in a pulsed field at the PUNITA facility at JRC, Ispra. The detector has achieved a dynamic range of over 6 orders of magnitude, being able to measure single neutron pulses and showing saturation-free response for a reaction rate up to 10{sup 6} s{sup -1}. It has also proved effective in measuring the PUNITA facility pulse integral fluence.

  2. Structural dynamics of supercooled water from quasielastic neutron scattering and molecular simulations.

    Science.gov (United States)

    Qvist, Johan; Schober, Helmut; Halle, Bertil

    2011-04-14

    One of the outstanding challenges presented by liquid water is to understand how molecules can move on a picosecond time scale despite being incorporated in a three-dimensional network of relatively strong H-bonds. This challenge is exacerbated in the supercooled state, where the dramatic slowing down of structural dynamics is reminiscent of the, equally poorly understood, generic behavior of liquids near the glass transition temperature. By probing single-molecule dynamics on a wide range of time and length scales, quasielastic neutron scattering (QENS) can potentially reveal the mechanistic details of water's structural dynamics, but because of interpretational ambiguities this potential has not been fully realized. To resolve these issues, we present here an extensive set of high-quality QENS data from water in the range 253-293 K and a corresponding set of molecular dynamics (MD) simulations to facilitate and validate the interpretation. Using a model-free approach, we analyze the QENS data in terms of two motional components. Based on the dynamical clustering observed in MD trajectories, we identify these components with two distinct types of structural dynamics: picosecond local (L) structural fluctuations within dynamical basins and slower interbasin jumps (J). The Q-dependence of the dominant QENS component, associated with J dynamics, can be quantitatively rationalized with a continuous-time random walk (CTRW) model with an apparent jump length that depends on low-order moments of the jump length and waiting time distributions. Using a simple coarse-graining algorithm to quantitatively identify dynamical basins, we map the newtonian MD trajectory on a CTRW trajectory, from which the jump length and waiting time distributions are computed. The jump length distribution is gaussian and the rms jump length increases from 1.5 to 1.9 Å as the temperature increases from 253 to 293 K. The rms basin radius increases from 0.71 to 0.75 Å over the same range. The

  3. Simultaneous neutron and x-ray imaging of inertial confinement fusion experiments along a single line of sight at Omega

    Energy Technology Data Exchange (ETDEWEB)

    Danly, C. R.; Day, T. H.; Herrmann, H.; Kim, Y. H.; Martinez, J. I.; Merrill, F. E.; Schmidt, D. W.; Simpson, R. A.; Volegov, P. L.; Wilde, C. H. [Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States); Fittinghoff, D. N.; Izumi, N. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2015-04-15

    Neutron and x-ray imaging provide critical information about the geometry and hydrodynamics of inertial confinement fusion implosions. However, existing diagnostics at Omega and the National Ignition Facility (NIF) cannot produce images in both neutrons and x-rays along the same line of sight. This leads to difficulty comparing these images, which capture different parts of the plasma geometry, for the asymmetric implosions seen in present experiments. Further, even when opposing port neutron and x-ray images are available, they use different detectors and cannot provide positive information about the relative positions of the neutron and x-ray sources. A technique has been demonstrated on implosions at Omega that can capture x-ray images along the same line of sight as the neutron images. The technique is described, and data from a set of experiments are presented, along with a discussion of techniques for coregistration of the various images. It is concluded that the technique is viable and could provide valuable information if implemented on NIF in the near future.

  4. Dynamic proton polarisation on polymers in solution: creating contrast in neutron scattering

    International Nuclear Information System (INIS)

    Grinten, M.G.D. van der

    1995-01-01

    Dynamic nuclear polarisation (DNP) as an alternative or additional method to create contrast in neutron small angle scattering has been investigated with emphasis on the study of polymers in solution. The need for high polarisations imposes specific requirements on the sample and its environment. Vitreous beads have been used as samples. Nuclear relaxation times show that they contain dissolved air. Parasitic scattering from the solvent is observed, probably arising from nanometer air bubbles. DNP is shown to be useful, in particular for samples that consist of mixtures of hydrogen-free and hydrogen-rich molecules, where the different molecules can be highlighted by changing the polarisation. ((orig.))

  5. Advanced Neutron Source Dynamic Model (ANSDM) code description and user guide

    International Nuclear Information System (INIS)

    March-Leuba, J.

    1995-08-01

    A mathematical model is designed that simulates the dynamic behavior of the Advanced Neutron Source (ANS) reactor. Its main objective is to model important characteristics of the ANS systems as they are being designed, updated, and employed; its primary design goal, to aid in the development of safety and control features. During the simulations the model is also found to aid in making design decisions for thermal-hydraulic systems. Model components, empirical correlations, and model parameters are discussed; sample procedures are also given. Modifications are cited, and significant development and application efforts are noted focusing on examination of instrumentation required during and after accidents to ensure adequate monitoring during transient conditions

  6. Food structure and dynamics - what are the opportunities for x-ray and neutron scattering?

    International Nuclear Information System (INIS)

    Gilbert, Elliot Paul

    2010-01-01

    In the latter part of the 20th century, it became evident that major advances in understanding could be achieved by gathering together scientists from unique, diverse but nonetheless complementary disciplines. To what extent can this be achieved in materials science, food science, food technology and nutrition? In Australia, we have developed a programme of research in which we seek to investigate fundamental and industrial problems of national significance in food science. This presentation will illustrate some of the opportunities now available through strategic alliances with materials scientists in the application of methods such as X-ray and neutron scattering to gain a critical understanding of food microstructure, nanostructure and dynamics

  7. Methyl group dynamics in a glass and its crystalline counterpart by neutron scattering

    CERN Document Server

    Moreno, A J; Colmenero, J; Frick, B

    2002-01-01

    Methyl group dynamics in the same sample of sodium acetate trihydrate in crystalline and glassy states have been investigated by neutron scattering. Measurements have been carried out in the whole temperature range covering the crossover from rotational tunneling to classical hopping. The results in the crystalline sample have been analyzed according to the usual single-particle model, while those in the glass were analyzed in terms of a broad Gaussian distribution of single-particle potentials, with a standard deviation of 205 K. The average barrier in the glass (417 K) takes, within the experimental error, the same value as the unique barrier in the crystal. (orig.)

  8. Study of the molecular structure and dynamics of bakelite with neutron cross section measurements

    International Nuclear Information System (INIS)

    Voi, D.L.

