WorldWideScience

Sample records for bolometric x-ray sensors

  1. Colossal Magnetoresistive Manganite Based Fast Bolometric X-ray Sensors for Total Energy Measurements of Free Electron Lasers

    International Nuclear Information System (INIS)

    Bolometric detectors based on epitaxial thin films of rare earth perovskite manganites have been proposed as total energy monitors for X-ray pulses at the Linac Coherent Light Source free electron laser. We demonstrate such a detector scheme based on epitaxial thin films of the perovskite manganese oxide material Nd0.67Srx0.33MnO3, grown by pulsed laser deposition on buffered silicon substrates. The substrate and sensor materials are chosen to meet the conflicting requirements of radiation hardness, sensitivity, speed and linearity over a dynamic range of three orders of magnitude. The key challenge in the material development is the integration of the sensor material with Si. Si is required to withstand the free electron laser pulse impact and to achieve a readout speed three orders of magnitude faster than conventional cryoradiometers for compatibility with the Linac Coherent Light Source pulse rate. We discuss sensor material development and the photoresponse of prototype devices. This Linac Coherent Light Source total energy monitor represents the first practical application of manganite materials as bolometric sensors

  2. Soft x-ray and bolometric tomography in RFX

    International Nuclear Information System (INIS)

    The article presents the design and the first results of a new eight camera, soft x-ray (SXR) and bolometric tomography which has been installed in RFX, a large (R=2 m, a=0.46 m), high current reverse field pinch experiment operating in Padova. The main features of the diagnostic, which has been designed with standards compatible with the requirements of large fusion experiments, are: (a) it allows simultaneous reconstruction of both SXR and total radiation emissivity structures with high spatial and time resolution (bandwidth up to 200 kHz for SXR and 10 kHz for bolometry). Moreover, computer controlled remote actions which interchange up to five material filters in front of the detectors allow the exploration of different energy ranges; (b) it can be easily decoupled from the machine without breaking the main vacuum and can be operated during first wall baking up to 300 degree C thanks to a cooling circuit; (c) the detection chain is designed to measure very low signals [in the order of 1 nA for SXR diodes and of 100 μV for bolometers]; (d) it is equipped with a VME based 1 MHz data acquisition system which allows on-line processing of a large amount of data. To accomplish these features the diagnostic consists of eight fully remotely controlled manipulators which can insert eight photocameras, carrying 78 top-rated Si SXR and 48 miniaturized metal film bolometric detectors in their operating positions. Initial results are presented. copyright 1997 American Institute of Physics

  3. Hard X-ray photon index as an indicator of bolometric correction in active galactic nuclei

    OpenAIRE

    Zhou, Xin-Lin; Zhao, Yong-Heng

    2010-01-01

    We propose the rest-frame 2-10 keV photon index, \\ga, acting as an indicator of the bolometric correction, \\lb/$L_{\\rm 2-10keV}$ (where \\lb~ is the bolometric luminosity and $L_{\\rm 2-10keV}$ is the rest-frame 2-10 keV luminosity), in radio-quiet active galactic nuclei (AGNs). Correlations between \\ga~ and both bolometric correction and Eddington ratio are presented, based on simultaneous X-ray, UV, and optical observations of reverberation -mapped AGNs. These correlations can be compared wit...

  4. Soft x-ray and bolometric tomography in RFX (abstract)a

    International Nuclear Information System (INIS)

    The article presents the design and the first results of a new eight camera, soft x-ray (SXR) and bolometric tomography which has been installed in RFX, a large (R=2 m, a=0.46 m), high current reverse field pinch experiment operating in Padova. The main features of the diagnostic, which has been designed with standards compatible with the requirements of large fusion experiments, are: (a) it allows simultaneous reconstruction of both SXR and total radiation emissivity structures with high spatial and time resolution (bandwidth up to 200 kHz for SXR and 10 kHz for bolometry). Moreover, computer controlled remote actions which interchange up to five material filters in front of the detectors allow the exploration of different energy ranges; (b) it can be easily decoupled from the machine without breaking the main vacuum and can be operated during first wall baking up to 300 degree C thanks to a cooling circuit; (c) the detection chain is designed to measure very low signals [in the order of 1 nA for SXR diodes and of 100 μV for bolometers]; (d) it is equipped with a VME based 1 MHz data acquisition system which allows on-line processing of a large amount of data. To accomplish these features the diagnostic consists of eight fully remotely controlled manipulators which can insert eight photocameras, carrying 78 top-rated Si SXR and 48 miniaturized metal film bolometric detectors in their operating positions. Initial results are presented. copyright 1997 American Institute of Physics

  5. Bolometric luminosities and Eddington ratios of X-ray selected Active Galactic Nuclei in the XMM-COSMOS survey

    OpenAIRE

    Lusso, E.; Comastri, A.; Simmons, B. D.; M. Mignoli(INAF); Zamorani, G.; Vignali, C.; Brusa, M.; Shankar, F.; Lutz, D.; Trump, J. R.; R. Maiolino; Gilli, R.; Bolzonella, M.; Puccetti, S.; Salvato, M.

    2012-01-01

    Bolometric luminosities and Eddington ratios of both X-ray selected broad-line (Type-1) and narrow-line (Type-2) AGN from the XMM-Newton survey in the COSMOS field are presented. The sample is composed by 929 AGN (382 Type-1 AGN and 547 Type-2 AGN) and it covers a wide range of redshifts, X-ray luminosities and absorbing column densities. About 65% of the sources are spectroscopically identified as either Type-1 or Type-2 AGN (83% and 52% respectively), while accurate photometric redshifts ar...

  6. Characterization of Scintillating X-ray Optical Fiber Sensors

    Directory of Open Access Journals (Sweden)

    Dan Sporea

    2014-02-01

    Full Text Available The paper presents a set of tests carried out in order to evaluate the design characteristics and the operating performance of a set of six X-ray extrinsic optical fiber sensors. The extrinsic sensor we developed is intended to be used as a low energy X-ray detector for monitoring radiation levels in radiotherapy, industrial applications and for personnel dosimetry. The reproducibility of the manufacturing process and the characteristics of the sensors were assessed. The sensors dynamic range, linearity, sensitivity, and reproducibility are evaluated through radioluminescence measurements, X-ray fluorescence and X-ray imaging investigations. Their response to the operating conditions of the excitation source was estimated. The effect of the sensors design and implementation, on the collecting efficiency of the radioluminescence signal was measured. The study indicated that the sensors are efficient only in the first 5 mm of the tip, and that a reflective coating can improve their response. Additional tests were done to investigate the concentricity of the sensors tip against the core of the optical fiber guiding the optical signal. The influence of the active material concentration on the sensor response to X-ray was studied. The tests were carried out by measuring the radioluminescence signal with an optical fiber spectrometer and with a Multi-Pixel Photon Counter.

  7. New sensors for dental X-ray imaging

    Science.gov (United States)

    Fröjdh, C.; Andersson, J.; Bates, R.; Heuken, M.; Irsigler, R.; Petersson, C. S.; O'Shea, V.; Smith, K.; Stamatakis, H.; Welander, U.

    1999-09-01

    Digital systems for dental X-ray imaging are rapidly replacing conventional film techniques. The major advantages of digital systems are reduced X-ray doses due to increased sensitivity, time savings since no development is needed and reduced use of chemicals for film development. Most of the currently available digital systems are based on a silicon CCD coated with a scintillating material. In this paper we present some of the research going on in order to develop new X-ray imaging sensors with improved sensitivity.

  8. New sensors for dental X-ray imaging

    International Nuclear Information System (INIS)

    Digital systems for dental X-ray imaging are rapidly replacing conventional film techniques. The major advantages of digital systems are reduced X-ray doses due to increased sensitivity, time savings since no development is needed and reduced use of chemicals for film development. Most of the currently available digital systems are based on a silicon CCD coated with a scintillating material. In this paper we present some of the research going on in order to develop new X-ray imaging sensors with improved sensitivity. (author)

  9. Double junction photodiode for X-ray CMOS sensor IC

    International Nuclear Information System (INIS)

    A CMOS compatible P+/Nwell/Psub double junction photodiode pixel was proposed, which can efficiently detect fluorescence from CsI(Tl) scintillation in an X-ray sensor. Photoelectric and spectral responses of P+/Nwell, Nwell/Psub and P+/Nwell/Psub photodiodes were analyzed and modeled. Simulation results show P+/Nwell/Psub photodiode has larger photocurrent than P+/Nwell photodiode and Nwell/Psub photodiode, and its spectral response is more in accordance with CsI(Tl) fluorescence spectrum. Improved P+/Nwell/Psub photodiode detecting CsI(Tl) fluorescence was designed in CSMC 0.5 μm CMOS process, CTIA (capacitive transimpedance amplifier) architecture was used to readout photocurrent signal. CMOS X-ray sensor IC prototype contains 8 × 8 pixel array and pixel pitch is 100 × 100 μm2. Testing results show the dark current of the improved P+/Nwell/Psub photodiode (6.5 pA) is less than that of P+/Nwell and P+/Nwell/Psub photodiodes (13 pA and 11 pA respectively). The sensitivity of P+/Nwell/Psub photodiode is about 20 pA/lux under white LED. The spectrum response of P+/Nwell/Psub photodiode ranges from 400 nm to 800 nm with a peak at 532 nm, which is in accordance with the fluorescence spectrum of CsI(Tl) in an indirect X-ray sensor. Preliminary testing results show the sensitivity of X-ray sensor IC under Cu target X-ray is about 0.21 V·m2/W or 5097e−/pixel @ 8.05 keV considering the pixel size, integration time and average energy of X-ray photons. (semiconductor devices)

  10. Large Area Transition Edge Sensor X-ray Microcalorimeters for Diffuse X-ray Background Studies

    Science.gov (United States)

    Morgan, K. M.; Busch, S. E.; Eckart, M. E.; Kilbourne, C. A.; McCammon, D.

    2014-08-01

    We are developing transition edge sensor (TES) mirocalorimeters with large area (0.72 mm) absorbers to study the keV diffuse X-ray background. The goal is to develop a 2 cm array of 256 pixels for a sounding rocket payload. We present a pixel design which includes a Mo/Au bilayer TES coupled to a large (850 x 850 x 0.2 m) gold absorber. Our simulations indicate that such a design can achieve energy resolution as good as 1.6 eV FWHM in our target bandpass of 0.05-1 keV. Additionally, thermal modelling shows that for typical gold layers, the position-dependent variation of the pulse shape over the large area of the absorber is not expected to significantly degrade this energy resolution. An array of devices will be fabricated in late 2013 to test this design.

  11. Fast bolometric sensor built-in into polycrystalline CVD diamond

    International Nuclear Information System (INIS)

    Diamond, with its unique combination of physical properties, is a promising material for electronic devices operating under extreme conditions. Due to its exceptionally high thermal conductivity, diamond-based bolometers should possess very short response time. A fast bolometric sensor was formed within a polycrystalline diamond plate by ion implantation and subsequent annealing. The response kinetics of the structure was studied under a nitrogen laser pulsed illumination. The response time at room temperature was less than 20 ns. The spatial-temporal distribution of responses allowed us to distinguish between thermal responses and those of different nature (e.g. photoconductivity). This study was supported by the Russian Foundation for Basic Research, project nos. 05-02-17545 and 07-02-00575

  12. Fast bolometric sensor built-in into polycrystalline CVD diamond

    Energy Technology Data Exchange (ETDEWEB)

    Klokov, A Yu [P.N. Lebedev Physical Institute, Leninskii pr., 53, 119991 Moscow (Russian Federation); Sharkov, A I [P.N. Lebedev Physical Institute, Leninskii pr., 53, 119991 Moscow (Russian Federation); Galkina, T I [P.N. Lebedev Physical Institute, Leninskii pr., 53, 119991 Moscow (Russian Federation); Khmelnitsky, R A [P.N. Lebedev Physical Institute, Leninskii pr., 53, 119991 Moscow (Russian Federation); Dravin, V A [P.N. Lebedev Physical Institute, Leninskii pr., 53, 119991 Moscow (Russian Federation); Ralchenko, V G [General Physics Institute, Vavilova ul., 38, 119991 Moscow (Russian Federation); Gippius, A A [P.N. Lebedev Physical Institute, Leninskii pr., 53, 119991 Moscow (Russian Federation)

    2007-12-15

    Diamond, with its unique combination of physical properties, is a promising material for electronic devices operating under extreme conditions. Due to its exceptionally high thermal conductivity, diamond-based bolometers should possess very short response time. A fast bolometric sensor was formed within a polycrystalline diamond plate by ion implantation and subsequent annealing. The response kinetics of the structure was studied under a nitrogen laser pulsed illumination. The response time at room temperature was less than 20 ns. The spatial-temporal distribution of responses allowed us to distinguish between thermal responses and those of different nature (e.g. photoconductivity). This study was supported by the Russian Foundation for Basic Research, project nos. 05-02-17545 and 07-02-00575.

  13. X-ray Performance of Back-Side Illuminated Type of Kyoto's X-ray Astronomical SOI Pixel Sensor, XRPIX

    CERN Document Server

    Itou, Makoto; Tanaka, Takaaki; Takeda, Ayaki; Matsumura, Hideaki; Ohmura, Shunichi; Nakashima, Shinya; Arai, Yasuo; Mori, Koji; Takenaka, Ryota; Nishioka, Yusuke; Kohmura, Takayoshi; Tamasawa, Koki; Tindall, Craig

    2016-01-01

    We have been developing X-ray SOI pixel Sensors, called "XRPIX", for future X-ray astronomy satellites that enable us to observe in the wide energy band of 0.5-40 keV. Since XRPIXs have the circuitry layer with a thickness of about 8 {\\mu}m in the front side of the sensor, it is impossible to detect low energy X-rays with a front-illuminated type. So, we have been developing back-illuminated type of XRPIX with a less 1 {\\mu}m dead layer in the back-side, which enables the sensitivity to reach 0.5 keV. We produced two types of back-side illuminated (BI) XRPIXs, one of which is produced in "Pizza process" which LBNL developed and the other is processed in the ion implantation and laser annealing. We irradiated both of the BI-XRPIXs with soft X-ray and investigate soft X-ray performance of them. We report results from soft X-ray evaluation test of the device.

  14. X-ray microcalorimeter based on superconducting transition edge sensors.

    Science.gov (United States)

    Ohno, Masashi; Takahashi, Hiroyuki; Damayanthi, R M Thushara; Minamikawa, Yasuhiro; Mori, Fumiakira

    2008-01-01

    We have tried to realize an X-ray imaging spectrometer based on the superconducting transition edge sensor (TES) with high energy resolution, a large pixel array, a relatively high absorption efficiency and a high count rate. Our single pixel of Ir/Au TES achieved an excellent energy resolution of 9.4 eV for 5.9 keV X-rays. We have also proposed a pixellated array of Ir-TES where we slightly modify the bias point of each pixel and identify the pixel from the response function of each pixel. Our 10-pixel device, where all pixels are parallel biased, obtained 13 eV (FWHM) at 3 keV energy resolution and 80 microm position resolution. So far, we could successfully operate a 20-pixels device. Further, we are now trying to improve the count rate and the absorption efficiency of TESes, by developing our original new TES geometry which having a radiation absorber that self-adjusts the operating temperature. PMID:18187844

  15. Comparison of some x-ray sensors for verification

    Energy Technology Data Exchange (ETDEWEB)

    Moss, C.E.; Berzins, G.J.; Felthauser, H.E.; Sweet, M.R.; Valencia, J.E.

    1990-01-01

    More efficient alternatives to silicon sensors in an instrument to measure x-rays over several channels, or energy windows, offer some advantages. First if the source is cool, the responses in the high-energy channels measured with silicon sensors will be low. If these responses do not exceed the electronic thresholds of their uncertainties are large, then they can not be used to determine the spectral shape. Using more efficient sensors will mitigate this problem. Second, if the efficiency of the high-energy channels is high enough so that their thresholds are exceeded, then coincidence between low-energy channels and high-energy channels can be used to greatly reduce false event rates. Two potential disadvantages are higher sensitivity to radiation damage and slower rise time. This report describes the results for the high-Z semiconductor CdTe, the high-Z scintillator CsI(Tl) mounted on a silicon photodiode, and scintillation fiber. 4 refs., 7 figs.

  16. Novel large-area MIS-type x-ray image sensor for digital radiography

    Science.gov (United States)

    Kameshima, Toshio; Kaifu, Noriyuki; Takami, Eiichi; Morishita, Masakazu; Yamazaki, Tatsuya

    1998-07-01

    We have developed a brand new, large-area X-ray image sensor for Digital Radiography System (DRS). The sensor utilizes a thin film transistor (TFT)/metal insulator semiconductor (MIS)-type photoelectric converter array made from hydrogenated amorphous silicon (a-Si:H). The sensor has 2688 X 2688 pixels at a pitch of 160 micrometer. The active area is 17 inch X 17 inch. The sensor utilizes scintillator coupled to the array. The light generated by X-rays is detected by the MIS-type photoelectric converters, and the resultant signals are scanned out by switching the TFTs. The a-Si TFT/MIS-type photoelectric converter array is characterized by high signal to noise ratio (SNR) and simple fabrication process. We will describe the principle and the performance of the sensor. In addition, we will present some X-ray images of a human subject obtained with this sensor. Dynamic range of the sensor covers most of the exposure range for radiography. SNR is limited almost only by the X-ray photon noise. MTF is sufficient for digital chest radiography. X-ray images have good contrast. The experimental results and obtained images show that the brand new sensor has great advantages for replacing X-ray film. The simple fabrication process of the sensor promises high productivity and low cost of DRS.

  17. Microtopographical Characterization of Microcavities on X-Rays Sensor Array

    Science.gov (United States)

    Costa, Manuel F. M.

    2008-04-01

    A large number of medical imaging methods, such as computed tomography, ultrasound and magnetic resonance imaging, are for quite some time digital. X-ray imaging was kept analogue until recently. Over last half a dozen years' digital radiography systems are being successfully developed. Among other advantages common to other medical imaging methods, digital X-ray imaging allow an important reduction of the X-ray doses involved in different medical diagnosis. The communication herein reports to the microtopographic inspection of laser ablation opened microcavities during development of an X-rays microdetector based on an array of wells filled with scintillator crystals. The wells were obtained by laser ablation of a 500 microns thick aluminum film. X-ray energy is converted to visible light within the crystals and then detected by a photodetector fabricated in a standard CMOS process. Aluminium thick-films were chosen as present good reflectivity in the visible range improving the amount of photons collected at each photodetector. Square wells 100 microns wide and 490 microns deep were targeted. In this communication we will report on the process of optical microtopographic characterization of the aluminium wells. This metrological process was performed in order to optimize the laser ablation system parameter in order to obtain the desired size square wells with almost vertical smooth sidewalls.

  18. Microtopographical Characterization of Microcavities on X-Rays Sensor Array

    International Nuclear Information System (INIS)

    A large number of medical imaging methods, such as computed tomography, ultrasound and magnetic resonance imaging, are for quite some time digital. X-ray imaging was kept analogue until recently. Over last half a dozen years' digital radiography systems are being successfully developed. Among other advantages common to other medical imaging methods, digital X-ray imaging allow an important reduction of the X-ray doses involved in different medical diagnosis. The communication herein reports to the microtopographic inspection of laser ablation opened microcavities during development of an X-rays microdetector based on an array of wells filled with scintillator crystals. The wells were obtained by laser ablation of a 500 microns thick aluminum film. X-ray energy is converted to visible light within the crystals and then detected by a photodetector fabricated in a standard CMOS process. Aluminium thick-films were chosen as present good reflectivity in the visible range improving the amount of photons collected at each photodetector. Square wells 100 microns wide and 490 microns deep were targeted. In this communication we will report on the process of optical microtopographic characterization of the aluminium wells. This metrological process was performed in order to optimize the laser ablation system parameter in order to obtain the desired size square wells with almost vertical smooth sidewalls

  19. Characterisation of a Thin Fully-Depleted SOI Pixel Sensor with Soft X-ray Radiation

    CERN Document Server

    Battaglia, Marco; Celestre, Richard; Contarato, Devis; Denes, Peter; Mattiazzo, Serena; Tindall, Craig

    2011-01-01

    This paper presents the results of the characterisation of a back-illuminated pixel sensor manufactured in Silicon-On-Insulator technology on a high-resistivity substrate with soft X-rays. The sensor is thinned and a thin Phosphor layer contact is implanted on the back-plane. The response to X-rays from 2.12 up to 8.6 keV is evaluated with fluorescence radiation at the LBNL Advanced Light Source.

  20. Amorphous silicon sensor arrays for X-ray and document imaging

    International Nuclear Information System (INIS)

    Large area amorphous silicon image sensor arrays are important for X-ray medical imaging and document scanning as well as a variety of other applications where large sensor size is required. The paper first summarizes the present state of the flat panel X-ray imager technology, and compares the two main approaches for X-ray detection. The authors then describe the performance of a new, large area, high resolution, radiographic imager based o a single amorphous silicon array with 2,304 x 3,200 pixels, and an active area of 30 x 40 cm (12 x 16 inches)

  1. X-ray imaging and spectroscopy using low cost COTS CMOS sensors

    Energy Technology Data Exchange (ETDEWEB)

    Lane, David W., E-mail: d.w.lane@cranfield.ac.uk [Department of Engineering and Applied Science, Cranfield University, Shrivenham, Swindon SN6 8LA (United Kingdom)

    2012-08-01

    Whilst commercial X-ray sensor arrays are capable of both imaging and spectroscopy they are currently expensive and this can limit their widespread use. This study examines the use of very low cost CMOS sensors for X-ray imaging and spectroscopy based on the commercial off the shelf (COTS) technology used in cellular telephones, PC multimedia and children's toys. Some examples of imaging using a 'webcam' and a modified OmniVision OV7411 sensor are presented, as well as a simple energy dispersive X-ray detector based on an OmniVision OV7221 sensor. In each case X-ray sensitivity was enabled by replacing the sensor's front glass window with a 5 {mu}m thick aluminium foil, with X-rays detected as an increase in a pixel's dark current due to the generation of additional electron-hole pairs within its active region. The exposure control and data processing requirements for imaging and spectroscopy are discussed. The modified OV7221 sensor was found to have a linear X-ray energy calibration and a resolution of approximately 510 eV.

  2. The mechanism, characteristics and recent trend of the various X-ray imaging sensors

    International Nuclear Information System (INIS)

    In nondestructive inspections, the intensity distribution of the X-ray transmitted through an object is visualized. The high voltage of X-ray tubes ranges from 20 to 450 kV. Proper sensors for the visualization under various conditions have been developed and commercialized. Recently the performance of sensors has been much improved due to the progress of semiconductor production process, the speedup of data transmission interface, and the improvement of the speed and possible amount of the data in processing by personal computers. 'Sensors' are actually X-ray detectors including the photodiode array combine with scintillators, the X-ray film, the computed radiography, the scintillator plate camera, the X-ray CCD camera, the flat panel detector, and so on. Performance of these sensors, together with that of X-ray generator, will determine the quality of images. Each sensor involves specific technologies on materials, design, fabrication and inspection. Characteristics and recent trend of these sensors are presented. (J.P.N.)

  3. Energy discrimination type photon counting radiation line sensor (X-ray color scanner)

    International Nuclear Information System (INIS)

    An X-ray color scanner that can distinguish between photon energies has been developed using X-ray line sensors. This scanner consists of a 64-channel cadmium telluride (CdTe) radiation detection array, a 64-channel application specific integrated circuit (ASIC), and a signal processing circuit that controls both the ASIC and data communication. An X-ray or gamma ray photon absorbed by the CdTe detector is converted into an electric charge proportional to the energy of the incident photon and amplified to an electric pulse with an amplitude proportional to the photon energy. The pulse height is then analyzed by the ASIC using 5 different threshold voltages. The X-ray color scanner has the ability to count up to approximately 2 million photons per CdTe element per second. When used as a photon counting system, the X-ray color sensor has a very high signal to noise ratio, since it removes electric noise in the low energy spectrum during the analysis process. When appropriately selected energy thresholds are used, X-ray color scanners, used for X-ray imaging or X-ray CT, were shown to remove the effects of beam-scattering noise and beam-hardening. (author)

  4. Effect of sputtering pressure on microstructure and bolometric properties of Nb:TiO{sub 2−x} films for infrared image sensor applications

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, Y. Ashok Kumar, E-mail: akreddy111@gmail.com; Shin, Young Bong; Kang, In-Ku; Lee, Hee Chul [Department of Electrical Engineering, Korea Advanced Institute of Science and Technology, 335 Gwahangno, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

    2016-01-28

    This study aims to investigate the influence of the sputtering pressure (P{sub S}) on Nb:TiO{sub 2−x} films to enhance the bolometric properties. A decrease in the growth rate with the sputtering pressure was perceived in amorphous Nb:TiO{sub 2−x} films. The incorporation of oxygen with P{sub S} was confirmed in an X-ray photo electron spectroscopy analysis. The electrical resistivity was increased with an increase in P{sub S} due to a decrease in the number of oxygen vacancies. The linear I-V characteristics confirmed the ohmic contact behavior between the Nb:TiO{sub 2−x} layer and the electrode material. The present investigation finds that the sample with lower resistivity has good bolometric properties with low noise and high universal bolometric parameters. Finally, the Nb:TiO{sub 2−x} sample deposited at a sputtering pressure of 2 mTorr shows better bolometric properties than other materials for infrared image sensor applications.

  5. Effect of sputtering pressure on microstructure and bolometric properties of Nb:TiO2−x films for infrared image sensor applications

    International Nuclear Information System (INIS)

    This study aims to investigate the influence of the sputtering pressure (PS) on Nb:TiO2−x films to enhance the bolometric properties. A decrease in the growth rate with the sputtering pressure was perceived in amorphous Nb:TiO2−x films. The incorporation of oxygen with PS was confirmed in an X-ray photo electron spectroscopy analysis. The electrical resistivity was increased with an increase in PS due to a decrease in the number of oxygen vacancies. The linear I-V characteristics confirmed the ohmic contact behavior between the Nb:TiO2−x layer and the electrode material. The present investigation finds that the sample with lower resistivity has good bolometric properties with low noise and high universal bolometric parameters. Finally, the Nb:TiO2−x sample deposited at a sputtering pressure of 2 mTorr shows better bolometric properties than other materials for infrared image sensor applications

  6. X-ray apparatus with scintillator and charge-coupled devices (CCD) sensor for dental radiography

    International Nuclear Information System (INIS)

    The apparatus includes an X-ray source coupled with a receiver both being placed on a support which can rotate about a vertical axis. The receiver comprises a slit receiving incident X-rays which are collected by a charge-coupled device (CCD) sensor via a scintillator screen. The sensor consists of an array of X-ray detectors which generate the X-ray image line by line. The image is transferred to an output amplifier and processed so that each element of the image is digitized and stored in a memory unit. The receiver also includes a mobile part which can be moved with the speed of a radiography film. The advantage of this technology is to enable panoramic images of objects using CCD detectors which can be adapted to existing apparatus. (authors). 2 figs

  7. CMOS-sensors for energy-resolved X-ray imaging

    Science.gov (United States)

    Doering, D.; Amar-Youcef, S.; Baudot, J.; Deveaux, M.; Dulinski, W.; Kachel, M.; Linnik, B.; Müntz, C.; Stroth, Joachim

    2016-01-01

    Due to their low noise, CMOS Monolithic Active Pixel Sensors are suited to sense X-rays with a few keV quantum energy, which is of interest for high resolution X-ray imaging. Moreover, the good energy resolution of the silicon sensors might be used to measure this quantum energy. Combining both features with the good spatial resolution of CMOS sensors opens the potential to build ``color sensitive" X-ray cameras. Taking such colored images is hampered by the need to operate the CMOS sensors in a single photon counting mode, which restricts the photon flux capability of the sensors. More importantly, the charge sharing between the pixels smears the potentially good energy resolution of the sensors. Based on our experience with CMOS sensors for charged particle tracking, we studied techniques to overcome the latter by means of an offline processing of the data obtained from a CMOS sensor prototype. We found that the energy resolution of the pixels can be recovered at the expense of reduced quantum efficiency. We will introduce the results of our study and discuss the feasibility of taking colored X-ray pictures with CMOS sensors.

  8. CMOS-sensors for energy-resolved X-ray imaging

    International Nuclear Information System (INIS)

    Due to their low noise, CMOS Monolithic Active Pixel Sensors are suited to sense X-rays with a few keV quantum energy, which is of interest for high resolution X-ray imaging. Moreover, the good energy resolution of the silicon sensors might be used to measure this quantum energy. Combining both features with the good spatial resolution of CMOS sensors opens the potential to build ''color sensitive' X-ray cameras. Taking such colored images is hampered by the need to operate the CMOS sensors in a single photon counting mode, which restricts the photon flux capability of the sensors. More importantly, the charge sharing between the pixels smears the potentially good energy resolution of the sensors. Based on our experience with CMOS sensors for charged particle tracking, we studied techniques to overcome the latter by means of an offline processing of the data obtained from a CMOS sensor prototype. We found that the energy resolution of the pixels can be recovered at the expense of reduced quantum efficiency. We will introduce the results of our study and discuss the feasibility of taking colored X-ray pictures with CMOS sensors

  9. Space station application of CCD image sensors for x-ray imaging

    International Nuclear Information System (INIS)

    Charge Coupled Device (CCD) type solid state image sensors are employed in a number of space based imaging experiments and will be the basis for a camera system to acquire x-ray diffraction images on board the Space Station. This paper will present the system engineering considerations that led to the selection of CCDs over other x-ray imaging technologies and the design of the camera system. This will include discussion of the special requirements imposed by the space environment and this x-ray crystallography mission. This systems engineering discussion will be followed by a summary of high spatial resolution CCDs that are candidates for this camera, what may become available in the future, and what improvements would make CCDs even more suited to such X-ray imaging applications on the ground as well as in space

  10. Amorphous silicon image sensors for x-ray detection in NDT

    International Nuclear Information System (INIS)

    Acquiring radiographic images in a digital format offers significant advantages over film. Besides eliminating the need for chemical processing, a digital image can be easily stored for more convenient retrieval, transmitted to remote locations for interpretation, and image processed to provide enhanced interpretation and greater latitude in exposure. Amorphous silicon image sensors, developed by dpiX, a Xerox Company, offer an improved method of acquiring digital x-ray images. Amorphous silicon image sensor technology provides the opportunity to have large format size similar to x-ray film, high resolution, and a compact package for ease of use in NDT applications. This technology can also be used to replace x-ray image intensifier tubes to provide real-time fluoroscopic imaging for capturing time related events such as x-ray examination of objects on a conveyor belt. This paper presents a description of amorphous silicon image sensor technology and provides examples of the performance that can be achieved using a system that has an 8 x 10 inch x-ray image acquisition area and 127 micron pixels for 4 lp/mm resolution

  11. A high dynamic radiation measurements instrument: the Bolometric Oscillation Sensor (BOS)

    OpenAIRE

    Zhu, P.; Ruymbeke, M. Van; Ö. Karatekin; J.-P. Noël; Thuillier, G.; S. Dewitte; Chevalier, A.; C. Conscience; Janssen, E.; M. Meftah; Irbah, A.

    2014-01-01

    The bolometric oscillation sensor (BOS) is a broadband radiation measurement instrument onboard the PICARD satellite that has been active between 2010 and 2014. The main detector is a thermistor attached black coated surface, which was permanently exposed to space without any optical and aperture accessories. The temperature measurements are used within a transfer function to determine variations in incoming solar irradiance as well as the terrestrial radi...

  12. A high dynamic radiation measurements instrument : the Bolometric Oscillation Sensor (BOS)

    OpenAIRE

    Zhu, P.; Ruymbeke, M. Van; Karatekin, Ö.; Noël, J.-P.; Thuillier, G.; S. Dewitte; Chevalier, A.; C. Conscience; Janssen, E.; M. Meftah; Irbah, A.

    2015-01-01

    The Bolometric Oscillation Sensor (BOS) is a broadband radiation measurement instrument onboard the PICARD satellite that was active between 2010 and 2014. The main detector is a thermistor attached black coated surface, which was permanently exposed to space without any optical and aperture accessories. The temperature measurements are used within a transfer function to determine variations in incoming solar irradiance as well as the terrestrial radiation. In the present ar...

  13. Development of CdTe line sensors for a fast X-ray CT scanner

    International Nuclear Information System (INIS)

    A Fast scanning X-ray CT system was developed to visualize dynamic motion of interface in multi-phase flow. The scanning time less than 4 msec. was achieved by using 18 pulsed X-ray generators and highly sensitive 256-pixel CdTe line sensor modules. The sensor device technology is based on their prototypes previously assembled for high-resolution radiography and tomography imaging of electronic parts. Equipped with the above CdTe modules, the fast X-ray CT system was able to visualize the 50 mm diameter cross section with a spatial resolution of 2.8 mm. When the system was applied to an air-water two-phase flow and a simplified fluidized bed system, it successfully quantified the multi-dimensional characteristics of interface in flow. (author)

  14. Stitched large format CMOS image sensors for dental x-ray digital radiography

    Science.gov (United States)

    Liu, Xinqiao (Chiao); Fowler, Boyd; Do, Hung; Jaffe, Mark; Rassel, Richard; Leidy, Bob

    2012-10-01

    In this paper, we present a family of large format CIS's designed for dental x-ray applications. The CIS areas vary from small 31.5mm x 20.1mm, to medium 34.1mm x 26.3mm, to large 37.1mm x 26.3mm. Pixel size is 19.5um x 19.5um. The sensor family was fabricated in a 0.18um CIS process. Stitching is used in the CIS fabrication for the medium and large size sensors. We present the CIS and detector system design that includes pixel circuitry, readout circuitry, x-ray trigger mechanism, scintillator, and the camera electronics. We also present characterization results including the detector performances under both visible light and x-ray radiation.

  15. Defects correction for digital dental x-ray sensors

    Science.gov (United States)

    Kim, Jong D.; Kim, Seo-Gyoo; Kim, Jongwon

    2001-05-01

    As medical imaging is adapting to the digital technology, solid imaging sensors are replacing the classical films in dental application. CCD is one of the typical image senors in this are. In the oral imaging, however, the size of image sensors should be large because there is not enough space for optical path of lens inside the mouth. The unavoidable defects are usually occurred in the large format CCD sensor. Practically it is not possible to get the defect free sensor because its cost is rapidly increasing to reduce the defects. In this paper we will present an efficient strategy to handle these defects. As the lighting is highly controllable differently from the common cameras, the controlled illumination is used to create uniform images with various levels. The local statistics in each controlled image are investigated to find defected areas. All the defected regions of each image are accumulated forming image-like representation. The defected regions are concealed with their neighbors by linear interpolation.

  16. High-resolution kaonic-atom x-ray spectroscopy with transition-edge-sensor microcalorimeters

    CERN Document Server

    Okada, S; Doriese, W B; Fowler, J W; Irwin, K D; Ishimoto, S; Sato, M; Schmidt, D R; Swetz, D S; Tatsuno, H; Ullom, J N; Yamada, S

    2014-01-01

    We are preparing for an ultra-high resolution x-ray spectroscopy of kaonic atoms using an x-ray spectrometer based on an array of superconducting transition-edge-sensor microcalorimeters developed by NIST. The instrument has excellent energy resolutions of 2 - 3 eV (FWHM) at 6 keV and a large collecting area of about 20 mm^2. This will open new door to investigate kaon-nucleus strong interaction and provide new accurate charged-kaon mass value.

  17. High-Resolution Kaonic-Atom X-ray Spectroscopy with Transition-Edge-Sensor Microcalorimeters

    Science.gov (United States)

    Okada, S.; Bennett, D. A.; Doriese, W. B.; Fowler, J. W.; Irwin, K. D.; Ishimoto, S.; Sato, M.; Schmidt, D. R.; Swetz, D. S.; Tatsuno, H.; Ullom, J. N.; Yamada, S.

    2014-09-01

    We are preparing for an ultra-high resolution X-ray spectroscopy of kaonic atoms using an X-ray spectrometer based on an array of superconducting transition-edge-sensor microcalorimeters developed by NIST. The instrument has excellent energy resolutions of 2-3 eV (FWHM) at 6 keV and a large collecting area of about 20 mm. This will open new door to investigate kaon-nucleus strong interaction and provide new accurate charged-kaon mass value.

  18. High-resolution X-ray imaging based on pixel-structured CsI:Tl scintillating screens for indirect X-ray image sensors

    International Nuclear Information System (INIS)

    We introduce the development of pixel-structured screens with a thallium-doped CsI (CsI:Tl) scintillator for indirect digital X-ray imaging sensors. The indirect-conversion detection method based on the pixel-structured CsI:Tl scintillator provides high spatial resolution X-ray imaging without sacrificing the light spread in thick scintillation layers. The scintillation screens were fabricated by using a vacuum deposition process and filling the CsI:Tl scintillating powders into a two-dimensional pixel-structured silicon array. Pixel structures with 100 μm and 50 μm pixel sizes with wall widths of 20 μm and 200 μm thickness were prepared and the fabricated CsI:Tl scintillating powders were filled into the trench of the pixel structure through a vacuum process. The final scintillation screens with 2.5 cm x 2.5 cm size were prepared and directly coupled to a CCD image sensor with an optical lens for performance evaluation of X-ray imaging. The imaging performance of the samples was investigated in terms of the relative light intensity, the X-ray linearity and the spatial resolution under practical X-ray exposure conditions. These preliminary results imply that pixel-structured CsI:Tl scintillating screens show high spatial resolution by less lateral spread of the emitted visible photons within pixel-structured silicon arrays. However, these X-ray detectors still require improved X-ray sensitivity by coating the reflective layer onto an inner silicon wall surface and filling the scintillating power into pixel structures completely.

  19. X-ray CCD image sensor with a thick depletion region

    International Nuclear Information System (INIS)

    To develop a solid-state image sensor for high energy X-ray above 1 -- 2 keV, basic studies have been made on the CCD (charge coupled device) with a thick depletion region. A method of super-imposing a high DC bias voltage on low voltage signal pulses was newly proposed. The characteristics of both SCCD and BCCD were investigated, and their ability as X-ray sensors was compared. It was found that a depletion region of 60 μm thick was able to be obtained with ordinary doping density of 1020/m3, and that even thicker over 1 mm depletion region was able to be obtained with doping density of about 1018/m3, and a high bias voltage above 1 kV was able to be applied. It is suggested that the CCD image sensors for 8 keV or 24 keV X-ray can be realized since the absorption length of these X-ray in Si is about 60 μm and 1 mm, respectively. As for the characteristics other than the depletion thickness, the BCCD is preferable to SCCD for the present purpose because of lower noise and dark current. As for the transfer method, the frame-transfer method is recommended. (Aoki, K.)

  20. Design of a radiation hard silicon pixel sensor for X-ray science

    International Nuclear Information System (INIS)

    At DESY Hamburg the European X-ray Free-Electron Laser (EuXFEL) is presently under construction. The EuXFEL has unique properties with respect to X-ray energy, instantaneous intensity, pulse length, coherence and number of pulses/sec. These properties of the EuXFEL pose very demanding requirements for imaging detectors. One of the detector systems which is currently under development to meet these challenges is the Adaptive Gain Integrating Pixel Detector, AGIPD. It is a hybrid pixel-detector system with 1024 x 1024 p+ pixels of dimensions 200 μm x 200 μm, made of 16 p+nn+- silicon sensors, each with 10.52 cm x 2.56 cm sensitive area and 500 μm thickness. The particular requirements for the AGIPD are a separation between noise and single photons down to energies of 5 keV, more than 104 photons per pixel for a pulse duration of less than 100 fs, negligible pile-up at the EuXFEL repetition rate of 4.5 MHz, operation for X-ray doses up to 1 GGy, good efficiency for X-rays with energies between 5 and 20 keV, and minimal inactive regions at the edges. The main challenge in the sensor design is the required radiation tolerance and high operational voltage, which is required to reduce the so-called plasma effect. This requires a specially optimized sensor. The X-ray radiation damage results in a build-up of oxide charges and interface traps which lead to a reduction of the breakdown voltage, increased leakage current, increased interpixel capacitances and charge losses. Extensive TCAD simulations have been performed to understand the impact of X-ray radiation damage on the detector performance and optimize the sensor design. To take radiation damage into account in the simulation, radiation damage parameters have been determined on MOS capacitors and gate-controlled diodes as function of dose. The optimized sensor design was fabricated by SINTEF. Irradiation tests on test structures and sensors show that the sensor design is radiation hard and performs as predicted by

  1. Fabrication of Transition Edge Sensor Microcalorimeters for X-Ray Focal Planes

    Science.gov (United States)

    Chervenak, James A.; Adams, Joseph S.; Audley, Heather; Bandler, Simon R.; Betancourt-Martinez, Gabriele; Eckart, Megan E.; Finkbeiner, Fred M.; Kelley, Richard L.; Kilbourne, Caroline; Lee, Sang Jun; Mateo, Jennette; Sadleir, John E.; Smith, Stephen J.; Wassell, Edward; Yoon, Wonsik

    2015-01-01

    Requirements for focal planes for x-ray astrophysics vary widely depending on the needs of the science application such as photon count rate, energy band, resolving power, and angular resolution. Transition edge sensor x-ray calorimeters can encounter limitations when optimized for these specific applications. Balancing specifications leads to choices in, for example, pixel size, thermal sinking arrangement, and absorber thickness and material. For the broadest specifications, instruments can benefit from multiple pixel types in the same array or focal plane. Here we describe a variety of focal plane architectures that anticipate science requirements of x-ray instruments for heliophysics and astrophysics. We describe the fabrication procedures that enable each array and explore limitations for the specifications of such arrays, including arrays with multiple pixel types on the same array.

  2. Fast signal transfer in a large-area X-ray CMOS image sensor

    International Nuclear Information System (INIS)

    For 2-d X-ray imaging, such as mammography and non-destructive test, a sensor should have a large-area because the sensor for typical X-ray beams cannot use optical lens system. To make a large-area 2-d X-ray image sensor using crystal Si, a technique of tiling unit CMOS image sensors into 2 × 2 or 2 × 3 array can be used. In a unit CMOS image sensor made of most common 8-inch Si wafers, the signal line can be up to ∼ 180 mm long. Then its parasitic capacitance is up to ∼ 25 pF and its resistance is up to ∼ 51 kΩ (0.18 μm, 1P3M process). This long signal line may enlarge the row time up to ∼ 50 μsec in case of the signal from the top row pixels to the readout amplifiers located at the bottom of the sensor chip. The output signal pulse is typically characterized by three components in sequence; a charging time (a rising part), a reading time and a discharging time (a falling part). Among these, the discharging time is the longest, and it limits the speed or the frame rate of the X-ray imager. We proposed a forced discharging method which uses a bypass transistor in parallel with the current source of the column signal line. A chip for testing the idea was fabricated by a 0.18 μm process. A active pixel sensor with three transistors and a 3-π RC model of the long line were simulated together. The test results showed that the turning on-and-off of the proposed bypass transistor only during the discharging time could dramatically reduce the discharging time from ∼ 50 μsec to ∼ 2 μsec, which is the physically minimum time determined by the long metal line capacitance

  3. Fast signal transfer in a large-area X-ray CMOS image sensor

    Science.gov (United States)

    Kim, M. S.; Kang, D. U.; Lee, D. H.; Kim, H.; Cho, G.; Jae, M.

    2014-08-01

    For 2-d X-ray imaging, such as mammography and non-destructive test, a sensor should have a large-area because the sensor for typical X-ray beams cannot use optical lens system. To make a large-area 2-d X-ray image sensor using crystal Si, a technique of tiling unit CMOS image sensors into 2 × 2 or 2 × 3 array can be used. In a unit CMOS image sensor made of most common 8-inch Si wafers, the signal line can be up to ~ 180 mm long. Then its parasitic capacitance is up to ~ 25 pF and its resistance is up to ~ 51 kΩ (0.18 μm, 1P3M process). This long signal line may enlarge the row time up to ~ 50 μsec in case of the signal from the top row pixels to the readout amplifiers located at the bottom of the sensor chip. The output signal pulse is typically characterized by three components in sequence; a charging time (a rising part), a reading time and a discharging time (a falling part). Among these, the discharging time is the longest, and it limits the speed or the frame rate of the X-ray imager. We proposed a forced discharging method which uses a bypass transistor in parallel with the current source of the column signal line. A chip for testing the idea was fabricated by a 0.18 μm process. A active pixel sensor with three transistors and a 3-π RC model of the long line were simulated together. The test results showed that the turning on-and-off of the proposed bypass transistor only during the discharging time could dramatically reduce the discharging time from ~ 50 μsec to ~ 2 μsec, which is the physically minimum time determined by the long metal line capacitance.