    1990-06-01

    The molecular structure and dynamics of calcined bakelite were studied with neutron transmission and scattering cross section measurements. The total cross sections determined were correlated with data obtained with infra-red spectroscopy, elemental analysis and other techniques to get the probable molecular formulae of bakelite. The total cross section determined showed a deviation smaller than 5% from the literature values. The frequency distribution as well as overall experimental results allowed to suggest a structural model like polycyclic hydrocarbons for bakelite calcined at 800 0 C. (F.E.). 65 refs, 31 figs, 5 tabs

  9. Dynamic MR imaging in Tolosa-Hunt syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Haque, Tabassum Laz; Miki, Yukio; Kashii, Satoshi; Yamamoto, Akira; Kanagaki, Mitsunori; Takahashi, Takahiro; Fushimi, Yasutaka; Asato, Reinin; Murase, Nagako; Shibasaki, Hiroshi; Konishi, Junji

    2004-09-01

    Objective: To evaluate the cavernous sinuses with dynamic magnetic resonance (MR) imaging in patients with Tolosa-Hunt syndrome (THS). Methods: The sellar and parasellar regions of five patients with THS and 12 control subjects were examined with dynamic MR (1.5 T) imaging in the coronal plane. Dynamic images were obtained with spin-echo (SE) sequences in three patients, and with fast spin-echo (FSE) sequences in two patients and control subjects. Conventional MR images of the cranium including sellar and parasellar regions were also obtained on T1-weighted pre- and post-contrast SE, and T2-weighted FSE sequences in the coronal plane. Results: MR images revealed affected cavernous sinus with bulged convex lateral wall in three patients and concave lateral wall in two patients. In all control subjects, cavernous sinuses were observed with concave lateral wall. The signal intensity on T1- and T2-weighted images and contrast enhancement on post-contrast images of the affected cavernous sinuses in patients were similar to those of the unaffected cavernous sinuses in patients and control subjects. The dynamic images in all patients disclosed small areas adjacent to the cranial nerve filling-defects within the enhanced venous spaces of the affected cavernous sinus, which showed slow and gradual enhancement from the early to the late dynamic images. No such gradually enhancing area was observed in control subjects except one. The follow-up dynamic MR images after corticosteroid therapy revealed complete resolution of the gradually enhancing areas in the previously affected cavernous sinus. Conclusion: Dynamic MR imaging may facilitate the diagnosis of THS.

  10. Dynamic MR imaging in Tolosa-Hunt syndrome

    International Nuclear Information System (INIS)

    Haque, Tabassum Laz; Miki, Yukio; Kashii, Satoshi; Yamamoto, Akira; Kanagaki, Mitsunori; Takahashi, Takahiro; Fushimi, Yasutaka; Asato, Reinin; Murase, Nagako; Shibasaki, Hiroshi; Konishi, Junji

    2004-01-01

    Objective: To evaluate the cavernous sinuses with dynamic magnetic resonance (MR) imaging in patients with Tolosa-Hunt syndrome (THS). Methods: The sellar and parasellar regions of five patients with THS and 12 control subjects were examined with dynamic MR (1.5 T) imaging in the coronal plane. Dynamic images were obtained with spin-echo (SE) sequences in three patients, and with fast spin-echo (FSE) sequences in two patients and control subjects. Conventional MR images of the cranium including sellar and parasellar regions were also obtained on T1-weighted pre- and post-contrast SE, and T2-weighted FSE sequences in the coronal plane. Results: MR images revealed affected cavernous sinus with bulged convex lateral wall in three patients and concave lateral wall in two patients. In all control subjects, cavernous sinuses were observed with concave lateral wall. The signal intensity on T1- and T2-weighted images and contrast enhancement on post-contrast images of the affected cavernous sinuses in patients were similar to those of the unaffected cavernous sinuses in patients and control subjects. The dynamic images in all patients disclosed small areas adjacent to the cranial nerve filling-defects within the enhanced venous spaces of the affected cavernous sinus, which showed slow and gradual enhancement from the early to the late dynamic images. No such gradually enhancing area was observed in control subjects except one. The follow-up dynamic MR images after corticosteroid therapy revealed complete resolution of the gradually enhancing areas in the previously affected cavernous sinus. Conclusion: Dynamic MR imaging may facilitate the diagnosis of THS

  11. An Evaluation of Neutron Energy Spectrum Effects in Iron Based on Molecular Dynamics Displacement Cascade Simulations

    International Nuclear Information System (INIS)

    Greenwood, L.R.; Stoller, R.E.

    1998-01-01

    The results of molecular dynamics (MD) displacement cascade simulations in bcc iron have been used to obtain effective cross sections for two measures of primary damage production: (1) the number of surviving point defects expressed as a fraction of the displacements calculated using the standard secondary displacement model of Norgett, Robinson, and Torrens (NRT), and (2) the fraction of the surviving interstitials contained in clusters that formed during the cascade event. Primary knockon atom spectra for iron obtained from the SPECTER code have been used to weight these MD-based damage production cross sections in order to obtain spectrally-averaged values for several locations in commercial fission reactors and materials test reactors. An evaluation of these results indicates that neutron energy spectrum differences between the various enviromnents do not lead to significant differences between the average primary damage formation parameters. In particular, the defect production cross sections obtained for PWR and BWR neutron spectra were not significantly different. The variation of the defect production cross sections as a function of depth into the reactor pressure vessel wall is used as a sample application of the cross sections. A slight difference between the attenuation behavior of the PWR and BWR was noted; this difference could be explained by a subtle difference in the energy dependence of the neutron spectra. Overall, the simulations support the continued use of dpa as a damage correlation parameter

  12. Application of quasi-elastic neutron scattering to dynamics study of confined water

    International Nuclear Information System (INIS)

    Li Hua; Zhang Lili; Yi Zhou

    2014-01-01

    Background: Quasi-elastic neutron scattering (QENS) is an important experiment for dynamics study of confined water. It is significant to study the dynamics of confined water in cement paste. Purpose: In this paper, we have two aims. One is to present a reviewer of QENS study on dynamics of confined water in cement paste in recent years. The other is to illustrate the QENS application to the study on dynamics of confined water based on cement paste. Method: Relaxing cage model (RCM) is specially introduced for the analyses of QENS spectra. Results: Based on RCM, several parameters for describing the dynamics of confined water in cement paste, can be obtained from the analyses of QENS spectra: a fraction of mobile 'glassy' water molecules embedded in amorphous gel region surrounding the hydration products, 1-p, the capture time of confined water molecule in some place-τ 0 , the average translational relaxation time-<τ>, the self-diffusion coefficient-D, and a phenomenological shape parameter describing the uniform of amorphous in cement paste-β. Conclusion: All these provide a practical method for QENS study on dynamics of confined water in cement paste. (authors)

  13. Clustering Effects on Dynamics in Ionomer Solutions: A Neutron Spin Echo Insight

    Science.gov (United States)

    Perahia, Dvora; Wijesinghe, Sidath; Senanayake, Manjula; Wickramasinghe, Anuradhi; Mohottalalage, Supun S.; Ohl, Michael

    Ionizable blocks in ionomers associate into aggregates serving as physical cross-links and concurrently form transport pathways. The dynamics of ionomers underline their functionality. Incorporating small numbers of ionic groups into polymers significantly constraint their dynamics. Recent computational studies demonstrated a direct correlation between ionic cluster morphology and polymer dynamics. Here using neutron spin echo, we probe the segmental dynamics of polystyrene sulfonate (PSS) as the degree of sulfonation of the PSS and the solution dielectrics are varied. Specifically, 20Wt% PSS of 11,000 g/mol with polydispersity of 1.02 with 3% and 9% sulfonation were studies in toluene (dielectric constant ɛ = 2.8), a good solvent for polystyrene, and with 5Wt% of ethanol (ɛ = 24.3l) added. The dynamic structure factor S(q,t) was analyzed with a single exponential except for a limited q range where two time constants associated with constraint and mobile segments were detected. S(q,t) exhibits several distinctive time and length scales for the dynamics with a crossover appearing at the length scale of the ionic clusters. NSF DMR 1611136.