  4. QVD Sensors as Focal Plane Instruments for X-ray Timing Applications

    International Nuclear Information System (INIS)

    'QVD' detectors are based on thermoelectric heat-to-voltage (Q→V) conversion and digital (V→D) readout. For spectroscopic applications, the theoretical performance limits are competitive with superconducting tunnel junction (STJ) detectors and transition edge sensor (TES) devices. We discuss theoretical and demonstrated timing performance of QVD detectors with different design architectures. Detectors with lanthanum-cerium hexaboride sensors can be very fast, up to 100 MHz/pixel counting rates. They can serve as focal plane detectors for X-ray timing, in situations where very large apertures are used to gather X-ray photons at high event rates. Practical implementation of thermoelectric (QVD) detectors requires cryogenic thermoelectric sensors with high figures of merit. There can be different solutions: thin films, bulk materials and 'whiskers'. We are exploring all three design options and summarize progress in each area

  5. QVD Sensors as Focal Plane Instruments for X-ray Timing Applications

    Science.gov (United States)

    Wood, Kent S.; Gulian, Armen M.; Ray, Paul S.

    2004-07-01

    ``QVD'' detectors are based on thermoelectric heat-to-voltage (Q-->V) conversion and digital (V-->D) readout. For spectroscopic applications, the theoretical performance limits are competitive with superconducting tunnel junction (STJ) detectors and transition edge sensor (TES) devices. We discuss theoretical and demonstrated timing performance of QVD detectors with different design architectures. Detectors with lanthanum-cerium hexaboride sensors can be very fast, up to 100 MHz/pixel counting rates. They can serve as focal plane detectors for X-ray timing, in situations where very large apertures are used to gather X-ray photons at high event rates. Practical implementation of thermoelectric (QVD) detectors requires cryogenic thermoelectric sensors with high figures of merit. There can be different solutions: thin films, bulk materials and ``whiskers.'' We are exploring all three design options and summarize progress in each area.

  6. Study of X-ray radiation damage in the AGIPD sensor for the European XFEL

    CERN Document Server

    Zhang, Jiaguo; Graafsma, Heinz; Klanner, Robert; Kopsalis, Ioannis; Schwandt, Joern

    2013-01-01

    The European X-ray Free Electron Laser (XFEL), currently being constructed in Hamburg and planning to be operational in 2017 for users, will deliver 27,000 fully coherent, high brilliance X-ray pulses per second with duration less than 100 fs. The unique features of the X-ray beam pose major challenges for detectors used at the European XFEL for imaging experiments, in particular a radiation tolerance of silicon sensors for doses up to 1 GGy for 3 years of operation at an operating voltage above 500 V. One of the detectors under development at the European XFEL is the Adaptive Gain Integrating Pixel Detector (AGIPD), which is a hybrid detector system with ASICs bump-bonded to p+n silicon pixel sensors. We have designed the silicon sensors for the AGIPD, which have been fabricated by SINTEF and delivered in the beginning of February of 2013. To demonstrate the performance of the AGIPD sensor with regard to radiation hardness, mini-sensors with the same pixel and guard-ring designs as the AGIPD together with te...

  7. A directly converting high-resolution intra-oral X-ray imaging sensor

    CERN Document Server

    Spartiotis, K; Schulman, T; Puhakka, K; Muukkonen, K

    2003-01-01

    A digital intra-oral X-ray imaging sensor with an active area of 3.6x2.9 cm sup 2 and consisting of six charge-integrating CMOS signal readout circuits bump bonded to one high-resistivity silicon pixel detector has been developed and tested. The pixel size is 35 mu m. The X-rays entering the sensor window are converted directly to electrical charge in the depleted detector material yielding minimum lateral signal spread and maximum image sharpness. The signal charge is collected on the gates of the input field effect transistors of the CMOS signal readout circuits. The analog signal readout is performed by multiplexing in the current mode independent of the signal charge collection enabling multiple readout cycles with negligible dead time and thus imaging with wide dynamic range. Since no intermediate conversion material of X-rays to visible light is needed, the sensor structure is very compact. The analog image signals are guided from the sensor output through a thin cable to signal processing, AD conversio...

  8. Amorphous and Polycrystalline Photoconductors for Direct Conversion Flat Panel X-Ray Image Sensors

    Directory of Open Access Journals (Sweden)

    Karim S. Karim

    2011-05-01

    Full Text Available In the last ten to fifteen years there has been much research in using amorphous and polycrystalline semiconductors as x-ray photoconductors in various x-ray image sensor applications, most notably in flat panel x-ray imagers (FPXIs. We first outline the essential requirements for an ideal large area photoconductor for use in a FPXI, and discuss how some of the current amorphous and polycrystalline semiconductors fulfill these requirements. At present, only stabilized amorphous selenium (doped and alloyed a-Se has been commercialized, and FPXIs based on a-Se are particularly suitable for mammography, operating at the ideal limit of high detective quantum efficiency (DQE. Further, these FPXIs can also be used in real-time, and have already been used in such applications as tomosynthesis. We discuss some of the important attributes of amorphous and polycrystalline x-ray photoconductors such as their large area deposition ability, charge collection efficiency, x-ray sensitivity, DQE, modulation transfer function (MTF and the importance of the dark current. We show the importance of charge trapping in limiting not only the sensitivity but also the resolution of these detectors. Limitations on the maximum acceptable dark current and the corresponding charge collection efficiency jointly impose a practical constraint that many photoconductors fail to satisfy. We discuss the case of a-Se in which the dark current was brought down by three orders of magnitude by the use of special blocking layers to satisfy the dark current constraint. There are also a number of polycrystalline photoconductors, HgI2 and PbO being good examples, that show potential for commercialization in the same way that multilayer stabilized a-Se x-ray photoconductors were developed for commercial applications. We highlight the unique nature of avalanche multiplication in a-Se and how it has led to the development of the commercial HARP video-tube. An all solid state version of the

  9. Empirical electro-optical and x-ray performance evaluation of CMOS active pixels sensor for low dose, high resolution x-ray medical imaging.

    Science.gov (United States)

    Arvanitis, C D; Bohndiek, S E; Royle, G; Blue, A; Liang, H X; Clark, A; Prydderch, M; Turchetta, R; Speller, R

    2007-12-01

    Monolithic complementary metal oxide semiconductor (CMOS) active pixel sensors with high performance have gained attention in the last few years in many scientific and space applications. In order to evaluate the increasing capabilities of this technology, in particular where low dose high resolution x-ray medical imaging is required, critical electro-optical and physical x-ray performance evaluation was determined. The electro-optical performance includes read noise, full well capacity, interacting quantum efficiency, and pixels cross talk. The x-ray performance, including x-ray sensitivity, modulation transfer function, noise power spectrum, and detection quantum efficiency, has been evaluated in the mammographic energy range. The sensor is a 525 x 525 standard three transistor CMOS active pixel sensor array with more than 75% fill factor and 25 x 25 microm pixel pitch. Reading at 10 f/s, it is found that the sensor has 114 electrons total additive noise, 10(5) electrons full well capacity with shot noise limited operation, and 34% interacting quantum efficiency at 530 nm. Two different structured CsI:Tl phosphors with thickness 95 and 115 microm, respectively, have been optically coupled via a fiber optic plate to the array resulting in two different system configurations. The sensitivity of the two different system configurations was 43 and 47 electrons per x-ray incident on the sensor. The MTF at 10% of the two different system configurations was 9.5 and 9 cycles/mm with detective quantum efficiency of 0.45 and 0.48, respectively, close to zero frequency at approximately 0.44 microC/kg (1.72 mR) detector entrance exposure. The detector was quantum limited at low spatial frequencies and its performance was comparable with high resolution a: Si and charge coupled device based x-ray imagers. The detector also demonstrates almost an order of magnitude lower noise than active matrix flat panel imagers. The results suggest that CMOS active pixel sensors when coupled

  10. Improving charge-collection efficiency of SOI pixel sensors for X-ray astronomy

    Science.gov (United States)

    Matsumura, Hideaki; Tsuru, Takeshi Go; Tanaka, Takaaki; Takeda, Ayaki; Arai, Yasuo; Mori, Koji; Nishioka, Yusuke; Takenaka, Ryota; Kohmura, Takayoshi; Nakashima, Shinya; Hatsui, Takaki; Kohmura, Yoshiki; Takei, Dai; Kameshima, Takashi

    2015-09-01

    We have been developing a new type of active pixel sensor, referred to as "XRPIX" for future X-ray astronomy satellites on the basis of silicon-on-insulator CMOS technology. The problem on our previous device, XRPIX1b, was degradation of the charge-collection efficiency (CCE) at pixel borders. In order to investigate the non-uniformity of the CCE within a pixel, we measured sub-pixel response with X-ray beams whose diameters are 10 μmΦ at SPring-8. We found that the X-ray detection efficiency and CCE degrade in the sensor region under the pixel circuitry placed outside the buried p-wells (BPW). A 2D simulation of the electric fields with the semiconductor device simulator HyDeLEOS shows that the isolated pixel circuitry outside the BPW makes local minimums in the electric potentials at the interface between the sensor and buried oxide layers, where a part of charge is trapped and is not collected to the BPW. Based on this result, we modified the placement of the in-pixel circuitry in the next device, XRPIX2b, for the electric fields to be converged toward the BPW, and confirmed that the CCE at pixel borders is successfully improved.

  11. Observation of iron spin-states using tabletop x-ray emission spectroscopy and microcalorimeter sensors

    Science.gov (United States)

    Joe, Y. I.; O'Neil, G. C.; Miaja-Avila, L.; Fowler, J. W.; Jimenez, R.; Silverman, K. L.; Swetz, D. S.; Ullom, J. N.

    2016-01-01

    X-ray emission spectroscopy (XES) is a powerful probe of the electronic and chemical state of elemental species embedded within complex compounds. X-ray sensors that combine high resolving power and high collecting efficiency are desirable for photon-starved XES experiments such as measurements of dilute, gaseous, and radiation-sensitive samples, time-resolved measurements, and in-laboratory XES. To assess whether arrays of cryogenic microcalorimeters will be useful in photon-starved XES scenarios, we demonstrate that these emerging energy-dispersive sensors can detect the spin-state of 3d electrons of iron in two different compounds, Fe2O3 and FeS2. The measurements were conducted with a picosecond pulsed laser-driven plasma as the exciting x-ray source. The use of this tabletop source suggests that time-resolved in-laboratory XES will be possible in the future. We also present simulations of {{K}}α and {{K}}β spectra that reveal the spin-state sensitivity of different combinations of sensor resolution and accumulated counts. These simulations predict that our current experimental apparatus can perform time-resolved XES measurements on some samples with a measurement time of a few 10 s of hours per time delay.

  12. Feasibility study of a gas electron multiplier detector as an X-Ray image sensor

    Science.gov (United States)

    Shin, Sukyoung; Jung, Jaehoon; Lee, Soonhyouk

    2015-07-01

    For its ease of manufacture, flexible geometry, and cheap manufacturing cost, the gas electron multiplier (GEM) detector can be used as an X-ray image sensor. For this purpose, we acquired relative detection efficiencies and suggested a method to increase the detection efficiency in order to study the possibility of using a GEM detector as an X-ray image sensor. The GEM detector system is composed of GEM foils, the instrument system, the gas system, and the negative power supply. The instrument system consists of an A225 charge sensitive preamp, an A206 discriminator, and a MCA8000D multichannel analyzer. For the gas system, argon gas was mixed with CO2 in a ratio of 8:2, and for the negative 2,000 volts, a 3106D power supply was used. A CsI-coated GEM foil was used to increase the detection efficiency. Fe-55 was used as an X-ray source, and the relative efficiency was acquired by using the ratio of the efficiency of the GEM detector to that of the CdTe detector. The total count method and the energy spectrum method were used to calculate the relative efficiency. The relative detection efficiency of the GEM detector for Fe-55 by using total count method was 32%, and the relative detection efficiencies were 5, 43, 33, 37, 35, and 36%, respectively, for 2-, 3-, 4-, 5-, 6-, and 7- keV energy spectrum by using the energy spectrum method. In conclusion, we found that the detection efficiency of the two-layered GEM detector is insufficient for use as an X-ray image sensor, so we suggest a CsI-coated GEM foil to increase the efficiency, with resulting value being increased to 41%.

  13. Feasibility Study of Gas Electron Multiplier Detector as an X-Ray Image Sensor

    CERN Document Server

    Shin, Sukyoung; Lee, Soonhyouk

    2015-01-01

    For its ease manufacturing, flexible geometry, and cheap manufacturing cost, the gas electron multiplier (GEM) detector can be used as an x-ray image sensor. For this purpose, we acquired relative detection efficiencies and suggested a method to increase the detection efficiency in order to study the possibility of GEM detector as an x-ray image sensor. The GEM detector system is composed of GEM foils, the instrument system, the gas system, and the negative power supply. The instrument system consists of the A225 charge sensitive preamp, A206 discriminator, and MCA8000D multichannel analyzer. For the gas system, Argon gas was mixed with CO2 to the ratio of 8:2, and for the negative 2,000 volts, the 3106D power supply was used. The CsI-coated GEM foil was used to increase the detection efficiency. Fe-55 was used as an x-ray source and the relative efficiency was acquired by using the ratio of GEM detector to the CdTe detector. The total count method and the energy spectrum method were used to calculate the rel...

  14. Active Pixel Sensors for direct detection of soft X-rays

    International Nuclear Information System (INIS)

    The imaging of soft X-ray images is typically performed with charge coupled devices (CCDs). However, these can have limited readout speed, dynamic range and can also require significant cooling to obtain the required signal to noise ratio. Active pixel sensors (APS) are able to combine faster readout speeds and higher dynamic range with in-pixel intelligence to allow region of interest readout and adaptive gain. To obtain high detection efficiency and 100% pixel fill factor the sensor is back thinned and illuminated from the backside. We report on the characterization of a back-thinned APS (Vanilla); an array of 512 × 512 pixels of size 25 × 25 microns. The sensor has a 12-bit digital output for full frame mode, as well as being able to be readout in a fully programmable Region-Of-Interest (ROI) analogue mode. In full frame, the sensor can operate at a readout rate of more than 100 frames per second. Characterization of the detector was carried out through the analysis of photon transfer curves to yield measurements of the full well capacity, noise levels, gain constants and device linearity. Spectral response measurements were made to show the improvement in detection efficiency using a backthinned sensor. A typical synchrotron experiment was performed at the Diamond Light Source (DLS) using Soft X-rays ( ∼ 700 eV) to produce a diffraction pattern from a permalloy sample. The pattern was imaged at a range of frame rates, up to 20Hz, and a range of temperatures for both a back-thinned Vanilla and a Princeton PIXIS-XO: 2048B CCD. The results of which are compared. The detection efficiency of the APS is shown to be comparable to the CCD for a given frame rate (0.1Hz), with similar noise levels. We suggest that the back-thinned APS are a viable technology choice for the direct detection of soft X-rays for synchrotron applications.

  15. A high dynamic radiation measurements instrument: the Bolometric Oscillation Sensor (BOS

    Directory of Open Access Journals (Sweden)

    P. Zhu

    2014-12-01

    Full Text Available The bolometric oscillation sensor (BOS is a broadband radiation measurement instrument onboard the PICARD satellite that has been active between 2010 and 2014. The main detector is a thermistor attached black coated surface, which was permanently exposed to space without any optical and aperture accessories. The temperature measurements are used within a transfer function to determine variations in incoming solar irradiance as well as the terrestrial radiation. In the present article, the measurement principle of BOS and its transfer function are presented. The performance of the instrument is discussed based on laboratory experiments and space observations from the PICARD satellite. The comparison of the short term variation of Total Solar Irradiance (TSI with absolute radiometers such as VIRGO/SOHO and TIM/SORCE over the same period of time, suggests that BOS is a relatively much simpler but very effective sensor to monitor electromagnetic radiation variations from visible to infrared wavelengths.

  16. Commercial CMOS image sensors as X-ray imagers and particle beam monitors

    International Nuclear Information System (INIS)

    CMOS image sensors are widely used in several applications such as mobile handsets webcams and digital cameras among others. Furthermore they are available across a wide range of resolutions with excellent spectral and chromatic responses. In order to fulfill the need of cheap systems as beam monitors and high resolution image sensors for scientific applications we exploited the possibility of using commercial CMOS image sensors as X-rays and proton detectors. Two different sensors have been mounted and tested. An Aptina MT9v034, featuring 752 × 480 pixels, 6μm × 6μm pixel size has been mounted and successfully tested as bi-dimensional beam profile monitor, able to take pictures of the incoming proton bunches at the DeFEL beamline (1–6 MeV pulsed proton beam) of the LaBeC of INFN in Florence. The naked sensor is able to successfully detect the interactions of the single protons. The sensor point-spread-function (PSF) has been qualified with 1MeV protons and is equal to one pixel (6 mm) r.m.s. in both directions. A second sensor MT9M032, featuring 1472 × 1096 pixels, 2.2 × 2.2 μm pixel size has been mounted on a dedicated board as high-resolution imager to be used in X-ray imaging experiments with table-top generators. In order to ease and simplify the data transfer and the image acquisition the system is controlled by a dedicated micro-processor board (DM3730 1GHz SoC ARM Cortex-A8) on which a modified LINUX kernel has been implemented. The paper presents the architecture of the sensor systems and the results of the experimental measurements

  17. Developments in Time-Division Multiplexing of X-ray Transition-Edge Sensors

    Science.gov (United States)

    Doriese, W. B.; Morgan, K. M.; Bennett, D. A.; Denison, E. V.; Fitzgerald, C. P.; Fowler, J. W.; Gard, J. D.; Hays-Wehle, J. P.; Hilton, G. C.; Irwin, K. D.; Joe, Y. I.; Mates, J. A. B.; O'Neil, G. C.; Reintsema, C. D.; Robbins, N. O.; Schmidt, D. R.; Swetz, D. S.; Tatsuno, H.; Vale, L. R.; Ullom, J. N.

    2016-07-01

    Time-division multiplexing (TDM) is a mature scheme for the readout of arrays of transition-edge sensors (TESs). TDM is based on superconducting-quantum-interference-device (SQUID) current amplifiers. Multiple spectrometers based on gamma-ray and X-ray microcalorimeters have been operated with TDM readout, each at the scale of 200 sensors per spectrometer, as have several astronomical cameras with thousands of sub-mm or microwave bolometers. Here we present the details of two different versions of our TDM system designed to read out X-ray TESs. The first has been field-deployed in two 160-sensor (8 columns × 20 rows) spectrometers and four 240-sensor (8 columns × 30 rows) spectrometers. It has a three-SQUID-stage architecture, switches rows every 320 ns, and has total readout noise of 0.41 μ Φ 0 / surd Hz. The second, which is presently under development, has a two-SQUID-stage architecture, switches rows every 160 ns, and has total readout noise of 0.19 μ Φ 0 / surd Hz. Both quoted noise values are non-multiplexed and referred to the first-stage SQUID. In a demonstration of this new architecture, a multiplexed 1-column × 32-row array of NIST TESs achieved average energy resolution of 2.55± 0.01 eV at 6 keV.

  18. High-speed superconducting x-ray calorimeter using a transition edge sensor

    International Nuclear Information System (INIS)

    A high-speed superconducting x-ray calorimeter that uses a transition edge sensor (TES) was developed and tested for industrial applications such as microanalysis used in the semiconductor industry. The calorimeter consisted of a Au/Ti bilayer TES formed on a bridge-type SiNx membrane. A count rate of at least 10 000 cps was achieved by designing the calorimeter to have a decay time constant of less than 16 μs. Preliminary experiments involved using the calorimeter (cooled by using a 3He refrigerator with a base temperature below 350 mK) to detect heat pulses and x-rays. To evaluate the response of the calorimeter, we measured the dependence of the decay time constant on the bias current, the pulse height of a heat pulse and the current noise. At the optimal bias point, the calorimeter showed a measured decay time constant of 15 μs and a pulse height of 4 μA when detecting x-rays. (author)

  19. Absorber Materials for Transition-Edge Sensor X-ray Microcalorimeters

    Science.gov (United States)

    Brown, Ari-David; Bandler, Simon; Brekosky, Regis; Chervenak, James; Figueroa-Feliciano, Enectali; Finkbeiner, Fred; Sadleir, Jack; Iyomoto, Naoko; Kelley, Richard; Kilbourne, Caroline; Porter, F. Scott; Smith, Stephen; Saab, Tarek; Sadleir, Jac,

    2007-01-01

    Arrays of superconducting transition-edge sensors (TES) can provide high spatial and energy resolution necessary for x-ray astronomy. High quantum efficiency and uniformity of response can be achieved with a suitable absorber material, in which absorber x-ray stopping power, heat capacity, and thermal conductivity are relevant parameters. Here we compare these parameters for bismuth and gold. We have fabricated electroplated gold, electroplated gold/electroplated bismuth, and evaporated gold/evaporated bismuth 8x8 absorber arrays and find that a correlation exists between the residual resistance ratio (RRR) and thin film microstructure. This finding indicates that we can tailor absorber material conductivity via microstructure alteration, so as to permit absorber thermalization on timescales suitable for high energy resolution x-ray microcalorimetry. We show that by incorporating absorbers possessing large grain size, including electroplated gold and electroplated gold/electroplated bismuth, into our current Mo/Au TES, devices with tunable heat capacity and energy resolution of 2.3 eV (gold) and 2.1 eV (gold/bismuth) FWHM at 6 keV have been fabricated.

  20. Multi-Absorber Transition-Edge Sensors for X-Ray Astronomy Applications

    Science.gov (United States)

    Smith, S. J.; Adams, J. S.; Bandler, S. R.; Busch, S. E.; Chervenak, J. A.; Eckart, M. E.; Ewin, A. J.; Finkbeiner, F. M.; Kelley, R. L.; Kelly, D. P.; Kilbourne, C. A.; Porst, J. P.; Porter, F. S.; Sadleir, J. E.; Wassell, E. J.

    2012-01-01

    We are developing multi-absorber Transition-Edge Sensors (TESs) for applications in x-ray astronomy. These position-sensitive devices consist of multiple x-ray absorbers each with a different thermal coupling to a single readout TES. Heat diffusion between the absorbers and the TES gives rise to a characteristic pulse shape corresponding to each absorber element and enables position discrimination. The development of these detectors is motivated by a desire to maximize focal plane arrays with the fewest number of readout channels. In this contribution we report on the first results from devices consisting of nine) 65 X 65 sq. microns Au x-ray absorbers) 5 microns thick. These are coupled to a single 35 X 35 sq. microns Mo/Au bilayer TES. These devices have demonstrated full-width-half-maximum (FWHM) energy resolution of 2.1 eV at 1.5 keV) 2.5 eV at 5.9 keV and 3.3 eV at 8 keV. This is coupled with position discrimination from pulse shape over the same energy range. We use a finite-element model to reproduce the measured pulse shapes and investigate the detector non-linearity with energy) which impacts on the devices position sensitivity and energy resolution.

  1. Performance studies of a monolithic scintillator-CMOS image sensor for X-ray application

    International Nuclear Information System (INIS)

    We proposed the direct deposition of CsI(Tl) scintillator layer with pixelated structure on a CMOS image sensor (CIS) in order to improve the spatial resolution. CMOS sensors developed for test have a 128x128 photodiode array with 50 μm pixel pitch and integrated readout-electronics including a 10 bit pipe-lined ADC. CsI(Tl) layer has thickness of 50 μm. The modulation transfer function, the noise power spectrum, and the detective quantum efficiency of pixelated and non-pixelated CsI(Tl) X-ray image sensors (XIS) were estimated with a 50 kVp X-ray beam. At 10% of modulation transfer function (MTF), the spatial resolution of pixelated and non-pixleated XIS are about 8 and 6 lp/mm, respectively. It implies that pixelation enhances the spatial resolution by reducing the lateral light diffusion. Though the NPS of pixelated XIS was slightly higher than the non-pixelated XIS, its detective quantum efficiency (DQE) values were much better than non-pixelated XIS especially at high spatial frequencies

  2. X-ray diagnostic study on the optimization of digital radiography in dentistry. Optimal exposure conditions for X-ray CCD sensor

    International Nuclear Information System (INIS)

    The purpose of this research is to reduce the patient dose by optimization of irradiation conditions of an X-ray CCD sensor in intra-oral digital radiography. The X-ray diagnosis was divided into two, high quality-of-image diagnosis and low quality-of-image diagnosis, and it optimized by using the exposure of necessary minimum for each. The image quality of CCD was evaluated using the signal-to-noise ratio (SNR) in order to estimate the influence of irradiation conditions. The dose based on CCD maker setting value was set up so that the highest quality of image might be obtained mostly. In low quality-of-image diagnosis, even if it reduced the dose to 13.2% of standard irradiation, SNR was 40% and interpretation was possible. In high quality-of-image diagnosis, even if it reduces the dose to 49% of standard irradiation, SNR remained 80% and there were few differences of the image with a standard. A study of the digital X-ray examination taken at the dental clinic showed high quality-of-image diagnosis was 69% and low quality-of-image one was 31%. When this optimization was performed, it was presumed that reduction of about 62% of the dose is possible. (author)

  3. Hard-X-Ray/Soft-Gamma-Ray Imaging Sensor Assembly for Astronomy

    Science.gov (United States)

    Myers, Richard A.

    2008-01-01

    An improved sensor assembly has been developed for astronomical imaging at photon energies ranging from 1 to 100 keV. The assembly includes a thallium-doped cesium iodide scintillator divided into pixels and coupled to an array of high-gain avalanche photodiodes (APDs). Optionally, the array of APDs can be operated without the scintillator to detect photons at energies below 15 keV. The array of APDs is connected to compact electronic readout circuitry that includes, among other things, 64 independent channels for detection of photons in various energy ranges, up to a maximum energy of 100 keV, at a count rate up to 3 kHz. The readout signals are digitized and processed by imaging software that performs "on-the-fly" analysis. The sensor assembly has been integrated into an imaging spectrometer, along with a pair of coded apertures (Fresnel zone plates) that are used in conjunction with the pixel layout to implement a shadow-masking technique to obtain relatively high spatial resolution without having to use extremely small pixels. Angular resolutions of about 20 arc-seconds have been measured. Thus, for example, the imaging spectrometer can be used to (1) determine both the energy spectrum of a distant x-ray source and the angular deviation of the source from the nominal line of sight of an x-ray telescope in which the spectrometer is mounted or (2) study the spatial and temporal development of solar flares, repeating - ray bursters, and other phenomena that emit transient radiation in the hard-x-ray/soft- -ray region of the electromagnetic spectrum.

  4. Development of Position-sensitive Transition-edge Sensor X-ray Detectors

    Science.gov (United States)

    Smith, S. J.; Bandler, S. R.; Brekosky, R. P.; Brown, A.-D.; Chervenak, J. A.; Eckard, M. E.; Finkbeiner, F. M.; Kelley, R. L.; Kilbourne, C. A.; Porter, F. s.; Sad (eor. K/ E/); Figueroa-Feliciano, E.

    2008-01-01

    We report on the development of position-sensitive transition-edge sensors (PoST's) for future x-ray astronomy missions such as the International X-ray Observatory (IXO), currently under study by NASA and ESA. PoST's consist of multiple absorbers each with a different thermal coupling to one or more transition-edge sensor (TES). This differential thermal coupling between absorbers and TES's results in different characteristic pulse shapes and allows position discrimination between the different pixels. The development of PoST's is motivated by a desire to achieve maximum focal-plane area with the least number of readout channels and as such. PoST's are ideally suited to provide a focal-plane extension to the Constellation-X microcalorimeter array. We report the first experimental results of our latest one and two channel PoST's, which utilize fast thermalizing electroplated Au/Bi absorbers coupled to low noise Mo/Au TES's - a technology already successfully implemented in our arrays of single pixel TES's. We demonstrate 6 eV energy resolution coupled with spatial sensitivity in the keV energy range. We also report on the development of signal processing algorithms to optimize energy and position sensitivity of our detectors.

  5. High Count-Rate Studies of Small-Pitch Transition-Edge Sensor X-ray Microcalorimeters

    Science.gov (United States)

    Lee, S. J.; Bandler, S. R.; Busch, S. E.; Adams, J. S.; Chervenak, J. A.; Eckart, M. E.; Ewin, A. J.; Finkbeiner, F. M.; Kelley, R. L.; Kilbourne, C. A.; Porst, J.-P.; Porter, F. S.; Sadleir, J. E.; Smith, S. J.; Wassel, E. J.

    2014-08-01

    We are developing kilo-pixel arrays of small-pitch transition-edge sensors for high spectral-resolving, high count-rate applications in astrophysics and solar physics measurements. We have fabricated and tested pixels that are m in size on a silicon substrate with an X-ray flux of counts per second (cps) per pixel. The X-ray pulses were recorded and analyzed in various ways to obtain high throughput with good energy resolution. We have demonstrated 2.3 eV FWHM resolution with 99.6 % throughput for a 6-keV X-ray flux of 100 cps.

  6. X-ray induced radiation damage at the Si-SiO2 interface of silicon sensors

    International Nuclear Information System (INIS)

    Silicon pixel sensors will be used for imaging experiments at the European X-ray Free Electron Laser (XFEL). In 3 years of operation the sensors will be exposed to doses of up to 1 GGy of 12 keV X-rays. Hence, to develop such a radiation-hard silicon pixel sensor for the European XFEL a good understanding of X-ray induced radiation damage is necessary. Using capacitance/conductance-voltage, current-voltage and thermal dielectric relaxation current measurements on MOS capacitors and gate-controlled diodes, the oxide-charge density, the interface-trap density and the surface-current density have been measured for X-ray doses up to 1 GGy. The results have been used as input in TCAD simulations for the optimization of the pixel sensor. This talk will introduce the physical processes of X-ray induced radiation damage, review the important factors which impact on the formation of the defects in the SiO2 and at the Si-SiO2 interface, present the main results on the dose dependence of the oxide-charge density and the surface-current density, and summarize their influence on the electrical performance of silicon sensors.

  7. Edgeless silicon sensors for Medipix-based large-area X-ray imaging detectors

    International Nuclear Information System (INIS)

    Some X-ray imaging applications demand sensitive areas exceeding the active area of a single sensor. This requires a seamless tessellation of multiple detector modules with edgeless sensors. Our research is aimed at minimising the insensitive periphery that isolates the active area from the edge. Reduction of the edge-defect induced charge injection, caused by the deleterious effects of dicing, is an important step. We report on the electrical characterisation of 300 μm thick edgeless silicon p+-ν-n+ diodes, diced using deep reactive ion etching. Sensors with both n-type and p-type stop rings were fabricated in various edge topologies. Leakage currents in the active area are compared with those of sensors with a conventional design. As expected, we observe an inverse correlation between leakage-current density and both the edge distance and stop-ring width. From this correlation we determine a minimum acceptable edge distance of 50 μm. We also conclude that structures with a p-type stop ring show lower leakage currents and higher breakdown voltages than the ones with an n-type stop ring.

  8. Development of Kilo-Pixel Arrays of Transition-Edge Sensors for X-Ray Spectroscopy

    Science.gov (United States)

    Adams, J. S.; Bandler, S. R.; Busch, S. E.; Chervenak, J. A.; Chiao, M. P.; Eckart, M. E.; Ewin, A. J.; Finkbeiner, F. M.; Kelley, R. L.; Kelly, D. P.; Kilbourne, C. A.; Leutenegger, M. A.; Porst, J.-P.; Porter, F. S.; Ray, C. A.; Sadleir, J. E.; Smith, S. J.; Wassell, E. J.; Doriese, W. B.; Fowler, J. W.; Hilton, G. C.; Irwin, K. D.; Reintsema, C. D.; Smith, D. R.; Swetz, D. S.

    2012-01-01

    We are developing kilo-pixel arrays of transition-edge sensor (TES) microcalorimeters for future X-ray astronomy observatories or for use in laboratory astrophysics applications. For example, Athena/XMS (currently under study by the european space agency) would require a close-packed 32x32 pixel array on a 250-micron pitch with < 3.0 eV full-width-half-maximum energy resolution at 6 keV and at count-rates of up to 50 counts/pixel/second. We present characterization of 32x32 arrays. These detectors will be readout using state of the art SQUID based time-domain multiplexing (TDM). We will also present the latest results in integrating these detectors and the TDM readout technology into a 16 row x N column field-able instrument.

  9. First application of superconducting transition-edge-sensor microcalorimeters to hadronic-atom x-ray spectroscopy

    CERN Document Server

    Okada, S; Curceanu, C; Doriese, W B; Fowler, J W; Gard, J; Gustafsson, F P; Hashimoto, T; Hayano, R S; Hirenzaki, S; Hays-Wehle, J P; Hilton, G C; Ikeno, N; Iliescu, M; Ishimoto, S; Itahashi, K; Iwasaki, M; Koike, T; Kuwabara, K; Ma, Y; Marton, J; Noda, H; O'Neil, G C; Outa, H; Reintsema, C D; Sato, M; Schmidt, D R; Shi, H; Suzuki, K; Suzuki, T; Swetz, D S; Tatsuno, H; Uhlig, J; Ullom, J N; Widmann, E; Yamada, S; Yamagata-Sekihara, J; Zmeskal, J

    2016-01-01

    High-resolution pionic-atom x-ray spectroscopy was performed with an x-ray spectrometer based on a 240-pixel array of superconducting transition-edge-sensor (TES) microcalorimeters at the piM1 beam line of the Paul Scherrer Institute. X-rays emitted by pionic carbon via the 4f->3d transition and the parallel 4d->3p transition were observed with a full-width-at-half-maximum energy resolution of 6.8 eV at 6.4 keV. Measured x-ray energies are consistent with calculated electromagnetic values which considered the strong-interaction effect assessed via the Seki-Masutani potential for the 3p energy level, and favor the electronic population of two filled 1s electrons in the K-shell. Absolute energy calibration with an uncertainty of 0.1 eV was demonstrated under a high-rate hadron beam condition of 1.45 MHz. This is the first application of a TES spectrometer to hadronic-atom x-ray spectroscopy and is an important milestone towards next-generation high-resolution kaonic-atom x-ray spectroscopy.

  10. Development of hard X-ray and gamma-ray spectrometer using superconducting transition edge sensor

    International Nuclear Information System (INIS)

    Superconducting transition edge sensors (TES) are used for high-resolution X-ray spectroscopy. In our group, we developed an Ir-TES and reported an energy resolution of 6.9 eV FWHM at 5.9 keV (Kunieda et al., 2004). In this study, we have designed a new TES detector using a superconducting tin (Sn) absorber to detect high energy photons over 100 keV. The Sn absorber is coupled to an Ir/Au superconducting film which is deposited on an ultra-thin SiN membrane (500 nm thick) with a small amount of epoxy post (Stycast 2850FT) by handling with a flip-chip bonding machine. The measured energy resolution is 485 eV FWHM at 60 keV and is better than that of HPGe detector. -- Highlights: ► We designed a Gamma-ray Spectrometer using superconducting transition edge sensor. ► Sn absorber was coupled to an Ir/Au superconducting film through the Stycast epoxy. ► An extremely small epoxy post was fabricated on a 500 nm thick SiN membrane. ► The absorber was coupled to a superconducting film using flip-chip bonding machine. ► We have achieved a better energy resolution than conventional HPGe detectors

  11. A CMOS active pixel sensor system for laboratory- based x-ray diffraction studies of biological tissue.

    Science.gov (United States)

    Bohndiek, Sarah E; Cook, Emily J; Arvanitis, Costas D; Olivo, Alessandro; Royle, Gary J; Clark, Andy T; Prydderch, Mark L; Turchetta, Renato; Speller, Robert D

    2008-02-01

    X-ray diffraction studies give material-specific information about biological tissue. Ideally, a large area, low noise, wide dynamic range digital x-ray detector is required for laboratory-based x-ray diffraction studies. The goal of this work is to introduce a novel imaging technology, the CMOS active pixel sensor (APS) that has the potential to fulfil all these requirements, and demonstrate its feasibility for coherent scatter imaging. A prototype CMOS APS has been included in an x-ray diffraction demonstration system. An industrial x-ray source with appropriate beam filtration is used to perform angle dispersive x-ray diffraction (ADXRD). Optimization of the experimental set-up is detailed including collimator options and detector operating parameters. Scatter signatures are measured for 11 different materials, covering three medical applications: breast cancer diagnosis, kidney stone identification and bone mineral density calculations. Scatter signatures are also recorded for three mixed samples of known composition. Results are verified using two independent models for predicting the APS scatter signature: (1) a linear systems model of the APS and (2) a linear superposition integral combining known monochromatic scatter signatures with the input polychromatic spectrum used in this case. Cross validation of experimental, modelled and literature results proves that APS are able to record biologically relevant scatter signatures. Coherent scatter signatures are sensitive to multiple materials present in a sample and provide a means to quantify composition. In the future, production of a bespoke APS imager for x-ray diffraction studies could enable simultaneous collection of the transmitted beam and scattered radiation in a laboratory-based coherent scatter system, making clinical transfer of the technique attainable. PMID:18199908

  12. Predictive sensor based x-ray calibration using a physical model

    International Nuclear Information System (INIS)

    Many computer assisted surgery systems are based on intraoperative x-ray images. To achieve reliable and accurate results these images have to be calibrated concerning geometric distortions, which can be distinguished between constant distortions and distortions caused by magnetic fields. Instead of using an intraoperative calibration phantom that has to be visible within each image resulting in overlaying markers, the presented approach directly takes advantage of the physical background of the distortions. Based on a computed physical model of an image intensifier and a magnetic field sensor, an online compensation of distortions can be achieved without the need of an intraoperative calibration phantom. The model has to be adapted once to each specific image intensifier through calibration, which is based on an optimization algorithm systematically altering the physical model parameters, until a minimal error is reached. Once calibrated, the model is able to predict the distortions caused by the measured magnetic field vector and build an appropriate dewarping function. The time needed for model calibration is not yet optimized and takes up to 4 h on a 3 GHz CPU. In contrast, the time needed for distortion correction is less than 1 s and therefore absolutely acceptable for intraoperative use. First evaluations showed that by using the model based dewarping algorithm the distortions of an XRII with a 21 cm FOV could be significantly reduced. The model was able to predict and compensate distortions by approximately 80% to a remaining error of 0.45 mm (max) (0.19 mm rms)

  13. Charge Summing in Spectroscopic X-Ray Detectors With High-Z Sensors

    CERN Document Server

    Koenig, Thomas; Cecilia, Angelica; Ballabriga, Rafael; Baumbach, Tilo; Llopart, Xavier; Fiederle, Michael; Zuber, Marcus; Hamann, Elias; Fauler, Alex; Campbell, Michael

    2013-01-01

    The spectroscopic performance of photon counting detectors is limited by the effects of charge sharing between neighboring pixels and the emission of characteristic X-rays. For these reasons, an event can be either missed or counted more than once. These effects become more and more of a concern when pixel pitches are reduced, and for the technology available so far, this meant that there would always be a trade-off between a high spatial and a high spectral resolution. In this work, we present first measurements obtained with the new Medipix3RX ASIC, which features a network of charge summing circuits establishing a communication between pixels which helps to mitigate these effects. Combined with cadmium telluride sensors, we show that this new technology is successful at improving a detector's spectroscopic capabilities even at pixel pitches as small as 55 mu m. At this pitch, we measure an energy response function similar to that observed for a pixel pitch of 165 mu m in the absence of a charge summing cir...

  14. The Dexela 2923 CMOS X-ray detector: A flat panel detector based on CMOS active pixel sensors for medical imaging applications

    OpenAIRE

    Konstantinidis, A. C.; Szafraniec, M. B.; Speller, R.D.; Olivo, A.

    2012-01-01

    Complementary metal-oxide-semiconductors (CMOS) active pixel sensors (APS) have been introduced recently in many scientific applications. This work reports on the performance (in terms of signal and noise transfer) of an X-ray detector that uses a novel CMOS APS which was developed for medical X-ray imaging applications. For a full evaluation of the detector's performance, electro-optical and X-ray characterizations were carried out. The former included measuring read noise, full well capacit...

  15. X-ray radiation damage studies and design of a silicon pixel sensor for science at the XFEL

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jiaguo

    2013-06-15

    Experiments at the European X-ray Free Electron Laser (XFEL) require silicon pixel sensors which can withstand X-ray doses up to 1 GGy. For the investigation of Xray radiation damage up to these high doses, MOS capacitors and gate-controlled diodes built on high resistivity n-doped silicon with crystal orientations left angle 100 right angle and left angle 111 right angle produced by four vendors, CiS, Hamamatsu, Canberra and Sintef have been irradiated with 12 keV X-rays at the DESY DORIS III synchrotron-light source. Using capacitance/ conductance-voltage, current-voltage and thermal dielectric relaxation current measurements, the densities of oxide charges and interface traps at the Si-SiO{sub 2} interface, and the surface-current densities have been determined as function of dose. Results indicate that the dose dependence of the oxide-charge density, the interface-trap density and the surface-current density depend on the crystal orientation and producer. In addition, the influence of the voltage applied to the gates of the MOS capacitor and the gate-controlled diode during X-ray irradiation on the oxide-charge density, the interface-trap density and the surface-current density has been investigated at doses of 100 kGy and 100 MGy. It is found that both strongly depend on the gate voltage if the electric field in the oxide points from the surface of the SiO{sub 2} to the Si-SiO{sub 2} interface. To verify the long-term stability of irradiated silicon sensors, annealing studies have been performed at 60 C and 80 C on MOS capacitors and gate-controlled diodes irradiated to 5 MGy as well, and the annealing kinetics of oxide charges and surface current were determined. Moreover, the macroscopic electrical properties of segmented sensors have slao been investigated as function of dose. It is found that the defects introduced by X-rays increase the full depletion voltage, the surface leakage current and the inter-electrode capacitance of the segmented sensor. An

  16. X-ray radiation damage studies and design of a silicon pixel sensor for science at the XFEL

    International Nuclear Information System (INIS)

    Experiments at the European X-ray Free Electron Laser (XFEL) require silicon pixel sensors which can withstand X-ray doses up to 1 GGy. For the investigation of Xray radiation damage up to these high doses, MOS capacitors and gate-controlled diodes built on high resistivity n-doped silicon with crystal orientations left angle 100 right angle and left angle 111 right angle produced by four vendors, CiS, Hamamatsu, Canberra and Sintef have been irradiated with 12 keV X-rays at the DESY DORIS III synchrotron-light source. Using capacitance/ conductance-voltage, current-voltage and thermal dielectric relaxation current measurements, the densities of oxide charges and interface traps at the Si-SiO2 interface, and the surface-current densities have been determined as function of dose. Results indicate that the dose dependence of the oxide-charge density, the interface-trap density and the surface-current density depend on the crystal orientation and producer. In addition, the influence of the voltage applied to the gates of the MOS capacitor and the gate-controlled diode during X-ray irradiation on the oxide-charge density, the interface-trap density and the surface-current density has been investigated at doses of 100 kGy and 100 MGy. It is found that both strongly depend on the gate voltage if the electric field in the oxide points from the surface of the SiO2 to the Si-SiO2 interface. To verify the long-term stability of irradiated silicon sensors, annealing studies have been performed at 60 C and 80 C on MOS capacitors and gate-controlled diodes irradiated to 5 MGy as well, and the annealing kinetics of oxide charges and surface current were determined. Moreover, the macroscopic electrical properties of segmented sensors have slao been investigated as function of dose. It is found that the defects introduced by X-rays increase the full depletion voltage, the surface leakage current and the inter-electrode capacitance of the segmented sensor. An electron

  17. Transition-edge sensor microcalorimeters for a diffuse soft X-ray sounding rocket mission

    Science.gov (United States)

    Morgan, Kelsey M.

    The extent and composition of the soft Diffuse X-ray Background (DXRB) has been the subject of debate since its discovery in the 1960s. Initially assumed to be extragalactic, it was soon realized that most of the emission observed between 0.1-1 keV originated inside the Galaxy and was most likely thermal emission from hot gas. However, when a few high resolution spectral measurements became available in the 1990s and early 2000s it became apparent that standard thermal models were not a good fit to the observations. It has also become apparent that a significant fraction of the diffuse background, particularly in the 1/4 keV energy range, may actually be produced by charge exchange within the Solar System. An essential part of understanding the different contributions to the DXRB is obtaining more high spectral resolution data. The large number of closely-spaced emission lines in the 1/4 keV energy range requires 1-2 eV FWHM energy resolution to resolve individual lines. This thesis details efforts to design a detector array capable of < 2 eV FWHM resolution at 250 eV using a superconducting transition-edge sensor thermometer coupled to a thin gold absorber. I show that 2 eV FWHM energy resolution is possible while still maintaining enough collecting area and efficiency to enable a sounding rocket observation with currently available readout and cryogenic technology. In thin, large area absorbers, position dependent pulse shape can degrade energy resolution. Simulations of thermal diffusion in thin gold layers indicate that broadening due to position dependent pulse shape is expected to be minimal in these devices. Results from test devices are presented, with energy resolution and broadening due to position dependent pulse shape showing good agreement with modeled behavior.

  18. Photostimulable SrS:Eu,Sm phosphor as a storage material for two-dimensional X-ray image sensor

    International Nuclear Information System (INIS)

    In this paper, we report the first observation of intense PSL in Eu and Sm co-doped SrS (SrS;Eu,Sm) phosphor at room temperature (RT) and the PSL characteristics of SrS:Eu,Sm phosphor as a storage material for two-dimensional imaging sensor for the electromagnetic waves such as X-ray. (J.P.N.)

  19. Low Dose X-Ray Sources and High Quantum Efficiency Sensors: The Next Challenge in Dental Digital Imaging?

    International Nuclear Information System (INIS)

    Objective(s). The major challenge encountered to decrease the milliamperes (mA) level in X-ray imaging systems is the quantum noise phenomena. This investigation evaluated dose exposure and image resolution of a low dose X-ray imaging (LDXI) prototype comprising a low mA X-ray source and a novel microlens-based sensor relative to current imaging technologies. Study Design. A LDXI in static (group 1) and dynamic (group 2) modes was compared to medical fluoroscopy (group 3), digital intraoral radiography (group 4), and CBCT scan (group 5) using a dental phantom. Results. The Mann-Whitney test showed no statistical significance (α = 0.01) in dose exposure between groups 1 and 3 and 1 and 4 and timing exposure (seconds) between groups 1 and 5 and 2 and 3. Image resolution test showed group 1 > group 4 > group 2 > group 3 > group 5. Conclusions. The LDXI proved the concept for obtaining a high definition image resolution for static and dynamic radiography at lower or similar dose exposure and smaller pixel size, respectively, when compared to current imaging technologies. Lower mA at the X-ray source and high QE at the detector level principles with microlens could be applied to current imaging technologies to considerably reduce dose exposure without compromising image resolution in the near future

  20. Low Dose X-Ray Sources and High Quantum Efficiency Sensors: The Next Challenge in Dental Digital Imaging?

    International Nuclear Information System (INIS)

    Objective(s). The major challenge encountered to decrease the milli amperes (mA) level in X-ray imaging systems is the quantum noise phenomena. This investigation evaluated dose exposure and image resolution of a low dose X-ray imaging (LDXI) prototype comprising a low mA X-ray source and a novel micro lens-based sensor relative to current imaging technologies. Study Design. A LDXI in static (group 1) and dynamic (group 2) modes was compared to medical fluoroscopy (group 3), digital intraoral radiography (group 4), and CBCT scan (group 5) using a dental phantom. Results. The Mann-Whitney test showed no statistical significance (α=0.01) in dose exposure between groups 1 and 3 and 1 and 4 and timing exposure (seconds) between groups 1 and 5 and 2 and 3. Image resolution test showed group 1 > group 4 > group 2 > group 3 > group 5. Conclusions. The LDXI proved the concept for obtaining a high definition image resolution for static and dynamic radiography at lower or similar dose exposure and smaller pixel size, respectively, when compared to current imaging technologies. Lower mA at the X-ray source and high QE at the detector level principles with micro lens could be applied to current imaging technologies to considerably reduce dose exposure without compromising image resolution in the near future.

  1. Bolometric properties of reactively sputtered TiO2−x films for thermal infrared image sensors

    International Nuclear Information System (INIS)

    A heat-sensitive layer (TiO2−x) was successfully deposited by RF reactive magnetron sputtering for infrared (IR) image sensors at different relative mass flow of oxygen gas (R O2) levels. The deposition rate was decreased with an increase in the percentage of R O2 from 3.4% to 3.7%. TiO2−x samples deposited at room temperature exhibited amorphous characteristics. Oxygen deficiency causes a change in the oxidation state and is assumed to decrease the Ti4+ component on the surfaces of TiO2−x films. The oxygen stoichiometry (x) in TiO2−x films decreased from 0.35 to 0.05 with increasing the R O2 level from 3.4% to 3.7%, respectively. In TiO2−x−test-patterned samples, the resistivity decreased with the temperature, confirming the typical semiconducting property. The bolometric properties of the resistivity, temperature coefficient of resistance (TCR), and the flicker (1/ f) noise parameter were determined at different x values in TiO2−x samples. The rate of TCR dependency with regard to the 1/ f noise parameter is a universal bolometric parameter (β), acting as the dynamic element in a bolometer. It is high when a sample has a relatively low resistivity (0.82 Ω·cm) and a lower 1/ f noise parameter (3.16   ×   10−12). The results of this study indicate that reactively sputtered TiO2−x is a viable bolometric material for uncooled IR image sensor devices. (paper)

  2. Performance of a Diamond X-ray Sensor Fabricated with Metal-less Graphitic Contacts

    OpenAIRE

    Sellin, P.J.; Galbiati, A

    2005-01-01

    We report the x-ray photocurrent response of a coplanar chemical vapor deposition diamond detector fabricated using a metal-less graphitic ohmic contact. Ion implantation of 70 keV boron ions to a dose of 2x10(16) cm(-2) was performed through a patterned photoresist to produce a coplanar graphitic contact structure. The device photocurrent showed a fast response to pulsed x-ray irradiation, and showed no evidence of photocurrent persistence that is observed in devices fabricated using metal S...

  3. Development and characterization of the latest X-ray SOI pixel sensor for a future astronomical mission

    International Nuclear Information System (INIS)

    We have been developing active pixel sensors based on silicon-on-insulator technology for future X-ray astronomy missions. Recently we fabricated the new prototype named “XRPIX2”, and investigated its spectroscopic performance. For comparison and evaluation of different chip designs, XRPIX2 consists of 3 pixel types: Small Pixel, Large Pixel 1, and Large Pixel 2. In Small Pixel, we found that the gains of the 68% pixels are within 1.4% of the mean value, and the energy resolution is 656 eV (FWHM) for 8 keV X-rays, which is the best spectroscopic performance in our development. The pixel pitch of Large Pixel 1 and Large Pixel 2 is twice as large as that of Small Pixel. Charge sharing events are successfully reduced for Large Pixel 1. Moreover Large Pixel 2 has multiple nodes for charge collection in a pixel. We confirmed that the multi-nodes structure is effective to increase charge collection efficiency. -- Highlights: •We performed the evaluation of the newly fabricated SOI sensor for X-ray astronomy. •The pixel-to-pixel gain variation is small in the 64 ×144 pixel format. •The energy resolution is improved by the optimization of the pixel design. •The multi charge collection nodes improved the charge collection efficiency

  4. Progress in the Development of Mo-Au Transition-Edge Sensors for X-Ray Spectroscopy

    Science.gov (United States)

    Stahle, Caroline K.; Brekosky, Regis P.; Figueroa-Feliciano, Enectali; Finkbeiner, Fred M.; Gygax, John D.; Li, Mary J.; Lindeman, Mark A..; Porter, F. Scott; Tralshawalaa, Nilesh

    2000-01-01

    X-ray microcalorimeters using transition-edge sensors (TES) show great promise for use in astronomical x-ray spectroscopy. We have obtained very high energy resolution (2.8 electronvolts at 1.5 kiloelectronvolts and 3.7 electronvolts at 3.3 kiloelectronvolts) in a large, isolated TES pixel using a Mo/Au proximity-effect bilayer on a silicon nitride membrane. We will discuss the performance and our characterization of that device. In order to be truly suitable for use behind an x-ray telescope, however, such devices need to be arrayed with a pixel size and focal-plane coverage commensurate with the telescope focal length and spatial resolution. Since this requires fitting the TES and its thermal link, a critical component of each calorimeter pixel, into a far more compact geometry than has previously been investigated, we must study the fundamental scaling laws in pixel optimization. We have designed a photolithography mask that will allow us to probe the range in thermal conductance that can be obtained by perforating the nitride membrane in a narrow perimeter around the sensor. This mask will also show the effects of reducing the TES area. Though we have not yet tested devices of the compact designs, we will present our progress in several of the key processing steps and discuss the parameter space of our intended investigations.

  5. Development and characterization of the latest X-ray SOI pixel sensor for a future astronomical mission

    Energy Technology Data Exchange (ETDEWEB)

    Nakashima, Shinya, E-mail: shinya@cr.scphys.kyoto-u.ac.jp [Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Gando Ryu, Syukyo; Tanaka, Takaaki; Go Tsuru, Takeshi [Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Takeda, Ayaki [Department of Particle and Nuclear Physics, Graduate School of High Energy Accelerator Science, The Graduate University for Advanced Studies (SOKENDAI), High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Arai, Yasuo [Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba 305-0801 (Japan); Imamura, Toshifumi; Ohmoto, Takafumi; Iwata, Atsushi [A-R-Tec Corp., Hiroshima Techno Plaza 405, 3-13-26 Kagamiyama, Higashi-Hiroshima 739-0046 (Japan)

    2013-12-11

    We have been developing active pixel sensors based on silicon-on-insulator technology for future X-ray astronomy missions. Recently we fabricated the new prototype named “XRPIX2”, and investigated its spectroscopic performance. For comparison and evaluation of different chip designs, XRPIX2 consists of 3 pixel types: Small Pixel, Large Pixel 1, and Large Pixel 2. In Small Pixel, we found that the gains of the 68% pixels are within 1.4% of the mean value, and the energy resolution is 656 eV (FWHM) for 8 keV X-rays, which is the best spectroscopic performance in our development. The pixel pitch of Large Pixel 1 and Large Pixel 2 is twice as large as that of Small Pixel. Charge sharing events are successfully reduced for Large Pixel 1. Moreover Large Pixel 2 has multiple nodes for charge collection in a pixel. We confirmed that the multi-nodes structure is effective to increase charge collection efficiency. -- Highlights: •We performed the evaluation of the newly fabricated SOI sensor for X-ray astronomy. •The pixel-to-pixel gain variation is small in the 64 ×144 pixel format. •The energy resolution is improved by the optimization of the pixel design. •The multi charge collection nodes improved the charge collection efficiency.

  6. CCD [charge-coupled device] sensors in synchrotron x-ray detectors

    International Nuclear Information System (INIS)

    The intense photon flux from advanced synchrotron light sources, such as the 7-GeV synchrotron being designed at Argonne, require integrating-type detectors. Charge-coupled devices (CCDs) are well suited as synchrotron x-ray detectors. When irradiated indirectly via a phosphor followed by reducing optics, diffraction patterns of 100 cm2 can be imaged on a 2 cm2 CCD. With a conversion efficiency of ∼1 CCD electron/x-ray photon, a peak saturation capacity of >106 x rays can be obtained. A programmable CCD controller operating at a clock frequency of 20 MHz has been developed. The readout rate is 5 x 106 pixels/s and the shift rate in the parallel registers is 106 lines/s. The test detector was evaluated in two experiments. In protein crystallography diffraction patterns have been obtained from a lysozyme crystal using a conventional rotating anode x-ray generator. Based on these results we expect to obtain at a synchrotron diffraction images at the rate of ∼1 frame/s or a complete 3-dimensional data set from a single crystal in ∼2 min. 16 refs., 16 figs., 2 tabs

  7. Thermal Acoustic Sensor for High Pulse Energy X-ray FEL Beams

    International Nuclear Information System (INIS)

    The pulse energy density of X-ray FELs will saturate or destroy conventional X-ray diagnostics, and the use of large beam attenuation will result in a beam that is dominated by harmonics. We present preliminary results at the LCLS from a pulse energy detector based on the thermal acoustic effect. In this type of detector an X-ray resistant material (boron carbide in this system) intercepts the beam. The pulse heating of the target material produces an acoustic pulse that can be detected with high frequency microphones to produce a signal that is linear in the absorbed energy. The thermal acoustic detector is designed to provide first- and second-order calorimetric measurement of X-ray FEL pulse energy. The first-order calorimetry is a direct temperature measurement of a target designed to absorb all or most of the FEL pulse power with minimal heat leak. The second-order measurement detects the vibration caused by the rapid thermoelastic expansion of the target material each time it absorbs a photon pulse. Both the temperature change and the amplitude of the acoustic signal are directly related to the photon pulse energy.

  8. Fabrication and characterization of a ZnO X-ray sensor using a high-resistivity ZnO single crystal grown by the hydrothermal method

    International Nuclear Information System (INIS)

    We investigated the X-ray detection capability of a fabricated Pt/ZnO diode using a high-resistivity ZnO single crystal grown by the hydrothermal method. The X-ray sensor consists of a Pt electrode on the Zn-face, an Au/Ti electrode on the O-face and a (0 0 0 1) ZnO substrate with high resistivity. The fabricated X-ray sensor showed ohmic-like characteristics in the measurement of current-applied voltage characteristics. We attributed these ohmic characteristics to degradation of the surface quality of the ZnO substrate caused by handling damage that occurred when carrying out a series of electrical and optical ZnO characterizations. The fabricated X-ray sensor at a bias of 20 V responded to X-rays in current-mode measurement. The sensor current increased linearly with X-ray tube current at 60 keV, and the results showed that sensitivity was approximately 1.5 μC/Gy. We demonstrated that a ZnO single crystal has potential for the development of an X-ray detector.

  9. Large area CMOS active pixel sensor x-ray imager for digital breast tomosynthesis: Analysis, modeling, and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Chumin; Kanicki, Jerzy, E-mail: kanicki@eecs.umich.edu [Solid-State Electronics Laboratory, Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109 (United States); Konstantinidis, Anastasios C. [Department of Medical Physics and Biomedical Engineering, University College London, London WC1E 6BT, United Kingdom and Diagnostic Radiology and Radiation Protection, Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester M20 4BX (United Kingdom); Patel, Tushita [Department of Physics, University of Virginia, Charlottesville, Virginia 22908 (United States)

    2015-11-15

    Purpose: Large area x-ray imagers based on complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) technology have been proposed for various medical imaging applications including digital breast tomosynthesis (DBT). The low electronic noise (50–300 e{sup −}) of CMOS APS x-ray imagers provides a possible route to shrink the pixel pitch to smaller than 75 μm for microcalcification detection and possible reduction of the DBT mean glandular dose (MGD). Methods: In this study, imaging performance of a large area (29 × 23 cm{sup 2}) CMOS APS x-ray imager [Dexela 2923 MAM (PerkinElmer, London)] with a pixel pitch of 75 μm was characterized and modeled. The authors developed a cascaded system model for CMOS APS x-ray imagers using both a broadband x-ray radiation and monochromatic synchrotron radiation. The experimental data including modulation transfer function, noise power spectrum, and detective quantum efficiency (DQE) were theoretically described using the proposed cascaded system model with satisfactory consistency to experimental results. Both high full well and low full well (LFW) modes of the Dexela 2923 MAM CMOS APS x-ray imager were characterized and modeled. The cascaded system analysis results were further used to extract the contrast-to-noise ratio (CNR) for microcalcifications with sizes of 165–400 μm at various MGDs. The impact of electronic noise on CNR was also evaluated. Results: The LFW mode shows better DQE at low air kerma (K{sub a} < 10 μGy) and should be used for DBT. At current DBT applications, air kerma (K{sub a} ∼ 10 μGy, broadband radiation of 28 kVp), DQE of more than 0.7 and ∼0.3 was achieved using the LFW mode at spatial frequency of 0.5 line pairs per millimeter (lp/mm) and Nyquist frequency ∼6.7 lp/mm, respectively. It is shown that microcalcifications of 165–400 μm in size can be resolved using a MGD range of 0.3–1 mGy, respectively. In comparison to a General Electric GEN2 prototype DBT system (at

  10. Lead iodide films as X-ray sensors tested in the mammography energy region

    International Nuclear Information System (INIS)

    We present an alternative method for the deposition of thin films of lead iodide (PbI2), which is a promising semiconductor candidate for applications in medical digital radiography. The spray pyrolysis technique enables the fabrication of thick films with a deposition rate of about 3.3 As-1. We investigate the influence of the main deposition parameters on the final properties of the films. They were substrate temperature from 150 up to 270 oC and nozzle-spray distance to substrate from 13.0 to 16.5 cm. The films were mainly investigated using X-ray diffraction (XRD), Atomic Force Microscopy (AFM), and Photoluminescence (PL) spectroscopy. Also, electrical characterizations were made in the dark as a function of temperature, and with the samples submitted to X-ray exposures in the energy range of mammography diagnosis

  11. Evaluation of a SOI pixel sensor with thick depletion layer for future X-ray astronomical missions

    Science.gov (United States)

    Nakashima, Shinya; Ryu, Sykyo Gando; Tsuru, Takeshi Go; Takeda, Ayaki; Arai, Yasuo; Miyoshi, Toshinobu; Ichimiya, Ryo; Ikemoto, Yukiko; Imamura, Toshifumi; Ohmoto, Takafumi; Iwata, Atsushi

    2012-03-01

    We report on the evaluation test of our novel pixel sensor named "XRPIX1-FZ" which is developed for the future X-ray astronomy mission. The mean gain of XRPIX1-FZ is 3.3 µV/e. and the dispersion of the gain among the pixels is 1% in the standard deviation. We confirmed the energy resolution of 260 eV in FWHM at 8 keV. We achieved the full depletion (250 µm) at 30 V back bias voltage.

  12. Development and characterization of the latest X-ray SOI pixel sensor for a future astronomical mission

    Science.gov (United States)

    Nakashima, Shinya; Gando Ryu, Syukyo; Tanaka, Takaaki; Go Tsuru, Takeshi; Takeda, Ayaki; Arai, Yasuo; Imamura, Toshifumi; Ohmoto, Takafumi; Iwata, Atsushi

    2013-12-01

    We have been developing active pixel sensors based on silicon-on-insulator technology for future X-ray astronomy missions. Recently we fabricated the new prototype named “XRPIX2”, and investigated its spectroscopic performance. For comparison and evaluation of different chip designs, XRPIX2 consists of 3 pixel types: Small Pixel, Large Pixel 1, and Large Pixel 2. In Small Pixel, we found that the gains of the 68% pixels are within 1.4% of the mean value, and the energy resolution is 656 eV (FWHM) for 8 keV X-rays, which is the best spectroscopic performance in our development. The pixel pitch of Large Pixel 1 and Large Pixel 2 is twice as large as that of Small Pixel. Charge sharing events are successfully reduced for Large Pixel 1. Moreover Large Pixel 2 has multiple nodes for charge collection in a pixel. We confirmed that the multi-nodes structure is effective to increase charge collection efficiency.

  13. X-ray microanalysis with transition edge sensors. The future of material analysis with scanning electron microscopes

    Energy Technology Data Exchange (ETDEWEB)

    Hollerith, C.

    2006-07-05

    In current experiments and technical applications the demand for new and advanced concepts for the detection of radiation and particle is increasing. Low temperature detectors such as Transition Edge Sensors (TES) have been developed as ultrahigh-resolution radiation and particle detectors offering advantages in manifold applications. They were designed primarily for astrophysical experiments such as the dark matter search. In material analysis they have been introduced to revolutionize mass spectroscopy of biological molecules and Energy Dispersive X-ray Spectroscopy (EDS). EDS is the determination of the elemental constitution of samples in scanning electron microscopes (SEMs) with characteristic X-ray radiation excited by the electron beam. The use of TES detectors improves the EDS analysis of small volumes such as particles or thin layers. This is especially important for the semiconductor industry because of the continual shrinking of device size. Current structure sizes of 65 nm are already demanding new approaches in analytic methodology. In this thesis the introduction and improvement of a fully automated TES detector system in the industrial environment of a semiconductor failure analysis lab is described. This system, marketed under the trade name of 'Polaris' by the manufacturer, is based on a mechanical pulse tube cooler in combination with an adiabatic demagnetization refrigerator (ADR) for cooling the TES detector to its operating temperature. Several large improvements had to be made to the system during the total system integration. The energy resolution could be improved significantly thus enabling a better peak separation and the measurement of chemical shifts. Due to the small area of TES detectors compared with conventional EDS detectors the efficiency of the system proved to be too low for everyday use. A polycapillary X-ray lens was added to the system in order to solve this problem. The application of the lens, however, brought its

  14. Design and First Tests of a Radiation-Hard Pixel Sensor for the European X-Ray Free-Electron Laser

    CERN Document Server

    Schwandt, Joern; Klanner, Robert; Kopsalis, Ioannis; Zhang, Jiaguo

    2014-01-01

    The high intensity and high repetition rate of the European X-ray Free-Electron Laser, presently under construction in Hamburg, requires silicon sensors which can stand X-ray doses of up to 1 GGy for 3 years of operation at high bias voltage. Within the AGIPD Collaboration the X-ray-radiation damage in MOS Capacitors and Gate-Controlled Diodes fabricated by four vendors on high-ohmic n-type silicon with two crystal orientations and dif- ferent technological parameters, has been studied for doses between 1 kGy and 1 GGy. The extracted values of oxide-charge and surface-current densi- ties have been used in TCAD simulations, and the layout and technological parameters of the AGIPD pixel sensor optimized. It is found that the op- timized layout for high X-ray doses is significantly different from the one for non-irradiated sensors. First sensors and test structures have been de-livered in early 2013. Measurement results for X-ray doses of 0 to 10 MGy and their comparison to simulations are presented. They demons...

  15. Flexible Gd2O2S:Tb scintillators pixelated with polyethylene microstructures for digital x-ray image sensors

    International Nuclear Information System (INIS)

    Flexible scintillators for digital x-ray image sensors were designed, fabricated and characterized. In these scintillaotrs, terbium-doped gadolinium oxysulfide (Gd2O2S:Tb) scintillator pixels were embedded into a polyethylene (PE) substrate. To evaluate the difference in the spatial resolution according to the pixel size, we designed three scintillators with pixels of different pitch sizes: 50 µm pitch size (P50), 100 µm pitch size (P100) and 200 µm pitch size (P200). Because of the high flexibility and good formability, polyethylene was used as the substrate of the scintillator. To fabricate nickel micromolds with high-aspect-ratio microstructures, two microfabrication techniques were employed: silicon dry-etching using a deep reactive ion etching (DRIE) process and nickel electroforming. The pixelated PE microstructures were fabricated by a hot embossing process. Because the solution-type Gd2O2S:Tb precursor can be handled at room temperature, Gd2O2S:Tb was used as the scintillator material. The measured sensitivities of the P50 and P100 models were, respectively, about 65% and 97% of that of the P200 model. The lower sensitivity values of the models with a small pitch size were due to two factors, such as the different pixel heights and the different fill factors. Because a scintillator with a small pixel size has a low fill factor, the sensitivity of the scintillator decreases as the pixel size decreases. The fill factors of the P50, P100 and P200 models were 36%, 49% and 56.25%, respectively. On the other hand, the spatial resolution of the scintillator increases as the pixel size decreases. Therefore, P50 gave the best spatial resolution among the designed models. The spatial frequency at 10% of the modulation transfer function (MTF) with P50 was 13.5 mm−1, while that with P200 was 10.0 mm−1. The resolution pattern and the tooth x-ray images obtained from a scintillator with a smaller pixel size was also clearer than that obtained from a scintillator

  16. Fine pitch transition-edge sensor X-ray microcalorimeters with sub-eV energy resolution at 1.5 keV

    Science.gov (United States)

    Lee, S. J.; Adams, J. S.; Bandler, S. R.; Chervenak, J. A.; Eckart, M. E.; Finkbeiner, F. M.; Kelley, R. L.; Kilbourne, C. A.; Porter, F. S.; Sadleir, J. E.; Smith, S. J.; Wassell, E. J.

    2015-11-01

    We are developing arrays of X-ray microcalorimeters on a 50-µm pitch that utilize transition-edge sensors as the sensor to measure the temperature rise when X-rays are absorbed. An array of this type of pixel has great potential for the study of point sources in future X-ray observatory missions. The pixels have gold absorbers with dimensions 45 × 45 × 4.2 µm3. We measured an energy resolution of 0.72 ± 0.03 eV full width at half maximum for the Al Kα complex in a subset of pixels within the array, which is the best resolution to date using a non-dispersive detector at this energy. We describe our characterization of this device including measurements of the heat capacity, thermal conductance to the heat bath, and the temperature and current sensitivity of the detector, and discuss its potential for improved performance.

  17. The solar irradiance registered at a flat- hemispherical field of view- bolometric oscillation sensor on board PICARD satellite

    Science.gov (United States)

    Zhu, Ping; Karatekin, Ozgur; van Ruymbeke, Michel; Dewitte, Steven; Thuillier, Gerard

    2014-05-01

    The value of the Total Solar Irradiance (TSI) is varying over the 11-year sunspot cycle. The cycle amplitude is about 0.1% solar constant, which could be traced with the absolute radiometers onboard dedicated space missions. The operating principle of the absolute radiometer is measuring the electrical heating power of the heat sensing unit during the closed and opened phase of each measurement cycle. The difference between the power integrated cross the closed phase and the power integrated cross the open phase gives the value of the solar irradiance. The cadence of the measurement is usually from one to several minutes. The final TSI value in physics unit is obtained after taking into account the electronic calibration, correction of the instruments effects, and normalizing to 1 AU. The Bolometric Oscillation Sensor on board PICARD microsatellite is a new designed remote sensing instrument. The BOS is operated continually with a 10 seconds cadence to fill the time gaps between open and close phases of the SOVAP absolute radiometer. The BOS has two sensing surfaces, the main one with a light mass is black coated, the second surface is white painted with a heavier mass. The sensor has a hemispherical field of view. The heat flux absorbed by the main detector is thermally conducted by a thin shunt to the heat sink. The principle of the measurements is that the sum of the power of the blacked coated surface and the power along the shunt is equal to the incoming electromagnetic radiation. However as the BOS has a HFOV, the incoming radiation caught by it, has three kinds of origin: the solar irradiance, the reflected solar visible light form the Earth and the terrestrial infrared radiation. In this work, we are going to discuss the solar irradiance isolated from the measurements of the BOS instrument as well as the comparison with the sunspot number and the TSI composite from the VIRGO/SOHO and TIM/SORCE experiments.

  18. High-contrast X-ray radiography using hybrid semiconductor pixel detectors with 1 mm thick Si sensor as a tool for monitoring liquids in natural building stones

    International Nuclear Information System (INIS)

    For the preservation of buildings and other cultural heritage, the application of various conservation products such as consolidants or water repellents is often used. X-ray radiography utilizing semiconductor particle-counting detectors stands out as a promising tool in research of consolidants inside natural building stones. However, a clear visualization of consolidation products is often accomplished by doping with a contrast agent, which presents a limitation. This approach causes a higher attenuation for X-rays, but also alters the penetration ability of the original consolidation product. In this contribution, we focus on the application of Medipix type detectors newly equipped with a 1 mm thick Si sensor. This thicker sensor has enhanced detection efficiency leading to extraordinary sensitivity for monitoring consolidants and liquids in natural building stones even without any contrast agent. Consequently, methods for the direct monitoring of organosilicon consolidants and dynamic visualization of the water uptake in the Opuka stone using high-contrast X-ray radiography are demonstrated. The presented work demonstrates a significant improvement in the monitoring sensitivity of X-ray radiography in stone consolidation studies and also shows advantages of this detector configuration for X-ray radiography in general

  19. Phase-sensitive X-ray imager

    Science.gov (United States)

    Baker, Kevin Louis

    2013-01-08

    X-ray phase sensitive wave-front sensor techniques are detailed that are capable of measuring the entire two-dimensional x-ray electric field, both the amplitude and phase, with a single measurement. These Hartmann sensing and 2-D Shear interferometry wave-front sensors do not require a temporally coherent source and are therefore compatible with x-ray tubes and also with laser-produced or x-pinch x-ray sources.

  20. Fabrication of transition edge sensor X-ray microcalorimeters for Constellation-X

    International Nuclear Information System (INIS)

    NASA's Constellation-X (Con-X) mission is a driver for advancing low-temperature detector technologies, requiring 1000-pixel two-dimensional arrays with >95% filling fraction and quantum efficiency at 6 keV and better than 4 eV energy resolution for 1-10 keV photons. We describe a robust transition edge sensor fabrication process that can produce detector arrays with integrated absorbers approaching the specifications of Con-X. We address issues such as the methods of superconducting bilayer deposition, detector geometry definition, and absorber interface

  1. Fabrication of thin film x-ray sensor using particle-in-binder method for automatic exposure control in digital radiography

    International Nuclear Information System (INIS)

    An automatic exposure control (AEC) detector is a control device that ensures consistent x-ray image quality and limits patient exposure in digital radiography. Among several kinds of AEC detectors, solid-state sensors offer several advantages such as geometric efficiency due to small thickness, high sensitivity, fast reaction time, and excellent stability. Commercially, the use of single-crystal silicon sensors for AEC detector has grown over time, but is still severely limited by large-area production techniques and mechanically fragile properties. Therefore, our study focused on developing a method of fabricating solid-state sensors that do not suffer from these limitations. The particle-in-binder method was used to fabricate silicon dioxide-based photoconductor films. Because silicon dioxide has a low atomic number and a low work function, it is a suitable material for generating sufficient electron-hole pairs by incident x-rays as well as not negatively affect the image detector of the digital radiography. To verify the feasibility of the silicon dioxide film as an AEC detector, electrical properties such as x-ray transmission and x-ray linearity were measured and compared with those of a commercialized silicon film. Over 90% x-ray transmission was achieved using a 500 μ m silicon dioxide film, which is suitable for an AEC detector. Also, an error below 3% was obtained from both x-ray current and voltage linearity tests. The results of bending tests demonstrated the properties of the silicon dioxide film to be more mechanically strong and stable compared with the commercialized silicon film. These properties were a result of the use of binder materials, which resulted in the flexibility of the film

  2. Chromatic X-Ray imaging with a fine pitch CdTe sensor coupled to a large area photon counting pixel ASIC

    OpenAIRE

    Bellazzini, R.; Spandre, G.; Brez, A.; Minuti, M.; Pinchera, M.; Mozzo, P

    2012-01-01

    An innovative X-ray imaging sensor with intrinsic digital characteristics is presented. It is based on Chromatic Photon Counting technology. The detector is able to count individually the incident X-ray photons and to separate them according to their energy (two 'color' images per exposure). The energy selection occurs in real time and at radiographic imaging speed (GHz global counting rate). Photon counting, color mode and a very high spatial resolution (more than 10 l.p./mm at MTF50) allow ...

  3. Investigation of X-ray induced radiation damage at the Si-SiO2 interface of silicon sensors for the European XFEL

    CERN Document Server

    Zhang, Jiaguo; Klanner, Robert; Pintilie, Ioana; Schwandt, Joern; Turcato, Monica

    2012-01-01

    Experiments at the European X-ray Free Electron Laser (XFEL) require silicon pixel sensors which can withstand X-ray doses up to 1 GGy. For the investigation of X-ray radiation damage up to these high doses, MOS capacitors and gate-controlled diodes built on high resistivity n-doped silicon with crystal orientations and produced by two vendors, CiS and Hamamatsu, have been irradiated with 12 keV X-rays at the DESY DORIS III synchrotron light source. Using capacitance/conductance-voltage, current-voltage and thermal dielectric relaxation current measurements, the surface densities of oxide charges and interface traps at the Si-SiO2 interface, and the surface-current densities have been determined as function of dose. Results indicate that the dose dependence of the surface density of oxide charges and the surface-current density depend on the crystal orientation and producer. In addition, the influence of the voltage applied to the gates of the MOS capacitor and the gate-controlled diode during X-ray irradia...

  4. 50 μm pixel pitch wafer-scale CMOS active pixel sensor x-ray detector for digital breast tomosynthesis

    Science.gov (United States)

    Zhao, C.; Konstantinidis, A. C.; Zheng, Y.; Anaxagoras, T.; Speller, R. D.; Kanicki, J.

    2015-12-01

    Wafer-scale CMOS active pixel sensors (APSs) have been developed recently for x-ray imaging applications. The small pixel pitch and low noise are very promising properties for medical imaging applications such as digital breast tomosynthesis (DBT). In this work, we evaluated experimentally and through modeling the imaging properties of a 50 μm pixel pitch CMOS APS x-ray detector named DynAMITe (Dynamic Range Adjustable for Medical Imaging Technology). A modified cascaded system model was developed for CMOS APS x-ray detectors by taking into account the device nonlinear signal and noise properties. The imaging properties such as modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE) were extracted from both measurements and the nonlinear cascaded system analysis. The results show that the DynAMITe x-ray detector achieves a high spatial resolution of 10 mm-1 and a DQE of around 0.5 at spatial frequencies  CMOS APS x-ray detector, image aquisition geometry and image reconstruction techniques should be considered.

  5. Performance of Frequency Division Multiplexing Readout System for AC-Biased Transition-Edge Sensor X-ray Microcalorimeters

    Science.gov (United States)

    Yamamoto, R.; Sakai, K.; Takei, Y.; Yamasaki, N. Y.; Mitsuda, K.

    2014-08-01

    Frequency division multiplexing (FDM) is a promising approach to read out a large format transition-edge sensor (TES) array for future astrophysical missions. We constructed a four channel FDM readout system using baseband feedback in the MHz band. We demonstrated the principle of our FDM method with an actual TES array, a multiplexing SQUID and LC band-pass filters under 100 mK. The resonant frequencies of LC filters were consistent with the design value with an accuracy of better than 3 %. We successfully obtained X-ray pulses from two TESs simultaneously but the energy resolution was degraded to about 100 eV at 5.9 keV and crosstalk effects were observed. The origin of the crosstalk effects is investigated by modified setups. Based on comparative experiments and numerical calculations, we conclude that the non-linearity of the SQUID is the cause of some of the crosstalk effects. Unlike the regular crosstalk effect from the adjoining channels, the crosstalk effect due to non-linearity observed in this paper occurs in all channels. Solving these problems will help us to obtain FDM readout with sufficient energy resolution.

  6. Evaluation of mixed-signal noise effects in photon-counting X-ray image sensor readout circuits

    International Nuclear Information System (INIS)

    In readout electronics for photon-counting pixel detectors, the tight integration between analog and digital blocks causes the readout electronics to be sensitive to on-chip noise coupling. This noise coupling can result in faulty luminance values in grayscale X-ray images, or as color distortions in a color X-ray imaging system. An exploration of simulating noise coupling in readout circuits is presented which enables the discovery of sensitive blocks at as early a stage as possible, in order to avoid costly design iterations. The photon-counting readout system has been simulated for noise coupling in order to highlight the existing problems of noise coupling in X-ray imaging systems. The simulation results suggest that on-chip noise coupling should be considered and simulated in future readout electronics systems for X-ray detectors

  7. Integration of an amorphous silicon passive pixel sensor array with a lateral amorphous selenium detector for large area indirect conversion x-ray imaging applications

    Science.gov (United States)

    Wang, Kai; Yazdandoost, Mohammad Y.; Keshavarzi, Rasoul; Shin, Kyung-Wook; Hristovski, Christos; Abbaszadeh, Shiva; Chen, Feng; Majid, Shaikh Hasibul; Karim, Karim S.

    2011-03-01

    Previously, we reported on a single-pixel detector based on a lateral a-Se metal-semiconductor-metal structure, intended for indirect conversion X-ray imaging. This work is the continuous effort leading to the first prototype of an indirect conversion X-ray imaging sensor array utilizing lateral amorphous selenium. To replace a structurally-sophisticated vertical multilayer amorphous silicon photodiode, a lateral a-Se MSM photodetector is employed which can be easily integrated with an amorphous silicon thin film transistor passive pixel sensor array. In this work, both 2×2 macro-pixel and 32×32 micro-pixel arrays were fabricated and tested along with discussion of the results.

  8. Characterization of CdTe Sensors with Schottky Contacts Coupled to Charge-Integrating Pixel Array Detectors for X-Ray Science

    CERN Document Server

    Becker, Julian; Shanks, Katherine S; Philipp, Hugh T; Weiss, Joel T; Purohit, Prafull; Chamberlain, Darol; Ruff, Jacob P C; Gruner, Sol M

    2016-01-01

    Pixel Array Detectors (PADs) consist of an x-ray sensor layer bonded pixel-by-pixel to an underlying readout chip. This approach allows both the sensor and the custom pixel electronics to be tailored independently to best match the x-ray imaging requirements. Here we present characterizations of CdTe sensors hybridized with two different charge-integrating readout chips, the Keck PAD and the Mixed-Mode PAD (MM-PAD), both developed previously in our laboratory. The charge-integrating architecture of each of these PADs extends the instantaneous counting rate by many orders of magnitude beyond that obtainable with photon counting architectures. The Keck PAD chip consists of rapid, 8-frame, in-pixel storage elements with framing periods $<$150 ns. The second detector, the MM-PAD, has an extended dynamic range by utilizing an in-pixel overflow counter coupled with charge removal circuitry activated at each overflow. This allows the recording of signals from the single-photon level to tens of millions of x-rays/...

  9. Development of the next generation transition-edge sensor microcalorimeter X-ray detector for SEM-EDS analysis and its applications

    International Nuclear Information System (INIS)

    We have developed an energy dispersive X-ray spectrometer system for scanning electron microscope utilizing a transition-edge sensor (TES) microcalorimeter X-ray detector and mounted it on a FE-SEM (JSM-7000F). The microcalorimeter is composed of a gold (Au) X-ray absorber, a bilayer Au/Ti thermometer, a heat sink and a thermal isolation structure with a SiNx membrane. The operating temperature of 100-150 mK is obtained via a dilution refrigerator. The achieved energy resolution was 19 eV for Al Kα (1487 eV) at an acceleration voltage of 5 kV. When natural mineral (cosalite: Pb2Bi2S5) and alloy (Cu alloy containing both Ni and Zn) were analyzed using this system at an acceleration voltage of 5 kV, the S K, Pb M and Bi M lines in the former, and L lines of the Ni, Cu and Zn in the latter were clearly separated, respectively. These peaks were not discernable by a solid-state detector (SSD), owing to its low energy resolution. In addition, a single particle of natural particulate matter was successfully analyzed by this spectrometer at a low acceleration voltage. These results suggest that this system has high potential in applications for X-ray microanalysis of environmental materials. (author)

  10. Joint x-ray

    Science.gov (United States)

    X-ray - joint; Arthrography; Arthrogram ... x-ray technologist will help you position the joint to be x-rayed on the table. Once in place, pictures are taken. The joint may be moved into other positions for more ...

  11. 50 μm pixel pitch wafer-scale CMOS active pixel sensor x-ray detector for digital breast tomosynthesis

    International Nuclear Information System (INIS)

    Wafer-scale CMOS active pixel sensors (APSs) have been developed recently for x-ray imaging applications. The small pixel pitch and low noise are very promising properties for medical imaging applications such as digital breast tomosynthesis (DBT). In this work, we evaluated experimentally and through modeling the imaging properties of a 50 μm pixel pitch CMOS APS x-ray detector named DynAMITe (Dynamic Range Adjustable for Medical Imaging Technology). A modified cascaded system model was developed for CMOS APS x-ray detectors by taking into account the device nonlinear signal and noise properties. The imaging properties such as modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE) were extracted from both measurements and the nonlinear cascaded system analysis. The results show that the DynAMITe x-ray detector achieves a high spatial resolution of 10 mm−1 and a DQE of around 0.5 at spatial frequencies  <1 mm−1. In addition, the modeling results were used to calculate the image signal-to-noise ratio (SNRi) of microcalcifications at various mean glandular dose (MGD). For an average breast (5 cm thickness, 50% glandular fraction), 165 μm microcalcifications can be distinguished at a MGD of 27% lower than the clinical value (∼1.3 mGy). To detect 100 μm microcalcifications, further optimizations of the CMOS APS x-ray detector, image aquisition geometry and image reconstruction techniques should be considered. (paper)

  12. Response of a superconducting transition-edge sensor microcalorimeter with a mushroom-shaped absorber to L X-rays emitted by transuranium elements

    International Nuclear Information System (INIS)

    A four-pixel-array superconducting transition-edge sensor (TES) microcalorimeter with a mushroom-shaped absorber was fabricated for the energy dispersive spectroscopy performed on a transmission electron microscope. The TES consists of a bilayer of Au/Ti with either a 50-nm or 120-nm thickness. The absorber of 5.0 µm thick is made from a Au layer and its stem is deposited in the center of the TES surface. A Ta2O5 insulating layer of 100-nm thickness is inserted between the overhang region of the absorber and the TES surface. A selected pixel of the TES microcalorimeter was operated for the detection of Np L X-rays emitted from an 241Am source. A response of the TES microcalorimeter to L X-rays was obtained by analyzing detection signal pulses with using the optimal filter method. An energy resolution was obtained to be 33 eV of the full width at half maximum value at 17.751 keV of Np Lβ1 considering its natural width of 13.4 eV. Response to L X-rays emitted from a mixture source of 238Pu, 239Pu and 241Am was obtained by operating the selected pixel of the TES microcalorimeter. Major L X-ray peaks of progeny elements of α-decay of Pu and Am isotopes were clearly identified in the obtained energy spectrum. The experimental results demonstrated the separation of 241Am and plutonium isotopes by L X-ray spectroscopy. (author)

  13. Note: A disposable x-ray camera based on mass produced complementary metal-oxide-semiconductor sensors and single-board computers

    Science.gov (United States)

    Hoidn, Oliver R.; Seidler, Gerald T.

    2015-08-01

    We have integrated mass-produced commercial complementary metal-oxide-semiconductor (CMOS) image sensors and off-the-shelf single-board computers into an x-ray camera platform optimized for acquisition of x-ray spectra and radiographs at energies of 2-6 keV. The CMOS sensor and single-board computer are complemented by custom mounting and interface hardware that can be easily acquired from rapid prototyping services. For single-pixel detection events, i.e., events where the deposited energy from one photon is substantially localized in a single pixel, we establish ˜20% quantum efficiency at 2.6 keV with ˜190 eV resolution and a 100 kHz maximum detection rate. The detector platform's useful intrinsic energy resolution, 5-μm pixel size, ease of use, and obvious potential for parallelization make it a promising candidate for many applications at synchrotron facilities, in laser-heating plasma physics studies, and in laboratory-based x-ray spectrometry.

  14. Note: A disposable x-ray camera based on mass produced complementary metal-oxide-semiconductor sensors and single-board computers.

    Science.gov (United States)

    Hoidn, Oliver R; Seidler, Gerald T

    2015-08-01

    We have integrated mass-produced commercial complementary metal-oxide-semiconductor (CMOS) image sensors and off-the-shelf single-board computers into an x-ray camera platform optimized for acquisition of x-ray spectra and radiographs at energies of 2-6 keV. The CMOS sensor and single-board computer are complemented by custom mounting and interface hardware that can be easily acquired from rapid prototyping services. For single-pixel detection events, i.e., events where the deposited energy from one photon is substantially localized in a single pixel, we establish ∼20% quantum efficiency at 2.6 keV with ∼190 eV resolution and a 100 kHz maximum detection rate. The detector platform's useful intrinsic energy resolution, 5-μm pixel size, ease of use, and obvious potential for parallelization make it a promising candidate for many applications at synchrotron facilities, in laser-heating plasma physics studies, and in laboratory-based x-ray spectrometry. PMID:26329247

  15. Note: A disposable x-ray camera based on mass produced complementary metal-oxide-semiconductor sensors and single-board computers

    International Nuclear Information System (INIS)

    We have integrated mass-produced commercial complementary metal-oxide-semiconductor (CMOS) image sensors and off-the-shelf single-board computers into an x-ray camera platform optimized for acquisition of x-ray spectra and radiographs at energies of 2–6 keV. The CMOS sensor and single-board computer are complemented by custom mounting and interface hardware that can be easily acquired from rapid prototyping services. For single-pixel detection events, i.e., events where the deposited energy from one photon is substantially localized in a single pixel, we establish ∼20% quantum efficiency at 2.6 keV with ∼190 eV resolution and a 100 kHz maximum detection rate. The detector platform’s useful intrinsic energy resolution, 5-μm pixel size, ease of use, and obvious potential for parallelization make it a promising candidate for many applications at synchrotron facilities, in laser-heating plasma physics studies, and in laboratory-based x-ray spectrometry

  16. Note: A disposable x-ray camera based on mass produced complementary metal-oxide-semiconductor sensors and single-board computers

    Energy Technology Data Exchange (ETDEWEB)

    Hoidn, Oliver R.; Seidler, Gerald T., E-mail: seidler@uw.edu [Physics Department, University of Washington, Seattle, Washington 98195 (United States)

    2015-08-15

    We have integrated mass-produced commercial complementary metal-oxide-semiconductor (CMOS) image sensors and off-the-shelf single-board computers into an x-ray camera platform optimized for acquisition of x-ray spectra and radiographs at energies of 2–6 keV. The CMOS sensor and single-board computer are complemented by custom mounting and interface hardware that can be easily acquired from rapid prototyping services. For single-pixel detection events, i.e., events where the deposited energy from one photon is substantially localized in a single pixel, we establish ∼20% quantum efficiency at 2.6 keV with ∼190 eV resolution and a 100 kHz maximum detection rate. The detector platform’s useful intrinsic energy resolution, 5-μm pixel size, ease of use, and obvious potential for parallelization make it a promising candidate for many applications at synchrotron facilities, in laser-heating plasma physics studies, and in laboratory-based x-ray spectrometry.