  14. Robust image registration for multiple exposure high dynamic range image synthesis

    Science.gov (United States)

    Yao, Susu

    2011-03-01

    Image registration is an important preprocessing technique in high dynamic range (HDR) image synthesis. This paper proposed a robust image registration method for aligning a group of low dynamic range images (LDR) that are captured with different exposure times. Illumination change and photometric distortion between two images would result in inaccurate registration. We propose to transform intensity image data into phase congruency to eliminate the effect of the changes in image brightness and use phase cross correlation in the Fourier transform domain to perform image registration. Considering the presence of non-overlapped regions due to photometric distortion, evolutionary programming is applied to search for the accurate translation parameters so that the accuracy of registration is able to be achieved at a hundredth of a pixel level. The proposed algorithm works well for under and over-exposed image registration. It has been applied to align LDR images for synthesizing high quality HDR images..

  15. Evaluation of dynamic elasticity module in samples of Portland (type 1) cement paste exposed to neutronic irradiation

    International Nuclear Information System (INIS)

    Rosa Junior, A.A.; Lucki, G.

    1986-01-01

    The fast neutron radiation effects and temperature on Portland cement are studied. The Dynamic Elasticity Module (Ed) in samples of Portland cement paste was evaluated. Ultrassonic technics were applied (resonance frequency and pulse velocity). The samples were irradiated with fast neutrons to fluence of 7,2 x 10 18 n/cm 2 (E approx. 1 MeV), at temperature of 120 + - 5 0 C, due to gamma heating. This temperature was simulated in laboratory in a microwave oven. (Author) [pt

  16. Monte Carlo modeling of neutron and gamma-ray imaging systems

    International Nuclear Information System (INIS)

    Hall, J.

    1996-04-01

    Detailed numerical prototypes are essential to design of efficient and cost-effective neutron and gamma-ray imaging systems. We have exploited the unique capabilities of an LLNL-developed radiation transport code (COG) to develop code modules capable of simulating the performance of neutron and gamma-ray imaging systems over a wide range of source energies. COG allows us to simulate complex, energy-, angle-, and time-dependent radiation sources, model 3-dimensional system geometries with ''real world'' complexity, specify detailed elemental and isotopic distributions and predict the responses of various types of imaging detectors with full Monte Carlo accuray. COG references detailed, evaluated nuclear interaction databases allowingusers to account for multiple scattering, energy straggling, and secondary particle production phenomena which may significantly effect the performance of an imaging system by may be difficult or even impossible to estimate using simple analytical models. This work presents examples illustrating the use of these routines in the analysis of industrial radiographic systems for thick target inspection, nonintrusive luggage and cargoscanning systems, and international treaty verification

  17. Single photon image from PET with insertable collimator for boron neutron capture therapy

    International Nuclear Information System (INIS)

    Jung, Jooyoung; Suh, Tae Suk; Hong, Key Jo

    2014-01-01

    Boron neutron capture therapy (BNCT) is a radiation therapy technique for treating deep-seated brain tumors by irradiation with a thermal neutron in which boron-labelled low molecular weight compounds. Once completed, a single photon emission computed tomography (SPECT) scan is conducted to investigate for the region of therapy using an isotope exclusive to SPECT. In the case of an existing PET/SPECT combination system, at least two types of isotopes should be used for each scan with their purposes. Recently, researchers examined the effects of PET/SPECT dual modality on animal imaging systems. They reported that the PET/SPECT combination system was effective for simultaneous achievement of a single event and coincidence. The aim of our proposed system is to confirm the feasibility of extraction of two types of images from one PET module with an insertable collimator for brain tumor treatment during the BNCT. We attempted to acquire the PET and SPECT images simultaneously using only PET without an additional isotope. Single photon images were acquired using an insertable collimator on a PET detector

  18. A new transmission based monochromator for energy-selective neutron imaging at the ICON beamline

    International Nuclear Information System (INIS)

    Peetermans, S.; Tamaki, M.; Hartmann, S.; Kaestner, A.; Morgano, M.; Lehmann, E.H.

    2014-01-01

    A new type of monochromator has been developed for energy-selective neutron imaging at continuous sources. It combines the use of a mechanical neutron velocity selector with pyrolytic graphite crystals of different mosaicity. The beam can be monochromatized to similar levels as a standard double crystal monochromator. It can flexibly produce different desired spectral shapes, even an asymmetric one. Intrinsically, no higher order contamination of the spectrum is present. Working with the transmitted beam, the beam divergence (and thus the spatial resolution) is uncompromised. The device has been calibrated, characterized and its performance demonstrated with the measurement of Bragg edges for iron and lead, resolving them more sharply than if solely a mechanical velocity selector was used

  19. Nano-confined water in the interlayers of hydrocalumite: Reorientational dynamics probed by neutron spectroscopy and molecular dynamics computer simulations

    Science.gov (United States)

    Kalinichev, A. G.; Faraone, A.; Udovic, T.; Kolesnikov, A. I.; de Souza, N. R.; Reinholdt, M. X.; Kirkpatrick, R.

    2008-12-01

    Layered double hydroxides (LDHs, anionic clays) represent excellent model systems for detailed molecular- level studies of the structure, dynamics, and energetics of nano-confined water in mineral interlayers and nano-pores, because LDH interlayers can have a well-defined structures and contain H2O molecules and a wide variety of anions in structurally well-defined positions and coordinations. [Ca2Al(OH)6]Cl·2H2O, also known as hydrocalumite or Friedel's salt, has a well- ordered Ca,Al distribution in the hydroxide layer and a very high degree of H2O,Cl ordering in the interlayer. It is also one of the only LDH phase for which a single crystal structure refinement is available. Thus, it is currently the best model compound for understanding the structure and dynamical behavior of interlayer and surface species in other, less-ordered, LDHs. We investigated the structural and dynamic behavior of water in the interlayers of hydrocalumite using inelastic (INS) and quasielastic (QENS) neutron scattering and molecular dynamics computer simulations. The comperehensive neutron scattering studies were performed for one fully hydrated and one dehydrated sample of hydrocalumite using several complementary instruments (HFBS, DCS and FANS at NCNR; HRMECS and QENS at IPNS) at temperatures above and below the previously discovered order-disorder interlayer phase transition. Together the experimental and molecular modeling results capture the important details of the dynamics of nano-confined water and the effects of the orientational ordering of H2O molecules above and below the phase transition. They provide otherwise unobtainable experimental information about the transformation of H2O librational and diffusional modes across the order-disorder phase transition and significantly add to our current understanding of the structure and dynamics of water in LDH phases based on the earlier NMR, IR, X-ray, and calorimetric measurements. The approach can now be extended to probe the

  20. GPU-based prompt gamma ray imaging from boron neutron capture therapy

    International Nuclear Information System (INIS)