  17. Chromatic X-Ray imaging with a fine pitch CdTe sensor coupled to a large area photon counting pixel ASIC

    CERN Document Server

    Bellazzini, R; Brez, A; Minuti, M; Pinchera, M; Mozzo, P

    2012-01-01

    An innovative X-ray imaging sensor with intrinsic digital characteristics is presented. It is based on Chromatic Photon Counting technology. The detector is able to count individually the incident X-ray photons and to separate them according to their energy (two 'color' images per exposure). The energy selection occurs in real time and at radiographic imaging speed (GHz global counting rate). Photon counting, color mode and a very high spatial resolution (more than 10 l.p./mm at MTF50) allow to obtain an optimal ratio between image quality and absorbed dose. The individual block of the imaging system is a two-side buttable semiconductor radiation detector made of a thin pixellated CdTe crystal (the sensor) coupled to a large area VLSI CMOS pixel ASIC. 1, 2, 4, 8 tile units have been built. The 8 tiles unit has 25cm x 2.5cm sensitive area. Results and images obtained from in depth testing of several configurations of the system are presented. The X-Ray imaging system is the technological platform of PIXIRAD Im...

  18. Chromatic X-ray imaging with a fine pitch CdTe sensor coupled to a large area photon counting pixel ASIC

    International Nuclear Information System (INIS)

    An innovative X-ray imaging sensor based on Chromatic Photon Counting technology with intrinsic digital characteristics is presented. The system counts individually the incident X-ray photons and selects them according to their energy to produce two color images per exposure. The energy selection occurs in real time and at radiographic imaging speed (GHz global counting rate). Photon counting, color mode and a very fine spatial resolution (more than 10 LP/mm at MTF50) allow to obtain a high ratio between image quality and absorbed dose. The individual building block of the imaging system is a two-side buttable semiconductor radiation detector made of a thin pixellated CdTe crystal coupled to a large area VLSI CMOS pixel ASIC. Modules with 1, 2, 4, and 8 block units have been built. The largest module has 25 × 2.5 cm2 sensitive area. Results and images obtained from testing different modules are presented.

  19. The Dexela 2923 CMOS X-ray detector: A flat panel detector based on CMOS active pixel sensors for medical imaging applications

    International Nuclear Information System (INIS)

    Complementary metal-oxide-semiconductors (CMOS) active pixel sensors (APS) have been introduced recently in many scientific applications. This work reports on the performance (in terms of signal and noise transfer) of an X-ray detector that uses a novel CMOS APS which was developed for medical X-ray imaging applications. For a full evaluation of the detector's performance, electro-optical and X-ray characterizations were carried out. The former included measuring read noise, full well capacity and dynamic range. The latter, which included measuring X-ray sensitivity, presampling modulation transfer function (pMTF), noise power spectrum (NPS) and the resulting detective quantum efficiency (DQE), was assessed under three beam qualities (28 kV, 50 kV (RQA3) and 70 kV (RQA5) using W/Al) all in accordance with the IEC standard. The detector features an in-pixel option for switching the full well capacity between two distinct modes, high full well (HFW) and low full well (LFW). Two structured CsI:Tl scintillators of different thickness (a “thin” one for high resolution and a thicker one for high light efficiency) were optically coupled to the sensor array to optimize the performance of the system for different medical applications. The electro-optical performance evaluation of the sensor results in relatively high read noise (∼360 e−), high full well capacity (∼1.5×106 e−) and wide dynamic range (∼73 dB) under HFW mode operation. When the LFW mode is used, the read noise is lower (∼165) at the expense of a reduced full well capacity (∼0.5×106 e−) and dynamic range (∼69 dB). The maximum DQE values at low frequencies (i.e. 0.5 lp/mm) are high for both HFW (0.69 for 28 kV, 0.71 for 50 kV and 0.75 for 70 kV) and LFW (0.69 for 28 kV and 0.7 for 50 kV) modes. The X-ray performance of the studied detector compares well to that of other mammography and general radiography systems, obtained under similar experimental conditions. This demonstrates the

  20. Chest x-ray

    Science.gov (United States)

    Chest radiography; Serial chest x-ray; X-ray - chest ... You stand in front of the x-ray machine. You will be told to hold your breath when the x-ray is taken. Two images are usually taken. You will ...

  1. Thoracic spine x-ray

    Science.gov (United States)

    Vertebral radiography; X-ray - spine; Thoracic x-ray; Spine x-ray; Thoracic spine films; Back films ... care provider's office. You will lie on the x-ray table in different positions. If the x-ray ...

  2. Chest X-Ray

    Medline Plus

    Full Text Available ... the most commonly performed x-ray exams and use a very small dose of ionizing radiation to ... to your health. While a chest x-ray use a tiny dose of ionizing radiation, the benefit ...

  3. Dental x-rays

    Science.gov (United States)

    X-ray - teeth; Radiograph - dental; Bitewings; Periapical film; Panoramic film ... dentist's office. There are many types of dental x-rays. Some are: Bitewing Periapical Palatal (also called occlusal) ...

  4. X-ray (image)

    Science.gov (United States)

    X-rays are a form of ionizing radiation that can penetrate the body to form an image on ... will be shades of gray depending on density. X-rays can provide information about obstructions, tumors, and other ...

  5. X-ray apparatus

    International Nuclear Information System (INIS)

    A diagnostic x-ray device, readily convertible between conventional radiographic and tomographic operating modes, is described. An improved drive system interconnects and drives the x-ray source and the imaging device through coordinated movements for tomography

  6. Bandwidth in bolometric interferometry

    CERN Document Server

    Charlassier, R; Hamilton, J -Ch; Kaplan, J; Malu, S

    2009-01-01

    Bolometric Interferometry is a technology currently under development that will be first dedicated to the detection of B-mode polarization fluctuations in the Cosmic Microwave Background. A bolometric interferometer will have to take advantage of the wide spectral detection band of its bolometers in order to be competitive with imaging experiments. A crucial concern is that interferometers are presumed to be importantly affected by a spoiling effect known as bandwidth smearing. In this paper, we investigate how the bandwidth modifies the work principle of a bolometric interferometer and how it affects its sensitivity to the CMB angular power spectra. We obtain analytical expressions for the broadband visibilities measured by broadband heterodyne and bolometric interferometers. We investigate how the visibilities must be reconstructed in a broadband bolometric interferometer and show that this critically depends on hardware properties of the modulation phase shifters. Using an angular power spectrum estimator ...

  7. Investigation of Toshiba 130nm CMOS process as a possible candidate for active silicon sensors in HEP and X-ray experiments

    International Nuclear Information System (INIS)

    Following the advances of commercial semiconductor manufacturing technologies there has recently been an increased interest within experimental physics community in applying CMOS manufacturing processes to developing active silicon sensors. Possibility of applying high voltage bias combined with high resistivity substrate allows for better depletion of sensor and therefore quicker and more efficient charge collection. One of processes that accommodates those features is Toshiba 130 nm CMOS technology (CMOS3E). Within our group a test chip was designed to examine the suitability of this technology for physics experiment (both for HEP and X-ray imaging). Design consisted of 4 pixel matrices with total of 12 different pixel flavors allowing for evaluation of various pixel geometries and architectures in terms of depletion depth, noise performance, charge collection efficiency, etc. During this talk initial outcome of this evaluation is presented, starting with brief introduction to technology itself, followed by results of TCAD simulations, description of final design and first measurements results.

  8. X-Rays

    Science.gov (United States)

    X-rays are a type of radiation called electromagnetic waves. X-ray imaging creates pictures of the inside of your ... different amounts of radiation. Calcium in bones absorbs x-rays the most, so bones look white. Fat and ...

  9. Chest X-Ray

    Medline Plus

    Full Text Available ... by: Image/Video Gallery Your radiologist explains chest x-ray. Transcript Welcome to Radiology Info dot org! Hello, ... you about chest radiography also known as chest x-rays. Chest x-rays are the most commonly performed ...

  10. X-Ray Imaging

    Science.gov (United States)

    ... Brain Surgery Imaging Clinical Trials Basics Patient Information X-Ray Imaging Print This Page X-ray imaging is perhaps the most familiar type of imaging. Images produced by X-rays are due to the different absorption rates of ...

  11. Amorphous In–Ga–Zn–O thin-film transistor active pixel sensor x-ray imager for digital breast tomosynthesis

    International Nuclear Information System (INIS)

    Purpose: The breast cancer detection rate for digital breast tomosynthesis (DBT) is limited by the x-ray image quality. The limiting Nyquist frequency for current DBT systems is around 5 lp/mm, while the fine image details contained in the high spatial frequency region (>5 lp/mm) are lost. Also today the tomosynthesis patient dose is high (0.67–3.52 mGy). To address current issues, in this paper, for the first time, a high-resolution low-dose organic photodetector/amorphous In–Ga–Zn–O thin-film transistor (a-IGZO TFT) active pixel sensor (APS) x-ray imager is proposed for next generation DBT systems. Methods: The indirect x-ray detector is based on a combination of a novel low-cost organic photodiode (OPD) and a cesium iodide-based (CsI:Tl) scintillator. The proposed APS x-ray imager overcomes the difficulty of weak signal detection, when small pixel size and low exposure conditions are used, by an on-pixel signal amplification with a significant charge gain. The electrical performance of a-IGZO TFT APS pixel circuit is investigated by SPICE simulation using modified Rensselaer Polytechnic Institute amorphous silicon (a-Si:H) TFT model. Finally, the noise, detective quantum efficiency (DQE), and resolvability of the complete system are modeled using the cascaded system formalism. Results: The result demonstrates that a large charge gain of 31–122 is achieved for the proposed high-mobility (5–20 cm2/V s) amorphous metal-oxide TFT APS. The charge gain is sufficient to eliminate the TFT thermal noise, flicker noise as well as the external readout circuit noise. Moreover, the low TFT (<10−13 A) and OPD (<10−8 A/cm2) leakage currents can further reduce the APS noise. Cascaded system analysis shows that the proposed APS imager with a 75 μm pixel pitch can effectively resolve the Nyquist frequency of 6.67 lp/mm, which can be further improved to ∼10 lp/mm if the pixel pitch is reduced to 50 μm. Moreover, the detector entrance exposure per

  12. Amorphous In–Ga–Zn–O thin-film transistor active pixel sensor x-ray imager for digital breast tomosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Chumin; Kanicki, Jerzy, E-mail: kanicki@eecs.umich.edu [Solid-State Electronic Laboratory, Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2014-09-15

    Purpose: The breast cancer detection rate for digital breast tomosynthesis (DBT) is limited by the x-ray image quality. The limiting Nyquist frequency for current DBT systems is around 5 lp/mm, while the fine image details contained in the high spatial frequency region (>5 lp/mm) are lost. Also today the tomosynthesis patient dose is high (0.67–3.52 mGy). To address current issues, in this paper, for the first time, a high-resolution low-dose organic photodetector/amorphous In–Ga–Zn–O thin-film transistor (a-IGZO TFT) active pixel sensor (APS) x-ray imager is proposed for next generation DBT systems. Methods: The indirect x-ray detector is based on a combination of a novel low-cost organic photodiode (OPD) and a cesium iodide-based (CsI:Tl) scintillator. The proposed APS x-ray imager overcomes the difficulty of weak signal detection, when small pixel size and low exposure conditions are used, by an on-pixel signal amplification with a significant charge gain. The electrical performance of a-IGZO TFT APS pixel circuit is investigated by SPICE simulation using modified Rensselaer Polytechnic Institute amorphous silicon (a-Si:H) TFT model. Finally, the noise, detective quantum efficiency (DQE), and resolvability of the complete system are modeled using the cascaded system formalism. Results: The result demonstrates that a large charge gain of 31–122 is achieved for the proposed high-mobility (5–20 cm{sup 2}/V s) amorphous metal-oxide TFT APS. The charge gain is sufficient to eliminate the TFT thermal noise, flicker noise as well as the external readout circuit noise. Moreover, the low TFT (<10{sup −13} A) and OPD (<10{sup −8} A/cm{sup 2}) leakage currents can further reduce the APS noise. Cascaded system analysis shows that the proposed APS imager with a 75 μm pixel pitch can effectively resolve the Nyquist frequency of 6.67 lp/mm, which can be further improved to ∼10 lp/mm if the pixel pitch is reduced to 50 μm. Moreover, the

  13. Bolometric Luminosity Correction of H2O Maser AGNs

    Indian Academy of Sciences (India)

    Q. Guo; J. S. Zhang; J. Wang

    2014-09-01

    For the H2O maser host AGN sample, we derived their bolometric luminosity corrections, based on their X-ray data and [O III] emission line luminosities. Our results for maser AGNs is comparable to that of non-maser AGNs.

  14. Eu-doped CsBr phosphor as a new optically-stimulable phosphor material for medical x-ray imaging sensor

    International Nuclear Information System (INIS)

    CsBr phosphor ceramics doped with different luminescence centres such as In2O3, Eu2O3, EuCl3, SmCl3, TbCl3, GdCl3 or NdCl3 as the candidate for a new optically-stimulable phosphor for medical X-ray imaging sensor were prepared using a conventional ceramic fabrication process. It was found that X-ray-irradiated Eu-doped CsBr (CsBr:Eu) exhibited intense optically stimulated luminescence (OSL). The peak wavelength of the OSL emission and stimulation spectra of CsBr:Eu phosphor ceramic sample were 450 and 690 nm, respectively. The dependence of OSL properties on the conditions of preparation of phosphor ceramic samples, such as Eu concentration, sintering temperature and sintering time, were studied. The optimum preparation conditions were also studied. It was found that the OSL intensity of CsBr:Eu phosphor ceramics fabricated under optimum preparation conditions is higher than that of commercially available imaging plates using BaFBr:Eu. (authors)

  15. Performance of a prototype 32×32 pixel indirect x-ray imager based on a lateral selenium passive pixel sensor

    Science.gov (United States)

    Keshavarzi, Rasoul; Wang, Kai; Yazdandoost, Mohammad Y.; Shin, Kyung-Wook; Chen, Feng; Majid, Shaikh Hasibul; Abbaszadeh, Shiva; Karim, Karim S.

    2012-03-01

    An interface has been developed to capture frames taken by X-ray array imagers up to 64×64 pixels. An application specific integrated circuit (ASIC) designed solely for X-ray flat panel imaging readout circuitry, manufactured by FLIR® called Indigo (also known as ISC9717), was used as part of charge-amplifier block. An Altera Cyclone II FPGA is used to serve three purposes: Create pulses required for gate-driver block, Receive fast-stream data coming from the Indigo chip, and Send data through RS-232 protocol over a serial cable to a personal computer. Initial results for a 32×32 passive pixel sensor (PPS) with lateral amorphous Selenium metal-semiconductor-metal (MSM) photodetector were presented in [1]. This work focuses more on methods used to improve the images obtained from the array. Sharper images produced in sync with the light source are presented. In addition, insight into array readout circuitry and capturing a frame from an array is discussed.

  16. Thin film growth of Cd{sub 1-x}Zn{sub x}Te and its application to X-ray sensor

    Energy Technology Data Exchange (ETDEWEB)

    Mochizuki, K.; Takahashi, J.; Nakamura, N. [Department of Information Technology and Electronics, Ishinomaki-Senshu University, 1-Shinmito, Minami-sakai 986-0580 (Japan)

    2015-06-15

    Cd{sub 1-x}Zn{sub x}Te (x∝0.5) thin films with less than 300μm are grown on ITO/glass substrate by Hot-wall and PVT methods, one of the sublimation methods. In order to obtain the films with high resistivity and good quality for X-ray sensor, three attempts have been tried in the experiments. The one is stoichiometry control of CZT (x = 0.04) films, which were grown under controlled Cd vapor pressure. The second is excess chlorine doping to the films (x = 0.04) by controlling CdCl{sub 2} vapor pressure during growth process. The third is to change composition x = 0.04-0.50, which increases band gap. Through these methods, best films with good X-ray response was obtained for the third case of the films with the composition x = 0.20. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. X-Ray Polarimetry

    OpenAIRE

    Kaaret, Philip

    2014-01-01

    We review the basic principles of X-ray polarimetry and current detector technologies based on the photoelectric effect, Bragg reflection, and Compton scattering. Recent technological advances in high-spatial-resolution gas-filled X-ray detectors have enabled efficient polarimeters exploiting the photoelectric effect that hold great scientific promise for X-ray polarimetry in the 2-10 keV band. Advances in the fabrication of multilayer optics have made feasible the construction of broad-band ...

  18. Effect of Heat Treatment on Electrical Properties and Charge Collection Efficiency of X-Ray Sensors Based on Chrome-Compensated Gallium Arsenide

    Science.gov (United States)

    Zarubin, A. N.; Kolesnikova, I. I.; Lozinskaya, A. D.; Novikov, V. A.; Skakunov, M. S.; Tolbanov, O. P.; Tyazhev, A. V.; Shemeryankina, A. V.

    2016-06-01

    We present the results of experimental studies of the dependences of the specific resistance, charge collection efficiency, product of the mobility on the lifetime (μ×τ)n, and current-voltage characteristics on the heat treatment regimes of X-ray Me-GaAs:Cr-Me-sensors. Experimental samples were the pad-sensors with the area of 0.1-0.25 cm2 and sensitive-layer thickness in the range of 400-500 μm. The values of (μ×τ)n were evaluated by measuring the dependence of the charge collection efficiency on the bias voltage when exposed to gamma rays from the source of 241Am. It is shown that heat treatment in the temperature range 200-500°C does not lead to a significant degradation of properties of Me-GaAs:Cr-Me-sensors and can be used in the manufacturing technology of matrix detectors of ionizing radiation.

  19. X-ray photoelectron spectroscopic and electrochemical impedance spectroscopic analysis of RuO2-Ta2O5 thick film pH sensors.

    Science.gov (United States)

    Manjakkal, Libu; Cvejin, Katarina; Kulawik, Jan; Zaraska, Krzysztof; Socha, Robert P; Szwagierczak, Dorota

    2016-08-10

    The paper reports on investigation of the pH sensing mechanism of thick film RuO2-Ta2O5 sensors by using X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS). Interdigitated conductimetric pH sensors were screen printed on alumina substrates. The microstructure and elemental composition of the films were examined by scanning electron microscopy and energy dispersive spectroscopy. The XPS studies revealed the presence of Ru ions at different oxidation states and the surface hydroxylation of the sensing layer increasing with increasing pH. The EIS analysis carried out in the frequency range 10 Hz-2 MHz showed that the electrical parameters of the sensitive electrodes in the low frequency range were distinctly dependent on pH. The charge transfer and ionic exchange occurring at metal oxide-solution interface were indicated as processes responsible for the sensing mechanism of thick film RuO2-Ta2O5 pH sensors. PMID:27282750

  20. Image Quality Assessment of a CMOS/Gd2O2S:Pr,Ce,F X-Ray Sensor

    OpenAIRE

    Christos Michail

    2015-01-01

    The aim of the present study was to examine the image quality performance of a CMOS digital imaging optical sensor coupled to custom made gadolinium oxysulfide powder scintillators, doped with praseodymium, cerium, and fluorine (Gd2O2S:Pr,Ce,F). The screens, with coating thicknesses 35.7 and 71.2 mg/cm2, were prepared in our laboratory from Gd2O2S:Pr,Ce,F powder (Phosphor Technology, Ltd.) by sedimentation on silica substrates and were placed in direct contact with the optical sensor. Image q...

  1. X-ray interferometers

    International Nuclear Information System (INIS)

    An improved type of amplitude-division x-ray interferometer is described. The wavelength at which the interferometer can operate is variable, allowing the instrument to be used to measure x-ray wavelength, and the angle of inclination is variable for sample investigation. (U.K.)

  2. X-ray - skeleton

    Science.gov (United States)

    A skeletal x-ray is an imaging test used to look at the bones. It is used to detect fractures , tumors, or ... in the health care provider's office by an x-ray technologist. You will lie on a table or ...

  3. Extremity x-ray

    Science.gov (United States)

    An extremity x-ray is an image of the hands, wrist, feet, ankle, leg, thigh, forearm humerus or upper arm, hip, shoulder ... term "extremity" often refers to a human limb. X-rays are a form of radiation that passes through ...

  4. Dental x-rays

    Science.gov (United States)

    ... addition, many dentists are taking x-rays using digital technology. The image runs through a computer. The amount of radiation given off during the procedure is less than traditional methods. Other types of dental x-rays can create a 3-D picture ...

  5. Image Quality Assessment of a CMOS/Gd2O2S:Pr,Ce,F X-Ray Sensor

    Directory of Open Access Journals (Sweden)

    Christos Michail

    2015-01-01

    Full Text Available The aim of the present study was to examine the image quality performance of a CMOS digital imaging optical sensor coupled to custom made gadolinium oxysulfide powder scintillators, doped with praseodymium, cerium, and fluorine (Gd2O2S:Pr,Ce,F. The screens, with coating thicknesses 35.7 and 71.2 mg/cm2, were prepared in our laboratory from Gd2O2S:Pr,Ce,F powder (Phosphor Technology, Ltd. by sedimentation on silica substrates and were placed in direct contact with the optical sensor. Image quality was determined through single index (information capacity, IC and spatial frequency dependent parameters, by assessing the Modulation Transfer Function (MTF and the Normalized Noise Power Spectrum (NNPS. The MTF was measured using the slanted-edge method. The CMOS sensor/Gd2O2S:Pr,Ce,F screens combinations were irradiated under the RQA-5 (IEC 62220-1 beam quality. The detector response function was linear for the exposure range under investigation. Under the general radiography conditions, both Gd2O2S:Pr,Ce,F screen/CMOS combinations exhibited moderate imaging properties, in terms of IC, with previously published scintillators, such as CsI:Tl, Gd2O2S:Tb, and Gd2O2S:Eu.

  6. Image Quality Assessment of a CMOS/Gd2O2S:Pr,Ce,F X-ray Sensor

    Science.gov (United States)

    Michail, C. M.; Seferis, I. E.; Sideras, T.; Valais, I. G.; Fountos, G. P.; Bakas, A.; Panayiotakis, G. S.; Kandarakis, I. S.

    2015-09-01

    The aim of the present study was to examine the image quality performance of a CMOS digital imaging optical sensor coupled to custom made gadolinium oxysulfide powder scintillators, doped with praseodymium, cerium and fluorine (Gd2O2S:Pr,Ce,F) screens. The screens, with coating thicknesses 35.7 and 71.2 mg/cm2, were prepared in our laboratory from Gd2O2S:Pr,Ce,F powder (Phosphor Technology, Ltd) by sedimentation on silica substrates and were placed in direct contact with the optical sensor. Image quality was determined through a single index image quality parameter (information capacity). The CMOS sensor/Gd2O2S:Pr,Ce,F screens combinations were irradiated under the RQA-5 (IEC 62220-1) beam quality. The detector response function was linear for the exposure range under investigation. Under the general radiography conditions, both Gd2O2S:Pr,Ce,F screen/CMOS combinations exhibited comparable overall imaging properties, in terms of the information capacity, to previously published scintillators, such as Gd2O2S:Eu.

  7. The color of X-rays: Spectral X-ray computed tomography using energy sensitive pixel detectors

    NARCIS (Netherlands)

    E.J. Schioppa

    2014-01-01

    Energy sensitive X-ray imaging detectors are produced by connecting a semiconductor sensor to a spectroscopic pixel readout chip. In this thesis, the applicability of such detectors to X-ray Computed Tomography (CT) is studied. A prototype Medipix based silicon detector is calibrated using X-ray flu

  8. X-ray crystallography

    Science.gov (United States)

    2001-01-01

    X-rays diffracted from a well-ordered protein crystal create sharp patterns of scattered light on film. A computer can use these patterns to generate a model of a protein molecule. To analyze the selected crystal, an X-ray crystallographer shines X-rays through the crystal. Unlike a single dental X-ray, which produces a shadow image of a tooth, these X-rays have to be taken many times from different angles to produce a pattern from the scattered light, a map of the intensity of the X-rays after they diffract through the crystal. The X-rays bounce off the electron clouds that form the outer structure of each atom. A flawed crystal will yield a blurry pattern; a well-ordered protein crystal yields a series of sharp diffraction patterns. From these patterns, researchers build an electron density map. With powerful computers and a lot of calculations, scientists can use the electron density patterns to determine the structure of the protein and make a computer-generated model of the structure. The models let researchers improve their understanding of how the protein functions. They also allow scientists to look for receptor sites and active areas that control a protein's function and role in the progress of diseases. From there, pharmaceutical researchers can design molecules that fit the active site, much like a key and lock, so that the protein is locked without affecting the rest of the body. This is called structure-based drug design.

  9. Analysis of noise characteristics for the active pixels in CMOS image sensors for X-ray imaging

    Science.gov (United States)

    Kim, Young Soo; Cho, Gyuseong; Bae, Jun-Hyung

    2006-09-01

    CMOS image sensors have poorer performance compared to conventional charge coupled devices (CCDs). Since CMOS Active Pixel Sensors (APSs) in general have higher temporal noise, higher dark current, smaller full well charge capacitance, and lower spectral response, they cannot provide the same wide dynamic range and superior signal to noise ratio as CCDs. In view of electronic noise, the main source for the CMOS APS is the pixel, along with other signal processing blocks such as row and column decoder, analog signal processor (ASP), analog-to-digital converter (ADC), and timing and control logic circuitry. Therefore, it is important and necessary to characterize noise of the active pixels in CMOS APSs, and we performed experimental measurements and comparisons with theoretical estimations. To derive noise source of the pixels, we designed and fabricated four types of CMOS active pixels, and each pixel is composed of a photodiode and three MOS transistors. The size of these pixels is 100 μm×100 μm. The test chip was fabricated using ETRI 0.8 μm (2P/2M) standard CMOS process. It was found that the dominant noise in CMOS active pixels is shot noise during integration under normal operating conditions. And, it was also seen that epitaxial type pixels have similar noise level compared to non-epitaxial type, and the noise of diffusion type pixel is larger than for a well type pixel on the same substrate type.

  10. Analysis of noise characteristics for the active pixels in CMOS image sensors for X-ray imaging

    International Nuclear Information System (INIS)

    CMOS image sensors have poorer performance compared to conventional charge coupled devices (CCDs). Since CMOS Active Pixel Sensors (APSs) in general have higher temporal noise, higher dark current, smaller full well charge capacitance, and lower spectral response, they cannot provide the same wide dynamic range and superior signal to noise ratio as CCDs. In view of electronic noise, the main source for the CMOS APS is the pixel, along with other signal processing blocks such as row and column decoder, analog signal processor (ASP), analog-to-digital converter (ADC), and timing and control logic circuitry. Therefore, it is important and necessary to characterize noise of the active pixels in CMOS APSs, and we performed experimental measurements and comparisons with theoretical estimations. To derive noise source of the pixels, we designed and fabricated four types of CMOS active pixels, and each pixel is composed of a photodiode and three MOS transistors. The size of these pixels is 100 μmx100 μm. The test chip was fabricated using ETRI 0.8 μm (2P/2M) standard CMOS process. It was found that the dominant noise in CMOS active pixels is shot noise during integration under normal operating conditions. And, it was also seen that epitaxial type pixels have similar noise level compared to non-epitaxial type, and the noise of diffusion type pixel is larger than for a well type pixel on the same substrate type

  11. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small ... X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive medical ...

  12. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small dose ... limitations of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is ...

  13. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very ... of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive ...

  14. Lumbosacral spine x-ray

    Science.gov (United States)

    X-ray - lumbosacral spine; X-ray - lower spine ... The test is done in a hospital x-ray department or your health care provider's office by an x-ray technician. You will be asked to lie on the x-ray table ...

  15. Bone X-Ray (Radiography)

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very ... of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive ...

  16. Abdomen X-Ray (Radiography)

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Abdomen Abdominal x-ray uses a very ... of an abdominal x-ray? What is abdominal x-ray? An x-ray (radiograph) is a noninvasive medical ...

  17. X-ray apparatus

    International Nuclear Information System (INIS)

    A patient support system for X-ray equipment in arteriographic studies of the heart is described in detail. The support system has been designed to overcome many of the practical problems encountered in using previous types of arteriographic X-ray equipment. The support system is capable of horizontal movement and, by a series of shafts attached to the main support system, the X-ray source and image intensifier or detector may be rotated through the same angle. The system is highly flexible and details are given of several possible operational modes. (U.K.)

  18. X-ray lasers

    CERN Document Server

    Elton, Raymond C

    2012-01-01

    The first in its field, this book is both an introduction to x-ray lasers and a how-to guide for specialists. It provides new entrants and others interested in the field with a comprehensive overview and describes useful examples of analysis and experiments as background and guidance for researchers undertaking new laser designs. In one succinct volume, X-Ray Lasers collects the knowledge and experience gained in two decades of x-ray laser development and conveys the exciting challenges and possibilities still to come._Add on for longer version of blurb_M>The reader is first introduced

  19. X-Ray Diffraction.

    Science.gov (United States)

    Smith, D. K.; Smith, K. L.

    1980-01-01

    Reviews applications in research and analytical characterization of compounds and materials in the field of X-ray diffraction, emphasizing new developments in applications and instrumentation in both single crystal and powder diffraction. Cites 414 references. (CS)

  20. Medical X-Rays

    Science.gov (United States)

    ... The Conference of Radiation Control Program Directors (CRCPD) publishes Suggested State Regulations for the Control of Radiation , ... eSubmitter Guidance for Industry and Food and Drug Administration Staff - Assembler's Guide to Diagnostic X-Ray Equipment ...

  1. Chest X-Ray

    Medline Plus

    Full Text Available ... also be useful to help diagnose and monitor treatment for a variety of lung conditions such as pneumonia, emphysema and cancer. A chest x-ray requires no special preparation. ...

  2. Chest X-Ray

    Medline Plus

    Full Text Available ... However, it’s important to consider the likelihood of benefit to your health. While a chest x-ray use a tiny dose of ionizing radiation, the benefit of an accurate diagnosis far outweighs any risk. ...

  3. Chest X-Ray

    Medline Plus

    Full Text Available ... chest x-ray is used to evaluate the lungs, heart and chest wall and may be used ... diagnose and monitor treatment for a variety of lung conditions such as pneumonia, emphysema and cancer. A ...

  4. Chest X-Ray

    Medline Plus

    Full Text Available ... Angioplasty & vascular stenting Video: Arthrography Video: Contrast Material Radiology and You Take our survey About this Site ... radiologist explains chest x-ray. Transcript Welcome to Radiology Info dot org! Hello, I’m Dr. Geoffrey ...

  5. Chest X-Ray

    Medline Plus

    Full Text Available ... of ionizing radiation, the benefit of an accurate diagnosis far outweighs any risk. For more information about chest x-rays, visit Radiology Info dot org. Thank you for your time! ...

  6. Chest X-Ray

    Medline Plus

    Full Text Available ... Site Index A-Z Spotlight June is Men's Health Month Recently posted: Focused Ultrasound for Uterine Fibroids ... to consider the likelihood of benefit to your health. While a chest x-ray use a tiny ...

  7. X-ray tubes

    International Nuclear Information System (INIS)

    An improved form of x-ray tube is described which consists of a rotatable anode disc and an electron beam source enclosed in an envelope. The beam of electrons strikes the edge of the anode disc at an acute angle, producing x-rays which are transmitted through a window in the envelope. To improve performance and life of the anode disc it is additionally reciprocated back and forth along its axis of rotation. Dimensions are specified. (U.K.)

  8. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... around or in bones. top of page How should I prepare? Most bone x-rays require no ... might interfere with the x-ray images. Women should always inform their physician and x-ray technologist ...

  9. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... drawer under the table holds the x-ray film or image recording plate . Sometimes the x-ray ... extended over the patient while an x-ray film holder or image recording plate is placed beneath ...

  10. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... standards used by radiology professionals. Modern x-ray systems have very controlled x-ray beams and dose ...

  11. X-ray laser

    International Nuclear Information System (INIS)

    X-ray is among the most important research tools today, and has given priceless contributions to all disciplines within the natural sciences. State of the art in this field is called XFEL, X-ray Free Electron Laser, which may be 10 thousand million times stronger than the x-rays at the European Synchrotron Radiation Facility in Grenoble. In addition XFEL has properties that allow the study of processes which previously would have been impossible. Of special interest are depictions on atomic- and molecular level by the use of x-ray holographic methods, and being able to study chemical reactions in nature's own timescale, the femtosecond. Conclusion: The construction of x-ray lasers is a natural development in a scientific field which has an enormous influence on the surrounding society. While the discovery of x-ray was an important breakthrough in itself, new applications appear one after the other: Medical depiction, dissemination, diffraction, DNA and protein structures, synchrotron radiation and tomography. There is reason to believe that XFEL implies a technological leap as big as the synchrotrons some decades ago. As we are now talking about studies of femtosecond and direct depiction of chemical reactions, it is obvious that we are dealing with a revolution to come, with extensive consequences, both scientifically and culturally. (EW)

  12. Expected performance of the DEPFET sensor with signal compression: A large format X-ray imager with mega-frame readout capability for the European XFEL

    International Nuclear Information System (INIS)

    The new DSSC (DEPFET sensor with signal compression) detector system is being developed in order to fulfil the requirements of the future XFEL in Hamburg. The instrument will be able to record X-ray images with a maximum frame rate of 5 MHz and to achieve a high dynamic range. The system is based on a silicon pixel sensor with a new designed non-linear-DEPFET as a central amplifier structure. The detector chip is bump-bonded to mixed signal readout ASICs that provide full parallel readout and temporary data storage. The signals coming from the detector are processed by an analog filter, immediately digitized by 8-ENOB ADCs and locally stored in a custom designed memory. The ASICs are designed in 130 nm CMOS technology. During the time gap of 99 ms of the XFEL machine, the digital data are sent off the focal plane to a DAQ electronics that acts as an interface to the back-end of the whole instrument. The pixel sensor has been designed so as to combine high energy resolution at low signal charge with high dynamic range. This has been motivated by the desire to be able to be sensitive to single low energy photons and, at the same time, to measure at other positions of the detector signals corresponding to up to 104 photons of 1 keV. In order to fit this dynamic range into a reasonable output signal swing, achieving at the same time single photon resolution, a strongly non-linear characteristic is required. The new proposed DEPFET provides the required dynamic range compression at the sensor level, considerably facilitating the task of the electronics. At the same time the DEPFET charge handling capacitance is enormously increased with respect to standard DEPFETs. The sensor matrix will comprise 1024x1024 pixels of hexagonal shape with a side-length of 136μm. The simultaneous implementation of the 5 MHz frame rate, of the single low-energy photon resolution and of the high dynamic range goes beyond all the existing instruments and requires the development of new

  13. Crystallization and preliminary X-ray crystallographic studies of the oxidative-stress sensor SoxR and its complex with DNA

    International Nuclear Information System (INIS)

    The crystallization and preliminary X-ray analysis of SoxR from E. coli and its complex with DNA are reported. SoxR, a member of the MerR family of transcriptional activators, functions as a sensor of oxidative stress. The redox states of the 2Fe–2S cluster of SoxR regulate the activity of SoxR. Here, the crystallization and preliminary crystallographic analysis of SoxR and its complex with DNA are reported. Crystals of SoxR were obtained using PEG 10 000 and glycerol as precipitants. The crystals of SoxR belong to space group P62 or P64, with unit-cell parameters a = b = 80.0, c = 88.1 Å. Crystals of the SoxR–DNA complex were obtained using a 20 bp DNA fragment from a condition containing PEG 10 000 and sodium/potassium tartrate. The crystals of the SoxR–DNA complex belong to space group P6122 or P6522, with unit-cell parameters a = b = 53.5, c = 355.6 Å. Diffraction data were collected to a maximum resolution of 3.2 and 2.7 Å for SoxR and the SoxR–DNA complex, respectively

  14. Automatic focus algorithms for TDI X-Ray image reconstruction

    OpenAIRE

    Dörr, J; Rosenbaum, M.; Sauer-Greff, W.; Urbansky, R.

    2012-01-01

    In food industry, most products are checked by X-rays for contaminations. These X-ray machines continuously scan the product passing through. To minimize the required X-ray power, a Time, Delay and Integration (TDI) CCD-sensor is used to capture the image. While the product moves across the sensor area, the X-ray angle changes during the pass. As a countermeasure, adjusting the sensor shift speed on a single focal plane of the product can be selected. However, the changing a...

  15. X-ray nanotomography

    Science.gov (United States)

    Sasov, Alexander

    2004-10-01

    A compact laboratory x-ray "nano-CT" scanner has been created for 3D non-invasive imaging with 150-200 nanometers 3D spatial resolution, using advanced x-ray technologies and specific physical phenomena for signal detection. This spatial resolution in volume terms is 3 orders better than can be achieved in synchrotron tomography, 5 orders better then in existing laboratory micro-CT instruments and 10-12 orders better in comparison to clinical CT. The instrument employs an x-ray source with a 300-400nm x-ray spot size and uses small-angle scattering to attain a detail detectability of 150-200nm. An object manipulator allows positioning and rotation with an accuracy of 150nm. The x-ray detector is based on an intensified CCD with single-photon sensitivity. A typical acquisition cycle for 3D reconstruction of the full object volume takes from 10 to 60 minutes, with the collection of several hundred angular views. Subsequent volumetric reconstruction produces results as a set of cross sections with isotropic voxel size down to 140 x 140 x 140nm, or as a 3D-model, which can be virtually manipulated and measured. This unique spatial resolution in non-invasive investigations gives previously unattainable 3D images in several application areas, such as composite materials, paper and wood microstructure, biomedical applications and others.

  16. X-ray Pulsars

    CERN Document Server

    Walter, Roland

    2016-01-01

    X-ray pulsars shine thanks to the conversion of the gravitational energy of accreted material to X-ray radiation. The accretion rate is modulated by geometrical and hydrodynamical effects in the stellar wind of the pulsar companions and/or by instabilities in accretion discs. Wind driven flows are highly unstable close to neutron stars and responsible for X-ray variability by factors $10^3$ on time scale of hours. Disk driven flows feature slower state transitions and quasi periodic oscillations related to orbital motion and precession or resonance. On shorter time scales, and closer to the surface of the neutron star, X-ray variability is dominated by the interactions of the accreting flow with the spinning magnetosphere. When the pulsar magnetic field is large, the flow is confined in a relatively narrow accretion column, whose geometrical properties drive the observed X-ray emission. In low magnetized systems, an increasing accretion rate allows the ignition of powerful explosive thermonuclear burning at t...

  17. X-ray astronomy

    International Nuclear Information System (INIS)

    This book contains the lectures, and the most important seminars held at the NATO meeting on X-Ray astronomy in Erice, July 1979. The meeting was an opportune forum to discuss the results of the first 8-months of operation of the X-ray satellite, HEAO-2 (Einstein Observatory) which was launched at the end of 1978. Besides surveying these results, the meeting covered extragalactic astronomy, including the relevant observations obtained in other portions of the electromagnetic spectrum (ultra-violet, optical, infrared and radio). The discussion on galactic X-ray sources essentially covered classical binaries, globular clusters and bursters and its significance to extragalactic sources and to high energy astrophysics was borne in mind. (orig.)

  18. Evolution of X-ray emission from young massive star clusters

    OpenAIRE

    Oskinova, L. M.

    2005-01-01

    The evolution of X-ray emission from young massive star clusters is modeled, taking into account the emission from the stars as well as from the cluster wind. It is shown that the level and character of the soft (0.2-10 keV) X-ray emission change drastically with cluster age and are tightly linked with stellar evolution. Using the modern X-ray observations of massive stars we show that the correlation between bolometric and X-ray luminosity known for single O stars also holds for O+O and O+Wo...

  19. CRL X-RAY TUBE

    OpenAIRE

    Kolchevsky, N. N.; Petrov, P. V.

    2015-01-01

    A novel types of X-ray tubes with refractive lenses are proposed. CRL-R X-ray tube consists of Compound Refractive Lens- CRL and Reflection X-ray tube. CRL acts as X-ray window. CRL-T X-ray consists of CRL and Transmission X-ray tube. CRL acts as target for electron beam. CRL refractive lens acts as filter, collimator, waveguide and focusing lens. Properties and construction of the CRL X-ray tube are discussed.

  20. AGN dust tori: the X-ray-infrared connection

    CERN Document Server

    Rowan-Robinson, Michael; Nandra, Kirpal

    2009-01-01

    We have combined the CLASX Chandra survey in Lockman with the Spitzer SWIRE survey data to study the X-ray-infrared connection for AGN. The sample consists of 401 X-ray-sources, of which 306 are detected by Spitzer, and a further 257 AGN candidates detected through their dust torus, but not by Chandra. For X-ray sources the X-ray hardness ratio has been modelled in terms of a power-law with absorption N(H). The optical and infrared data have been modelled in terms of our well-established optical galaxy and QSO templates, and infrared templates based on radiative transfer models. Our estimate of the N(H) distribution is consistent with other studies, but we do find a higher proportion of low absorption objects at z 0.5. While we find only one X-ray AGN with N(H) > 10^{24} cm^{-2}, we argue that 10 objects with torus luminosity apparently exceeding the bolometric X-ray to 3 \\mu m luminosity are strong candidates for being heavily absorbed in X-rays. We also estimate that at least half of the infrared-detected ...

  1. Crystallization and preliminary X-ray crystallographic analysis of Ca2+-free primary Ca2+-sensor of Na+/Ca2+ exchanger

    International Nuclear Information System (INIS)

    The plasma-membrane Na+/Ca2+ exchanger (NCX) regulates intracellular Ca2+ levels in cardiac myocytes. Two Ca2+-binding domains (CBD1 and CBD2) exist in the large cytosolic loop of NCX. Recombinant CBD1 (NCX1 372–508) with a molecular weight of 16 kDa has been crystallized by the sitting-drop vapour-diffusion method at 293 K. The plasma-membrane Na+/Ca2+ exchanger (NCX) regulates intracellular Ca2+ levels in cardiac myocytes. Two Ca2+-binding domains (CBD1 and CBD2) exist in the large cytosolic loop of NCX. The binding of Ca2+ to CBD1 results in conformational changes that stimulate exchange to exclude Ca2+ ions, whereas CBD2 maintains the structure, suggesting that CBD1 is the primary Ca2+-sensor. In order to clarify the structural scaffold for the Ca2+-induced conformational transition of CBD1 at the atomic level, X-ray structural analysis of its Ca2+-free form was attempted; the structure of the Ca2+-bound form is already available. Recombinant CBD1 (NCX1 372–508) with a molecular weight of 16 kDa was crystallized by the sitting-drop vapour-diffusion method at 293 K. The crystals belonged to the hexagonal space group P6222 or P6422, with unit-cell parameters a = b = 56.99, c = 153.86 Å, β = 120°, and contained one molecule per asymmetric unit (VM = 2.25 Å3 Da−1) with a solvent content of about 55% (VS = 45.57%). Diffraction data were collected within the resolution range 27.72–3.00 Å using an R-AXIS detector and gave a data set with an overall Rmerge of 10.8% and a completeness of 92.8%

  2. Crystallization and preliminary X-ray analysis of a putative sensor histidine kinase domain: the C-­terminal domain of HksP4 from Aquifex aeolicus VF5

    OpenAIRE

    Horita, Shoichiro; Yamanaka, Yosuke; Yamamura, Akihiro; Okada, Akitoshi; Nakayama, Jiro; Nagata, Koji; Tanokura, Masaru

    2011-01-01

    The putative sensor histidine kinase domain of the cytoplasmic protein HksP4 from the hyperthermophilic bacterium A. aeolicus VF5 was expressed, purified and crystallized by the sitting-drop vapour-diffusion method. Crystals were obtained in the presence of ATP and AMPPNP; they were found to belong to the same space group P212121 and diffracted X-rays to 3.1 and 2.9 Å resolution, respectively.

  3. X-ray astronomical spectroscopy

    Science.gov (United States)

    Holt, Stephen S.

    1987-01-01

    The contributions of the Goddard group to the history of X-ray astronomy are numerous and varied. One role that the group has continued to play involves the pursuit of techniques for the measurement and interpretation of the X-ray spectra of cosmic sources. The latest development is the selection of the X-ray microcalorimeter for the Advanced X-ray Astrophysics Facility (AXAF) study payload. This technology is likely to revolutionize the study of cosmic X-ray spectra.

  4. X-ray properties of BzK-selected galaxies in the deepest X-ray fields

    CERN Document Server

    Rangel, Cyprian; Laird, Elise; Orange, Philip

    2012-01-01

    We investigate the X-ray properties of BzK-selected galaxies at z $\\sim$ 2 using deep X-ray data in the Chandra Deep Field South and North (CDFS and CDFN). Of these we directly detect in X-rays 49 sBzKs in CDFS and 32 sBzKs in CDFN. Stacking the undetected sources also reveals a significant X-ray signal. Investigating the X-ray detection rate and stacked flux versus the IR excess parameter (i.e. SFRtotal/SFRUV,corr), we find no strong evidence for an increased X-ray detection rate, or a harder X-ray spectrum in IR Excess sBzKs. This is particularly the case when one accounts for the strong correlation between the IR excess parameter and the bolometric IR luminosity (LIR), e.g. when controlling for LIR, the IR Non-Excess sBzKs show a detection rate at least as high. While both direct detections and stacking suggest that the AGN fraction in sBzK galaxies is high, there is no clear evidence for widespread Compton thick activity in either the sBzK population generally, or the IR Excess sBzK subsample. The very ha...