    Yoon, Do-Kun; Jung, Joo-Young; Suk Suh, Tae; Jo Hong, Key; Sil Lee, Keum

    2015-01-01

    Purpose: The purpose of this research is to perform the fast reconstruction of a prompt gamma ray image using a graphics processing unit (GPU) computation from boron neutron capture therapy (BNCT) simulations. Methods: To evaluate the accuracy of the reconstructed image, a phantom including four boron uptake regions (BURs) was used in the simulation. After the Monte Carlo simulation of the BNCT, the modified ordered subset expectation maximization reconstruction algorithm using the GPU computation was used to reconstruct the images with fewer projections. The computation times for image reconstruction were compared between the GPU and the central processing unit (CPU). Also, the accuracy of the reconstructed image was evaluated by a receiver operating characteristic (ROC) curve analysis. Results: The image reconstruction time using the GPU was 196 times faster than the conventional reconstruction time using the CPU. For the four BURs, the area under curve values from the ROC curve were 0.6726 (A-region), 0.6890 (B-region), 0.7384 (C-region), and 0.8009 (D-region). Conclusions: The tomographic image using the prompt gamma ray event from the BNCT simulation was acquired using the GPU computation in order to perform a fast reconstruction during treatment. The authors verified the feasibility of the prompt gamma ray image reconstruction using the GPU computation for BNCT simulations

  1. Unfolding and smoothing applied to the quality enhancement of neutron tomographic images

    International Nuclear Information System (INIS)

    Almeida, Gevaldo L. de; Silvani, Maria I.; Lopes, Ricardo T.

    2008-01-01

    Resolution and contrast are the major parameters defining the quality of a computer-aided tomographic image. These parameters depend upon several features of the image acquisition system, such as detector resolution, geometrical arrangement of the source-object-detector, beam divergence, source strength, detector efficiency and counting time. Roughly, the detector finite resolution is the main source of systematic errors affecting the separation power of the image acquisition system, while the electronic noise and statistical fluctuation are responsible for the data dispersion, which spoils the contrast. An algorithm has been developed in this work aiming at the improvement of the image quality through the minimization of both types of errors. The systematic ones are reduced by a mathematical unfolding of the position spectra - used as projections to reconstruct the 2D-images - using the Line Spread Function - LSF of the neutron tomographic system. The principle behind this technique is that every single channel contains information about all channels of the spectrum, but it is concealed due to the automatic integration carried out by the detector. Therefore, knowing the shape of this curve, it is possible to retrieve the original spectra. These spectra are unfortunately corrupted by the unavoidable statistical fluctuation, and by oscillations arising from the unfolding process, which strongly affects the quality of the final unfolded image. In order to reduce this impact, the spectra have been filtered by a Fourier transform technique or smoothed with a least square fitting procedure. The algorithm has been applied to spectra of some test-bodies generated by an earlier developed tomographic simulator, which reproduces the spectra furnished by a thermal neutron tomographic system employing a position sensitive detector. The obtained results have shown that the unfolded spectra produce final images capable to resolve features otherwise not achievable with the

  2. Dynamic Chest Image Analysis: Model-Based Perfusion Analysis in Dynamic Pulmonary Imaging

    Directory of Open Access Journals (Sweden)

    Kiuru Aaro

    2003-01-01

    Full Text Available The "Dynamic Chest Image Analysis" project aims to develop model-based computer analysis and visualization methods for showing focal and general abnormalities of lung ventilation and perfusion based on a sequence of digital chest fluoroscopy frames collected with the dynamic pulmonary imaging technique. We have proposed and evaluated a multiresolutional method with an explicit ventilation model for ventilation analysis. This paper presents a new model-based method for pulmonary perfusion analysis. According to perfusion properties, we first devise a novel mathematical function to form a perfusion model. A simple yet accurate approach is further introduced to extract cardiac systolic and diastolic phases from the heart, so that this cardiac information may be utilized to accelerate the perfusion analysis and improve its sensitivity in detecting pulmonary perfusion abnormalities. This makes perfusion analysis not only fast but also robust in computation; consequently, perfusion analysis becomes computationally feasible without using contrast media. Our clinical case studies with 52 patients show that this technique is effective for pulmonary embolism even without using contrast media, demonstrating consistent correlations with computed tomography (CT and nuclear medicine (NM studies. This fluoroscopical examination takes only about 2 seconds for perfusion study with only low radiation dose to patient, involving no preparation, no radioactive isotopes, and no contrast media.

  3. Staging of pancreatic ductal adenocarcinoma using dynamic MR imaging

    International Nuclear Information System (INIS)

    Murakami, Kouji; Nawano, Shigeru; Moriyama, Noriyuki; Sekiguchi, Ryuzou; Satake, Mituo; Iwata, Ryouko; Hayashi, Takayuki; Nemoto, Kazuhisa.

    1997-01-01

    Single breath-hold gradient echo images were obtained before and immediately after bolus intravenous administration of Gd-DTPA (dynamic MR imaging) in the study of the pancreas. Of 37 patients with pathologically proved pancreatic ductal adenocarcinoma, seventeen patients who underwent both dynamic MR imaging studies and curative surgery were included in this study. Correlations between histologic findings in the resected specimens and MR images were analyzed as to tumor extension and staging according to the General Rules for the Study of Pancreatic Cancer (4th Edition) published by the Japan Pancreas Society. In comparison with conventional MR images, dynamic MR imaging improved the detectability of pancreatic carcinoma and delineation of the vasculature by clarifying the margin of the tumor and the vessels. Nonenhanced T1-weighted imaging is the best sequence to estimate peripancreatic tumor extension, because the contrast between the tumor and peripancreatic fat deteriorates with the use of contrast material. There is a tendency to overestimate vascular invasion on MR images, the reason for which is considered to be the contractive nature of fibrotic change induced by pancreatic carcinoma. The diagnostic efficacy of lymph node metastasis remains insufficient on MR images because some cases show no enlargement of lymph nodes in spite of the existence of pathological metastasis. Our results suggest that dynamic MR imaging has the advantage of improving the conspicuity of the tumor and the vasculature. (author)

  4. Microscopic dynamics of the hydrogen bonded systems studied by quasi-elastic slow neutron scattering

    International Nuclear Information System (INIS)

    Padureanu, I.; Aranghel, D.; Radulescu, A.; Ion, M.; Lechner, R. E.; Desmedt, A.; Pieper, J.

    2002-01-01

    The detailed understanding of the dynamical properties in highly viscous liquids such as glycerol, as well the supercooled and glassy state has attracted a great deal of attention. Glycerol is a hydrogen bonded forming system considered as intermediate between fragile and strong glasses with a glass transition temperature T g ∼ 185 K, melting temperature T m 290 K and a sound velocity V S ∼ 3330 m/s. Incoherent neutron scattering experiments from glasses generally show a broad feature with a maximum around 2 to 10 meV. This large contribution of such unusual low frequency excitations obeying the Bose-Einstein statistics to the density of states is referred to as 'boson peak' (BP) with a maximum near a frequency of 1 THz. A very much-debated question is the dramatic changes in the properties as well as the nature of the boson peak and the acoustic modes occurring in the neighborhood of this frequency. So far the experiments were not able to give a definite answer concerning the excitations giving rise to the boson peak. The inelastic X-ray scattering across the liquid glass transition in glycerol revealed propagating collective excitations in the whole liquid-glass transition temperature range. This conclusion challenges the present understanding of glasses and supercooled liquids particularly with their thermal properties. New experiments at lower temperatures than those investigated so far where the phonon scattering processes are less hard have been proposed. The relationship between the low frequency features, the microscopic structure, the nature of the forces and the atomic motions taking place at low frequencies is still an open question. According to the mode coupling theory (MCT) the glass transition is interpreted as a two-step process where the glass structure is softened by fast local motions (β - process) until some temperature T c >T g , where the structure breaks down leading to diffusion (α-process). It is an open question, whether MCT can

  5. A neutron image plate quasi-Laue diffractometer for protein crystallography

    Energy Technology Data Exchange (ETDEWEB)

    Cipriani, F.; Castagna, J.C.; Wilkinson, C. [European Molecular Biology Laboratory, Grenoble (France)] [and others

    1994-12-31

    An instrument which is based on image plate technology has been constructed to perform cold neutron Laue crystallography on protein structures. The crystal is mounted at the center of a cylindrical detector which is 400mm long and has a circumference of 1000mm, with gadolinium oxide-containing image plates mounted on its exterior surface. Laue images registered on the plate are read out by rotating the drum and translating a laser read head parallel to the cylinder axis, giving a pixel size of 200{mu}m x 200{mu}m and a total read time of 5 minutes. Preliminary results indicate that it should be possible to obtain a complete data set from a protein crystal to atomic resolution in about two weeks.

  6. Theoretical and experimental study of the dark signal in CMOS image sensors affected by neutron radiation from a nuclear reactor

    Science.gov (United States)

    Xue, Yuanyuan; Wang, Zujun; He, Baoping; Yao, Zhibin; Liu, Minbo; Ma, Wuying; Sheng, Jiangkun; Dong, Guantao; Jin, Junshan

    2017-12-01

    The CMOS image sensors (CISs) are irradiated with neutron from a nuclear reactor. The dark signal in CISs affected by neutron radiation is studied theoretically and experimentally. The Primary knock-on atoms (PKA) energy spectra for 1 MeV incident neutrons are simulated by Geant4. And the theoretical models for the mean dark signal, dark signal non-uniformity (DSNU) and dark signal distribution versus neutron fluence are established. The results are found to be in good agreement with the experimental outputs. Finally, the dark signal in the CISs under the different neutron fluence conditions is estimated. This study provides the theoretical and experimental evidence for the displacement damage effects on the dark signal CISs.

  7. Quantitative neutron radiography using neutron absorbing honeycomb

    International Nuclear Information System (INIS)

    Tamaki, Masayoshi; Oda, Masahiro; Takahashi, Kenji; Ohkubo, Kohei; Tasaka, Kanji; Tsuruno, Akira; Matsubayashi, Masahito.

    1993-01-01

    This investigation concerns quantitative neutron radiography and computed tomography by using a neutron absorbing honeycomb collimator. By setting the neutron absorbing honeycomb collimator between object and imaging system, neutrons scattered in the object were absorbed by the honeycomb material and eliminated before coming to the imaging system, but the neutrons which were transmitted the object without interaction could reach the imaging system. The image by purely transmitted neutrons gives the quantitative information. Two honeycombs were prepared with coating of boron nitride and gadolinium oxide and evaluated for the quantitative application. The relation between the neutron total cross section and the attenuation coefficient confirmed that they were in a fairly good agreement. Application to quantitative computed tomography was also successfully conducted. The new neutron radiography method using the neutron-absorbing honeycomb collimator for the elimination of the scattered neutrons improved remarkably the quantitativeness of the neutron radiography and computed tomography. (author)

  8. Neutron scattering studies on protein dynamics using the human myelin peripheral membrane protein P2

    Directory of Open Access Journals (Sweden)

    Laulumaa Saara

    2015-01-01

    Full Text Available Myelin is a multilayered proteolipid membrane structure surrounding selected axons in the vertebrate nervous system, which allows the rapid saltatory conduction of nerve impulses. Deficits in myelin formation and maintenance may lead to chronic neurological disease. P2 is an abundant myelin protein from peripheral nerves, binding between two apposing lipid bilayers. We studied the dynamics of the human myelin protein P2 and its mutated P38G variant in hydrated powders using elastic incoherent neutron scattering. The local harmonic vibrations at low temperatures were very similar for both samples, but the mutant protein had increased flexibility and softness close to physiological temperatures. The results indicate that a drastic mutation of proline to glycine at a functional site can affect protein dynamics, and in the case of P2, they may explain functional differences between the two proteins.

  9. Neutron scattering studies on protein dynamics using the human myelin peripheral membrane protein P2

    Science.gov (United States)

    Laulumaa, Saara; Kursula, Petri; Natali, Francesca

    2015-01-01

    Myelin is a multilayered proteolipid membrane structure surrounding selected axons in the vertebrate nervous system, which allows the rapid saltatory conduction of nerve impulses. Deficits in myelin formation and maintenance may lead to chronic neurological disease. P2 is an abundant myelin protein from peripheral nerves, binding between two apposing lipid bilayers. We studied the dynamics of the human myelin protein P2 and its mutated P38G variant in hydrated powders using elastic incoherent neutron scattering. The local harmonic vibrations at low temperatures were very similar for both samples, but the mutant protein had increased flexibility and softness close to physiological temperatures. The results indicate that a drastic mutation of proline to glycine at a functional site can affect protein dynamics, and in the case of P2, they may explain functional differences between the two proteins.

  10. Dynamics in poly vinyl alcohol (PVA) based hydrogel: Neutron scattering study

    Energy Technology Data Exchange (ETDEWEB)

    Prabhudesai, S. A., E-mail: swapnil@barc.gov.in; Mitra, S.; Mukhopadhyay, R. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 40085 (India); Lawrence, Mathias B. [Department of Physics, St. Xavier’s College, Mapusa, Goa 403507 (India); Desa, J. A. E. [Department of Physics, Goa University, Taleigao Plateau, Goa 403206 (India)

    2015-06-24

    Results of quasielastic neutron scattering measurements carried out on Poly Vinyl Alcohol (PVA) based hydrogels are reported here. PVA hydrogels are formed using Borax as a cross-linking agent in D{sub 2}O solvent. This synthetic polymer can be used for obtaining the hydrogels with potential use in the field of biomaterials. The aim of this paper is to study the dynamics of polymer chain in the hydrogel since it is known that polymer mobility influences the kinetics of loading and release of drugs. It is found that the dynamics of hydrogen atoms in the polymer chain could be described by a model where the diffusion of hydrogen atoms is limited within a spherical volume of radius 3.3 Å. Average diffusivity estimated from the behavior of quasielastic width is found to be 1.2 × 10{sup −5} cm{sup 2}/sec.

  11. RADIANCE DOMAIN COMPOSITING FOR HIGH DYNAMIC RANGE IMAGING

    Directory of Open Access Journals (Sweden)

    M.R. Renu

    2013-02-01

    Full Text Available High dynamic range imaging aims at creating an image with a range of intensity variations larger than the range supported by a camera sensor. Most commonly used methods combine multiple exposure low dynamic range (LDR images, to obtain the high dynamic range (HDR image. Available methods typically neglect the noise term while finding appropriate weighting functions to estimate the camera response function as well as the radiance map. We look at the HDR imaging problem in a denoising frame work and aim at reconstructing a low noise radiance map from noisy low dynamic range images, which is tone mapped to get the LDR equivalent of the HDR image. We propose a maximum aposteriori probability (MAP based reconstruction of the HDR image using Gibb’s prior to model the radiance map, with total variation (TV as the prior to avoid unnecessary smoothing of the radiance field. To make the computation with TV prior efficient, we extend the majorize-minimize method of upper bounding the total variation by a quadratic function to our case which has a nonlinear term arising from the camera response function. A theoretical justification for doing radiance domain denoising as opposed to image domain denoising is also provided.