  5. ISO investigates the nature of extremely-red hard X-ray sources responsible for the X-ray background

    CERN Document Server

    Franceschini, A; Césarsky, C J; Elbaz, D; Flores, H; Granato, G L; Franceschini, Alberto; Fadda, Dario; Cesarsky, Catherine; Elbaz, David; Flores, Hector; Granato, Gian Luigi

    2001-01-01

    We analyse very deep X-ray and mid-IR surveys in common areas of the Lockman Hole and the HDF North to study the sources of the X-ray background (XRB) and to test the standard obscured accretion paradigm. We detect with ISO a rich population of X-ray luminous sources with red optical colours, including a fraction identified with Extremely Red Objects (R-K > 5) and galaxies with SEDs typical of normal massive ellipticals or spirals at z ~ 1. The high 0.5-10 keV X-ray luminosities of these objects (1E43-1E45 erg/s) indicate that the ultimate energy source is gravitational accretion, while the X-ray to IR flux ratios and the X-ray spectral hardness show evidence of photoelectric absorption at low X-ray energies. An important hint on the physics comes from the mid-IR data at 6.7 and 15 um, well reproduced by model spectra of completely obscured quasars under standard assumptions and l.o.s. optical depths tau ~ 30-40. Other predictions of the standard XRB picture, like the distributions of intrinsic bolometric lum...

  6. X-ray apparatus

    International Nuclear Information System (INIS)

    The invention discloses an X-ray apparatus that can be used for tomography with the aid of a computer. With this apparatus plus computer, it is possible to quickly achieve the required edge values whereby the influence of the movement is diminished

  7. Chest X-Ray

    Medline Plus

    Full Text Available ... Pediatric Ultrasound Video: Angioplasty & vascular stenting Video: Arthrography Radiology and You About this Site RadiologyInfo.org is ... radiologist explains chest x-ray. Transcript Welcome to Radiology Info dot org! Hello, I’m Dr. Geoffrey ...

  8. Medical x-ray

    International Nuclear Information System (INIS)

    This book describes the fundamental subject about medical radiography. It is a multidisciplinary field that requires cross professional input from scientists, engineers and medical doctors. However, it is presented in simple language to suit different levels of readers from x-ray operators and radiographers to physists, general practitioners and radiology specialists.The book is written in accordance to the requirements of the standard syllabus approved by the Ministry of Health Malaysia for the training of medical x-ray operator and general practitioners. In general, the content is not only designed to provide relevant and essential subject for related professionals in medical radiological services such as x-ray operator, radiographer and radiologists, but also to address those in associated radiological services including nurses, medical technologists and physicists.The book is organized and arranged sequentially into 3 parts for easy reference: Radiation safety; X-ray equipment and associated facilities; Radiography practices. With proper grasping of all these parts, the radiological services could be provided with confident and the highest professional standard. Thus, medical imaging with highest quality that can provide useful diagnostic information at minimum doses and at cost effective could be assured

  9. Chest X-Ray

    Medline Plus

    Full Text Available ... this Site RadiologyInfo.org is produced by: Image/Video Gallery Your radiologist explains chest x-ray. Transcript ... Recently posted: Focused Ultrasound for Uterine Fibroids Dementia Video: General Ultrasound Video: Pediatric Nuclear Medicine Radiology and ...

  10. Chest X-Ray

    Medline Plus

    Full Text Available ... this Site RadiologyInfo.org is produced by: Image/Video Gallery Your radiologist explains chest x-ray. Transcript ... time! Spotlight Recently posted: Pediatric MRI Intravascular Ultrasound Video: Chest CT Video:Thyroid Ultrasound Video: Head CT ...

  11. Pyroelectric x-ray detectors and x-ray pyrometers

    International Nuclear Information System (INIS)

    This paper discusses pyroelectric detectors which are very promising x-ray detectors for intense pulsed x-ray/γ-ray measurements and can be used as x-ray pyrometers. They are fast, passive, and inherently flat in spectral response for low energy x-rays. The authors report tests of LiTaO3, Sr.5Ba.5Nb2O6 and LiNbO3 detectors at Nova laser with 1 ns low energy x-rays and at Zapp Z-pinch machine with 100 ns x-rays. The temporal and spectral responses are discussed

  12. Pyroelectric x-ray detectors and x-ray pyrometers

    International Nuclear Information System (INIS)

    Pyroelectric detectors are very promising x-ray detectors for intense pulsed x-ray/γ-ray measurements and can be used as x-ray pyrometers. They are fast, passive, and inherently flat in spectral response for low-energy x rays. We report our tests of LiTaO3 detectors at Nova laser with 1-ns low-energy x rays and at Zapp Z-pinch machine with 100-ns x rays. The temporal and spectral responses are discussed

  13. X ray Production. Chapter 5

    International Nuclear Information System (INIS)

    The differential absorption of X rays in tissues and organs, owing to their atomic composition, is the basis for the various imaging methods used in diagnostic radiology. The principles in the production of X rays have remained the same since their discovery. However, much refinement has gone into the design of X ray tubes to achieve the performance required for today’s radiological examinations. In this chapter, an outline of the principles of X ray production and a characterization of the radiation output of X ray tubes will be given. The basic processes producing X rays are dealt with in Section 1.4

  14. X-ray microtomography

    International Nuclear Information System (INIS)

    In this paper the authors describe the application of a new high-resolution X-ray tomographic microscope to the study of porous media. The microscope was designed to exploit the properties of a synchrotron X-ray source to perform three dimensional tomography on millimeter sized objects with micron resolution and has been used in materials science studies with both synchrotron and conventional and synchrotron sources will be compared. In this work the authors have applied the microscope to measure the three dimensional structure of fused bead packs and berea sandstones with micron resolution and have performed preliminary studies of flow in these media with the microscope operated in a digital subtraction radiography mode. Computer graphics techniques have been applied to the data to visually display the structure of the pore body system. Tomographic imaging after flow experiments should detect the structure of the oil-water interface in the pore network and this work is ongoing

  15. X-ray generators

    International Nuclear Information System (INIS)

    Volume 4 provides a comparative survey on generators for stationary applications as available on the German market. It provides decision-making tools, physical characteristics, suggestions for radiation protection and for safe appliance operation as well as a concept for inspections all of which have been developed jointly by physicians of various specialities, physicists, engineers, business men, hospital experts and medicotechnical X-ray staff on the basis of a well-tried working concept. The systematic representation of correlations relevant to decision-making processes is based on a profile of technico-physical characteristics (standard product information) which was established by way of interdisciplinary dialog and which will enable any hospital or clinic to easily equip its X-ray department in an economic and purposeful way. The information on device data, device descriptions and market survey furnish the data tested by the manufacturers without guarantee and subject to correction. (orig./HP)

  16. X-ray lithography

    International Nuclear Information System (INIS)

    An invention relating to the development of photo-resists used in X-ray lithography is described. A COP resist which has been exposed to X-ray radiation, is developed with methyl ethyl ketone (MEK) developer and an ethanol solvent. The resist is first developed in a strong developing solution and then with a weaker developer whose concentration is slightly above that required to obtain complete development. Preferably the resist is exposed so as to obtain about a fifty per cent developed thickness and the developing is carried out in steps, the first with a concentration of 5:1.8 (MEK to ethanol) for five seconds, the second using concentrations of 5:1.8 and 5:2.7 for ten seconds and the third with a concentration of 5:2.7 for five seconds. (author)

  17. X-ray diffraction

    International Nuclear Information System (INIS)

    We have been interested in structural elucidation by x-ray diffraction of compounds of biological interest. Understanding exactly how atoms are arranged in three-dimensional arrays as molecules can help explain the relationship between structure and functions. The species investigated may vary in size and shape; our recent studies included such diverse substances as antischistosomal drugs, a complex of cadmium with nucleic acid base, nitrate salts of adenine, and proteins

  18. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... foot. top of page What are some common uses of the procedure? A bone x-ray is ... care is taken during x-ray examinations to use the lowest radiation dose possible while producing the ...

  19. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... top of page What are the benefits vs. risks? Benefits Bone x-rays are the fastest and ...

  20. Dental X-ray apparatus

    International Nuclear Information System (INIS)

    Intra-oral dental X-ray apparatus for panoramic radiography is described in detail. It comprises a tubular target carrier supporting at its distal end a target with an inclined forward face. Image definition is improved by positioning in the path of the X-rays a window of X-ray transmitting ceramic material, e.g. 90% oxide of Be, or Al, 7% Si02. The target carrier forms a probe which can be positioned in the patient's mouth. X-rays are directed forwardly and laterally of the target to an X-ray film positioned externally. The probe is provided with a detachable sleeve having V-form arms of X-ray opaque material which serve to depress the tongue out of the radiation path and also shield the roof of the mouth and other regions of the head from the X-ray pattern. A cylindrical lead shield defines the X-ray beam angle. (author)

  1. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... position possible that still ensures x-ray image quality. top of page Who interprets the results and ...

  2. Soft X-ray Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Seely, John

    1999-05-20

    The contents of this report cover the following: (1) design of the soft x-ray telescope; (2) fabrication and characterization of the soft x-ray telescope; and (3) experimental implementation at the OMEGA laser facility.

  3. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... and x-rays. A Word About Minimizing Radiation Exposure Special care is taken during x-ray examinations ... patient's body not being imaged receive minimal radiation exposure. top of page What are the limitations of ...

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... images for evaluation. National and international radiology protection organizations continually review and update the technique standards used by radiology professionals. Modern x-ray systems have very controlled x-ray beams and dose ...

  5. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... fracture. guide orthopedic surgery, such as spine repair/fusion, joint replacement and fracture reductions. look for injury, ... and Media Arthritis X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to X-ray ( ...

  6. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... As a result, bones appear white on the x-ray, soft tissue shows up in shades of gray and air appears black. Until recently, x-ray images were maintained on large film sheets (much ...

  7. Panoramic Dental X-Ray

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Panoramic Dental X-ray Panoramic dental x-ray uses a ... a large photographic negative). Today, most images are digital files that are stored electronically. These stored images ...

  8. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... that helps physicians diagnose and treat medical conditions. Imaging with x-rays involves exposing a part of ... oldest and most frequently used form of medical imaging. A bone x-ray makes images of any ...

  9. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... wrist, arm, elbow, shoulder, spine, pelvis, hip, thigh, knee, leg (shin), ankle or foot. top of page ... the patient standing upright, as in cases of knee x-rays. A portable x-ray machine is ...

  10. Fabrication and characterization of a 32 x 32 array digital Si-PIN X-ray detector for a single photon counting image sensor

    International Nuclear Information System (INIS)

    A Si-PIN X-ray detector for digital x-ray imaging with single photon counting capability has been fabricated and characterized. It consists of an array of 32 x 32 pixels with an area of 80 x 80 μm2. An extrinsic gettering process was performed to reduce the leakage current by removing the impurities and defects from the X-ray detector's Si substrate. Multiple guard-rings (MGRs) and metal filed plates (MFPs) techniques were adopted to reduce the leakage current and to improve the breakdown performance. The simulation verified that the breakdown voltage was improved with the MGRs and that the leakage current was significantly reduced with the MFPs. The electrical properties, such as the leakage current and the breakdown voltage, of the Si-PIN X-ray detector were characterized. The extrinsic gettering process played a significant role in reducing the leakage current, and a leakage current lower than 60 pA could be achieved at 100 Vdc.

  11. Active X-ray Optics

    Czech Academy of Sciences Publication Activity Database

    Hudec, René; Inneman, A.; Pina, L.; Černá, D.; Tichý, V.

    Bellingham: SPIE, 2013 - (Juha, L.; Bajt, S.; London, R.; Hudec, R.; Pína, L.), 877718/1-877718/7. (Proceedings of SPIE. 8777). ISBN 9780819495792. [Damage to VUV, EUV, and X-ray Optics IV; and EUV and X-ray Optics: Synergy between Laboratory and Space III. Praha (CZ), 15.04.2013-18.04.2013] Institutional support: RVO:67985815 Keywords : X-ray optics * active optics * active X-ray optics Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  12. X-ray Crystallography Facility

    Science.gov (United States)

    2000-01-01

    Edward Snell, a National Research Council research fellow at NASA's Marshall Space Flight Center (MSFC), prepares a protein crystal for analysis by x-ray crystallography as part of NASA's structural biology program. The small, individual crystals are bombarded with x-rays to produce diffraction patterns, a map of the intensity of the x-rays as they reflect through the crystal.

  13. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... lies. A drawer under the table holds the x-ray film or image recording plate . Sometimes the x-ray ... that is extended over the patient while an x-ray film holder or image recording plate is placed beneath ...

  14. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... x-rays. top of page What does the equipment look like? The equipment typically used for bone x-rays consists of ... and joint abnormalities, such as arthritis. X-ray equipment is relatively inexpensive and widely available in emergency ...

  15. Tunable X-ray source

    Science.gov (United States)

    Boyce, James R.

    2011-02-08

    A method for the production of X-ray bunches tunable in both time and energy level by generating multiple photon, X-ray, beams through the use of Thomson scattering. The method of the present invention simultaneously produces two X-ray pulses that are tunable in energy and/or time.

  16. X-Ray Exam: Ankle

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Ankle KidsHealth > For Parents > X-Ray Exam: Ankle Print A A A Text Size ... español Radiografía: tobillo What It Is An ankle X-ray is a safe and painless test that uses ...

  17. X-Ray Exam: Finger

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Finger KidsHealth > For Parents > X-Ray Exam: Finger Print A A A Text Size ... español Radiografía: dedo What It Is A finger X-ray is a safe and painless test that uses ...

  18. X-Ray Exam: Wrist

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Wrist KidsHealth > For Parents > X-Ray Exam: Wrist Print A A A Text Size ... español Radiografía: muñeca What It Is A wrist X-ray is a safe and painless test that uses ...

  19. X-Ray Exam: Hip

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Hip KidsHealth > For Parents > X-Ray Exam: Hip Print A A A Text Size ... español Radiografía: cadera What It Is A hip X-ray is a safe and painless test that uses ...

  20. X-Ray Exam: Forearm

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Forearm KidsHealth > For Parents > X-Ray Exam: Forearm Print A A A Text Size ... español Radiografía: brazo What It Is A forearm X-ray is a safe and painless test that uses ...

  1. X-Ray Exam: Pelvis

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Pelvis KidsHealth > For Parents > X-Ray Exam: Pelvis Print A A A Text Size ... español Radiografía: pelvis What It Is A pelvis X-ray is a safe and painless test that uses ...

  2. X-Ray Exam: Foot

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Foot KidsHealth > For Parents > X-Ray Exam: Foot Print A A A Text Size ... español Radiografía: pie What It Is A foot X-ray is a safe and painless test that uses ...

  3. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... The x-ray tube is connected to a flexible arm that is extended over the patient while an x-ray film holder or image recording plate is placed beneath the patient. top of page How does the procedure work? X-rays are a form of radiation like ...

  4. X-ray diffraction

    International Nuclear Information System (INIS)

    The seventh edition of Philips' Review of literature on X-ray diffraction begins with a list of conference proceedings on the subject, organised by the Philips' organisation at regular intervals in various European countries. This is followed by a list of bulletins. The bibliography is divided according to the equipment (cameras, diffractometers, monochromators) and its applications. The applications are subdivided into sections for high/low temperature and pressure, effects due to the equipment, small angle scattering and a part for stress, texture and phase analyses of metals and quantitative analysis of minerals

  5. X-ray detector

    International Nuclear Information System (INIS)

    The multicell X-ray or gamma detector is used in computer tomography. To achieve good spatial resolution, the electrode plates are narrowly spaced in each cell and are designed identical over the whole length of the detector group. The uniform spacing and precise check of the angles between the electrodes and accurate control of the dimensions of the whole detector structure are achieved by depositing, in the fabrication process, a viscous, resin type material (e.g., epoxy resin) or glue at selected points between the electrodes and insulators. (ORU)

  6. X-ray Photon Counting and Two-Color X-ray Imaging Using Indirect Detection.

    Science.gov (United States)

    Dierickx, Bart; Yao, Qiang; Witvrouwen, Nick; Uwaerts, Dirk; Vandewiele, Stijn; Gao, Peng

    2016-01-01

    In this paper, we report on the design and performance of a 1 cm², 90 × 92-pixel image sensor. It is made X-ray sensitive by the use of a scintillator. Its pixels have a charge packet counting circuit topology with two channels, each realizing a different charge packet size threshold and analog domain event counting. Here, the sensor's performance was measured in setups representative of a medical X-ray environment. Further, two-energy-level photon counting performance is demonstrated, and its capabilities and limitations are documented. We then provide an outlook on future improvements. PMID:27240362

  7. CMOS APS detector characterization for quantitative X-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Endrizzi, Marco, E-mail: m.endrizzi@ucl.ac.uk [Dipartimento di Fisica, Università di Siena, Via Roma 56, 53100 Siena (Italy); Istituto Nazionale di Fisica Nucleare INFN, sezione di Pisa, 56127 Pisa (Italy); Oliva, Piernicola [Dipartimento di Chimica e Farmacia, Università di Sassari, via Piandanna 4, 07100 Sassari (Italy); Istituto Nazionale di Fisica Nucleare INFN, Sezione di Cagliari, 09042 Cagliari (Italy); Golosio, Bruno [Sezione di Matematica, Fisica e Ingegneria dell' Informazione, Università di Sassari, via Piandanna 4, 07100 Sassari (Italy); Istituto Nazionale di Fisica Nucleare INFN, Sezione di Cagliari, 09042 Cagliari (Italy); Delogu, Pasquale [Dipartimento di Fisica “E. Fermi”, Università di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Istituto Nazionale di Fisica Nucleare INFN, sezione di Pisa, 56127 Pisa (Italy)

    2013-03-01

    An X-ray Imaging detector based on CMOS Active Pixel Sensor and structured scintillator is characterized for quantitative X-ray imaging in the energy range 11–30 keV. Linearity, dark noise, spatial resolution and flat-field correction are the characteristics of the detector subject of investigation. The detector response, in terms of mean Analog-to-Digital Unit and noise, is modeled as a function of the energy and intensity of the X-rays. The model is directly tested using monochromatic X-ray beams and it is also indirectly validated by means of polychromatic X-ray-tube spectra. Such a characterization is suitable for quantitative X-ray imaging and the model can be used in simulation studies that take into account the actual performance of the detector.

  8. The response of silicon PNCCD sensors with aluminium on-chip filter to visible light, UV- and X-ray radiation

    International Nuclear Information System (INIS)

    There are various scientific applications, from astronomical observations to free electron lasers, that make use of X-ray semiconductor detectors like PNCCDs. The PNCCD is a pixelized semiconductor detector for simultaneous X-ray imaging and spectroscopy. For the seven PNCCD cameras of the eROSITA space telescope, a radiation entrance window including an on-chip optical blocking filter has been designed. The blocking filter is a necessity to minimize electron generation by visible light and UV radiation affecting X-ray spectroscopy. A PNCCD with such a blocking filter has not been used so far in astronomy. The following work deals with the analysis of the response of PNCCDs with on-chip filter. This includes the study of photon absorption and emission processes as well as the transport of electrons inside the detector entrance window. Furthermore it comprises the experimental characterization of the detector properties regarding the attenuation of light as well as their X-ray spectral redistribution function and quantum efficiency. With the ability to reveal the involved physical processes, the PNCCD is subject of analysis and measurement device at the same time. In addition to the results of the measurements, simulations of the solid state physics inside the detector are presented. A Geant4 Monte-Carlo code is extended by the treatment of charge loss in the entrance window and is verified by comparison with experimental data. Reproducing the chain of processes from photon absorption to charge collection, this work provides a detailed understanding of the formation of PNCCD spectra. The spectral features observed in the measurements are attributed to their point of origin inside the detector volume and explained by the model. The findings of this work allow high precision analysis of spectra of silicon detectors, e.g. of the eROSITA data, based on the presented detailed spectral response model.

  9. The response of silicon PNCCD sensors with aluminium on-chip filter to visible light, UV- and X-ray radiation

    Energy Technology Data Exchange (ETDEWEB)

    Granato, Stefanie

    2012-10-18

    There are various scientific applications, from astronomical observations to free electron lasers, that make use of X-ray semiconductor detectors like PNCCDs. The PNCCD is a pixelized semiconductor detector for simultaneous X-ray imaging and spectroscopy. For the seven PNCCD cameras of the eROSITA space telescope, a radiation entrance window including an on-chip optical blocking filter has been designed. The blocking filter is a necessity to minimize electron generation by visible light and UV radiation affecting X-ray spectroscopy. A PNCCD with such a blocking filter has not been used so far in astronomy. The following work deals with the analysis of the response of PNCCDs with on-chip filter. This includes the study of photon absorption and emission processes as well as the transport of electrons inside the detector entrance window. Furthermore it comprises the experimental characterization of the detector properties regarding the attenuation of light as well as their X-ray spectral redistribution function and quantum efficiency. With the ability to reveal the involved physical processes, the PNCCD is subject of analysis and measurement device at the same time. In addition to the results of the measurements, simulations of the solid state physics inside the detector are presented. A Geant4 Monte-Carlo code is extended by the treatment of charge loss in the entrance window and is verified by comparison with experimental data. Reproducing the chain of processes from photon absorption to charge collection, this work provides a detailed understanding of the formation of PNCCD spectra. The spectral features observed in the measurements are attributed to their point of origin inside the detector volume and explained by the model. The findings of this work allow high precision analysis of spectra of silicon detectors, e.g. of the eROSITA data, based on the presented detailed spectral response model.

  10. Measurement of e{sup +}p neutral current deep inelastic scattering with a longitudinally polarised positron beam and X-ray radiation damage for silicon sensors

    Energy Technology Data Exchange (ETDEWEB)

    Januschek, Friederike

    2012-05-15

    The cross sections for Neutral Current e{sup +}p Deep Inelastic Scattering (NC DIS) with longitudinally polarised positron beams were measured at a centre-of-mass energy {radical}(s)=318 GeV using the ZEUS detector at HERA. Single-differential cross sections as a function of the virtuality of the exchanged boson, Q{sup 2}, of the inelasticity, y, and of the Bjorken scaling variable, x, and reduced cross sections (as a function of x and Q{sup 2}) were measured in the phase space region defined as Q{sup 2}>185 GeV{sup 2}, y<0.9 and y(1-x){sup 2}>0.004. The results, based on data corresponding to an integrated luminosity of 135.5 pb{sup -1}, are given for zero polarisation for the whole sample, as well as for both positive and negative values of the longitudinal polarisation of the positron beam. The measured cross sections are compared to the predictions of the Standard Model. The proton structure function xF{sub 3} is measured and the interference term xF{sup {gamma}}{sup Z}{sub 3} is extracted as a function of x at Q{sup 2}=1500 GeV{sup 2} by extrapolating the measurements done at different Q{sup 2} values. The presented measurements of the polarised e{sup +}p NC DIS cross sections, the xF{sub 3} structure function and the xF{sup {gamma}}{sup Z}{sub 3} interference term exceed the precision of previous ZEUS measurements. The uncertainties of the Parton Density Functions (PDFs) for the gluon and the u-valence quark are expected to be reduced at high-x values when the presented results are included in the PDF fits of the proton. A study is presented to further reduce PDF uncertainties for the gluon at very high x (above 10{sup -1}) through the inclusion of DIS dijet cross sections in a ZEUS-JETS-like PDF fit. An irradiation facility to study the X-ray-induced radiation damage of silicon sensors for the European XFEL was set up at HASYLAB. Nine gate-controlled diodes were irradiated with doses from 1 kGy to 1 GGy in several irradiation steps and the surface current I

  11. Einstein X-ray observations of Herbig Ae/Be stars

    Science.gov (United States)

    Damiani, F.; Micela, G.; Sciortino, S.; Harnden, F. R., Jr.

    1994-01-01

    We have investigated the X-ray emission from Herbig Ae/Be stars, using the full set of Einstein Imaging Proportional Counter (IPC) observations. Of a total of 31 observed Herbig stars, 11 are confidently identified with X-ray sources, with four additonal dubious identifications. We have used maximum likelihood luminosity functions to study the distribution of X-ray luminosity, and we find that Be stars are significantly brighter in X-rays than Ae stars and that their X-ray luminosity is independent of projected rotational velocity v sin i. The X-ray emission is instead correlated with stellar bolometric luminosity and with effective temperature, and also with the kinetic luminosity of the stellar wind. These results seem to exclude a solar-like origin for the X-ray emission, a possibility suggested by the most recent models of Herbig stars' structure, and suggest an analogy with the X-ray emission of O (and early B) stars. We also observe correlations between X-ray luminosity and the emission at 2.2 microns (K band) and 25 microns, which strengthen the case for X-ray emission of Herbig stars originating in their circumstellar envelopes.

  12. X-ray instrumentation for SR beamlines

    CERN Document Server

    Kovalchuk, M V; Zheludeva, S I; Aleshko-Ozhevsky, O P; Arutynyan, E H; Kheiker, D M; Kreines, A Y; Lider, V V; Pashaev, E M; Shilina, N Y; Shishkov, V A

    2000-01-01

    The main possibilities and parameters of experimental X-ray stations are presented: 'Protein crystallography', 'X-ray structure analysis', 'High-precision X-ray optics', 'X-ray crystallography and material science', 'X-ray topography', 'Photoelectron X-ray standing wave' that are being installed at Kurchatov SR source by A.V. Shubnikov Institute of Crystallography.

  13. Gamma detector for use with luggage X-ray systems

    International Nuclear Information System (INIS)

    A new gamma radiation sensor has been designed for installation on several types of luggage x-ray machines and mobile x-ray vans operated by the U.S. Customs Service and the U.S. Department of State. The use of gamma detectors on x-ray machines imposed difficulties not usually encountered in the design of gamma detectors because the spectrum of scattered x-rays, which varied from machine to machine, extended to energies significantly higher than those of the low-energy isotopic emissions. In the original design, the lower level discriminator was raised above the x-ray end point energy resulting in the loss of the americium line associated with plutonium. This reduced the overall sensitivity to unshielded plutonium by a factor of approximately 100. An improved method was subsequently developed wherein collimation was utilized in conjunction with a variable counting threshold to permit accommodation of differing conditions of x-ray scattering. This design has been shown to eliminate most of the problems due to x-ray scattering while still capturing the americium emissions. The overall sensitivity has remained quite high, though varying slightly from one model of x-ray machine to another, depending upon the x-ray scattering characteristics of each model. (author)

  14. X-ray lithography sources

    International Nuclear Information System (INIS)

    Synchrotron from dipole magnets in electron storage rings has emerged as a useful source of x-rays for lithography. To meet the need for these sources numerous groups around the world have embarked on projects to design and construct storage rings for x-ray lithography. Both conventional electromagnets as well as superconducting (SC) dipoles have been incorporated into the various designs. An overview of the worldwide effort to produce commercial x-ray sources will be presented. To better illustrate the elements involved in these sources a closer examination of the Superconducting X-ray Lithography Source Project (SXLS) at BNL will be presented. 11 refs., 1 fig., 5 tabs

  15. X-ray Absorption Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Yano, Junko; Yachandra, Vittal K.

    2009-07-09

    This review gives a brief description of the theory and application of X-ray absorption spectroscopy, both X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), especially, pertaining to photosynthesis. The advantages and limitations of the methods are discussed. Recent advances in extended EXAFS and polarized EXAFS using oriented membranes and single crystals are explained. Developments in theory in understanding the XANES spectra are described. The application of X-ray absorption spectroscopy to the study of the Mn4Ca cluster in Photosystem II is presented.

  16. X-ray Fluorescence Sectioning

    CERN Document Server

    Cong, Wenxiang

    2012-01-01

    In this paper, we propose an x-ray fluorescence imaging system for elemental analysis. The key idea is what we call "x-ray fluorescence sectioning". Specifically, a slit collimator in front of an x-ray tube is used to shape x-rays into a fan-beam to illuminate a planar section of an object. Then, relevant elements such as gold nanoparticles on the fan-beam plane are excited to generate x-ray fluorescence signals. One or more 2D spectral detectors are placed to face the fan-beam plane and directly measure x-ray fluorescence data. Detector elements are so collimated that each element only sees a unique area element on the fan-beam plane and records the x-ray fluorescence signal accordingly. The measured 2D x-ray fluorescence data can be refined in reference to the attenuation characteristics of the object and the divergence of the beam for accurate elemental mapping. This x-ray fluorescence sectioning system promises fast fluorescence tomographic imaging without a complex inverse procedure. The design can be ad...

  17. Radioisotope x-ray analysis

    International Nuclear Information System (INIS)

    Radioisotope x-ray fluorescence and x-ray preferential absorption (XRA) techniques are used extensively for the analysis of materials, covering such diverse applications as analysis of alloys, coal, environmental samples, paper, waste materials, and metalliferous mineral ores and products. Many of these analyses are undertaken in the harsh environment of industrial plants and in the field. Some are continuous on-line analyses of material being processed in industry, where instantaneous analysis information is required for the control of rapidly changing processes. Radioisotope x-ray analysis systems are often tailored to a specific but limited range of applications. They are simpler and often considerably less expensive than analysis systems based on x-ray tubes. These systems are preferred to x-ray tube techniques when simplicity, ruggedness, reliability, and cost of equipment are important; when minimum size, weight, and power consumption are necessary; when a very constant and predictable x-ray output is required; when the use of high-energy x-rays is advantageous; and when short x-ray path lengths are required to minimize the absorption of low-energy x-rays in air. This chapter reviews radioisotope XRF, preferential absorption, and scattering techniques. Some of the basic analysis equations are given. The characteristics of radioisotope sources and x-ray detectors are described, and then the x-ray analytical techniques are presented. The choice of radioisotope technique for a specific application is discussed. This is followed by a summary of applications of these techniques, with a more detailed account given of some of the applications, particularly those of considerable industrial importance. 79 refs., 28 figs., 7 tabs

  18. Moving-Article X-Ray Imaging System and Method for 3-D Image Generation

    Science.gov (United States)

    Fernandez, Kenneth R. (Inventor)

    2012-01-01

    An x-ray imaging system and method for a moving article are provided for an article moved along a linear direction of travel while the article is exposed to non-overlapping x-ray beams. A plurality of parallel linear sensor arrays are disposed in the x-ray beams after they pass through the article. More specifically, a first half of the plurality are disposed in a first of the x-ray beams while a second half of the plurality are disposed in a second of the x-ray beams. Each of the parallel linear sensor arrays is oriented perpendicular to the linear direction of travel. Each of the parallel linear sensor arrays in the first half is matched to a corresponding one of the parallel linear sensor arrays in the second half in terms of an angular position in the first of the x-ray beams and the second of the x-ray beams, respectively.

  19. The Fundamental Plane of Black Hole Activity Represented in Terms of Dimensionless Beam Power and Bolometric Luminosity

    OpenAIRE

    Daly, Ruth A.; Stout, Douglas A.; Mysliwiec, Jeremy N.

    2016-01-01

    The fundamental plane of black hole activity indicates a relationship between compact radio emission, X-ray luminosity, and black hole mass of black hole systems. The compact radio source is likely a tracer of jet power and the X-ray luminosity is likely a tracer of the bolometric luminosity of an accretion disk. To study the relationship between beam power, $L_j$, accretion disk bolometric luminosity, $L_{bol}$, and black hole mass or Eddington luminosity, $L_{EDD}$, for sources with various...

  20. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small dose of ionizing ...

  1. X-ray Dynamic Defectoscopy

    Czech Academy of Sciences Publication Activity Database

    Vavřík, Daniel; Visschers, J.; Jakůbek, J.; Ponchut, C.

    Orosei : IMC S.r.l., 2001. s. 47. [International Workshop on Radiation Imaging Detectors /3./. 23.09.2001-27.09.2001, Orosei] R&D Projects: GA ČR GA106/00/D064 Institutional research plan: CEZ:MSM 210000018 Keywords : X-ray Defectoscopy * Damage * X-ray Detectors Subject RIV: JL - Materials Fatigue, Friction Mechanics

  2. X-ray diagnostic equipment

    International Nuclear Information System (INIS)

    An X-ray tube is connected to several different image processing devices in X-ray diagnostic equipment. Only a single organ selector is allocated to it, for which the picture parameters for each image processing device are selected. The choice of the correct combination of picture parameters is made by means of a selector switch. (DG)

  3. X-ray tube arrangement

    International Nuclear Information System (INIS)

    An x-ray tube is described incorporating an elongated target/ anode over which the electron beam is deflected and from which x-rays are emitted. Improved methods of monitoring and controlling the amplitude of the beam deflection are presented. (U.K.)

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... frequently compared to current x-ray images for diagnosis and disease management. top of page How is the procedure performed? The technologist, an individual specially trained to perform radiology examinations, positions the patient on the x-ray ...

  5. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... clothing that might interfere with the x-ray images. Women should always inform their physician and x-ray ... small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Different ...

  6. X-ray photoelectron spectroscopy

    International Nuclear Information System (INIS)

    The methods and results of X-ray photoelectron spectroscopy in the study of plasmons, alloys and gold compounds are discussed. After a comprehensive introduction, seven papers by the author, previously published elsewhere, are reprinted and these cover a wide range of the uses of X-ray photoelectron spectroscopy. (W.D.L.)

  7. Synthesis, X-ray crystal structure and optical properties of novel 1,3,5-triarylpyrazoline derivatives and the fluorescent sensor for Cu2+

    Science.gov (United States)

    Wang, Sheng-Qing; Gao, Ying; Wang, Hao-Yan; Zheng, Xiao-Xin; Shen, Shi-Li; Zhang, Yan-Ru; Zhao, Bao-Xiang

    2013-04-01

    A series of novel 1,3,5-triarylpyrazoline derivatives was synthesized by the reaction of chalcone and 5-aryl-2-hydrazinyl-1,3,4-thiadiazole in 43.3-84.7% yields. The structures of compounds were characterized using IR, 1H NMR and HRMS spectroscopy and X-ray diffraction analysis. The absorption and fluorescence characteristics of the compounds were investigated in dichloromethane, toluene, acetonitrile, N,N-dimethylformamide and tetrahydrofuran. The results showed that the absorption maxima of the compounds vary from 366 to 370 nm depending on the group bound to benzene rings. The maximum emission spectra of the compounds in dichloromethane were dependent on nature of groups in benzene ring. Furthermore, the compound 3b can be used to determine Cu2+ ion with high selectivity and a low detection limit in the DMF:H2O = 1:1 (v/v) solution.

  8. Development of X-ray microcalorimeters for future Japanese X-ray astronomy missions

    International Nuclear Information System (INIS)

    A large format array of transition-edge-sensor (TES) microcalorimeters is a promising detector for high-resolution spectroscopy in X-ray astronomy. We are developing such a detector for future Japanese missions. In this paper, we present the recent progress in our work, particularly in the improvement of the energy resolution and the X-ray absorber fabrication. The energy resolution of our single pixel detector was improved to 25 eV (FWHM) at 5.9 keV. This is limited by pulse shape variation and excess noise. We describe the characteristics of these two limiting factors, and suggest several possible ways to improve the performance. As for attaching X-ray absorbers with a high coverage fraction, we are proposing an electrodeposition method involving a two-layer lift-off process. We describe the details of this method and show the results of the test sample fabricated on a silicon wafer. (author)

  9. X-ray Observations of Eight Young Open Star Clusters: I. Membership and X-ray Luminosity

    Indian Academy of Sciences (India)

    Himali Bhatt; J. C. Pandey; K. P. Singh; Ram Sagar; Brijesh Kumar

    2013-12-01

    We present a detailed investigation of X-ray source contents of eight young open clusters with ages between 4 to 46 Myr using archival X-ray data from XMM-NEWTON. The probable cluster memberships of the X-ray sources have been established on the basis of multi-wavelength archival data, and samples of 152 pre-main sequence (PMS) low mass (< 2⊙), 36 intermediate mass (2-10⊙) and 16 massive (> 10⊙) stars have been generated. X-ray spectral analyses of high mass stars reveal the presence of high temperature plasma with temperature < 2 keV, and mean /bol of 10-6.9. In the case of PMS low mass stars, the plasma temperatures have been found to be in the range of 0.2 keV to 3 keV with a median value of ∼ 1.3 keV, with no significant difference in plasma temperatures during their evolution from 4 to 46 Myr. The X-ray luminosity distributions of the PMS low mass stars have been found to be similar in the young star clusters under study. This may suggest a nearly uniform X-ray activity in the PMS low mass stars of ages ∼ 4–14 Myr. These observed values of /bol are found to have a mean value of 10-3.6 ± 0.4, which is below the X-ray saturation level. The /bol values for the PMS low mass stars are well correlated with their bolometric luminosities, that implies its dependence on the internal structure of the low mass stars. The difference between the X-ray luminosity distributions of the intermediate mass stars and the PMS low mass stars has not been found to be statistically significant. Their /bol values, however have been found to be significantly different from each other with a confidence level greater than 99.999% and the strength of X-ray activity in the intermediate mass stars is found to be lower compared to the low mass stars. However, the possibility of X-ray emission from the intermediate mass stars due to a low mass star in close proximity of the intermediate mass star can not be ruled out.

  10. Crystallization and preliminary X-ray analysis of a putative sensor histidine kinase domain: the C-terminal domain of HksP4 from Aquifex aeolicus VF5

    International Nuclear Information System (INIS)

    The putative sensor histidine kinase domain of the cytoplasmic protein HksP4 from the hyperthermophilic bacterium A. aeolicus VF5 was expressed, purified and crystallized by the sitting-drop vapour-diffusion method. Crystals were obtained in the presence of ATP and AMPPNP; they were found to belong to the same space group P212121 and diffracted X-rays to 3.1 and 2.9 Å resolution, respectively. The histidine kinase domain of the cytoplasmic protein HksP4 from the hyperthermophilic bacterium Aquifex aeolicus VF5, located in the C-terminal half of the protein, was expressed, purified and crystallized. Diffraction-quality crystals were obtained in the presence of adenosine triphosphate (ATP) or adenosine 5′-(β,γ-imido)triphosphate (AMPPNP) by the sitting-drop vapour-diffusion method using PEG 3350 as the precipitant. The crystals obtained in the presence of ATP and AMPPNP diffracted X-rays to 3.1 and 2.9 Å resolution, respectively, on BL-5A at Photon Factory (Ibaraki, Japan) and were found to belong to the same space group P212121, with unit-cell parameters a = 80.2, b = 105.5, c = 122.0 Å and a = 81.5, b = 105.5, c = 130.9 Å, respectively. Their Matthews coefficients (VM = 2.74 and 2.51 Å3 Da−1, respectively) indicated that both crystals contained four protein molecules per asymmetric unit

  11. Semiconductor X-ray detectors

    CERN Document Server

    Lowe, Barrie Glyn

    2014-01-01

    Identifying and measuring the elemental x-rays released when materials are examined with particles (electrons, protons, alpha particles, etc.) or photons (x-rays and gamma rays) is still considered to be the primary analytical technique for routine and non-destructive materials analysis. The Lithium Drifted Silicon (Si(Li)) X-Ray Detector, with its good resolution and peak to background, pioneered this type of analysis on electron microscopes, x-ray fluorescence instruments, and radioactive source- and accelerator-based excitation systems. Although rapid progress in Silicon Drift Detectors (SDDs), Charge Coupled Devices (CCDs), and Compound Semiconductor Detectors, including renewed interest in alternative materials such as CdZnTe and diamond, has made the Si(Li) X-Ray Detector nearly obsolete, the device serves as a useful benchmark and still is used in special instances where its large, sensitive depth is essential. Semiconductor X-Ray Detectors focuses on the history and development of Si(Li) X-Ray Detect...

  12. X-ray quasars and the X-ray background

    International Nuclear Information System (INIS)

    The Einstein X-ray observations of a sample of 202 radio-and optically-selected quasars due to Ku, Helfand and Lucy and to Zamorani et al. are analysed. Correlations between X-ray, optical and radio luminosities are examined. The contribution of radio-loud quasars to the 2-keV X-ray background is estimated using high-frequency radio-source counts, and the contribution due to radio-quiet, optically bright quasars using optical counts. It is shown that radio-loud quasars and radio-quiet optically bright quasars together contribute approximately 15 per cent of the observed 2-keV X-ray background. The contribution of optically faint radio-quiet quasars is uncertain, but may be limited to a maximum of approximately 30 per cent if recent indications of a flattening in optical counts at faint magnitudes are correct. (author)

  13. Flywheel-powered X-ray generator

    Science.gov (United States)

    Siedband, M. P.

    1984-01-01

    The use of a small flywheel appears to be a practical alternative to other power sources for mobile X-ray system applications. A 5 kg flywheel has been constructed which runs at 10 krpm and stores 30 KJ while requiring less than 500 W to bring the system up to speed. The wheel is coupled to an aircraft alternator and can yield pulsed power levels over 50 KWp. The aircraft alternator has the advantage of high frequency output which has also permitted the design of smaller high voltage transformers. A series of optical sensors detecting shaft position function as an electronic commutator so that the alternator may operate as a motor to bring the wheel up to operating speed. The system permits the generation of extremely powerful X-rays from a variety of low power sources such as household power outlets, automobile batteries or sources of poorly regulated electrical power such as those found in third world countries.

  14. X-ray diffraction apparatus

    International Nuclear Information System (INIS)

    The invention provides an x-ray diffraction apparatus permitting the rotation of the divergence sit in conjunction with the rotation of the x-ray irradiated specimen, whereby the dimensions of the x-ray irradiated portion of the specimen remain substantially constant during the rotation of the specimen. In a preferred embodiment, the divergence slit is connected to a structural element linked with a second structural element connected to the specimen such that the divergence slit rotates at a lower angular speed than the specimen

  15. X-ray crystal interferometers

    International Nuclear Information System (INIS)

    Various configurations of the X-ray crystal interferometer are reviewed. The interferometer applications considered include metrology, the measurement of fundamental physical constants, the study of weakly absorbing phase objects, time-resolved diagnostics, the determination of hard X-ray beam parameters, and the characterization of structural defects in the context of developing an X-ray Michelson interferometer. The three-crystal Laue interferometer (LLL-interferometer), its design, and the experimental opportunities it offers are given particular attention. (instruments and methods of investigation)

  16. Gated x-ray detector for the National Ignition Facility

    International Nuclear Information System (INIS)

    Two new gated x-ray imaging cameras have recently been designed, constructed, and delivered to the National Ignition Facility in Livermore, CA. These gated x-Ray detectors are each designed to fit within an aluminum airbox with a large capacity cooling plane and are fitted with an array of environmental housekeeping sensors. These instruments are significantly different from earlier generations of gated x-ray images due, in part, to an innovative impedance matching scheme, advanced phosphor screens, pulsed phosphor circuits, precision assembly fixturing, unique system monitoring, and complete remote computer control. Preliminary characterization has shown repeatable uniformity between imaging strips, improved spatial resolution, and no detectable impedance reflections

  17. X-ray microcalorimeter arrays fabricated by surface micromachining

    Energy Technology Data Exchange (ETDEWEB)

    Hilton, G.C. E-mail: hilton@boulder.nist.gov; Beall, J.A.; Deiker, S.; Vale, L.R.; Doriese, W.B.; Beyer, Joern; Ullom, J.N.; Reintsema, C.D.; Xu, Y.; Irwin, K.D

    2004-03-11

    We are developing arrays of Mo/Cu transition edge sensor-based detectors for use as X-ray microcalorimeters and sub-millimeter bolometers. We have fabricated 8x8 pixel X-ray microcalorimeter arrays using surface micromachining. Surface-micromachining techniques hold the promise of scalability to much larger arrays and may allow for the integration of in-plane multiplexer elements. In this paper we describe the surface micromachining process and recent improvements in the device geometry that provide for increased mechanical strength. We also present X-ray and heat pulse spectra collected using these detectors.

  18. X-ray microcalorimeter arrays fabricated by surface micromachining

    International Nuclear Information System (INIS)

    We are developing arrays of Mo/Cu transition edge sensor-based detectors for use as X-ray microcalorimeters and sub-millimeter bolometers. We have fabricated 8x8 pixel X-ray microcalorimeter arrays using surface micromachining. Surface-micromachining techniques hold the promise of scalability to much larger arrays and may allow for the integration of in-plane multiplexer elements. In this paper we describe the surface micromachining process and recent improvements in the device geometry that provide for increased mechanical strength. We also present X-ray and heat pulse spectra collected using these detectors

  19. ASCA Observation of an X-Ray-Luminous Active Nucleus in Markarian 231

    CERN Document Server

    Maloney, P R; Maloney, Philip R.; Reynolds, Christopher S

    2000-01-01

    We have obtained a moderately long (100 kilosecond) ASCA observation of the Seyfert 1 galaxy Markarian 231, the most luminous of the local ultraluminous infrared galaxy (ULIRG) population. In the best-fitting model we do not see the X-ray source directly; the spectrum consists of a scattered power-law component and a reflection component, both of which have been absorbed by a column N_H \\approx 3 X 10^(22)/cm^2. About 3/4 of the observed hard X-rays arise from the scattered component, reducing the equivalent width of the iron K alpha line. The implied ratio of 1-10 keV X-ray luminosity to bolometric luminosity, L_x/L_bol \\sim 2%, is typical of Sy 1 galaxies and radio-quiet QSOs of comparable bolometric luminosities, and indicates that the bolometric luminosity is dominated by the AGN. Our estimate of the X-ray luminosity also moves Mrk 231 in line with the correlations found for AGN with extremely strong Fe II emission. A second source separated by about 2 arcminutes is also clearly detected, and contributes ...