  12. Flux weighted method for solution of stiff neutron dynamic equations and its application

    International Nuclear Information System (INIS)

    Li Huiyun; Jiao Huixian

    1987-12-01

    To analyze reactivity event for nuclear power plants, it is necessary to solve the neutron dynamic equations, which is a group of typical stiff constant differential equations. Very small time steps could only be adopted when the group of equations is solved by common methods. However, a large time steps might be selected if the Flux Weighted Medthod introduced in this paper is used. Generally, weighted factor θ i1 is set as a constant. Naturally, this treatment method can decrease the accuracy of calculation for the increase of the steadiness of solving the equations. An accurate theoretical formula of 4 x 4 matrix of θ i1 is rigorously derived so that the accuracy of calculation is ensured, as well as the steadiness of solved equations is increased. This method have the advantage over classical Runge-kutta Method and other methods. The time steps could be increased by a factor of 1 ∼ 3 orders of magnitude so as to save a lot of computating time. The programe solving neutron dynamic equation, which is prepared by using Flux Weighted Method, could be sued for real time analog of training simulator, as well as for analysis and computation of reactivity event (including rod jumping out event)

  13. Life at extreme conditions: neutron scattering studies of biological molecules suggest that evolution selected dynamics

    International Nuclear Information System (INIS)

    Zaccai, Joseph Giuseppe

    2008-01-01

    The short review concentrates on recent work performed at the neutrons in biology laboratories of the Institut Laue Langevin and Institut de Biologie Structurale in Grenoble. Extremophile organisms have been discovered that require extreme conditions of temperature, pressure or solvent environment for survival. The existence of such organisms poses a significant challenge in understanding the physical chemistry of their proteins, in view of the great sensitivity of protein structure and stability to the aqueous environment and to external conditions in general. Results of neutron scattering measurements on the dynamics of proteins from extremophile organisms, in vitro as well as in vivo, indicated remarkably how adaptation to extreme conditions involves forces and fluctuation amplitudes that have been selected specifically, suggesting that evolutionary macromolecular selection proceeded via dynamics. The experiments were performed on a halophilic protein, and membrane adapted to high salt, a thermophilic enzyme adapted to high temperature and its mesophilic (adapted to 37 degC) homologue; and in vivo for psychrophilic, mesophilic, thermophilic and hyperthermophilic bacteria, adapted respectively to temperatures of 4 degC, 37 degC, 75 degC and 85 degC. Further work demonstrated the existence of a water component of exceptionally low mobility in an extreme halophile from the Dead Sea, which is not present in mesophile bacterial cells. (author)

  14. Accretion dynamics and polarized x-ray emission of magnetized neutron stars

    International Nuclear Information System (INIS)

    Arons, J.

    1991-01-01

    The basic ideas of accretion onto magnetized neutron stars are outlined. These are applied to a simple model of the structure of the plasma mound sitting at the magnetic poles of such as star, in which upward diffusion of photons is balanced by their downward advection. This steady flow model of the plasma's dynamical state is used to compute the emission of polarized X-rays from the optically thick, birefringent medium. The linear polarization of the continuum radiation emerging from the quasi-static mound is found to be as much as 40% at some rotation phases, but is insensitive to the geometry of the accretion flow. The role of the accretion shock, whose detailed polarimetric and spectral characteristics have yet to be calculated, is emphasized as the final determinant of the properties of the emerging X-rays. Some results describing the fully time dependent dynamics of the flow are also presented. In particular, steady flow onto a neutron star is shown to exhibit formation of ''photon bubbles,'' regions of greatly reduced plasma density filled with radiation which form and rise on millisecond time scales. The possible role of these complex structures in the flow for the formation of the emergent spectrum is briefly outlined

  15. Accretion dynamics and polarized X-ray emission of magnetized neutron stars

    Science.gov (United States)

    Arons, Jonathan

    1991-01-01

    The basic ideas of accretion onto magnetized neutron stars are outlined. These are applied to a simple model of the structure of the plasma mound sitting at the magnetic poles of such a star, in which upward diffusion of photons is balanced by their downward advection. This steady flow model of the plasma's dynamical state is used to compute the emission of polarized X-raysfrom the optically thick, birefringent medium. The linear polarization of the continuum radiation emerging from the quasi-static mound is found to be as much as 40 percent at some rotation phases, but is insensitive to the geometry of the accretion flow. The role of the accretion shock, whose detailed polarimetric and spectral characteristics have yet to be calculated, is emphasized as the final determinant of the properties of the emerging X-rays. Some results describing the fully time dependent dynamics of the flow are also presented. In particular, steady flow onto a neutron star is shown to exhibit formation of 'photon bubbles', regions of greatly reduced plasma density filled with radiation which form and rise on millisecond time scale. The possible role of these complex structures in the flow for the formation of the emergent spectrum is briefly outlined.

  16. I-Love-Q relations for neutron stars in dynamical Chern Simons gravity

    Science.gov (United States)

    Gupta, Toral; Majumder, Barun; Yagi, Kent; Yunes, Nicolás

    2018-01-01

    Neutron stars are ideal to probe, not only nuclear physics, but also strong-field gravity. Approximate universal relations insensitive to the star’s internal structure exist among certain observables and are useful in testing general relativity, as they project out the uncertainties in the equation of state. One such set of universal relations between the moment of inertia (I), the tidal Love number and the quadrupole moment (Q) has been studied both in general relativity and in modified theories. In this paper, we study the relations in dynamical Chern–Simons gravity, a well-motivated, parity-violating effective field theory, extending previous work in various ways. First, we study how projected constraints on the theory using the I-Love relation depend on the measurement accuracy of I with radio observations and that of the Love number with gravitational-wave observations. Provided these quantities can be measured with future observations, we find that the latter could place bounds on dynamical Chern–Simons gravity that are six orders of magnitude stronger than current bounds. Second, we study the I–Q and Q-Love relations in this theory by constructing slowly-rotating neutron star solutions to quadratic order in spin. We find that the approximate universality continues to hold in dynamical Chern–Simons gravity, and in fact, it becomes stronger than in general relativity, although its existence depends on the normalization of the dimensional coupling constant of the theory. Finally, we study the variation of the eccentricity of isodensity contours inside a star and its relation to the degree of universality. We find that, in most cases, the eccentricity variation is smaller in dynamical Chern–Simons gravity than in general relativity, providing further support to the idea that the approximate self-similarity of isodensity contours is responsible for universality.