  20. Development of microstructured large area magnetic calorimeters with Au:Er- and Ag:Er-sensors for the detection of x-ray quanta and high energetic particles

    International Nuclear Information System (INIS)

    This thesis describes the development of large-area magnetic calorimeters which could for example be used for the investigation of the dissociative recombination or the measurement of the Lamb-shift for hydrogenlike heavy ions. The detectors consist of two meandershaped niobium thin film pickup coils and a paramagnetic sensor. The deposition of energy in the sensor results in a temperature change and therefore in a change of magnetisation of the sensor, which can be measured by a SQUID-magnetometer with high precision. As sensormaterials a dilute alloy of gold-erbium (Au:Er) as well as silver-erbium (Ag:Er) were used. Whereas the Ag:Er-sensor was glued on the pickup coil the Au:Er-sensor was for the first time microstructured by a novel microstructuring process established in this thesis. For the characterisation of the detectors and the sensormaterials a fluorescence source and a 55Fe source were used. The thermodynamic properties of the Au:Er-sensors thereby show promising results, as the magnetisation shows bulk properties down to 20 mK. The measurements of the signalize and the magnetisation with the detector which was equipped with a Ag:Er-sensor showed that the thermodynamic properties of the Ag:Eralloy could be fully described. Furthermore the shape of the pulses, the noise and the energy resolution of both detectors will be discussed. (orig.)

  1. Neutron and X-ray Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Carini, Gabriella [SLAC National Accelerator Lab., Menlo Park, CA (United States); Denes, Peter [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gruener, Sol [Cornell Univ., Ithaca, NY (United States); Lessner, Elianne [Dept. of Energy (DOE), Washington DC (United States). Office of Science Office of Basic Energy Sciences

    2012-08-01

    (and two computing hurdles that result from the corresponding increase in data volume) for the detector community to overcome in order to realize the full potential of BES neutron and X-ray facilities. Resolving these detector impediments will improve scientific productivity both by enabling new types of experiments, which will expand the scientific breadth at the X-ray and neutron facilities, and by potentially reducing the beam time required for a given experiment. These research priorities are summarized in the table below. Note that multiple, simultaneous detector improvements are often required to take full advantage of brighter sources. High-efficiency hard X-ray sensors: The fraction of incident particles that are actually detected defines detector efficiency. Silicon, the most common direct-detection X-ray sensor material, is (for typical sensor thicknesses) 100% efficient at 8 keV, 25%efficient at 20 keV, and only 3% efficient at 50 keV. Other materials are needed for hard X-rays. Replacement for 3He for neutron detectors: 3He has long been the neutron detection medium of choice because of its high cross section over a wide neutron energy range for the reaction 3He + n —> 3H + 1H + 0.764 MeV. 3He stockpiles are rapidly dwindling, and what is available can be had only at prohibitively high prices. Doped scintillators hold promise as ways to capture neutrons and convert them into light, although work is needed on brighter, more efficient scintillator solutions. Neutron detectors also require advances in speed and resolution. Fast-framing X-ray detectors: Today’s brighter X-ray sources make time-resolved studies possible. For example, hybrid X-ray pixel detectors, initially developed for particle physics, are becoming fairly mature X-ray detectors, with considerable development in Europe. To truly enable time-resolved studies, higher frame rates and dynamic range are required, and smaller pixel sizes are desirable. High-speed spectroscopic X-ray detectors

  2. The color of X-rays Spectral X-ray computed tomography using energy sensitive pixel detectors

    CERN Document Server

    Schioppa, Enrico Junior

    Energy sensitive X-ray imaging detectors are produced by connecting a semiconductor sensor to a spectroscopic pixel readout chip. In this thesis, the applicability of such detectors to X-ray Computed Tomography (CT) is studied. A prototype Medipix based silicon detector is calibrated using X-ray fluorescence. The charge transport properties of the sensor are characterized using a high energy beam of charged particles at the Super Proton Synchrotron (SPS) at the European Center for Nuclear Research (CERN). Monochromatic X-rays at the European Synchrotron Radiation Facility (ESRF) are used to determined the energy response function. These data are used to implement a physics-based CT projection operator that accounts for the transmission of the source spectrum through the sample and detector effects. Based on this projection operator, an iterative spectral CT reconstruction algorithm is developed by extending an Ordered Subset Expectation Maximization (OSEM) method. Subsequently, a maximum likelihood based algo...

  3. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... x-ray machine produces a small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Different parts of the body absorb the x- ...

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... an image on photographic film or a special detector. Different parts of the body absorb the x-rays in varying degrees. Dense bone absorbs much of the radiation while soft tissue, such as muscle, fat and ...

  5. Duodenal X-ray diagnostics

    International Nuclear Information System (INIS)

    The publication provides an overview of duodenal X-ray diagnostics with the aid of barium meals in 1362 patients. The introducing paragraphs deal with the topographic anatomy of the region and the methodics of X-ray investigation. The chapter entitled ''processes at the duodenum itself'' describes mainly ulcers, diverticula, congenital anomalies, tumors and inflammations. The neighbourhood processes comprise in the first place diseases having their origin at the pancreas and bile ducts. As a conclusion, endoscopic rectograde cholangio-pancreaticography and percutaneous transhepatic cholangiography are pointed out as advanced X-ray investigation methods. In the annex of X-ray images some of the described phenomena are shown in exemplary manner. (orig./MG)

  6. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... is commonly used to diagnose fractured bones or joint dislocation. Bone x-rays are the fastest and ... to view and assess bone fractures, injuries and joint abnormalities. This exam requires little to no special ...

  7. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... like a photographic negative). Today, most images are digital files that are stored electronically. These stored images ... and places the x-ray film holder or digital recording plate under the table in the area ...

  8. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the patient lies. A drawer under the table holds the x-ray film or image recording plate . ... when feasible to protect from radiation. You must hold very still and may be asked to keep ...

  9. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... technologist, an individual specially trained to perform radiology examinations, positions the patient on the x-ray table ... bone is forming), for comparison purposes. When the examination is complete, you may be asked to wait ...

  10. Picosecond x-ray science

    International Nuclear Information System (INIS)

    The report discusses the exciting times for short pulse X-rays and the current users of the technology in the United States. Tracking nuclear motions with X-rays transcends scientific disciplines and includes Biology, Materials Science, Condensed Matter and Chemistry. 1 picosecond accesses many phenomena previously hidden at 100ps. Synchrotron advantage over laser plasma and LCLS is that it's easily tunable. There is a large and diverse user community of this technology that is growing rapidly. A working group is being formed to implement 'fast track' Phases 1 and 2 which includes tunable, polarized, monochromatic, focused X-rays; variable pulse length (1 to 100ps) and 1 kHz, 109 X-rays/s with 1% bandwidth. ERL would be a major advance for ultrafast time-resolved studies.

  11. X-ray microtomographic scanners

    Energy Technology Data Exchange (ETDEWEB)

    Syryamkin, V. I., E-mail: klestov-simon@mail.ru; Klestov, S. A., E-mail: klestov-simon@mail.ru [National Research Tomsk State University, Tomsk, 634050 (Russian Federation)

    2015-11-17

    The article studies the operating procedures of an X-ray microtomographic scanner and the module of reconstruction and analysis 3D-image of a test sample in particular. An algorithm for 3D-image reconstruction based on image shadow projections and mathematical methods of the processing are described. Chapter 1 describes the basic principles of X-ray tomography and general procedures of the device developed. Chapters 2 and 3 are devoted to the problem of resources saving by the system during the X-ray tomography procedure, which is achieved by preprocessing of the initial shadow projections. Preprocessing includes background noise removing from the images, which reduces the amount of shadow projections in general and increases the efficiency of the group shadow projections compression. In conclusion, the main applications of X-ray tomography are presented.

  12. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... or in bones. top of page How should I prepare? Most bone x-rays require no special ... to 10 minutes. top of page What will I experience during and after the procedure? A bone ...

  13. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the body absorb the x-rays in varying degrees. Dense bone absorbs much of the radiation while ... is further reviewed by committees from the American College of Radiology (ACR) and the Radiological Society of ...

  14. Dental X-ray apparatus

    International Nuclear Information System (INIS)

    Intra-oral dental X-ray apparatus for panoramic dental radiography is described in detail. It comprises an electron gun having an elongated tubular target carrier extending into the patient's mouth. The carrier supports an inclined target for direction of an X-ray pattern towards a film positioned externally of the patient's mouth. Image definition is improved by a focusing anode which focuses the electron beam into a sharp spot (0.05 to 0.10 mm diameter) on the target. The potential on the focusing anode is adjustable to vary the size of the spot. An X-ray transmitting ceramic (oxides of Be, Al and Si) window is positioned adjacent to the front face of the target. The electron beam can be magnetically deflected to change the X-ray beam direction. (author)

  15. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures that ... around joints, and in evaluating the hips of children with congenital problems. top of page This page ...

  16. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... can be taken to the patient in a hospital bed or the emergency room. The x-ray ... and international radiology protection organizations continually review and update the technique standards used by radiology professionals. Modern ...

  17. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... top of page What are the benefits vs. risks? Benefits Bone x-rays are the fastest and ... in the typical diagnostic range for this exam. Risks There is always a slight chance of cancer ...

  18. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... in a known abnormality can be monitored over time. Follow-up examinations are sometimes the best way ...

  19. X-ray thickness gauge

    International Nuclear Information System (INIS)

    New design of X-ray gauge of rolled product thickness is suggested. It is supplied with self-compensation unit, removing the error, caused by changes of half-cycles of supply voltage of radiation source

  20. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... during x-ray examinations to use the lowest radiation dose possible while producing the best images for evaluation. National and international radiology protection organizations continually review and update the technique standards ...

  1. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Leave jewelry at home and wear loose, comfortable clothing. You may be asked to wear a gown. ... appliances, eye glasses and any metal objects or clothing that might interfere with the x-ray images. ...

  2. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... a large photographic negative). Today, most images are digital files that are stored electronically. These stored images ... and places the x-ray film holder or digital recording plate under the table in the area ...

  3. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... examination may also be necessary so that any change in a known abnormality can be monitored over ...

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... replacement and fracture reductions. look for injury, infection, arthritis , abnormal bone growths and bony changes seen in ... injuries, including fractures, and joint abnormalities, such as arthritis. X-ray equipment is relatively inexpensive and widely ...

  5. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the lowest radiation dose possible while producing the best images for evaluation. National and international radiology protection organizations continually review and update the technique standards used by radiology professionals. Modern x-ray systems ...

  6. Bone X-Ray (Radiography)

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    Full Text Available ... pregnant. Many imaging tests are not performed during pregnancy so as not to expose the fetus to ... See the Safety page for more information about pregnancy and x-rays. top of page What does ...

  7. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the patient in a hospital bed or the emergency room. The x-ray tube is connected to ... equipment is relatively inexpensive and widely available in emergency rooms, physician offices, ambulatory care centers, nursing homes ...

  8. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the baby. See the Safety page for more information about pregnancy and x-rays. top of page ... procedure varies. See the Safety page for more information about radiation dose. Women should always inform their ...

  9. X-Ray Assembler Data

    Data.gov (United States)

    U.S. Department of Health & Human Services — Federal regulations require that an assembler who installs one or more certified components of a diagnostic x-ray system submit a report of assembly. This database...

  10. The PERCIVAL soft X-ray imager

    Science.gov (United States)

    Wunderer, C. B.; Marras, A.; Bayer, M.; Correa, J.; Göttlicher, P.; Lange, S.; Shevyakov, I.; Smoljanin, S.; Tennert, M.; Viti, M.; Xia, Q.; Zimmer, M.; Das, D.; Guerrini, N.; Marsh, B.; Sedgwick, I.; Turchetta, R.; Cautero, G.; Gianoncelli, A.; Giuressi, D.; Menk, R.; Stebel, L.; Yousef, H.; Marchal, J.; Rees, N.; Tartoni, N.; Graafsma, H.

    2015-02-01

    With the increased brilliance of state-of-the-art Synchrotron radiation sources and the advent of Free Electron Lasers enabling revolutionary science on atomic length and time scales with EUV to X-ray photons comes an urgent need for suitable photon imaging detectors. Requirements include high frame rates, very large dynamic range, single-photon counting capability with low probability of false positives, and (multi)-megapixels. PERCIVAL (``Pixelated Energy Resolving CMOS Imager, Versatile And Large'') is currently being developed by a collaboration of DESY, RAL, Elettra, DLS and Pohang to address this need for the soft X-ray regime. PERCIVAL is a monolithic active pixel sensor (MAPS), i.e. based on CMOS technology. It will be back-thinned to access its primary energy range of 250 eV to 1 keV with target efficiencies above 90%. According to its preliminary specifications, the roughly 10 × 10 cm2, 3.5k × 3.7k monolithic ``PERCIVAL13M'' sensor will operate at frame rates up to 120 Hz (commensurate with most FELs) and use multiple gains within its 27 μm pixels to measure 1 to ~ 105 (500 eV) simultaneously-arriving photons. A smaller ``PERCIVAL2M'' with ~ 1.4k × 1.5k pixels is also planned. Currently, small-scale back-illuminated prototype systems (160 × 210 pixels of 25 μm pitch) are undergoing detailed testing with X-rays and optical photons. In March 2014, a prototype sensor was tested at 350 eV-2 keV at Elettra's TwinMic beamline. The data recorded include diffraction patterns at 350 eV and 400 eV, knife edge and sub-pixel pinhole illuminations, and comparisons of different pixel types. Another prototype chip will be submitted in fall 2014, first larger sensors could be in hand in late 2015.

  11. X-ray fluorescence holography

    CERN Document Server

    Hayashi, K; Takahashi, Y

    2003-01-01

    X-ray fluorescence holography (XFH) is a new structural analysis method of determining a 3D atomic arrangement around fluorescing atoms. We developed an XFH apparatus using advanced X-ray techniques and succeeded in obtaining high-quality hologram data. Furthermore, we introduced applications to the structural analysis of a thin film and the environment around dopants and, discussed the quantitative analysis of local lattice distortion. (author)

  12. Accelerator x-ray sources

    CERN Document Server

    Talman, Richard

    2007-01-01

    This first book to cover in-depth the generation of x-rays in particle accelerators focuses on electron beams produced by means of the novel Energy Recovery Linac (ERL) technology. The resulting highly brilliant x-rays are at the centre of this monograph, which continues where other books on the market stop. Written primarily for general, high energy and radiation physicists, the systematic treatment adopted by the work makes it equally suitable as an advanced textbook for young researchers.

  13. Electromechanical x-ray generator

    Energy Technology Data Exchange (ETDEWEB)

    Watson, Scott A; Platts, David; Sorensen, Eric B

    2016-05-03

    An electro-mechanical x-ray generator configured to obtain high-energy operation with favorable energy-weight scaling. The electro-mechanical x-ray generator may include a pair of capacitor plates. The capacitor plates may be charged to a predefined voltage and may be separated to generate higher voltages on the order of hundreds of kV in the AK gap. The high voltage may be generated in a vacuum tube.

  14. X-rays from magnetic intermediate mass Ap/Bp stars

    CERN Document Server

    Robrade, Jan

    2016-01-01

    The X-ray emission of magnetic intermediate mass Ap/Bp stars is reviewed and put into context of intrinsic as well as extrinsic hypotheses for its origin. New X-ray observations of Ap/Bp stars are presented and combined with an updated analysis of the available datasets, providing the largest sample of its type that is currently available. In the studied stars the X-ray detections are found predominantly among the more massive, hotter and more luminous targets. Their X-ray properties are quite diverse and beside strong soft X-ray emission significant magnetic activity is frequently present. While a connection between more powerful winds and brighter X-ray emission is expected in intrinsic models, the scatter in X-ray luminosity at given bolometric luminosity is so far unexplained and several observational features like X-ray light curves and flaring, luminosity distributions and spectral properties are often similar to those of low-mass stars. It remains to be seen if these features can be fully reproduced by...

  15. X-ray laser; Roentgenlaser

    Energy Technology Data Exchange (ETDEWEB)

    Samuelsen, Emil J.; Breiby, Dag W.

    2009-07-01

    X-ray is among the most important research tools today, and has given priceless contributions to all disciplines within the natural sciences. State of the art in this field is called XFEL, X-ray Free Electron Laser, which may be 10 thousand million times stronger than the x-rays at the European Synchrotron Radiation Facility in Grenoble. In addition XFEL has properties that allow the study of processes which previously would have been impossible. Of special interest are depictions on atomic- and molecular level by the use of x-ray holographic methods, and being able to study chemical reactions in nature's own timescale, the femtosecond. Conclusion: The construction of x-ray lasers is a natural development in a scientific field which has an enormous influence on the surrounding society. While the discovery of x-ray was an important breakthrough in itself, new applications appear one after the other: Medical depiction, dissemination, diffraction, DNA and protein structures, synchrotron radiation and tomography. There is reason to believe that XFEL implies a technological leap as big as the synchrotrons some decades ago. As we are now talking about studies of femtosecond and direct depiction of chemical reactions, it is obvious that we are dealing with a revolution to come, with extensive consequences, both scientifically and culturally. (EW)

  16. X-ray diagnostic apparatus

    International Nuclear Information System (INIS)

    A falling load type X-ray diagnostic apparatus comprises a low voltage power source, AC-DC converting means connected to the low voltage power source so as to apply a rectified low DC voltage, chopping means connected to the AC-DC converting means and chopping said DC voltage into a low AC voltage, high voltage applying means for transforming said low AC voltage into a high AC voltage, said high AC voltage being applied as a tube voltage to an X-ray tube from which X-rays are irradiated toward an object to be examined, means for controlling a filament heating power of the X-ray tube, programming means for supplying a control signal to said filament heating control means so as to reduce the emission current of said X-ray tube during the irradiation, and chopper control means for controlling the chopping ratio of said chopping means by evaluating said rectified DC voltage with a preset tube voltage generated in said programming means, said programming means compensating said tube voltage by receiving said control signal in such a manner that said tube voltage is maintained substantially constant during the irradiation by varying said preset tube voltage so as to control the chopping ratio based upon the reduction of the filament heating power for the X-ray tube

  17. Low energy (soft) x rays

    International Nuclear Information System (INIS)

    Dosimetry of low-energy (soft) X rays produced by the SOFTEX Model CMBW-2 was performed using Nuclear Associates Type 30 - 330 PTW, Exradin Type A2, and Shonka-Wyckoff ionization chambers with a Keithley Model 602 electrometer. Thermoluminescent (BeO chip) dosimeters were used with a Harshaw Detector 2000-A and Picoammeter-B readout system. Beam quality measurements were made using aluminum absorbers; exposure rates were assessed by the current of the X-ray tube and by exposure times. Dose distributions were established, and the average factors for non-uniformity were calculated. The means of obtaining accurate absorbed and exposed doses using these methods are discussed. Survival of V79 cells was assessed by irradiating them with soft X rays, 200 kVp X rays, and 60Co gamma rays. The relative biological effectiveness (RBE) values for soft X rays with 0, 0.2, 0.7 mm added thicknesses of aluminum were 1.6, which were compared to 60Co. The RBE of 200 kVp X rays relative to 60Co was 1.3. Results of this study are available for reference in future RERF studies of cell survival. (author)

  18. Tokamak x ray diagnostic instrumentation

    International Nuclear Information System (INIS)

    Three classes of x-ray diagnostic instruments enable measurement of a variety of tokamak physics parameters from different features of the x-ray emission spectrum. (1) The soft x-ray (1 to 50 keV) pulse-height-analysis (PHA) diagnostic measures impurity concentrations from characteristic line intensities and the continuum enhancement, and measures the electron temperature from the continuum slope. (2) The Bragg x-ray crystal spectrometer (XCS) measures the ion temperature and neutral-beam-induced toroidal rotation velocity from the Doppler broadening and wavelength shift, respectively, of spectral lines of medium-Z impurity ions. Impurity charge state distributions, precise wavelengths, and inner-shell excitation and recombination rates can also be studied. X rays are diffracted and focused by a bent crystal onto a position-sensitive detector. The spectral resolving power E/ΔE is greater than 104 and time resolution is 10 ms. (3) The x-ray imaging system (XIS) measures the spatial structure of rapid fluctuations (0.1 to 100 kHZ) providing information on MHD phenomena, impurity transport rates, toroidal rotation velocity, plasma position, and the electron temperature profile. It uses an array of silicon surface-barrier diodes which view different chords of the plasma through a common slot aperture and operate in current (as opposed to counting) mode. The effectiveness of shields to protect detectors from fusion-neutron radiation effects has been studied both theoretically and experimentally

  19. Center for X-Ray Optics, 1992

    International Nuclear Information System (INIS)

    This report discusses the following topics: Center for X-Ray Optics; Soft X-Ray Imaging wit Zone Plate Lenses; Biological X-Ray microscopy; Extreme Ultraviolet Lithography for Nanoelectronic Pattern Transfer; Multilayer Reflective Optics; EUV/Soft X-ray Reflectometer; Photoemission Microscopy with Reflective Optics; Spectroscopy with Soft X-Rays; Hard X-Ray Microprobe; Coronary Angiography; and Atomic Scattering Factors

  20. X-ray instrumentation for SR beamlines

    Energy Technology Data Exchange (ETDEWEB)

    Kovalchuk, M.V.; Shilin, Yu.N.; Zheludeva, S.I. E-mail: zheludeva@ns.crys.ras.ru; Aleshko-Ozhevsky, O.P.; Arutynyan, E.H.; Kheiker, D.M.; Kreines, A.Ya.; Lider, V.V.; Pashaev, E.M.; Shilina, N.Yu.; Shishkov, V.A

    2000-06-21

    The main possibilities and parameters of experimental X-ray stations are presented: 'Protein crystallography', 'X-ray structure analysis', 'High-precision X-ray optics', 'X-ray crystallography and material science', 'X-ray topography', 'Photoelectron X-ray standing wave' that are being installed at Kurchatov SR source by A.V. Shubnikov Institute of Crystallography.

  1. X-rays and some applications

    International Nuclear Information System (INIS)

    This book is one of the specialized books issued by the Arab Atomic Energy Agency about the key technologies of interest to Arab researchers . The book contains 10 chapters as follows: the nature of X-ray, methods of production and measurement of X-rays, X-ray and materials, X-ray crystallography, X-ray and chemistry, X-ray and physics, biological effects of X-ray, radiography in the field of medicine and biology, X-ray in the field of industry, other applications in agriculture, imaging artifacts and paintings and geology.

  2. Indirectly illuminated X-ray area detector for X-ray photon correlation spectroscopy.

    Science.gov (United States)

    Shinohara, Yuya; Imai, Ryo; Kishimoto, Hiroyuki; Yagi, Naoto; Amemiya, Yoshiyuki

    2010-11-01

    An indirectly illuminated X-ray area detector is employed for X-ray photon correlation spectroscopy (XPCS). The detector consists of a phosphor screen, an image intensifier (microchannel plate), a coupling lens and either a CCD or CMOS image sensor. By changing the gain of the image intensifier, both photon-counting and integrating measurements can be performed. Speckle patterns with a high signal-to-noise ratio can be observed in a single shot in the integrating mode, while XPCS measurement can be performed with much fewer photons in the photon-counting mode. By switching the image sensor, various combinations of frame rate, dynamic range and active area can be obtained. By virtue of these characteristics, this detector can be used for XPCS measurements of various types of samples that show slow or fast dynamics, a high or low scattering intensity, and a wide or narrow range of scattering angles. PMID:20975218

  3. X-ray Echo Spectroscopy

    Science.gov (United States)

    Shvyd'ko, Yuri

    2016-02-01

    X-ray echo spectroscopy, a counterpart of neutron spin echo, is being introduced here to overcome limitations in spectral resolution and weak signals of the traditional inelastic x-ray scattering (IXS) probes. An image of a pointlike x-ray source is defocused by a dispersing system comprised of asymmetrically cut specially arranged Bragg diffracting crystals. The defocused image is refocused into a point (echo) in a time-reversal dispersing system. If the defocused beam is inelastically scattered from a sample, the echo signal acquires a spatial distribution, which is a map of the inelastic scattering spectrum. The spectral resolution of the echo spectroscopy does not rely on the monochromaticity of the x rays, ensuring strong signals along with a very high spectral resolution. Particular schemes of x-ray echo spectrometers for 0.1-0.02 meV ultrahigh-resolution IXS applications (resolving power >108 ) with broadband ≃5 - 13 meV dispersing systems are introduced featuring more than 103 signal enhancement. The technique is general, applicable in different photon frequency domains.

  4. X-ray echo spectroscopy

    CERN Document Server

    Shvyd'ko, Yuri

    2015-01-01

    X-ray echo spectroscopy, a counterpart of neutron spin-echo, is being introduced here to overcome limitations in spectral resolution and weak signals of the traditional inelastic x-ray scattering (IXS) probes. An image of a point-like x-ray source is defocused by a dispersing system comprised of asymmetrically cut specially arranged Bragg diffracting crystals. The defocused image is refocused into a point (echo) in a time-reversal dispersing system. If the defocused beam is inelastically scattered from a sample, the echo signal acquires a spatial distribution, which is a map of the inelastic scattering spectrum. The spectral resolution of the echo spectroscopy does not rely on the monochromaticity of the x-rays, ensuring strong signals along with a very high spectral resolution. Particular schemes of x-ray echo spectrometers for 0.1--0.02-meV ultra-high-resolution IXS applications (resolving power $> 10^8$) with broadband $\\simeq$~5--13~meV dispersing systems are introduced featuring more than $10^3$ signal e...

  5. Dental X-ray apparatus

    International Nuclear Information System (INIS)

    Intra-oral X-ray apparatus which reduces the number of exposures necessary to obtain panoramic dental radiographs is described in detail. It comprises an electron gun, a tubular target carrier projecting from the gun along the beam axis and carrying at its distal end a target surrounded by a shield of X-ray opaque material. This shield extends forward and laterally of the target and has surfaces which define a wedge or cone-shaped radiation pattern delimited vertically by the root tips of the patient's teeth. A film holder is located externally of the patient's mouth. A disposable member can fit on the target carrier to depress the patient's tongue out of the radiation pattern and to further shield the roof of the mouth. The electron beam can be magnetically deflected to change the X-ray beam direction. (author)

  6. Extragalactic X-ray sources

    International Nuclear Information System (INIS)

    About 40% of the X-ray sources in the third UHURU catalogue are extragalactic. One, SMC X-1 has been identified with a binary star in the lesser Magellanic Cloud, while five sources, three probably binary stars, have been found in the greater Magellanic Cloud. X-ray sources in normal galaxies (M31), radiogalaxies (NGC5128), Seyfert galaxies (NGC4151), quasars (3C273) and galaxy clusters (Virgo X-1 and Perseus X-1) are briefly discussed. The most probable explanation for the origin of X-ray emissions from galaxy clusters appears at present to be that the cluster is filled with a thin, very hot gas which emits X-radiation by thermal bremsstrahlung. The main alternative is a socalled inverse Compton effect. (JIW)

  7. X-ray imaging: Perovskites target X-ray detection

    Science.gov (United States)

    Heiss, Wolfgang; Brabec, Christoph

    2016-05-01

    Single crystals of perovskites are currently of interest to help fathom fundamental physical parameters limiting the performance of perovskite-based polycrystalline solar cells. Now, such perovskites offer a technology platform for optoelectronic devices, such as cheap and sensitive X-ray detectors.

  8. Global X-ray properties of the O and B stars in Carina

    CERN Document Server

    Naze, Y; Oskinova, L; Townsley, L K; Cohen, D; Corcoran, M F; Evans, N R; Gagne, M; Moffat, A F J; Pittard, J M; Rauw, G; ud-Doula, A; Walborn, N R

    2011-01-01

    The key empirical property of the X-ray emission from O stars is a strong correlation between the bolometric and X-ray luminosities. In the framework of the Chandra Carina Complex Project, 129 O and B stars have been detected as X-ray sources; 78 of those, all with spectral type earlier than B3, have enough counts for at least a rough X-ray spectral characterization. This leads to an estimate of the Lx/Lbol ratio for an exceptional number of 60 O stars belonging to the same region and triples the number of Carina massive stars studied spectroscopically in X-rays. The derived log(Lx/Lbol) is -7.26 for single objects, with a dispersion of only 0.21dex. Using the properties of hot massive stars listed in the literature, we compare the X-ray luminosities of different types of objects. In the case of O stars, the Lx/Lbol ratios are similar for bright and faint objects, as well as for stars of different luminosity classes or spectral types. Binaries appear only slightly harder and slightly more luminous in X-rays t...

  9. An intraoral miniature x-ray tube based on carbon nanotubes for dental radiography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Jin; Kim, Hyun Nam; Raza, Hamid Saeed; Park, Han Beom; Cho, Sung Oh [Dept. of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2016-06-15

    A miniature X-ray tube based on a carbon-nanotube electron emitter has been employed for the application to a dental radiography. The miniature X-ray tube has an outer diameter of 7 mm and a length of 47 mm. The miniature X-ray tube is operated in a negative high-voltage mode in which the X-ray target is electrically grounded. In addition, X-rays are generated only to the teeth directions using a collimator while X-rays generated to other directions are shielded. Hence, the X-ray tube can be safely inserted into a human mouth. Using the intra-oral X-ray tube, a dental radiography is demonstrated where the positions of an X-ray source and a sensor are reversed compared with a conventional dental radiography system. X-ray images of five neighboring teeth are obtained and, furthermore, both left and right molar images are achieved by a single X-ray shot of the miniature X-ray tube.

  10. X-ray hot plasma diagnostics

    International Nuclear Information System (INIS)

    X-ray plasma emission study is powerful diagnostic tool of hot plasmas. In this review article the main techniques of X-ray plasma emission measurement are shortly presented: X-ray spectrometry using absorbent filters, crystal and grating spectrometers, imaging techniques using pinhole cameras, X-ray microscopes and Fresnel zone plate cameras, X-ray plasma emission calorimetry. Advances in these techniques with examples for different hot plasma devices are also presentes. (author)

  11. X-ray imaging for security applications

    Science.gov (United States)

    Evans, J. Paul

    2004-01-01

    The X-ray screening of luggage by aviation security personnel may be badly hindered by the lack of visual cues to depth in an image that has been produced by transmitted radiation. Two-dimensional "shadowgraphs" with "organic" and "metallic" objects encoded using two different colors (usually orange and blue) are still in common use. In the context of luggage screening there are no reliable cues to depth present in individual shadowgraph X-ray images. Therefore, the screener is required to convert the 'zero depth resolution' shadowgraph into a three-dimensional mental picture to be able to interpret the relative spatial relationship of the objects under inspection. Consequently, additional cognitive processing is required e.g. integration, inference and memory. However, these processes can lead to serious misinterpretations of the actual physical structure being examined. This paper describes the development of a stereoscopic imaging technique enabling the screener to utilise binocular stereopsis and kinetic depth to enhance their interpretation of the actual nature of the objects under examination. Further work has led to the development of a technique to combine parallax data (to calculate the thickness of a target material) with the results of a basis material subtraction technique to approximate the target's effective atomic number and density. This has been achieved in preliminary experiments with a novel spatially interleaved dual-energy sensor which reduces the number of scintillation elements required by 50% in comparison to conventional sensor configurations.

  12. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... exam requires little to no special preparation. Tell your doctor and the technologist if there is any possibility you are pregnant. Leave jewelry at home and wear loose, comfortable clothing. You may be asked to wear a gown. What is Bone X-ray (Radiography)? What are some ...

  13. X-ray image converters

    International Nuclear Information System (INIS)

    The invention pertains to rare earth phosphor admixtures utilizing thulium-activated lanthanum or gadolinium oxyhalide phosphor material. These materials increase the relative speed and resolution of an X-ray image compared with conventional phosphors as well as reducing the still serious crossover problem now experienced with conventional phosphors. (Auth.)

  14. Bone X-Ray (Radiography)

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    Full Text Available ... Images related to X-ray (Radiography) - Bone About this Site RadiologyInfo.org is produced by: Please note ... you can search the ACR-accredited facilities database . This website does not provide cost information. The costs ...

  15. Bone X-Ray (Radiography)

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    Full Text Available ... Safety En Español More Info Images/Videos News Physician Resources Professions Site Index A-Z X-ray ( ... are the fastest and easiest way for your doctor to view and assess bone fractures, injuries and ...

  16. X-Ray Diffractive Optics

    Science.gov (United States)

    Dennis, Brian; Li, Mary; Skinner, Gerald

    2013-01-01

    X-ray optics were fabricated with the capability of imaging solar x-ray sources with better than 0.1 arcsecond angular resolution, over an order of magnitude finer than is currently possible. Such images would provide a new window into the little-understood energy release and particle acceleration regions in solar flares. They constitute one of the most promising ways to probe these regions in the solar atmosphere with the sensitivity and angular resolution needed to better understand the physical processes involved. A circular slit structure with widths as fine as 0.85 micron etched in a silicon wafer 8 microns thick forms a phase zone plate version of a Fresnel lens capable of focusing approx. =.6 keV x-rays. The focal length of the 3-cm diameter lenses is 100 microns, and the angular resolution capability is better than 0.1 arcsecond. Such phase zone plates were fabricated in Goddard fs Detector Development Lab. (DDL) and tested at the Goddard 600-microns x-ray test facility. The test data verified that the desired angular resolution and throughput efficiency were achieved.

  17. X-ray diagnostic equipment

    International Nuclear Information System (INIS)

    Lateral and orbital scanning movements can be carried out with the equipment. The assessment is carried out by a computer. Differences in sensitivity of the detectors can be compensated for by displacement of the electron beam of the X-ray tube compared to the anti-cathode or by bending of the electron beam by electromagnetic coils. (RW)

  18. X-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    The seventh edition of Philips' Review of Literature on x-ray fluorescence spectrometry starts with a list of conference proceedings on the subject, organised by the Philips organisation at regular intervals in various European countries. It is followed by a list of bulletins. The bibliography is subdivided according to spectra, equipment, applications and absorption analysis

  19. X-ray film processing

    International Nuclear Information System (INIS)

    X-ray films have to be highly sensitive, for radiation protection reasons. The films used in radiology are coated on both sides with a photosensitive emulsion. This applies to all dental films. Their properties and the development of the different exposed films are explained. (DG)

  20. X-ray backscatter imaging

    Science.gov (United States)

    Dinca, Dan-Cristian; Schubert, Jeffrey R.; Callerame, J.

    2008-04-01

    In contrast to transmission X-ray imaging systems where inspected objects must pass between source and detector, Compton backscatter imaging allows both the illuminating source as well as the X-ray detector to be on the same side of the target object, enabling the inspection to occur rapidly and in a wide variety of space-constrained situations. A Compton backscatter image is similar to a photograph of the contents of a closed container, taken through the container walls, and highlights low atomic number materials such as explosives, drugs, and alcohol, which appear as especially bright objects by virtue of their scattering characteristics. Techniques for producing X-ray images based on Compton scattering will be discussed, along with examples of how these systems are used for both novel security applications and for the detection of contraband materials at ports and borders. Differences between transmission and backscatter images will also be highlighted. In addition, tradeoffs between Compton backscatter image quality and scan speed, effective penetration, and X-ray source specifications will be discussed.

  1. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone ...

  2. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... top of page What are the benefits vs. risks? Benefits Bone x-rays are the fastest and easiest ... cancer from excessive exposure to radiation. However, the benefit of an accurate diagnosis far outweighs the risk. The effective radiation dose for this procedure varies. ...

  3. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits Bone x-rays are the fastest and easiest ... cancer from excessive exposure to radiation. However, the benefit of an accurate diagnosis far outweighs the risk. ...

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits Bone x-rays are the fastest and easiest ... evaluation. National and international radiology protection organizations continually review and update the technique standards used by radiology ...

  5. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... benefit of an accurate diagnosis far outweighs the risk. The effective ... more information about radiation dose. Women should always inform their ...

  6. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos ... to current x-ray images for diagnosis and disease management. top of page How is the procedure ...

  7. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... for more information about pregnancy and x-rays. A Word About Minimizing Radiation Exposure Special care is ... encourage linking to this site. × Recommend RadiologyInfo to a friend Send to (friend's e-mail address): From ( ...

  8. High-Resolution X-ray Emission and X-ray Absorption Spectroscopy

    OpenAIRE

    de Groot, F. M. F.

    2001-01-01

    In this review, high-resolution X-ray emission and X-ray absorption spectroscopy will be discussed. The focus is on the 3d transition-metal systems. To understand high-resolution X-ray emission and reso-nant X-ray emission, it is first necessary to spend some time discussing the X-ray absorption process. Section II discusses 1s X-ray absorption, i.e., the K edges, and section III deals with 2p X-ray absorption, the L edges. X-ray emission is discussed in, respectively, the L edges. X-ray emis...

  9. Center for X-Ray Optics, 1986

    International Nuclear Information System (INIS)

    The Center for X-Ray Optics has made substantial progress during the past year on the development of very high resolution x-ray technologies, the generation of coherent radiation at x-ray wavelengths, and, based on these new developments, had embarked on several scientific investigations that would not otherwise have been possible. The investigations covered in this report are topics on x-ray sources, x-ray imaging and applications, soft x-ray spectroscopy, synchrotron radiation, advanced light source and magnet structures for undulators and wigglers

  10. Digital x-ray imaging

    International Nuclear Information System (INIS)

    Digital radiography is progressively replacing conventional (film-based) radiographic techniques promising consistently high levels of image quality, more effective use of radiation and more efficient work practices. At the same time its introduction poses new challenges to those physical scientists who design radiological imaging systems and those who provide scientific/technical support to a clinical radiology service. In this review scientific aspects of those digital x-ray imaging systems which are proving most successful are described. Physical measurement techniques developed to evaluate the imaging performance and radiation dose efficiency of clinical digital radiography systems are outlined. Finally, directions in which digital x-ray imaging technology may evolve in the coming decade are discussed. (author)

  11. Soft x-ray tomoholography

    International Nuclear Information System (INIS)

    We demonstrate an x-ray imaging method that combines Fourier transform holography with tomography (‘tomoholography’) for three-dimensional (3D) microscopic imaging. A 3D image of a diatom shell with a spatial resolution of 140 nm is presented. The experiment is realized by using a small gold sphere as the reference wave source for holographic imaging. This setup allows us to rotate the sample and to collect a number of 2D projections for tomography. (paper)

  12. Soft x-ray tomoholography

    OpenAIRE

    Guehrs, E.; Stadler, A.M.; Flewett, S.; Frömmel, S.; Geilhufe, J.; Pfau, B; Rander, T.; Schaffert, S.; Büldt, G; Eisebitt, S.

    2012-01-01

    We demonstrate an x-ray imaging method that combines Fourier transform holography with tomography ('tomoholography') for three-dimensional (3D) microscopic imaging. A 3D image of a diatom shell with a spatial resolution of 140 nm is presented. The experiment is realized by using a small gold sphere as the reference wave source for holographic imaging. This setup allows us to rotate the sample and to collect a number of 2D projections for tomography.

  13. X-ray tube arrangements

    International Nuclear Information System (INIS)

    A technique for ensuring the rapid correction of both amplitude and offset errors in the deflectional movement of an electron beam along an X-ray emissive target is described. The movement is monitored at at least two positions during a sweep and differences, between the two movements and a desired movement, at these positions are combined in different proportions to produce a corrective servo signal. Such arrangements find application, for example, in computerised tomographic scanners. (author)

  14. M dwarf stars-the by-product of X-ray selected AGN candidates

    Institute of Scientific and Technical Information of China (English)

    Yu Bai; Yan-Chun Sun; Xiang-Tao He; Yang Chen; Jiang-Hua Wu; Qing-Kang Li; Richard F.Green; Wolfgang Voges

    2012-01-01

    X-ray loud M dwarfs are a major source of by-products (contamination)in the X-ray band of the multiwavelength quasar survey.As a by-product,the low dispersion spectra of 22 M dwarfs are obtained in which the spectra of 16 sources are taken for the first time.The spectral types and distances of the sample arc given based on spectral indices CaH2,CaH3,and TiOS.The parameter (ι)TiO/CaH is calculated to separate the different metallicity classes among dwarfs,subdwarfs and extreme subdwarfs.We also discuss the distributions in the diagrams of log( Lx/ Lbol),the ratio between X-ray and bolometric luminosity versus spectral type and infrared colors.

  15. Swift detection of an intermediately long X-ray burst from the very faint X-ray binary XMMU J174716.1-281048

    CERN Document Server

    Degenaar, N; Kaur, R

    2011-01-01

    We report on the Swift detection of a thermonuclear X-ray burst from the very-faint quasi-persistent neutron star X-ray binary XMMU J174716.1-281048, which triggered the satellite's Burst Alert Telescope (BAT) on 2010 August 13. Analysis of the BAT spectrum yields an observed bolometric peak flux of ~4.5E-8 erg/cm2/s, from which we infer a source distance of <8.4 kpc. Follow-up observations with Swift's X-ray Telescope (XRT) suggest that the event had a duration of ~3 h, and classifies as an intermediately long X-ray burst. This is only the second X-ray burst ever reported from this source. Inspection of Swift/XRT observations performed between 2007-2010 suggests that the 2-10 keV accretion luminosity of the system is only ~5E34 erg/s for an assumed distance of 8.4 kpc. Despite being transient, XMMU J174716.1-281048 appears to have been continuously active since its discovery in 2003.

  16. X-ray-powered macronovae

    CERN Document Server

    Kisaka, Shota; Nakar, Ehud

    2015-01-01

    A macronova (or kilonova) was observed as an infrared excess several days after short gamma-ray burst, GRB 130603B. Although the $r$-process radioactivity is widely discussed as an energy source, it requires huge mass of ejecta from a neutron star (NS) binary merger. We propose that the X-ray excess simultaneously observed with the infrared excess can naturally heat the ejecta, leading to the thermal re-emission as observed in infrared. This X-ray-powered model explains both the X-ray and infrared excesses with a single energy source by the central engine like a black hole, and allows for broader parameter region, in particular smaller ejecta mass $\\sim10^{-3}-10^{-2}M_{\\odot}$ with iron mixed as suggested by general relativistic simulations for typical NS-NS mergers, than the previous models. We also discuss the other macronova candidates in GRB 060614 and GRB 080503, and implications for the search of electromagnetic counterparts to gravitational waves.

  17. X-Ray Crystallography Reagent

    Science.gov (United States)

    Morrison, Dennis R. (Inventor); Mosier, Benjamin (Inventor)

    2003-01-01

    Microcapsules prepared by encapsulating an aqueous solution of a protein, drug or other bioactive substance inside a semi-permeable membrane by are disclosed. The microcapsules are formed by interfacial coacervation under conditions where the shear forces are limited to 0-100 dynes per square centimeter at the interface. By placing the microcapsules in a high osmotic dewatering solution. the protein solution is gradually made saturated and then supersaturated. and the controlled nucleation and crystallization of the protein is achieved. The crystal-filled microcapsules prepared by this method can be conveniently harvested and stored while keeping the encapsulated crystals in essentially pristine condition due to the rugged. protective membrane. Because the membrane components themselves are x-ray transparent, large crystal-containing microcapsules can be individually selected, mounted in x-ray capillary tubes and subjected to high energy x-ray diffraction studies to determine the 3-D smucture of the protein molecules. Certain embodiments of the microcapsules of the invention have composite polymeric outer membranes which are somewhat elastic, water insoluble, permeable only to water, salts, and low molecular weight molecules and are structurally stable in fluid shear forces typically encountered in the human vascular system.

  18. X-Ray-powered Macronovae

    Science.gov (United States)

    Kisaka, Shota; Ioka, Kunihito; Nakar, Ehud

    2016-02-01

    A macronova (or kilonova) was observed as an infrared excess several days after the short gamma-ray burst GRB 130603B. Although the r-process radioactivity is widely discussed as an energy source, it requires a huge mass of ejecta from a neutron star (NS) binary merger. We propose a new model in which the X-ray excess gives rise to the simultaneously observed infrared excess via thermal re-emission, and explore what constraints this would place on the mass and velocity of the ejecta. This X-ray-powered model explains both the X-ray and infrared excesses with a single energy source such as the central engine like a black hole, and allows for a broader parameter region than the previous models, in particular a smaller ejecta mass ˜ {10}-3{--}{10}-2{M}⊙ and higher iron abundance mixed as suggested by general relativistic simulations for typical NS-NS mergers. We also discuss the other macronova candidates in GRB 060614 and GRB 080503, and the implications for the search of electromagnetic counterparts to gravitational waves.

  19. Aspergillosis - chest x-ray (image)

    Science.gov (United States)

    ... usually occurs in immunocompromised individuals. Here, a chest x-ray shows that the fungus has invaded the lung ... are usually seen as black areas on an x-ray. The cloudiness on the left side of this ...

  20. Stabilized x-ray generator power supply

    International Nuclear Information System (INIS)

    X-ray diffraction and X-ray fluorescence analysis are very much adopted in laboratories to determine the type and structure of the constituent compounds in solid materials, chemical composition of materials, stress developed on metals etc. These experiments need X-ray beam of fixed intensity and wave length. This can only be achieved by X-ray generator having highly stabilized tube voltage and tube current. This paper describes how X-ray tube high voltage and electron beam current are stabilized. This paper also highlights generation of X-rays, diffractometry and X-ray fluorescence analysis and their wide applications. Principle of operation for stabilizing the X-ray tube voltage and current, different protection circuits adopted, special features of the mains H.V. transformer and H.T. tank are described in this report. (author)

  1. Optical element for X-ray microscopy

    OpenAIRE

    Chadzitaskos, G.

    2008-01-01

    We present a proposal for a X-ray optical element suitable for X-ray microscopy and other X-ray-based display systems. Its principle is based on the Fresnel lenses condition and the Bragg condition for X-ray scattering on a slice of monocrystal. These conditions are fulfilled simultaneously due to a properly machined shape of the monocrystal with a stress at its ends.

  2. Center for X-ray Optics, 1988

    Energy Technology Data Exchange (ETDEWEB)

    1989-04-01

    This report briefly reviews the following topics: soft-x-ray imaging; reflective optics for hard x-rays; coherent XUV sources; spectroscopy with x-rays; detectors for coronary artery imaging; synchrotron-radiation optics; and support for the advanced light source.

  3. X-Ray Exam: Neck (For Parents)

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Neck KidsHealth > For Parents > X-Ray Exam: Neck Print A A A Text Size ... español Radiografía: cuello What It Is A neck X-ray is a safe and painless test that uses ...

  4. Cryotomography x-ray microscopy state

    Science.gov (United States)

    Le Gros, Mark; Larabell, Carolyn A.

    2010-10-26

    An x-ray microscope stage enables alignment of a sample about a rotation axis to enable three dimensional tomographic imaging of the sample using an x-ray microscope. A heat exchanger assembly provides cooled gas to a sample during x-ray microscopic imaging.

  5. Electron beam parallel X-ray generator

    Science.gov (United States)

    Payne, P.

    1967-01-01

    Broad X ray source produces a highly collimated beam of low energy X rays - a beam with 2 to 5 arc minutes of divergence at energies between 1 and 6 keV in less than 5 feet. The X ray beam is generated by electron bombardment of a target from a large area electron gun.

  6. Center for X-ray Optics, 1988

    International Nuclear Information System (INIS)

    This report briefly reviews the following topics: soft-x-ray imaging; reflective optics for hard x-rays; coherent XUV sources; spectroscopy with x-rays; detectors for coronary artery imaging; synchrotron-radiation optics; and support for the advanced light source

  7. X-ray tracing using Geant4

    International Nuclear Information System (INIS)

    We describe an extension to the Geant4 software package that allows it to be used as a general purpose X-ray tracing package. We demonstrate the use of our extension by building a model of the X-ray optics of the X-ray observatory XMM-Newton, calculating its effective area, and comparing the results with the published calibration curves.

  8. Automatic focus algorithms for TDI X-Ray image reconstruction

    Science.gov (United States)

    Dörr, J.; Rosenbaum, M.; Sauer-Greff, W.; Urbansky, R.

    2012-09-01

    In food industry, most products are checked by X-rays for contaminations. These X-ray machines continuously scan the product passing through. To minimize the required X-ray power, a Time, Delay and Integration (TDI) CCD-sensor is used to capture the image. While the product moves across the sensor area, the X-ray angle changes during the pass. As a countermeasure, adjusting the sensor shift speed on a single focal plane of the product can be selected. However, the changing angle result in a blurred image in dependance to the thickness of the product. This so-called ''laminographic effect'' can be compensated individually for one plane by inverse filtering. As the plane of contamination is unknown, the blurred image will be inversely filtered for different planes, but only one of these images shows the correctly focussed object. If the correct image can be found, the plane containing the contamination is identified. In this contribution we demonstrate how the correctly focussed images can be found by analyzing the images of all planes. Different characteristics for correctly and incorrectly focussed planes like sharpness, number of objects and edges are investigated by using image processing algorithms.

  9. Microfabrication of High Resolution X-ray Magnetic Calorimeters

    International Nuclear Information System (INIS)

    Metallic magnetic calorimeter (MMC) is one of the most promising x-ray detector technologies for providing the very high energy resolution needed for future astronomical x-ray imaging spectroscopy. For this purpose, we have developed micro-fabricated 5x5 arrays of MMC of which each individual pixel has excellent energy resolution as good as 3.4 eV at 6 keV x-ray. Here we report on the fabrication techniques developed to achieve good resolution and high efficiency. These include: processing of a thin insulation layer for strong magnetic coupling between the AuEr sensor film and the niobium pick-up coil; production of overhanging absorbers for enhanced efficiency of x-ray absorption; fabrication on SiN membranes to minimize the effects on energy resolution from athermal phonon loss. We have also improved the deposition of the magnetic sensor film such that the film magnetization is nearly completely that is expected from the AuEr sputter target bulk material. In addition, we have included a study of a positional sensitive design, the Hydra design, which allows thermal coupling of four absorbers to a common MMC sensor and circuit.

  10. Measurements of Si hybrid CMOS x-ray detector characteristics

    Science.gov (United States)

    Bongiorno, Stephen D.; Falcone, Abraham D.; Burrows, David N.; Cook, Robert

    2010-07-01

    The recent development of active pixel sensors as X-Ray focal plane arrays will place them in contention with CCDs on future satellite missions. Penn State University (PSU) is working with Teledyne Imaging Sensors (TIS) to develop X-Ray Hybrid CMOS devices (HCDs), a type of active pixel sensor with fast frame rates, adaptable readout timing and geometry, low power consumption, and inherent radiation hardness. CCDs have been used with great success on the current generation of X-Ray telescopes (e.g. Chandra, XMM, Suzaku, and Swift). However, their bucket-brigade readout architecture, which transfers charge across the chip with discrete component readout electronics, results in clockrate limited readout speeds that cause pileup (saturation) of bright sources and an inherent susceptibility to radiation induced displacement damage that limits mission lifetime. In contrast, HCDs read pixels through the detector substrate with low power, on-chip readout integrated circuits. Faster frame rates, achieved with adaptable readout timing and geometry, will allow the next generation's larger effective area telescopes to observe brighter sources free of pileup. In HCDs, radiation damaged lattice sites affect a single pixel instead of an entire row. The PSU X-ray group is currently testing 4 Teledyne HCDs, with low cross-talk CTIA devices in development. We will report laboratory measurements of HCD readnoise, interpixel-capacitance and its impact on event selection, linearity, and energy resolution as a function of energy.

  11. Energy weighted x-ray dark-field imaging

    CERN Document Server

    Pelzer, Georg; Anton, Gisela; Bayer, Florian; Horn, Florian; Kraus, Manuel; Rieger, Jens; Ritter, Andre; Wandner, Johannes; Weber, Thomas; Fauler, Alex; Fiederle, Michael; Wong, Winnie S; Campbell, Michael; Meiser, Jan; Meyer, Pascal; Mohr, Jürgen; Michel, Thilo

    2014-01-01

    The dark-field image obtained in grating-based x-ray phase-contrast imaging can provide information about the objects' microstructures on a scale smaller than the pixel size even with low geometric magnification. In this publication we demonstrate that the dark-field image quality can be enhanced with an energy-resolving pixel detector. Energy-resolved x-ray dark-field images were acquired with a 16-energy-channel photon-counting pixel detector with a 1 mm thick CdTe sensor in a Talbot-Lau x-ray interferometer. A method for contrast-noise-ratio (CNR) enhancement is proposed and validated experimentally. In measurements, a CNR improvement by a factor of 1.14 was obtained. This is equivalent to a possible radiation dose reduction of 23%.

  12. Zernike x-ray ptychography.

    Science.gov (United States)

    Vartiainen, Ismo; Mohacsi, Istvan; Stachnik, Karolina; Guizar-Sicairos, Manuel; David, Christian; Meents, Alke

    2016-02-15

    We present an imaging technique combining Zernike phase-contrast imaging and ptychography. The contrast formation is explained by following the theory of Zernike phase-contrast imaging. The method is demonstrated with x-rays at a photon energy of 6.2 keV, showing how ptychographic reconstruction of a phase sample leads to a Zernike phase-contrast image appearing in the amplitude reconstruction. In addition, the results presented in this Letter indicate an improvement of the resolution of the reconstructed object in the case of Zernike ptychography compared with the conventional one. PMID:26872172

  13. Protonium X-ray spectroscopy

    CERN Document Server

    Gotta, D

    1999-01-01

    The Lyman and Balmer transitions from antiprotonic hydrogen and deuterium were studied extensively at the low-energy-antiproton ring LEAR at CERN in order to determine the strong interaction effects. A first series of experiments $9 was performed with semiconductor and gaseous X-ray detectors. In the last years of LEAR operation using a Bragg crystal spectrometer, strong interaction parameters in the 2p states of antiprotonic hydrogen and deuterium were measured $9 directly. The results of the measurements support the meson-exchange models describing the medium and long range part of the nucleon-antinucleon interaction. (39 refs).

  14. X-ray tomographic apparatus

    International Nuclear Information System (INIS)

    An x-ray tomographic system consists of a radiation source such as gamma or x radiation which produces a fan-shaped beam. The fan is wide enough to encompass the patient circle. The system further includes means for rotating the radiation source about the patient for less than a full rotation, and detectors for detecting the radiation at positions that surround the patient by 1800 plus the angle of the fan beam plus the angle between adjacent fan detectors. Attenuation data from the detectors is sorted into detector fans of attenuation data, then processed. The convolved data is back-projected into an image memory and displayed on a video monitor

  15. X-ray Pulsations in the Supersoft X-ray Binary CAL 83

    OpenAIRE

    Schmidtke, P. C.; Cowley, A. P.

    2005-01-01

    X-ray data reveal that the supersoft X-ray binary CAL 83 exhibits 38.4 minute pulsations at some epochs. These X-ray variations are similar to those found in some novae and are likely to be caused by nonradial pulsations the white dwarf. This is the first detection of pulsations in a classical supersoft X-ray binary.

  16. High-sensitivity CCD-based x-ray detector

    International Nuclear Information System (INIS)

    The detector is designed for imaging measurements requiring relatively high sensitivity and high spatial resolution. The detector can discriminate single X-ray photons, yet has the wide dynamic range (∼10000:1) associated with integrating detectors. A GdO2S2 phosphor screen converts the incoming X-ray image into an optical image. The optical image is coupled (without demagnification) to the CCD image sensor using a fiber optic faceplate. The CCD (Philips Semiconductors) has an area of 4.9 x 8.6 cm with 4000 x 7000 12 μm pixels. A single 12 keV X-ray photon produces a signal of 100 e-. With 2 x 2 pixel binning, the total noise per 24 μm pixel in a 100 s image is ∼30 e-, the detective quantum efficiency is >0.6 at 1 X-ray photon per pixel, and the full image can be read out in <4 s. The spatial resolution is 50 μm. The CCD readout system is fully computer-controlled, allowing flexible operation in time-resolved experiments. The detector has been characterized using visible-light images, X-ray images and time-resolved muscle diffraction measurements.

  17. Development of a 3-D x-ray system

    CERN Document Server

    Evans, J P O

    1993-01-01

    major departure has been the introduction of a dual energy linear x-ray detector array which will allow, in general, the discrimination between organic and inorganic substances. The second design is a compromise between ease of visual inspection for human observers and optimum three-dimensional co-ordinate measurement capability. The system is part of an on going research programme into the possibility of introducing psychological depth cues into the resultant x-ray images. The research presented in this thesis was initiated to enhance the visual interpretation of complex x-ray images, specifically in response to problems encountered in the routine screening of freight by HM. Customs and Excise. This phase of the work culminated in the development of the first experimental machine. During this work the security industry was starting to adopt a new type of x-ray detector, namely the dual energy x-ray sensor. The Department of Transport made available funding to the Police Scientific Development Branch (P.S.D.B...

  18. Viewing spin structures with soft X-ray microscopy

    Directory of Open Access Journals (Sweden)

    Peter Fischer

    2010-09-01

    Full Text Available The spin of the electron and it's associated magnetic moment marks the basic unit for magnetic properties of matter1,2. Magnetism, in particular ferromagnetism and antiferromagnetism is described by a collective order of these spins, where the interaction between individual spins reflects a competition between exchange, anisotropy and dipolar energy terms. As a result the energetically favored ground state of a ferromagnetic system is a rather complex spin configuration, the magnetic domain structure3. Magnetism is one of the eldest scientific phenomena, yet it is one of the most powerful and versatile utilized physical effects in modern technologies, such as in magnetic storage and sensor devices. To achieve highest storage density, the relevant length scales, such as the bit size in disk drives is now approaching the nanoscale and as such further developments have to deal with nanoscience phenomena4–9. Advanced characterization tools are required to fully understand the underlying physical principles. Magnetic microscopes using polarized soft X-rays offer a close-up view into magnetism with unique features, these include elemental sensitivity due to X-ray magnetic dichroism effects as contrast mechanism, high spatial resolution provided by state-of-the-art X-ray optics and fast time resolution limited by the inherent time structure of current X-ray sources, which will be overcome with the introduction of ultrafast and high brilliant X-ray sources.

  19. Comets: mechanisms of x-ray activity

    Science.gov (United States)

    Ibadov, Subhon

    2016-07-01

    Basic mechanisms of X-ray activity of comets are considered, including D-D mechanism corresponding to generation of X-rays due to production of hot short-living plasma clumps at high-velocity collisions between cometary and interplanetary dust particles as well as M-M one corresponding to production of X-rays due to recombination of multicharge ions of solar wind plasma via charge exchange process at their collisions with molecules/atoms of the cometary atmospheres. Peculiarities of the variation of the comet X-ray spectrum and X-ray luminosity with variation of its heliocentric distance are revealed.

  20. Swift Observations of X-ray supernovae

    OpenAIRE

    Li, K. L.; Pun, Chun. S. J.

    2011-01-01

    We present a result of X-ray supernovae (SNe) survey using the Swift satellite public archive. An automatic searching program was designed to search X-ray SNe among all of the Swift archival observations between November 2004 and February 2011. Using the C++ program, 24 X-ray detectable supernovae have been found in the archive and 3 of them were newly-discovered in X-rays which are SN 1986L, SN 2003lx, and SN 2007od. In addition, SN 2003lx is a Type Ia supernova which may be the second X-ray...

  1. X-ray Spectroscopy of Cooling Cluster

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, J.R.; /SLAC; Fabian, A.C.; /Cambridge U., Inst. of Astron.

    2006-01-17

    We review the X-ray spectra of the cores of clusters of galaxies. Recent high resolution X-ray spectroscopic observations have demonstrated a severe deficit of emission at the lowest X-ray temperatures as compared to that expected from simple radiative cooling models. The same observations have provided compelling evidence that the gas in the cores is cooling below half the maximum temperature. We review these results, discuss physical models of cooling clusters, and describe the X-ray instrumentation and analysis techniques used to make these observations. We discuss several viable mechanisms designed to cancel or distort the expected process of X-ray cluster cooling.

  2. Symbiotic stars in X-rays

    OpenAIRE

    Luna, G. J. M.; Sokoloski, J. L.; Mukai, K; Nelson, T.

    2012-01-01

    Until recently, symbiotic binary systems in which a white dwarf accretes from a red giant were thought to be mainly a soft X-ray population. Here we describe the detection with the X-ray Telescope (XRT) on the Swift satellite of nine white dwarf symbiotics that were not previously known to be X-ray sources and one that had previously been detected as a supersoft X-ray source. The nine new X-ray detections were the result of a survey of 41 symbiotic stars, and they increase the number of symbi...

  3. X-ray characterization of CMOS imaging detector with high resolution for fluoroscopic imaging application

    International Nuclear Information System (INIS)

    This paper introduces complementary metal-oxide semiconductor (CMOS) active pixel sensor (APS)-based X-ray imaging detectors with high spatial resolution for medical imaging application. In this study, our proposed X-ray CMOS imaging sensor has been fabricated by using a 0.35 µm 1 Poly 4 Metal CMOS process. The pixel size is 100 µm×100 µm and the pixel array format is 24×96 pixels, which provide a field-of-view (FOV) of 9.6 mm×2.4 mm. The 14.3-bit extend counting analog-to digital converter (ADC) with built-in binning mode was used to reduce the area and simultaneously improve the image resolution. Both thallium-doped CsI (CsI:Tl) and Gd2O2S:Tb scintillator screens were used as converters for incident X-rays to visible light photons. The optical property and X-ray imaging characterization such as X-ray to light response as a function of incident X-ray exposure dose, spatial resolution and X-ray images of objects were measured under different X-ray energy conditions. The measured results suggest that our developed CMOS-based X-ray imaging detector has the potential for fluoroscopic imaging and cone-beam computed tomography (CBCT) imaging applications

  4. X-ray characterization of CMOS imaging detector with high resolution for fluoroscopic imaging application

    Science.gov (United States)

    Cha, Bo Kyung; Kim, Cho Rong; Jeon, Seongchae; Kim, Ryun Kyung; Seo, Chang-Woo; Yang, Keedong; Heo, Duchang; Lee, Tae-Bum; Shin, Min-Seok; Kim, Jong-Boo; Kwon, Oh-Kyung

    2013-12-01

    This paper introduces complementary metal-oxide semiconductor (CMOS) active pixel sensor (APS)-based X-ray imaging detectors with high spatial resolution for medical imaging application. In this study, our proposed X-ray CMOS imaging sensor has been fabricated by using a 0.35 μm 1 Poly 4 Metal CMOS process. The pixel size is 100 μm×100 μm and the pixel array format is 24×96 pixels, which provide a field-of-view (FOV) of 9.6 mm×2.4 mm. The 14.3-bit extend counting analog-to digital converter (ADC) with built-in binning mode was used to reduce the area and simultaneously improve the image resolution. Both thallium-doped CsI (CsI:Tl) and Gd2O2S:Tb scintillator screens were used as converters for incident X-rays to visible light photons. The optical property and X-ray imaging characterization such as X-ray to light response as a function of incident X-ray exposure dose, spatial resolution and X-ray images of objects were measured under different X-ray energy conditions. The measured results suggest that our developed CMOS-based X-ray imaging detector has the potential for fluoroscopic imaging and cone-beam computed tomography (CBCT) imaging applications.

  5. Spectroscopic Measurement of L X-rays Emitted by Transuranium Elements by Using TES Microcalorimeter

    Science.gov (United States)

    Maeda, M.; Maehata, K.; Iyomoto, N.; Ishibashi, K.; Takasaki, K.; Nakamura, K.; Aoki, K.; Mitsuda, K.; Tanaka, K.

    2014-09-01

    Energy spectra of L X-rays emitted by Np and uranium isotopes progenies of Am and plutonium isotopes were measured by a transition edge sensor (TES) microcalorimeter for demonstration of peak separation with high energy resolution. L X-ray photons emitted by transuranium (TRU) elements can to be utilized for a nondestructive TRU monitor. Major L X-ray peaks are clearly distinguished in the energy spectrum of L X-rays obtained by the simultaneous measurement for radiation sources of Am and plutonium isotopes. The value of full width at half maximum energy resolution is 60.21 eV for a peak corresponding to Np L X -rays of 17.751 keV in Am source measurement. Comparable energy resolutions were obtained in other experiments. This measurement demonstrated separation of Am and plutonium isotopes by L X-ray spectroscopy using TES microcalorimeter.

  6. Miniature x-ray point source for alignment and calibration of x-ray optics

    International Nuclear Information System (INIS)

    A miniature x-ray point source of high brightness similar to that of Rovinsky, et al. is described. One version of the x-ray source is used to align the x-ray optics on the Argus and Shiva laser systems. A second version is used to determine the spatial and spectral transmission functions of the x-ray optics. The spatial and spectral characteristics of the x-ray emission from the x-ray point source are described. The physical constraints including size, intensity and thermal limitations, and useful lifetime are discussed. The alignment and calibration techniques for various x-ray optics and detector combinations are described

  7. Management of dental x-ray exposure

    International Nuclear Information System (INIS)

    The effects of dental x-ray exposure and how they might be minimized were reviewed. The frequency of dental x-ray exposures in Japan was presented for each year, sex, age group and site of x-ray photography separately. The doses of exposure at various parts of the body per x-ray examination were also presented, and the probabilities of genetic damage, and of development of leukemia or cancer were calculated. The allowable dose of exposure for radiation workers was discussed. It is important to take account of radiation quality, area of irradiation field, and posture of patients to minimize the radiation effect. The actual statistics on the x-ray exposure at the dentists, distribution of the dispersed radiation in the x-ray room, methods of protection against exposure, and plans and designs of the x-ray room were discussed. (Kaihara, S.)

  8. X ray imaging microscope for cancer research

    Science.gov (United States)

    Hoover, Richard B.; Shealy, David L.; Brinkley, B. R.; Baker, Phillip C.; Barbee, Troy W., Jr.; Walker, Arthur B. C., Jr.

    1991-01-01

    The NASA technology employed during the Stanford MSFC LLNL Rocket X Ray Spectroheliograph flight established that doubly reflecting, normal incidence multilayer optics can be designed, fabricated, and used for high resolution x ray imaging of the Sun. Technology developed as part of the MSFC X Ray Microscope program, showed that high quality, high resolution multilayer x ray imaging microscopes are feasible. Using technology developed at Stanford University and at the DOE Lawrence Livermore National Laboratory (LLNL), Troy W. Barbee, Jr. has fabricated multilayer coatings with near theoretical reflectivities and perfect bandpass matching for a new rocket borne solar observatory, the Multi-Spectral Solar Telescope Array (MSSTA). Advanced Flow Polishing has provided multilayer mirror substrates with sub-angstrom (rms) smoothnesss for the astronomical x ray telescopes and x ray microscopes. The combination of these important technological advancements has paved the way for the development of a Water Window Imaging X Ray Microscope for cancer research.

  9. Parametric X-Ray Radiation

    Science.gov (United States)

    Shchagin, Alexander

    1997-10-01

    The main PXR properties [1,2] are considered in the paper: energy, width, smooth tuning of monochromatic PXR spectral line; fine structure and absolute differential yields of PXR in the vicinity of and at angular distances from Brag directions; angular spread of the PXR beam; the influence of incident electron energy and of the density effect on the PXR properties; linear polarization of PXR; background in PXR spectra. Experimental setups for linacs and the results of measurements are discussed. Experimental data are compared to theoretical calculations at PXR energies between 5 and 400 keV for incident electron energies ranging from 15 to 1200 MeV. Possible applications of PXR as a new source of a bright, tunable X-ray beam in science and industry are discussed. [1] A.V. Shchagin and N.A. Khizhnyak, NIM B119, 115-122 (1996). [2] A.V. Shchagin and X.K. Maruyama, "Parametric X-rays", a chapter in the book "Accelerator-based Atomic Physics Techniques and Applications", edited by S.M. Shafroth and J.C. Austin, AIP Press, 1997, pp 279-307.

  10. Full-field transmission x-ray imaging with confocal polycapillary x-ray optics

    OpenAIRE

    Sun, Tianxi; MacDonald, C. A.

    2013-01-01

    A transmission x-ray imaging setup based on a confocal combination of a polycapillary focusing x-ray optic followed by a polycapillary collimating x-ray optic was designed and demonstrated to have good resolution, better than the unmagnified pixel size and unlimited by the x-ray tube spot size. This imaging setup has potential application in x-ray imaging for small samples, for example, for histology specimens.

  11. Calibration Of X-Ray Imaging Devices For Accurate Intensity Measurement

    International Nuclear Information System (INIS)

    National Security Technologies (NSTec) has developed calibration procedures for X-ray imaging systems. The X-ray sources that are used for calibration are both diode type and diode/fluorescer combinations. Calibrating the X-ray detectors is key to accurate calibration of the X-ray sources. Both energy dispersive detectors and photodiodes measuring total flux were used. We have developed calibration techniques for the detectors using radioactive sources that are traceable to the National Institute of Standards and Technology (NIST). The German synchrotron at Physikalische Technische Bundestalt (PTB) is used to calibrate silicon photodiodes over the energy range from 50 eV to 60 keV. The measurements on X-ray cameras made using the NSTec X-ray sources have included quantum efficiency averaged over all pixels, camera counts per photon per pixel, and response variation across the sensor. The instrumentation required to accomplish the calibrations is described. X-ray energies ranged from 720 eV to 22.7 keV. The X-ray sources produce narrow energy bands, allowing us to determine the properties as a function of X-ray energy. The calibrations were done for several types of imaging devices. There were back illuminated and front illuminated CCD (charge coupled device) sensors, and a CID (charge injection device) type camera. The CCD and CID camera types differ significantly in some of their properties that affect the accuracy of X-ray intensity measurements. All cameras discussed here are silicon based. The measurements of quantum efficiency variation with X-ray energy are compared to models for the sensor structure. Cameras that are not back-thinned are compared to those that are.

  12. CALIBRATION OF X-RAY IMAGING DEVICES FOR ACCURATE INTENSITY MEASUREMENT

    Energy Technology Data Exchange (ETDEWEB)

    Haugh, M J; Charest, M R; Ross, P W; Lee, J J; Schneider, M B; Palmer, N E; Teruya, A T

    2012-02-16

    National Security Technologies (NSTec) has developed calibration procedures for X-ray imaging systems. The X-ray sources that are used for calibration are both diode type and diode/fluorescer combinations. Calibrating the X-ray detectors is key to accurate calibration of the X-ray sources. Both energy dispersive detectors and photodiodes measuring total flux were used. We have developed calibration techniques for the detectors using radioactive sources that are traceable to the National Institute of Standards and Technology (NIST). The German synchrotron at Physikalische Technische Bundestalt (PTB) is used to calibrate silicon photodiodes over the energy range from 50 eV to 60 keV. The measurements on X-ray cameras made using the NSTec X-ray sources have included quantum efficiency averaged over all pixels, camera counts per photon per pixel, and response variation across the sensor. The instrumentation required to accomplish the calibrations is described. X-ray energies ranged from 720 eV to 22.7 keV. The X-ray sources produce narrow energy bands, allowing us to determine the properties as a function of X-ray energy. The calibrations were done for several types of imaging devices. There were back illuminated and front illuminated CCD (charge coupled device) sensors, and a CID (charge injection device) type camera. The CCD and CID camera types differ significantly in some of their properties that affect the accuracy of X-ray intensity measurements. All cameras discussed here are silicon based. The measurements of quantum efficiency variation with X-ray energy are compared to models for the sensor structure. Cameras that are not back-thinned are compared to those that are.

  13. AMiBA: scaling relations between the integrated Compton-y and X-ray derived temperature, mass, and luminosity

    OpenAIRE

    Huang, Chih-Wei Locutus; Wu, Jiun-Huei Proty; Ho, Paul T. P.; Koch, Patrick M.; Liao, Yu-Wei; Lin, Kai-Yang; Liu, Guo-Chin; Molnar, Sandor M.; Nishioka, Hiroaki; Umetsu, Keiichi; Wang, Fu-Cheng; Altamirano, Pablo; Birkinshaw, Mark; Chang, Chia-Hao; Chang, Shu-Hao

    2009-01-01

    We investigate the scaling relations between the X-ray and the thermal Sunyaev-Zel'dovich Effect (SZE) properties of clusters of galaxies, using data taken during 2007 by the Y.T. Lee Array for Microwave Background Anisotropy (AMiBA) at 94 GHz for the six clusters A1689, A1995, A2142, A2163, A2261, and A2390. The scaling relations relate the integrated Compton-y parameter Y_{2500} to the X-ray derived gas temperature T_{e}, total mass M_{2500}, and bolometric luminosity L_X within r_{2500}. O...

  14. Cost effective segmented scintillating converters for hard x-rays

    International Nuclear Information System (INIS)

    Thick segmented scintillating converters coupled to optical imaging detectors offer the advantage of large area, high stopping power sensors for high energy X-ray digital imaging. The recent advent of high resolution and solid state optical sensors such as amorphous silicon arrays and CCD optical imaging detectors makes it feasible to build large, cost effective imaging arrays. This technology, however, shifts the sensor cost burden to the segmented scintillators needed for imaging. The required labor intensive fabrication of high resolution, large area hard X-ray converters results in high cost and questionable manufacturability on a large scale. The authors report on recent research of a new segmented X-ray imaging converter. This converter is fabricated using vacuum injection and crystal growth methods to induce defect free, high density scintillating fibers into a collimator matrix. This method has the potential to fabricate large area (>400 cm2), thick (10 cm) segmented scintillators. Spatial resolution calculations of these scintillator injected collimators show that the optical light spreading is significantly reduced compared to single crystalline scintillators and sub-millimeter resolution can be achieved for 10 MeV photons. They have produced 2.5 cm thick converters and sub-millimeter resolution X-ray images acquired with the segmented converter coupled to a cooled CCD camera provided the resolution to characterize the converter efficiency and noise. The proposed concept overcomes the above mentioned limitations by producing a cost-effective technique of fabricating large area X-ray scintillator converters with high stopping power and high spatial resolution. This technology will readily benefit diverse fields such as particle physics, astronomy, medicine, as well as industrial nuclear and non-destructive testing

  15. X-ray microtomography: applications and developments

    International Nuclear Information System (INIS)

    Full text: X-ray microtomography has followed a classical development path being originally available only to those with the expertise to piece together the often cumbersome components to required to make a practical x-ray microtomography system. Subsequent technological and scientific advances have meant that x-ray microtomography instruments are now off-the-shelf items with a cost well within the equipment budgets of research institutions and industry. The technological advances that have contributed to the development of x-ray microtomography include commercially available x-ray micro-sources, high-resolution CCD cameras and highspeed, low-cost computers. The scientific developments have been predominantly in image reconstruction. Some of these scientific developments are, with the advantage of hindsight, very simple while others, such as resolution enhancement using the Fresnel fringes in x-ray projection images, are not so intuitive. As a consequence of the availability of 'black-box' instruments, x-ray microtomography is spreading to a wide range of applications. The materials most suited to examination by x-ray microtomography are those with a medium level of x-ray absorption such as bone, teeth, rocks, porous metals, composite materials and plant materials. For these materials, 3D information can be obtained at resolutions comparable to the resolution of a high-quality optical microscope. A few of these applications will be demonstrated in the presentation. Technological advances that aid x-ray microtomography will continue with x-ray sources becoming smaller, computers becoming faster and CCD cameras having increased numbers of pixels. It will be interesting to see if nano x-ray microtomography is achieved. Developments in x-ray microtomography are required in areas such as contrast enhancement particularly for problematic materials such as soft tissue and low-density polymers. For low-density polymers x-ray absorption is very low while for soft tissue

  16. The X-ray-Optical Relations for Nine Clusters at z = 0.7-1.1

    CERN Document Server

    Rumbaugh, Nick; Gal, Roy R; Lemaux, Brian C; Lubin, Lori M; Fassnacht, Chris D; Squires, Gordon K

    2012-01-01

    We use Chandra observations of nine optically and X-ray selected clusters in five different structures at z ~ 0.7-1.1 from the Observations of Redshift Evolution in Large-Scale Environments (ORELSE) survey to study diffuse X-ray emission from galaxy clusters. X-ray gas temperatures and bolometric rest-frame luminosities are measured for each cluster in the sample. We present new redshift measurements, derived from dataobtained using the Deep Imaging Multi-Object Spectrograph on the Keck 10-m telescope, for two clusters in the RX J0910 supercluster at z ~ 1.1, from which velocity dispersions are measured. Dispersions for all clusters are combined with X-ray luminosities and gas temperatures to evaluate how the cluster properties compare to low-redshift scaling relations. We also measure the degree of substructure in each cluster by examining the velocity histograms, performing Dressler-Shectman tests, and computing the offsets between the X-ray emission center and optically-derived centroids. We find that only...

  17. X-ray and optical spectroscopy of the massive young open cluster IC1805

    CERN Document Server

    Rauw, Gregor

    2016-01-01

    Very young open clusters are ideal places to study the X-ray properties of a homogeneous population of early-type stars. In this respect, the IC1805 open cluster is very interesting as it hosts the O4If$^+$ star HD15570 thought to be in an evolutionary stage intermediate between a normal O-star and a Wolf-Rayet star. Such a star could provide a test for theoretical models aiming at explaining the empirical scaling relation between the X-ray and bolometric luminosities of O-type stars. We have observed IC1805 with XMM-Newton and further collected optical spectroscopy of some of the O-star members of the cluster. The optical spectra allow us to revisit the orbital solutions of BD+60$^{\\circ}$ 497 and HD15558, and provide the first evidence of binarity for BD+60$^{\\circ}$ 498. X-ray emission from colliding winds does not appear to play an important role among the O-stars of IC1805. Notably, the X-ray fluxes do not vary significantly between archival X-ray observations and our XMM-Newton pointing. The very fast r...

  18. The X-ray Properties of Million Solar Mass Black Holes

    CERN Document Server

    Plotkin, Richard M; Haardt, Francesco; Miller, Brendan P; Wood, Callum J L; Reines, Amy E; Wu, Jianfeng; Greene, Jenny E

    2016-01-01

    We present new Chandra X-ray observations of seven low-mass black holes (~1e6 Msun) accreting at low Eddington ratios between -2.0X-ray properties of these seven low-mass active galactic nuclei (AGN) to a total of 73 other low-mass AGN in the literature with published Chandra observations (with Eddington ratios extending from -2.0X-ray to ultraviolet luminosity ratios (aox), or in their X-ray spectral shapes. Furthermore, the aox distribution of low-L/Ledd AGN displays an X-ray weak tail that is also observed within high-L/Ledd objects. Our results indicate that between -2bolometric luminosity estimates for our low-L/Ledd objects with new Chandra obs...

  19. Diffuse X-Ray Emission from Late-Type Galaxy Haloes

    CERN Document Server

    Benson, A J; Frenk, C S; White, S D M

    1999-01-01

    Current theories of galaxy formation predict that spiral galaxies are embedded in a reservoir of hot gas. This gas is able to cool onto the galaxy replenishing cold gas that is consumed in star formation. Estimates of the X-ray luminosity emitted in the cooling region suggest a bolometric luminosity of order 10 x 10^41 ergs/s. We have used ROSAT PSPC data to search for extended X-ray emission from the haloes of three nearby, massive, late-type galaxies: NGC 2841, NGC 4594 and NGC 5529. We infer 95% upper limits on the bolometric X-ray luminosities of the haloes of NGC 2841, NGC 4594 and NGC 5529 of 0.4, 1.2 and 3.8 x 10^41 ergs/s respectively. Thus the true luminosity lies well below the straightforward theoretical prediction. We discuss this discrepancy and suggest a number of ways in which the theoretical model can be brought into agreement with the observational results. A possible solution is that the gravitational potentials of these galaxies' dark matter haloes are weaker than assumed in the current mod...

  20. An application of active optics to x-ray imaging: X-mas (x-ray milli arc-second) Project

    Science.gov (United States)

    Tsujimoto, Masahiro; Kitamoto, Shunji; Ohkubo, Yohsuke; Sato, Jun'ichi; Watanabe, Takeshi; Sudoh, Keisuke; Sekiguchi, Akiko; Suga, Kazuharu; Sekiguchi, Hiroyuki

    2006-06-01

    We report the current status of the "X-mas" (X-ray milli-arcsecond) project. X-mas is an application of the AO technology to the X-ray optics, aiming to obtain high-resolution defraction-limited X-ray images. Our X-ray telescope employs the Newton optics with a paraboloid primary and a 31-element deformable secondary mirrors. The aperture of the primary mirror is 80 millimeters with the focal length of 2 meters. Multi-layer coating of the mirrors by silicon and molybdenum realizes a large reflectivity of ~60% for the primary and 30-50% for the secondary mirror at 13.5 nm, which enables us to construct a normal incidence optics at this wavelength. We use a laser guide source and a wave front sensor to optimize the form of the secondary deformable mirror for the purpose of offsetting the large-scale figure errors in the X-ray optics. A back-side illumination X-ray CCD detector manufactured by Hamamatsu Photonics is used for X-ray detections. We have assembled all these elements and started to accumulate data. Closed-loop AO is in operation for the laser guide source. Likely X-ray images are obtained through the telescope. The results in 2005-2006 are presented.

  1. Anomalous x-ray scattering

    International Nuclear Information System (INIS)

    The availability of tunable synchrotron radiation has made it possible systematically to perform x-ray diffraction studies in regions of anomalous scattering near absorption edges, e.g. in order to derive phase information for crystal structure determination. An overview is given of recent experimental and theoretical work and discuss the properties of the anomalous atomic scattering factor, with emphasis on threshold resonances and damping effects. The results are applied to a discussion of the very strong anomalous dispersion recently observed near the L3 edge in a cesium complex. Also given is an overview of elements and levels where similar behavior can be expected. Finally, the influence of solid state and chemical effects on the absorption edge structure is discussed. 64 references

  2. Submicron X-ray diffraction

    International Nuclear Information System (INIS)

    At the Advanced Light Source in Berkeley the authors have instrumented a beam line that is devoted exclusively to x-ray micro diffraction problems. By micro diffraction they mean those classes of problems in Physics and Materials Science that require x-ray beam sizes in the sub-micron range. The beam line has a unity magnification toroidal mirror that produces a 50 by 200 micron focus just inside an x-ray hutch at the position of an x-y slit. The beam path in the hutch consists of source defining slits, a four bounce Ge or Si monochromator, followed by elliptically bent Kirkpatrick-Baez mirror pair which focuses the beam from the slits to sub micron dimensions (0.8 x 0.8 microns). An important feature of this arrangement is the ability to switch between white and monochromatic beams that are essential for characterizing crystals or crystal grains in the sub-micron range. Since sample rotation is fixed they have facilities for precision translation of the specimen to allow them to scan different crystal regions or grains. The sample stage rests on a state of the art six-circle diffractometer equipped with encoders in the main rotation stages calibrated to a second of arc. The detector is a 4K x 4K CCD (Bruker) with a 9 x 9 cm view area mounted on a detector arm that can be positioned around the sample. The detector itself can also be positioned to better than 1 micron along the detector arm. Using this facility they have been able to measure the orientation structure of single grains of passivated or buried Al interconnect test structures. Such structures or their equivalents are important in connecting individual components on integrated circuits. Their sub-micron dimensions result in very high current densities that can result in interconnect failures. The variation in sub-grain structure in a single grain is rich in detail. They have obtained detailed maps of misorientations in single grains using white beam Laue diffraction patterns From these they have been

  3. X-ray intensifying screens

    International Nuclear Information System (INIS)

    An x-ray intensifying screen comprises a support which has a luminescent composition comprising an isotropic phosphor and a polymer having an index of refraction within 0.02 of that of the phosphor over at least 80 percent of its emission spectrum. The support has an index of refraction up to or equal to 0.05 units higher than that of the phosphor and has a reflection optical density of at least 1.7 to light emitted by the phosphor. A preferred luminescent composition comprises Kl:Tl, Rbl:Tl at BaSrFCl:Eu mixed with two monomers such as 1-naphthylmethylmethacrylate, S(1-naphthylmethyl) thioacrylate, 1-bromo-2-naphthylacrylate, and benzyl methacrylate, coated on black anodised Al and polymerised in situ. The ratio of monomers is adjusted to give the desired refractive index. Other phosphors, polymers and supports are specified together with the preparation of the monomers and polymers. (author)

  4. X-ray flat panel detectors and X-ray tubes contributing to development of X-ray diagnostic systems

    International Nuclear Information System (INIS)

    X-ray flat panel detectors (FPDs) and X-ray tubes are key devices allowing X-ray diagnostic systems to support more sophisticated medical care. FPDs provide valuable information for the diagnosis of various diseases through the conversion of X-ray images of the human body into electronic signals, while X-ray tubes are used in a wide range of applications such as computed tomography (CT), angiography, fluoroscopy, mammography, and dental systems. Toshiba Electron Tubes and Devices Co., Ltd. has developed and commercialized FPDs providing high-quality diagnostic X-ray images with low dose exposure through the development of cutting-edge technologies including a fine crystal formation technology for cesium iodide (CsI) scintillators, thin-film transistor (TFT) arrays with photodiodes, and so on. In the field of X-ray tubes that can generate a high output of X-rays, we have developed a liquid metal hydrodynamic bearing (LM bearing) technology for various diagnostic systems including medical CT systems with a long lifetime and high rotation speed, and cardiovascular imaging systems with quiet operation. Furthermore, LM bearing technology reduces the burden on the environment by replacing insulating oil with water coolant for the cooling system and making the X-ray tubes more compact. (author)

  5. Development of confocal micro X-ray fluorescence instrument using two X-ray beams

    International Nuclear Information System (INIS)

    A new confocal micro X-ray fluorescence instrument was developed. This instrument has two independent micro X-ray tubes with Mo targets. A full polycapillary X-ray lens was attached to each X-ray tube. Another half polycapillary lens was attached to a silicon drift X-ray detector (SDD). The focal spots of the three lenses were adjusted to a common position. The effects of the excitation of two X-ray beams were investigated. The instrument enabled highly sensitive three-dimensional X-ray fluorescence analysis. We confirmed that the X-ray fluorescence intensity from the sample increased by applying the two independent X-ray tubes in confocal configuration. Elemental depth profiling of black wheat was demonstrated with the result that each element in the surface coat of a wheat grain showed unique distribution

  6. Acoustooptics of x-rays

    Energy Technology Data Exchange (ETDEWEB)

    Balakhanov, M.V.; Pustovoyt, V.I.; Radzhabov, R.U.; Khabibullayev, P.K.

    Scattering of x-rays by acoustic phonons in crystals during excitation of a noise phonon flux thermodynamically at equilibrium is analyzed from the standpoint of the dynamic diffraction theory, emphasis being put on the differences with the conventional acoustooptic effect attributable to lower frequencies and smaller amplitudes. The structural peak and the diffusional peak are calculated from known relations for the intensity of scattering in each mode, assuming that the Laue condition is satisfied. Interaction of x-rays and an acoustic wave is considered, the conditions for a diffraction peak being determined by the relations between location of that peak and angular dimensions of the structural peak. Experiments were performed in crystals of photosensitive piezoelectric semiconductors with phonon generation. Rectangular or variable-shape voltage pulses with amplitudes up to 800 V were applied to 6-60 ..mu..m thick CdS crystals at repetition rates up to 800 Hz. The electron concentration was (1.3-4.5) x 10/sup 14/ cm/sup -3/ and the electron mobility, according to saturation of the current-voltage characteristics, was differentially in time. The results reveal sharp anisotropy of scattering, evident in the dependence of scattering intensity on the angle of crystal rotation and the resulting lobar scattering pattern. Structural scattering varies exponentially and diffusional scattering varies linearly with increasing amplitude of the applied voltage. According to the dependence of the spectral density of phonon generation on the concentration of charge carriers, the phase of the scattering effect changes upon transition from the structural range to the diffusional range. 8 references, 3 figures.

  7. Soft x-ray interferometry

    International Nuclear Information System (INIS)

    The purpose of the soft x-ray interferometry workshop held at Lawrence Berkeley Laboratory was to discuss with the scientific community the proposed technical design of the soft x-ray Fourier-transform spectrometer being developed at the ALS. Different design strategies for the instrument's components were discussed, as well as detection methods, signal processing issues, and how to meet the manufacturing tolerances that are necessary for the instrument to achieve the desired levels of performance. Workshop participants were encouraged to report on their experiences in the field of Fourier transform spectroscopy. The ALS is developing a Fourier transform spectrometer that is intended to operate up to 100 eV. The motivation is solely improved resolution and not the throughput (Jaquinot) or multiplex (Fellgett) advantage, neither of which apply for the sources and detectors used in this spectral range. The proposed implementation of this is via a Mach-Zehnder geometry that has been (1) distorted from a square to a rhombus to get grazing incidence of a suitable angle for 100 eV and (2) provided with a mirror-motion system to make the path difference between the interfering beams tunable. The experiment consists of measuring the emergent light intensity (I(x)) as a function of the path difference (x). The resolving power of the system is limited by the amount of path difference obtainable that is 1 cm (one million half-waves at 200 angstrom wavelength) in the design thus allowing a resolving power of one million. The free spectral range of the system is limited by the closeness with which the function I(x) is sampled. It is proposed to illuminate a helium absorption cell with roughly 1%-band-width light from a monochromator thus allowing one hundred aliases without spectral overlap even for sampling of I(x) at one hundredth of the Nyquist frequency

  8. Evaluation of digital x-ray detectors for medical imaging applications

    OpenAIRE

    Konstantinidis, A.