  17. Non-destructive Faraday imaging of dynamically controlled ultracold atoms

    Science.gov (United States)

    Gajdacz, Miroslav; Pedersen, Poul; Mørch, Troels; Hilliard, Andrew; Arlt, Jan; Sherson, Jacob

    2013-05-01

    We investigate non-destructive measurements of ultra-cold atomic clouds based on dark field imaging of spatially resolved Faraday rotation. In particular, we pursue applications to dynamically controlled ultracold atoms. The dependence of the Faraday signal on laser detuning, atomic density and temperature is characterized in a detailed comparison with theory. In particular the destructivity per measurement is extremely low and we illustrate this by imaging the same cloud up to 2000 times. The technique is applied to avoid the effect of shot-to-shot fluctuations in atom number calibration. Adding dynamic changes to system parameters, we demonstrate single-run vector magnetic field imaging and single-run spatial imaging of the system's dynamic behavior. The method can be implemented particularly easily in standard imaging systems by the insertion of an extra polarizing beam splitter. These results are steps towards quantum state engineering using feedback control of ultracold atoms.

  18. 3D dynamic pituitary MR imaging with CAIPIRINHA: Initial experience and comparison with 2D dynamic MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Fushimi, Yasutaka, E-mail: yfushimi@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Kyoto 606-8507 (Japan); Okada, Tomohisa; Kanagaki, Mitsunori; Yamamoto, Akira; Kanda, Yumiko; Sakamoto, Ryo [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Kyoto 606-8507 (Japan); Hojo, Masato; Takahashi, Jun C.; Miyamoto, Susumu [Department of Neurosurgery, Kyoto University Graduate School of Medicine, Kyoto 606-8507 (Japan); Togashi, Kaori [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Kyoto 606-8507 (Japan)

    2014-10-15

    Objectives: To evaluate the validity of 3D dynamic pituitary MR imaging with controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA), with special emphasis on demarcation of pituitary posterior lobe and stalk. Methods: Participants comprised 32 patients who underwent dynamic pituitary MR imaging due to pituitary or parasellar lesions. 3D dynamic MR with CAIPIRINHA was performed at 3 T with 20-s-interval, precontrast, 1st to 5th dynamic images. Normalized values and enhanced ratios (dynamic postcontrast image values divided by precontrast ones) were compared between 3D and 2D dynamic MR imaging for patients with visual identification of posterior lobe and stalk. Results: In 3D, stalk was identified in 29 patients and unidentified in 3, and posterior lobe was identified in 28 and unidentified in 4. In 2D, stalk was identified in 26 patients and unidentified in 6 patients, and posterior lobe was identified in 15 and unidentified in 17. Normalized values of pituitary posterior lobe and stalk were higher in 3D than 2D (P < 0.001). No significant difference in enhancement ratio was seen between 3D and 2D. Conclusions: 3D dynamic pituitary MR provided better identification and higher normalized values of pituitary posterior lobe and stalk than 2D.

  19. Alternatives to argon for gas stopping volumes in the B194 neutron imager

    Energy Technology Data Exchange (ETDEWEB)

    Bleuel, D. L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Anderson, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Caggiano, J. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hall, J. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Johnson, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ratkiewicz, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Rusnak, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-05-17

    In a recent experiment at Lawrence Berkeley National Laboratory, the 40Ar(d,p)41Ar excitation function between 3-7 MeV was measured, confirming a previous estimation that there may be an intolerable radiation dose from 41Ar production by slowing to rest 6.74 MeV deuterons in the gas cell of the neutron imaging facility being constructed in B194. Gas alternatives to argon are considered, including helium, nitrogen (N2), neon, sulfur hexafluoride (SF6), krypton, and xenon, as well as high atomic number solid backings such as tantalum.

  20. Panoramic images of conventional radiographs: digital panoramic dynamic images

    International Nuclear Information System (INIS)

    Schultze, M.

    2001-01-01

    The benefits of digital technic s to od ontology are evident. Instant images, the possibility to handle them, the reduction of exposition time to radiations, better quality image, better quality information, Stocking them in a compact disc, occupying very little space, allows an easy transport and duplication, as well as the possibility to transfer and save it in an electronica l support.This kind of communication allows the transmission of digital images and every other type of data, instantaneously and no matter distances or geographical borders. Anyway, we should point out that conventional and digital technic s reveal the same information contents

  1. Cardiac MR imaging: Comparison with echocardiography and dynamic CT

    International Nuclear Information System (INIS)

    Colletti, P.M.; Norris, S.; Raval, J.; Boswell, W.; Lee, K.; Ralls, P.; Haywood, J.; Halls, J.

    1986-01-01

    The authors compared gated cardiac MR imaging with two-dimensional and Doppler echocardiography and dynamic CT. Gated cardiac MR imaging (VISTA unit, 0.5 T) was performed in 55 patients with a variety of conditions. Accuracy of diagnosis was compared. CT showed arterial, valvular, and pericardial calcifications not seen on MR imaging. Many lesions were seen as well on CT as on MR imaging. Two-dimensional echocardiography was superior in demonstrating wall motion and valvular disease. MR imaging was superior in demonstrating myocardial structures

  2. Dynamics of Phenanthrenequinone on Carbon Nano-Onion Surfaces Probed by Quasielastic Neutron Scattering

    International Nuclear Information System (INIS)

    Mamontov, Eugene; Brown, Gilbert M.; Overbury, Steven H.; Mavila Chathoth, Suresh

    2012-01-01

    We used quasielastic neutron scattering (QENS) to study the dynamics of phenanthrenequinone (PQ) on the surface of onion-like carbon (OLC), or so called carbon onions, as a function of surface coverage and temperature. For both the high- and low-coverage samples, we observed two diffusion processes; a faster process and nearly an order of magnitude slower process. On the high-coverage surface, the slow diffusion process is of long-range translational character, whereas the fast diffusion process is spatially localized on the length scale of ∼ 4.7. On the low-coverage surface, both diffusion processes are spatially localized; on the same length scale of ∼ 4.7 for the fast diffusion and a somewhat larger length scale for the slow diffusion. Arrhenius temperature dependence is observed except for the long-range diffusion on the high-coverage surface. We attribute the fast diffusion process to the generic localized in-cage dynamics of PQ molecules, and the slow diffusion process to the long-range translational dynamics of PQ molecules, which, depending on the coverage, may be either spatially restricted, or long-range. On the low-coverage surface, uniform surface coverage is not attained, and the PQ molecules experience the effect of spatial constraints on their long-range translational dynamics. Unexpectedly, the dynamics of PQ molecules on OLC as a function of temperature and surface coverage bears qualitative resemblance to the dynamics of water molecules on oxide surfaces, including practically temperature-independent residence times for the low-coverage surface. The dynamics features that we observed may be universal across different classes of surface adsorbates.

  3. The nano-structural dynamics of polymer aggregates using the neutron spin echo method

    International Nuclear Information System (INIS)

    Kanaya, T.; Koizumi, S.

    2004-01-01

    Dynamics of corona chains of polymer micelle and of two types of polyvinylalcohol (PVA) were studied in nano-meter scale. In micelle system a respiration mode caused by competition between osmotic pressure and entropy force was found out from experiments. This respiration mode died out when graft density of the corona chain on the surface of micelle core was reduced. The change from cooperative movements to individual movements was observed in polymer chain movements as depending on the difference of graft density. In the study of PVA gel dynamics, fluctuation measurements by small angle neutron scattering could successfully separate dynamic fluctuation from static one. The measurements indicated that fluctuation in PVA gel formed from a DMSO (dimethyl sulfoxide)/water mixed system was nearly frozen, but on the contrary all fluctuation in PVA gel formed in aqueous solution of borax was dynamical. Above result could be deduced from the fact that bridge points formed from hydrogen bonds could interchange among themselves. (Y. Kazumata)

  4. Quasi-elastic neutron scattering studies of the slow dynamics of supercooled and glassy aspirin

    International Nuclear Information System (INIS)

    Zhang Yang; Mamontov, Eugene; Tyagi, Madhusudan; Chen, Sow-Hsin

    2012-01-01

    Aspirin, also known as acetylsalicylic acid (ASA), is not only a wonderful drug, but also a good glass former. Therefore, it serves as an important molecular system to study the near-arrest and arrested phenomena. In this paper, a high-resolution quasi-elastic neutron scattering (QENS) technique is used to investigate the slow dynamics of supercooled liquid and glassy aspirin from 410 down to 350 K. The measured QENS spectra can be analyzed with a stretched exponential model. We find that (i) the stretched exponent β(Q) is independent of the wavevector transfer Q in the measured Q range and (ii) the structural relaxation time τ(Q) follows a power-law dependence on Q. Consequently, the Q-independent structural relaxation time τ 0 can be extracted for each temperature to characterize the slow dynamics of aspirin. The temperature dependence of τ 0 can be fitted with the mode-coupling power law, the Vogel-Fulcher-Tammann equation and a universal equation for fragile glass forming liquids recently proposed by Tokuyama in the measured temperature range. The calculated dynamic response function χ T (Q, t) using the experimentally determined self-intermediate scattering function of the hydrogen atoms of aspirin shows direct evidence of the enhanced dynamic fluctuations as the aspirin is increasingly supercooled, in agreement with the fixed-time mean squared displacement (x 2 ) and the non-Gaussian parameter α 2 extracted from the elastic scattering.

  5. Quasi-Elastic Neutron Scattering Studies of the Slow Dynamics of Supercooled and Glassy Aspirin

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yang [ORNL; Tyagi, M. [NCNR and University of Maryland; Mamontov, Eugene [ORNL; Chen, Sow-hsin H [ORNL

    2011-01-01

    Aspirin, also known as acetylsalicylic acid (ASA), is not only a wonderful drug, but also a good glass former. Therefore, it serves as an important molecular system to study the near-arrest and arrested phenomena. In this paper, a high-resolution quasi-elastic neutron scattering (QENS) technique is used to investigate the slow dynamics of supercooled liquid and glassy aspirin from 410 K down to 350 K. The measured QENS spectra can be analyzed with a stretched exponential model. We find that (i) the stretched exponent (Q) is independent of the wave vector transfer Q in the measured Q-range, and (ii) the structural relaxation time (Q) follows a power law dependence on Q. Consequently, the Q-independent structural relaxation time 0 can be extracted for each temperature to characterize the slow dynamics of aspirin. The temperature dependence of 0 can be fitted with the mode coupling power law, the Vogel-Fulcher-Tammann equation and a universal equation for fragile glass forming liquids recently proposed by M. Tokuyama in the measured temperature range. The calculated dynamic response function T(Q,t) using the experimentally determined self-intermediate scattering function of the hydrogen atoms of aspirin shows a direct evidence of the enhanced dynamic fluctuations as the aspirin is increasingly supercooled, in agreement with the fixed-time mean squared displacement x2 and non-Gaussian parameter 2 extracted from the elastic scattering.

  6. Quasi-elastic neutron scattering studies of the slow dynamics of supercooled and glassy aspirin

    Science.gov (United States)

    Zhang, Yang; Tyagi, Madhusudan; Mamontov, Eugene; Chen, Sow-Hsin

    2012-02-01

    Aspirin, also known as acetylsalicylic acid (ASA), is not only a wonderful drug, but also a good glass former. Therefore, it serves as an important molecular system to study the near-arrest and arrested phenomena. In this paper, a high-resolution quasi-elastic neutron scattering (QENS) technique is used to investigate the slow dynamics of supercooled liquid and glassy aspirin from 410 down to 350 K. The measured QENS spectra can be analyzed with a stretched exponential model. We find that (i) the stretched exponent β(Q) is independent of the wavevector transfer Q in the measured Q range and (ii) the structural relaxation time τ(Q) follows a power-law dependence on Q. Consequently, the Q-independent structural relaxation time τ0 can be extracted for each temperature to characterize the slow dynamics of aspirin. The temperature dependence of τ0 can be fitted with the mode-coupling power law, the Vogel-Fulcher-Tammann equation and a universal equation for fragile glass forming liquids recently proposed by Tokuyama in the measured temperature range. The calculated dynamic response function χT(Q, t) using the experimentally determined self-intermediate scattering function of the hydrogen atoms of aspirin shows direct evidence of the enhanced dynamic fluctuations as the aspirin is increasingly supercooled, in agreement with the fixed-time mean squared displacement langx2rang and the non-Gaussian parameter α2 extracted from the elastic scattering.

  7. Neutron study of non-Gaussian self dynamics in liquid parahydrogen

    International Nuclear Information System (INIS)

    Bafile, Ubaldo; Celli, Milva; Colognesi, Daniele; Zoppi, Marco; Guarini, Eleonora; De Francesco, Alessio; Formisano, Ferdinando; Neumann, Martin

    2012-01-01

    A time-honoured approach to single-molecule, or self, dynamics of liquids is based on the so-called Gaussian approximation (GA), where it is assumed that, in the whole dynamical range between hydrodynamic diffusion and free-particle streaming, the motion of a particle is fully determined by a unique function of time directly related to the velocity autocorrelation function. An evident support to the GA is offered by the fact that the approximation becomes exact in both above limit conditions. Yet, experimental inquiries into the presence of non-Gaussian dynamics are very scarce, particularly in liquid parahydrogen in spite of its importance as the prototype of a 'quantum Boltzmann liquid' which has also served as a benchmark for the development of quantum dynamics simulation algorithms. Though experimental evidence of the breakdown of the GA was obtained by some of the authors a few years ago, the localization in Q space of non-Gaussian behaviour was still undetermined, and no quantitative assessment of the effect was ever obtained. These issues have been tackled and solved by a new neutron investigation, which provides the first determination of non-Gaussian behaviour in the framework of the well-known theoretical approach by Rahman, Singwi and Sjölander.

  8. X-ray micro-CT and neutron CT as complementary imaging tools for non-destructive 3D imaging of rare silicified fossil plants

    Science.gov (United States)

    Karch, J.; Dudák, J.; Žemlička, J.; Vavřík, D.; Kumpová, I.; Kvaček, J.; Heřmanová, Z.; Šoltés, J.; Viererbl, L.; Morgano, M.; Kaestner, A.; Trtík, P.

    2017-12-01

    Computed tomography provides 3D information of inner structures of investigated objects. The obtained information is, however, strongly dependent on the used radiation type. It is known that as X-rays interact with electron cloud and neutrons with atomic nucleus, the obtained data often provide different contrast of sample structures. In this work we present a set of comparative radiographic and CT measurements of rare fossil plant samples using X-rays and