    2011-01-01

    Digital x-ray detectors are now the detector of choice in many X-ray examinations. They have been accepted into clinical practice over the past decade but there are still ongoing developments in the technology. Complementary metal oxide semiconductor (CMOS) active pixel sensors (APS) are a novel digital technology that offers advantages compared to some of the more established approaches (charge-coupled devices (CCD), thin film transistor arrays (TFT) and CMOS passive pixel sensors (PPS)). Th...

  9. X-ray monitoring for astrophysical applications on Cubesat

    Science.gov (United States)

    Pina, L.; Hudec, R.; Inneman, A.; Cerna, D.; Jakubek, J.; Sieger, L.; Dániel, V.; Cash, W.; Mikulickova, L.; Pavlica, R.; Belas, E.; Polak, J.

    2015-05-01

    The primary objective of the project VZLUSAT-1 is the development, manufacturing, qualification and experimental verification of products and technologies in Earth orbit (IOD - In-Orbit Demonstration). This work addresses the issue of X-ray monitoring for astrophysical applications. The proposed wide-field optical system has not been used in space yet. The proposed novel approach is based on the use of 1D "Lobster eye" optics in combination with Timepix X-ray detector in the energy range 3 - 40 keV. The proposed project includes theoretical study and a functional sample of the Timepix X-ray detector with multifoil wide-field X-ray "Lobster eye" optics. Using optics to focus X-rays on a detector is the only solution in cases the intensity of impinging X-ray radiation is below the sensitivity of the detector, e.g. while monitoring astrophysical objects in space, or phenomena in the Earth's atmosphere. On board the functions and features of Radiation Hardened Composite Housing (RHCH), Solar panels based on composite substrate and Hollow Retro Reflector Array based on composite (HRRA) will be verified. To verify the properties of the developed products the satellite is equipped by Health Monitoring system (HM). HM system includes temperature, volatiles, radiation and mechanical properties sensors. The custom ADCS algorithms are being developed within the project. Given the number of IOD experiments and the necessary power the 1U CubeSat is equipped with Composite Deployable Panels (CDP) where HM panels and additional Solar panels are located. Satellite platform is assembled from commercial parts. Mission VZLUSAT-1 is planned for 6 months with launch in 2016.

  10. Soft x-ray polarimeter laboratory tests

    Science.gov (United States)

    Murphy, Kendrah D.; Marshall, Herman L.; Schulz, Norbert S.; Jenks, Kevin; Sommer, Sophie J. B.; Marshall, Eric A.

    2010-07-01

    Multilayer-coated optics can strongly polarize X-rays and are central to a new design of a broad-band, soft X-ray polarimeter. We have begun laboratory work to verify the performance of components that could be used in future soft X-ray polarimetric instrumentation. We have reconfigured a 17 meter beamline facility, originally developed for testing transmission gratings for Chandra, to include a polarized X-ray source, an X-ray-dispersing transmission grating, and a multilayer-coated optic that illuminates a CCD detector. The X-rays produced from a Manson Model 5, multi-anode source are polarized by a multilayer-coated flat mirror. The current configuration allows for a 180 degree rotation of the source in order to rotate the direction of polarization. We will present progress in source characterization and system modulation measurements as well as null and robustness tests.

  11. X-rays for medical use

    Science.gov (United States)

    Hessenbruch, A.

    1995-11-01

    1995 is the centenary of the discovery of X-rays by the German physicist Wilhelm C Rontgen. In the past hundred years, the new rays have developed from being unknown to finding application in many walks of life, not least in medicine. This is so much so that in common speech the word `x-ray` refers not to a form of radiation but to an X-ray photograph taken for the purposes of diagnosis (as in: `I had an X-ray done to see if my leg was broken`). X-rays are now used routinely, and they are used both for diagnosis and for therapy. This paper will give an outline of the use of X-rays in medicine throughout our present century.

  12. Handbook of X-Ray Data

    CERN Document Server

    Zschornack, Günter

    2007-01-01

    This sourcebook is intended as an X-ray data reference for scientists and engineers working in the field of energy or wavelength dispersive X-ray spectrometry and related fields of basic and applied research, technology, or process and quality controlling. In a concise and informative manner, the most important data connected with the emission of characteristic X-ray lines are tabulated for all elements up to Z = 95 (Americium). This includes X-ray energies, emission rates and widths as well as level characteristics such as binding energies, fluorescence yields, level widths and absorption edges. The tabulated data are characterized and, in most cases, evaluated. Furthermore, all important processes and phenomena connected with the production, emission and detection of characteristic X-rays are discussed. This reference book addresses all researchers and practitioners working with X-ray radiation and fills a gap in the available literature.

  13. Clinical X-ray diagnostics. v. 1

    International Nuclear Information System (INIS)

    After introductory remarks on historical aspects of the development of X-ray diagnostics, the physical and technological fundamentals of the generation and recording of radiographs are elaborated. In a comprehensive chapter such topics as X-rays, X-ray tubes, X-ray generators, contrast media, interrelations between X-rays and patients as well as classical and recent methods of recording with regard to geometrical conditions, and of picture quality are outlined. Brief notes on analysis, documentation and filing of radiographs are added. Physico-technological fundamentals of radiation protection, remarks concerning radiation protection in the GDR, and special problems of radiation protection as to X-ray diagnostics are discussed

  14. Radiation safety in X-ray facilities

    International Nuclear Information System (INIS)

    The guide specifies the radiation safety requirements for structural shielding and other safety arrangements used in X-ray facilities in medical and veterinary X-ray activities and in industry, research and education. The guide is also applicable to premises in which X-ray equipment intended for radiation therapy and operating at a voltage of less than 25 kV is used. The guide applies to new X-ray facilities in which X-ray equipment that has been used elsewhere is transferred. The radiation safety requirements for radiation therapy X-ray devices operating at a voltage exceeding 25 kV, and for the premices in which such devices are used, are set out in Guide ST 2.2

  15. Radiation safety in X-ray facilities

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-09-01

    The guide specifies the radiation safety requirements for structural shielding and other safety arrangements used in X-ray facilities in medical and veterinary X-ray activities and in industry, research and education. The guide is also applicable to premises in which X-ray equipment intended for radiation therapy and operating at a voltage of less than 25 kV is used. The guide applies to new X-ray facilities in which X-ray equipment that has been used elsewhere is transferred. The radiation safety requirements for radiation therapy X-ray devices operating at a voltage exceeding 25 kV, and for the premices in which such devices are used, are set out in Guide ST 2.2.

  16. The X-Ray Microcalorimeter Spectrometer for the International X-Ray Observatory

    International Nuclear Information System (INIS)

    The International X-Ray Observatory (IXO) is under formulation by NASA, ESA and JAXA for deployment in 2022. IXO emerged over the last 18 months as the NASA Constellation-X and ESA/JAXA X-Ray Evolving Universe Spectrometer (XEUS) missions were combined. The driving performance requirements for the X-Ray Microcalorimeter Spectrometer (XMS) are a spectral resolution of 2.5 eV over the central 2'x2' in the 0.3-7.0 keV band, and 10 eV to the edge of the 5'x5' field of view (FOV). The XMS is now based on a microcalorimeter array of Transition-Edge Sensor (TES) thermometers with Au/Bi absorbers and a SQUID MUX readout. One of the concepts studied as part of the mission formulation has a core 40x40 array corresponding to a 2'x2' FOV with 3'' pixels surrounded by an outer, annular 52x52 array of 6'' pixels that extends the field of view to 5.4'x5.4' with better than 10 eV resolution. There are several options for implementing the readout and cooling system of the XMS under study in the US, Europe and Japan. The ADR system will have from two to five stages depending on the performance of the cryocooler. Mechanical coolers with sufficient cooling power at 4K are available now, and ∼2K coolers are under development. In this paper we give an overview of the XMS instrument, and some of the tradeoffs to be addressed for this observatory instrument.

  17. X-ray microlaminography with polycapillary optics

    International Nuclear Information System (INIS)

    We demonstrate layer-by-layer x-ray microimaging using polycapillary optics. The depth resolution is achieved without sample or source rotation and in a way similar to classical tomography or laminography. The method takes advantage from large angular apertures of polycapillary optics and from their specific microstructure, which is treated as a coded aperture. The imaging geometry is compatible with polychromatic x-ray sources and with scanning and confocal x-ray fluorescence setups.

  18. X-ray microlaminography with polycapillary optics

    Science.gov (United States)

    Dąbrowski, K. M.; Dul, D. T.; Wróbel, A.; Korecki, P.

    2013-06-01

    We demonstrate layer-by-layer x-ray microimaging using polycapillary optics. The depth resolution is achieved without sample or source rotation and in a way similar to classical tomography or laminography. The method takes advantage from large angular apertures of polycapillary optics and from their specific microstructure, which is treated as a coded aperture. The imaging geometry is compatible with polychromatic x-ray sources and with scanning and confocal x-ray fluorescence setups.

  19. X-ray spot film device

    International Nuclear Information System (INIS)

    Improvements are described in an X-ray spot film device which is used in conjunction with an X-ray table to make a selected number of radiographic exposures on a single film and to perform fluoroscopic examinations. To date, the spot film devices consist of two X-ray field defining masks, one of which is moved manually. The present device is more convenient to use and speeds up the procedure. (U.K.)

  20. X-ray microlaminography with polycapillary optics

    Energy Technology Data Exchange (ETDEWEB)

    Dabrowski, K. M.; Dul, D. T.; Wrobel, A.; Korecki, P. [Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Krakow (Poland)

    2013-06-03

    We demonstrate layer-by-layer x-ray microimaging using polycapillary optics. The depth resolution is achieved without sample or source rotation and in a way similar to classical tomography or laminography. The method takes advantage from large angular apertures of polycapillary optics and from their specific microstructure, which is treated as a coded aperture. The imaging geometry is compatible with polychromatic x-ray sources and with scanning and confocal x-ray fluorescence setups.

  1. Applications of soft x-ray lasers

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, C.H.

    1993-08-01

    The high brightness and short pulse duration of soft x-ray lasers provide unique advantages for novel applications. Imaging of biological specimens using x-ray lasers has been demonstrated by several groups. Other applications to fields such as chemistry, material science, plasma diagnostics, and lithography are beginning to emerge. We review the current status of soft x-ray lasers from the perspective of applications, and present an overview of the applications currently being developed.

  2. X-ray data booklet. Revision

    International Nuclear Information System (INIS)

    A compilation of data is presented. Included are properties of the elements, electron binding energies, characteristic x-ray energies, fluorescence yields for K and L shells, Auger energies, energy levels for hydrogen-, helium-, and neonlike ions, scattering factors and mass absorption coefficients, and transmission bands of selected filters. Also included are selected reprints on scattering processes, x-ray sources, optics, x-ray detectors, and synchrotron radiation facilities

  3. X-ray data booklet. Revision

    Energy Technology Data Exchange (ETDEWEB)

    Vaughan, D. (ed.)

    1986-04-01

    A compilation of data is presented. Included are properties of the elements, electron binding energies, characteristic x-ray energies, fluorescence yields for K and L shells, Auger energies, energy levels for hydrogen-, helium-, and neonlike ions, scattering factors and mass absorption coefficients, and transmission bands of selected filters. Also included are selected reprints on scattering processes, x-ray sources, optics, x-ray detectors, and synchrotron radiation facilities. (WRF)

  4. Novel optics for X-ray telescopes

    Czech Academy of Sciences Publication Activity Database

    Hudec, René; Pína, L.; Semencová, V.; Inneman, A.; Skulinová, Michaela; Nekola, Martin

    Berlin : Springer, 2009 - (Brandl, B.), s. 1-8 ISBN 978-90-481-2232-5. [400 Years of Astronomical Telescopes. Leiden (NL), 29.09.2008-02.10.2008] R&D Projects: GA AV ČR IAAX01220701; GA ČR GP202/07/P510 Institutional research plan: CEZ:AV0Z10030501 Keywords : X-ray telescopes * X-ray optics * X-ray astronomy Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  5. Minimalist coupled evolution model for stellar X-ray activity, rotation, mass loss, and magnetic field

    Science.gov (United States)

    Blackman, Eric G.; Owen, James E.

    2016-05-01

    Late-type main-sequence stars exhibit an X-ray to bolometric flux ratio that depends on {tilde{R}o}, the ratio of rotation period to convective turnover time, as {tilde{R}o}^{-ζ } with 2 ≤ ζ ≤ 3 for {tilde{R}o} > 0.13, but saturates with |ζ| rates and X-ray activity. The unsaturated stars have magnetic fields and rotation speeds that scale roughly with the square root of their age, though possibly flattening for stars older than the Sun. The connection between faster rotators, stronger fields, and higher activity has been established observationally, but a theory for the unified time-evolution of X-ray luminosity, rotation, magnetic field and mass loss that captures the above trends has been lacking. Here we derive a minimalist holistic framework for the time evolution of these quantities built from combining a Parker wind with new ingredients: (1) explicit sourcing of both the thermal energy launching the wind and the X-ray luminosity via dynamo produced magnetic fields; (2) explicit coupling of X-ray activity and mass-loss saturation to dynamo saturation (via magnetic helicity build-up and convection eddy shredding); (3) use of coronal equilibrium to determine how magnetic energy is divided into wind and X-ray contributions. For solar-type stars younger than the Sun, we infer conduction to be a subdominant power loss compared to X-rays and wind. For older stars, conduction is more important, possibly quenching the wind and reducing angular momentum loss. We focus on the time evolution for stars younger than the Sun, highlighting what is possible for further generalizations. Overall, the approach shows promise towards a unified explanation of all of the aforementioned observational trends.

  6. X-ray transient AGN and galaxies

    OpenAIRE

    Grupe, D.

    2001-01-01

    X-ray transience is the most extreme form of variability observed in AGN or normal in-active galaxies. While factors of 2-3 on timescales of days to years are quite commen among AGN, X-ray transients appear only once and vanish from the X-ray sky years later. The ROSAT All-Sky Survey was the tool to discover these sources. X-ray transience in AGN or galaxies can be caused by dramatic changes in the accretion rate of the central black hole or by changes of the properties of the accretion disk.

  7. Microfabrication of hard x-ray lenses

    DEFF Research Database (Denmark)

    Stöhr, Frederik

    characterization details that cannot be obtained by other means. The respective x-ray techniques largely benefit from continuously improved x-ray sources, x-ray detectors and x-ray optics. For instance, some techniques aiming for structural investigation of poly-crystalline materials directly benefit from more...... by their potential for compact integration, which makes them cost-effective, easy to handle and stable on-axis optics. A Si-CRL comprises multiple bi-parabolic cylindrical cavities. The bi-parabolic patterns are defined lithographically and vertically transferred into the Si substrate using deep reactive ion etching...

  8. Advanced X-ray diffractive optics

    OpenAIRE

    Vila-Comamala, J.; Jefimovs, K.; Pilvi, T.; Ritala, M; Sarkar, S S; Solak, H H; Guzenko, V.A.; Stampanoni, M.; Marone, F.; J. Raabe; G. Tzvetkov; Fink, R H; Grolimund, D.; Borca, C.N.; Kaulich, B

    2009-01-01

    X-ray microscopy greatly bene�ts from the advances in x-ray optics. At the Paul Scherrer Institut, developments in x-ray di�ractive optics include the manufacture and optimization of Fresnel zone plates (FZPs) and di�ractive optical elements for both soft and hard x-ray regimes. In particular, we demonstrate here a novel method for the production of ultra-high resolution FZPs. This technique is based on the deposition of a zone plate material (iridium) onto the sidewalls of a p...

  9. Microscopic x-ray luminescence computed tomography

    Science.gov (United States)

    Zhang, Wei; Zhu, Dianwen; Zhang, Kun; Li, Changqing

    2015-03-01

    X-ray luminescence computed tomography (XLCT) was emerged as a new hybrid imaging modality, in which the x-rays are used to excite phosphors emitting optical photons to be measured for imaging. In this paper, we reported a microscopic x-ray luminescence computed tomography (microXLCT) with a spatial resolution up to hundreds of micrometers for deep targets. We use a superfine x-ray pencil beam to scan the phosphor targets. The superfine x-ray pencil beam is generated by a small collimator mounted in front of a powerful x-ray tube (93212, Oxford Instrument). A CT detector is used to image the x-ray beam. We have generated an x-ray beam with a diameter of 192 micrometers with a collimator of 100 micrometers in diameter. The emitted optical photons on the top surface of phantom are reflected by a mirror and acquired by an electron multiplier charge-coupled device (EMCCD) camera (C9100-13, Hamamatsu Photonics). The microXLCT imaging system is built inside an x-ray shielding and light tight cabinet. The EMCCD camera is placed in a lead box. All the imaging components are controlled by a VC++ program. The optical photon propagation is modeled with the diffusion equation solved by the finite element method. We have applied different regularization methods including L2 and L1 in the microXLCT reconstruction algorithms. Numerical simulations and phantom experiments are used to validate the microXLCT imaging system.

  10. Imaging with x-ray lasers

    Energy Technology Data Exchange (ETDEWEB)

    Da Silva, L.B.; Cauble, B.; Frieders, G.; Koch, J.A.; MacGowan, B.J.; Matthews, D.L.; Mrowka, S.; Ress, D.; Trebes, J.E.; Weiland, T.L.

    1993-11-01

    Collisionally pumped soft x-ray lasers now operate over a wavelength range extending from 35--300 {Angstrom}. These sources have high peak brightness and are now being utilized for x-ray imaging and plasma interferometry. In this paper we will describe our efforts to probe long scalelength plasmas using Moire deflectrometry and soft x-ray imaging. The progress in the development of short pulse x-ray lasers using a double pulse irradiation technique which incorporates a travelling wave pump will also be presented.

  11. X-ray Emission from Elliptical Galaxies

    OpenAIRE

    Sarazin, Craig L.

    1996-01-01

    Elliptical galaxies are generally luminous sources of X-ray radiation, and contain large amounts of hot, interstellar gas. In the brighter X-ray galaxies, the inferred masses of hot gas are consistent with those expected given the present rates of stellar mass loss. The required rates of heating of the gas are also roughly consistent with those expected from the motions of gas losing stars. X-ray observations, particularly X-ray spectra, require a low rate of Type Ia supernova heating and che...

  12. X-ray Observations of Planetary Nebulae

    OpenAIRE

    Guerrero, M. A.; Chu, Y.-H.; Gruendl, R A

    2003-01-01

    Planetary nebulae (PNe) are an exciting addition to the zoo of X-ray sources. Recent Chandra and XMM-Newton observations have detected diffuse X-ray emission from shocked fast winds in PN interiors as well as bow-shocks of fast collimated outflows impinging on the nebular envelope. Point X-ray sources associated with PN central stars are also detected, with the soft X-ray (>0.5 keV) emission from instability shocks in the fast stellar wind itself or from a low-mass companion's coronal activit...

  13. Hard X-ray Modulation Telescope

    Institute of Scientific and Technical Information of China (English)

    LU Fangjun

    2011-01-01

    The Hard X-ray Modulation Telescope (HXMT) will be China's first astronomical satellite. On board HXMT there are three kinds of slat-collimated telescopes, the High Energy X-ray Telescope (HE, 20-250 keV, 5000 cm^2), the Medium Energy X-ray Telescope (ME, 5-30 keV, 952 cm^2), and the Low Energy X-ray Telescope (LE, 1-15 keV, 384 cm^2).

  14. X-ray pulsar rush in 1998

    International Nuclear Information System (INIS)

    We present recent remarkable topics about discoveries of X-ray pulsars. 1. Pulsations from two Soft Gamma-ray Repeaters: These pulsars have enormously strong magnetic field (B ∼ 1015 G), thus these are called as 'magnetar', new type of X-ray pulsars. 2. New Crab-like pulsars: These discoveries lead to suggesting universality of Crab-like pulsars. 3. An X-ray bursting millisecond pulsar: This is strong evidence for the recycle theory of generating radio millisecond pulsars. 4. X-ray pulsar rush in the SMC: This indicates the younger star formation history in the SMC. (author)

  15. The Lunar X-ray Observatory (LXO)

    Science.gov (United States)

    Porter, F. Scott

    2008-01-01

    X-ray emission from charge exchange recombination between the highly ionized solar wind and neutral material i n Earth's magnetosheath has complicated x-ray observations of celestial objects with x-ray observatories including ROSAT, Chandra, XMM-Newton, and Suzaku. However, the charge-exchange emission can also be used as an important diagnostic of the solar-wind interacting with the magnetosheath. Soft x-ray observations from low-earth orbit or even the highly eccentric orbits of Chandra and XMM-Newton are likely superpositions of the celestial object of interest, the true extra-solar soft x-ray background, geospheric charge exchange, and heliospheric charge exchange. We show that with a small x-ray telescope placed either on the moon, in a similar vein as the Apollo ALSOP instruments, or at a stable orbit near L1, we can begin t o disentangle the complicated emission structure in the soft x-ray band. Here we present initial results of a feasibility study recently funded by NASA t o place a small x-ray telescope on the lunar surface. The telescope operates during lunar night to observe charge exchange interactions between the solar wind and magnetospheric neutrals, between the solar wind and the lunar atmosphere, and an unobstructed view of the soft x-ray background without the geospheric component.

  16. Ultrashort X-ray pulse science

    Energy Technology Data Exchange (ETDEWEB)

    Chin, Alan Hap [Univ. of California, Berkeley, CA (US). Dept. of Physics; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    1998-05-01

    A variety of phenomena involves atomic motion on the femtosecond time-scale. These phenomena have been studied using ultrashort optical pulses, which indirectly probe atomic positions through changes in optical properties. Because x-rays can more directly probe atomic positions, ultrashort x-ray pulses are better suited for the study of ultrafast structural dynamics. One approach towards generating ultrashort x-ray pulses is by 90{sup o} Thomson scattering between terawatt laser pulses and relativistic electrons. Using this technique, the author generated {approx} 300 fs, 30 keV (0.4 {angstrom}) x-ray pulses. These x-ray pulses are absolutely synchronized with ultrashort laser pulses, allowing femtosecond optical pump/x-ray probe experiments to be performed. Using the right-angle Thomson scattering x-ray source, the author performed time-resolved x-ray diffraction studies of laser-perturbated InSb. These experiments revealed a delayed onset of lattice expansion. This delay is due to the energy relaxation from a dense electron-hole plasma to the lattice. The dense electron-hole plasma first undergoes Auger recombination, which reduces the carrier concentration while maintaining energy content. Longitudinal-optic (LO) phonon emission then couples energy to the lattice. LO phonon decay into acoustic phonons, and acoustic phonon propagation then causes the growth of a thermally expanded layer. Source characterization is instrumental in utilizing ultrashort x-ray pulses in time-resolved x-ray spectroscopies. By measurement of the electron beam diameter at the generation point, the pulse duration of the Thomson scattered x-rays is determined. Analysis of the Thomson scattered x-ray beam properties also provides a novel means of electron bunch characterization. Although the pulse duration is inferred for the Thomson scattering x-ray source, direct measurement is required for other x-ray pulse sources. A method based on the laser-assisted photoelectric effect (LAPE) has

  17. X-ray pulsars: a review

    CERN Document Server

    Caballero, I

    2012-01-01

    Accreting X-ray pulsars are among the most luminous objects in the X-ray sky. In highly magnetized neutron stars (B~10^12 G), the flow of matter is dominated by the strong magnetic field. The general properties of accreting X-ray binaries are presented, focusing on the spectral characteristics of the systems. The use of cyclotron lines as a tool to directly measure a neutron star's magnetic field and to test the theory of accretion are discussed. We conclude with the current and future prospects for accreting X-ray binary studies.

  18. Ultrashort X-ray pulse science

    International Nuclear Information System (INIS)

    A variety of phenomena involves atomic motion on the femtosecond time-scale. These phenomena have been studied using ultrashort optical pulses, which indirectly probe atomic positions through changes in optical properties. Because x-rays can more directly probe atomic positions, ultrashort x-ray pulses are better suited for the study of ultrafast structural dynamics. One approach towards generating ultrashort x-ray pulses is by 90o Thomson scattering between terawatt laser pulses and relativistic electrons. Using this technique, the author generated ∼ 300 fs, 30 keV (0.4 (angstrom)) x-ray pulses. These x-ray pulses are absolutely synchronized with ultrashort laser pulses, allowing femtosecond optical pump/x-ray probe experiments to be performed. Using the right-angle Thomson scattering x-ray source, the author performed time-resolved x-ray diffraction studies of laser-perturbated InSb. These experiments revealed a delayed onset of lattice expansion. This delay is due to the energy relaxation from a dense electron-hole plasma to the lattice. The dense electron-hole plasma first undergoes Auger recombination, which reduces the carrier concentration while maintaining energy content. Longitudinal-optic (LO) phonon emission then couples energy to the lattice. LO phonon decay into acoustic phonons, and acoustic phonon propagation then causes the growth of a thermally expanded layer. Source characterization is instrumental in utilizing ultrashort x-ray pulses in time-resolved x-ray spectroscopies. By measurement of the electron beam diameter at the generation point, the pulse duration of the Thomson scattered x-rays is determined. Analysis of the Thomson scattered x-ray beam properties also provides a novel means of electron bunch characterization. Although the pulse duration is inferred for the Thomson scattering x-ray source, direct measurement is required for other x-ray pulse sources. A method based on the laser-assisted photoelectric effect (LAPE) has been

  19. X-rays pinpoint tumour targets

    International Nuclear Information System (INIS)

    When a surgeon in Birmingham used an X-ray photograph to guide the removal of a needle buried in a woman's hand in January 1896, it became the first X-ray guided operation in medical history. Since then X-rays have been widely used for medical imaging, and 'computed tomography' now provides us with exquisite 2D cross-sectional images of the human body. The technique creates images by passing X-rays along a plane through the body and recording the transmitted signals from various angles. A 'CT scan' lets us locate and visualize tumours with a resolution of 1 mm. But there is more to X-rays than imaging - they can also treat patients by killing cancerous tumours. When X-rays interact with tissue, they release highly reactive radicals that break the double strands in DNA molecules and cause the rapidly dividing cancerous cells to die. But because X-rays kill both healthy and diseased tissue in equal measure, it is vital to minimize the radiation received by healthy organs and tissue surrounding the tumour. The goal of radiotherapy is to find the precise location of a tumour using a CT scan - or other imaging technique - and then concentrate the X-rays on it to destroy the diseased tissue. In the August issue of Physics World Matin Durrani describes how intensity-modulated radiation therapy can deliver precise doses of X-rays to tumours while leaving surrounding, healthy tissue relatively unscathed. (U.K.)

  20. X-ray imaging using a tunable coherent X-ray source based on parametric X-ray radiation

    International Nuclear Information System (INIS)

    A novel X-ray source based on parametric X-ray radiation (PXR) has been employed for X-ray imaging at the Laboratory for Electron Beam Research and Application (LEBRA), Nihon University. Notable features of PXR are tunable energy, monochromaticity with spatial chirp, narrow local bandwidth and spatial coherence. Since the X-ray beam from the PXR system has a large irradiation area with uniform flux density, the PXR-based source is suited for X-ray imaging, especially for application to phase-contrast imaging. Despite the cone-like X-ray beam, diffraction-enhanced imaging (DEI) can be employed as a phase contrast imaging technique. DEI experiments were performed using 14- to 34-keV X-rays and the phase-gradient images were obtained. The results demonstrated the capability of PXR as an X-ray source for phase-contrast imaging with a large irradiation field attributed to the cone-beam effect. Given the significant properties of the LEBRA-PXR source, the result suggests the possible construction of a compact linac-driven PXR-Imaging instrument and its application to medical diagnoses

  1. X-RAY SPECTRAL CUTOFF AND THE LACK OF HARD X-RAY EMISSION FROM TWO ULTRALUMINOUS X-RAY SOURCES M81 X-6 AND HOLMBERG IX X-1

    International Nuclear Information System (INIS)

    We present broadband X-ray spectral study of two ultraluminous X-ray sources (ULXs), M81 X-6 and Holmberg IX X-1, based on Suzaku and XMM-Newton observations. We perform joint broadband spectral analysis of the brightest sources in the field, i.e., the two ULXs and the active galactic nucleus (AGN) in M81, and demonstrate that the X-ray spectra of the ULXs cut off at energies ∼> 3 keV with negligible contribution at high energies in the Suzaku HXD/PIN band. The 90% upper limit on the 10-30 keV band luminosity of an underlying broadband power-law component is 3.5 × 1038 erg s–1 for M81 X-6 and 1.2 × 1039 erg s–1 for Holmberg IX X-1. These limits are more than an order of magnitude lower than the bolometric (0.1-30 keV) luminosity of 6.8 × 1039 erg s–1 for M81 X-6 and 1.9 × 1040 erg s–1 for Holmberg IX X-1. Our results confirm earlier indications of spectral cutoffs inferred from the XMM-Newton observations of bright ULXs and show that there is not an additional high-energy power-law component contributing significantly to the X-ray emission. The spectral form of the two ULXs are very different from those of Galactic black hole X-ray binaries (BHBs) or AGNs. This implies that the ULXs are neither simply scaled-up versions of stellar-mass BHBs nor scaled-down versions of AGNs.

  2. On the universal X-ray luminosity function of binary X-ray sources in galaxies

    OpenAIRE

    Postnov, K. A.

    2002-01-01

    The empirically determined universal power-law shape of X-ray luminosity function of high mass X-ray binaries in galaxies is explained by fundamental mass-luminosity and mass-radius relations for massive stars.

  3. Wide field x-ray telescopes: Detecting x-ray transients/afterglows related to GRBs

    International Nuclear Information System (INIS)

    The recent discovery of X-ray afterglows of GRBs opens the possibility of analyses of GRBs by their X-ray detections. However, imaging X-ray telescopes in current use mostly have limited fields of view. Alternative X-ray optics geometries achieving very large fields of view have been theoretically suggested in the 70's but not constructed and used so far. We review the geometries and basic properties of the wide-field X-ray optical systems based on one- and two-dimensional lobster-eye geometry and suggest technologies for their development and construction. First results of the development of double replicated X-ray reflecting flats for use in one-dimensional X-ray optics of lobster-eye type are presented and discussed. The optimum strategy for locating GRBs upon their X-ray counterparts is also presented and discussed

  4. KD901G X-ray system to reject contaminants

    International Nuclear Information System (INIS)

    Among the complaints to the foods that consumers bought, the proportion of the mixing of alien substances is more than 20%. The number of the cases classified by the kinds of alien substances, and that of minerals and animal substances are shown. The causes of the mixing of alien substances are classified into those due to the mixing in raw materials, production places, processing machines and workers. In case of using primary products as raw materials, the alien substances closely related to those raw materials are difficult to detect, such as bones and hairs in animal meat, fish bones, egg shells and fruit seeds. There are problems and limitation in the inspection of alien substance mixing by visual or touching inspection, metal detectors and the visual inspection of X-ray radiographs. The judgement of the presence of alien substances by automatically processing X-ray radiograph information has been tried one or two-dimensionally. The X-ray alien substance detector KD901G adopted the one-dimensional line sensor type, and its features are shown. The effective introduction of the X-ray alien substance detector, its comparison with metal detectors, and the safety of workers against radiation exposure and the safety of inspected foods are discussed. (K.I.)

  5. On the X-ray low- and high-velocity outflows in AGNs

    OpenAIRE

    Ramirez, J. M.; Tombesi, F.

    2011-01-01

    An exploration of the relationship between bolometric luminosity and outflow velocity, for two classes of X-ray outflows in a large sample of active galactic nuclei has been performed. We find that line radiation pressure could be one physical mechanism that might accelerate the gas we observe in warm absorber, v~100-1000 km/s, and on comparable but less stringent grounds the ultra-fast outflows (UFOs), v~0.03-0.3c. If comparable with the escape velocity of the system; the first is naturally ...

  6. Continuous heating of a giant X-ray flare on Algol

    OpenAIRE

    Schmitt, J. H. M. M.; Favata, F.

    1999-01-01

    Giant flares can release large amounts of energy within a few days: X-ray emission alone can be up to ten percent of the star's bolometric luminosity. These flares exceed the luminosities of the largest solar flares by many orders of magnitude, which suggests that the underlying physical mechanisms supplying the energy are different from those on the Sun. Magnetic coupling between the components in a binary system or between a young star and an accretion disk has been proposed as a prerequisi...

  7. Multicell X-ray detector

    International Nuclear Information System (INIS)

    A detector for X-radiation or other ionizing radiation is described comprising a pair of curved metal bars lying in spaced apart parallel planes. Ceramic members are bonded to the respective bars in facing relationship. Each ceramic member has a plurality of radially extending circumferentially spaced grooves facing similar grooves in the other member. A plurality of electrode plates are held in juxtaposed and circumferentially spaced apart relationship by disposing their respective upper and lower edges in the grooves of opposed ceramic members. The faces of adjacent electrode plates define gas-filled gaps in which photoelectron-ion pairs are produced when radiation enters from the front edges of the plates. The above described assembly is disposed within a pressurized gas-filled chamber having an X-ray transmissive window adjacent the front edges of the plates. A cover encloses the chamber. It has insulator feed-throughs for connecting the electrode plates with external electric circuits. Photoelectrons and/or ions, created by the ionizing radiation, are collected on the electrode plates and thereby generate an electrical signal which corresponds to the incident ionizing radiation. (Auth.)

  8. X-ray radiography facility

    International Nuclear Information System (INIS)

    The paper described a radiographic apparatus containing a radiation source, a diaphragm with collimating windows and a cassette holder with a cassette for the X-ray film. In order to increase the efficiency and quality of monitoring, the diaphragm and the cassette are made in the form of cylindrical shells, the centre of curvature of which coincides with the position of the radiation source focus. Each collimating window of the diaphragm is made in the form of two coaxially connected truncated cones, joined at the large bases in such a way that the angle at the vertex of the cone nearer the source is not less than the central angle with the vertex at the focus of the radiation source supported by the larger base, and 15-300 less than the angle at the vertex of the cone further from the source. By this means monitoring efficiency is increased by a factor of 1.5-2 and the quality of the radiographs improved. The apparatus is used for flaw detection in cylindrical objects. (author)

  9. Diffraction leveraged modulation of X-ray pulses using MEMS-based X-ray optics

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Daniel; Shenoy, Gopal; Wang, Jin; Walko, Donald A.; Jung, Il-Woong; Mukhopadhyay, Deepkishore

    2016-08-09

    A method and apparatus are provided for implementing Bragg-diffraction leveraged modulation of X-ray pulses using MicroElectroMechanical systems (MEMS) based diffractive optics. An oscillating crystalline MEMS device generates a controllable time-window for diffraction of the incident X-ray radiation. The Bragg-diffraction leveraged modulation of X-ray pulses includes isolating a particular pulse, spatially separating individual pulses, and spreading a single pulse from an X-ray pulse-train.

  10. Lenses for Soft X-Rays and X-ray Microscopy Experiments

    International Nuclear Information System (INIS)

    This paper discusses the development of zone plates as x-ray lenses by the use of a uv-holographic lithography technique. Condenser zone plates as well as scanning x-ray microscopes are described. In addition, results of x-ray microscopy experiments are presented, which have been performed with an imaging x-ray microscope installed at the BESSY electron storage ring in Berlin

  11. X-ray topography and multiple diffraction

    International Nuclear Information System (INIS)

    A short summary on X-ray topography, which is based on the dynamical theory of X-ray diffraction, is made. The applications and properties related to the use of the multiple diffraction technique are analized and discussed. (L.C.)

  12. Proton induced X-ray emission analysis

    International Nuclear Information System (INIS)

    The developments in proton induced X-ray emission analysis are reviewed. Techniques for analyzing thick and thin samples of different origin are described. Discussions on the application of proton induced X-ray emission analysis in different fields, comparison of the sensitivity of this method with other analytical techniques, its limitations and possible improvements are presented

  13. Rotatable target for x-ray tubes

    International Nuclear Information System (INIS)

    Distorsion of the focal trace results in reduction of X-ray intensity, which may stop the desired use of the X-ray tube early. This distorsion can be avoided almost by use of molybdenum alloys for base body and substrate. Different alloys together with belonging measured values are described. (J.K.)

  14. X-ray diagnosis in birds

    International Nuclear Information System (INIS)

    The author describes techniques of X- ray examination in birds and the advantages of using contrast medium. He gives the medical indications of such examinations and lists the main anatomical features to be well known in birds for a better interpretation of X-ray pictures

  15. X-ray spectroscopy of magnetic CVs

    Science.gov (United States)

    Matt, Giorgio

    I discuss two topics in X-ray spectroscopy of magnetic CVs: reflection from the white dwarf surface, and opacity effects in the post shock plasma. I also briefly mention future observational perspectives, with particular emphasis on the Constellation X-ray mission.

  16. Tracing the X-Ray Trail

    Science.gov (United States)

    What you need to know about… Tracing the X-ray Trail If you’ve just completed an x-ray, computed tomography (CT), magnetic resonance (MR) Start here! or other diagnostic imaging procedure, you probably want to know when you will ... los rayos X Si acaba de hacerse una radiografía, tomografía ¡Empezar ...

  17. Coccidioidomycosis - chest x-ray (image)

    Science.gov (United States)

    This chest x-ray shows the affects of a fungal infection, coccidioidomycosis. In the middle of the left lung (seen on the ... defined borders. Other diseases that may explain these x-ray findings include lung abscesses, chronic pulmonary tuberculosis, chronic ...

  18. X-ray diagnosis of retropatellar diseases

    International Nuclear Information System (INIS)

    The article reports on a comprehensive, stepwise diagnosis in diseases of the knee joints. This includes a description of the indication, the technique of taking X-ray films, and X-ray findings, as well as arthrography of the femoropatellar joint in retropatellar diseases such as chondropathia patellae, osteochondrosis dissecans, traumas of the knee joints and arthrosis deformans. (orig.)

  19. Adenocarcinoma - chest x-ray (image)

    Science.gov (United States)

    This chest x-ray shows adenocarcinoma of the lung. There is a rounded light spot in the right upper lung (left side ... density. Diseases that may cause this type of x-ray result would be tuberculous or fungal granuloma, and ...

  20. X-Ray Detection Visits the Classroom

    Science.gov (United States)

    Peralta, Luis; Farinha, Ana; Pinto, Ana

    2008-01-01

    Film has been used to detect x-rays since the early days of their discovery by Rontgen. Although nowadays superseded by other techniques, film still provides a cheap means of x-ray detection, making it attractive in high-school or undergraduate university courses. If some sort of quantitative result is required, the film's optical absorbance or…

  1. Soft x rays for radiobiological studies

    International Nuclear Information System (INIS)

    Lethal effects and chromosome aberrations induced in cells exposed to low energy (soft) X rays demonstrated that these relatively low energy X rays are just as effective as those of higher energy for radiobiological studies, and even more effective for irradiating cultured mammalian cells than laboratory animals. (author)

  2. X-Ray Exam: Scoliosis (For Parents)

    Science.gov (United States)

    ... Your Child All About Food Allergies X-Ray Exam: Scoliosis KidsHealth > For Parents > X-Ray Exam: Scoliosis Print A A A Text Size What's ... routinely check kids for scoliosis during regular physical exams, and some schools also test for scoliosis. If ...

  3. Large X-ray optics: lobster alternative

    Czech Academy of Sciences Publication Activity Database

    Hudec, René; Pína, L.; Inneman, A.

    Garching : MaxPlanck Institute for Extraterrestrial Physics, 2003 - (Hasinger, G.; Boller, T.; Parmer, A.), s. 271-277 [XEUS - studying the evolution of the hot Universe. Garching (DE), 11.03.2002-13.03.2002] Institutional research plan: CEZ:AV0Z1003909 Keywords : XEUS X-ray telescope * lobster eye X-ray optics Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  4. Accelerator-driven X-ray Sources

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Dinh Cong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-09

    After an introduction which mentions x-ray tubes and storage rings and gives a brief review of special relativity, the subject is treated under the following topics and subtopics: synchrotron radiation (bending magnet radiation, wiggler radiation, undulator radiation, brightness and brilliance definition, synchrotron radiation facilities), x-ray free-electron lasers (linac-driven X-ray FEL, FEL interactions, self-amplified spontaneous emission (SASE), SASE self-seeding, fourth-generation light source facilities), and other X-ray sources (energy recovery linacs, Inverse Compton scattering, laser wakefield accelerator driven X-ray sources. In summary, accelerator-based light sources cover the entire electromagnetic spectrum. Synchrotron radiation (bending magnet, wiggler and undulator radiation) has unique properties that can be tailored to the users’ needs: bending magnet and wiggler radiation is broadband, undulator radiation has narrow spectral lines. X-ray FELs are the brightest coherent X-ray sources with high photon flux, femtosecond pulses, full transverse coherence, partial temporal coherence (SASE), and narrow spectral lines with seeding techniques. New developments in electron accelerators and radiation production can potentially lead to more compact sources of coherent X-rays.

  5. X-ray scattering measurements from thin-foil x-ray mirrors

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; BYRNAK, BP; Hornstrup, Allan;

    1992-01-01

    Thin foil X-ray mirrors are to be used as the reflecting elements in the telescopes of the X-ray satellites Spectrum-X-Gamma (SRG) and ASTRO-D. High resolution X-ray scattering measurements from the Au coated and dip-lacquered Al foils are presented. These were obtained from SRG mirrors positioned...

  6. Soft X-Ray Spectra of AGN Discovered Via Their Hard X-Ray

    Science.gov (United States)

    Schwartz, Daniel

    1998-01-01

    This final report is a study of the Active Galactic Nuclei (AGN). Investigation of the soft x-ray spectra of AGN were performed by using their hard x-ray emission. ROSAT observations of AGN was also performed, which allowed for the study of these x-ray spectra and the structures of 7 clusters of galaxies.

  7. X-ray devices contributing to sophistication of X-ray diagnostic systems

    International Nuclear Information System (INIS)

    X-ray tubes to generate X-rays, as well as X-ray image intensifiers (I.I.s) and X-ray flat panel detectors (FPDs) to convert X-ray images into electronic signals, are key devices in X-ray diagnostic systems, which are playing a major role in the advancement of diagnosis and treatment. Toshiba Electron Tubes and Devices Co., Ltd. has been offering optimal products incorporating the most advanced technologies to customers through continuous technological innovations. These include a high-sensitivity technology for X-ray I.I.s and X-ray FPDs to suppress patient exposure doses, a focal spot design technology for X-ray tubes and high-resolution technologies for X-ray I.I.s and X-ray FPDs that enhance image quality and make it possible to detect smaller lesion areas, and a noise reduction technology for X-ray tubes to realize a comfortable medical environment with reduced stress on both patients and medical staff. (author)

  8. Propeller effect in the transient X-ray pulsar SMC X-2

    CERN Document Server

    Lutovinov, A; Krivonos, R; Molkov, S; Poutanen, J

    2016-01-01

    We report results of the monitoring campaign of the transient X-ray pulsar SMC X-2 performed with the Swift/XRT telescope in the period of Sept 2015 -- Jan 2016 during the Type II outburst. During this event bolometric luminosity of the source ranged from $\\simeq10^{39}$ down to $<10^{35}$ erg/s. Moreover, we discovered its dramatic drop by a factor of more than 100 below the limiting value of $L_{\\rm lim}\\simeq4\\times10^{36}$ erg/s, that can be interpreted as a transition to the propeller regime. These measurements make SMC X-2 the sixth pulsating X-ray source where such a transition is observed and allow us to estimate the magnetic field of the neutron star in the system $B\\simeq3\\times10^{12}$ G.

  9. High Energy Vision: Processing X-rays

    CERN Document Server

    DePasquale, Joseph; Edmonds, Peter

    2015-01-01

    Astronomy is by nature a visual science. The high quality imagery produced by the world's observatories can be a key to effectively engaging with the public and helping to inspire the next generation of scientists. Creating compelling astronomical imagery can, however, be particularly challenging in the non-optical wavelength regimes. In the case of X-ray astronomy, where the amount of light available to create an image is severely limited, it is necessary to employ sophisticated image processing algorithms to translate light beyond human vision into imagery that is aesthetically pleasing while still being scientifically accurate. This paper provides a brief overview of the history of X-ray astronomy leading to the deployment of NASA's Chandra X-ray Observatory, followed by an examination of the specific challenges posed by processing X-ray imagery. The authors then explore image processing techniques used to mitigate such processing challenges in order to create effective public imagery for X-ray astronomy. ...

  10. Requirements for industrial x-ray equipment

    International Nuclear Information System (INIS)

    This safety code is concerned with the protection of all individuals who may be exposed to radiation emitted by X-ray equipment operating at energies up to 1 MeV as used in industrial radiography. This code presents basic radiation safety information for the protection of personnel operating and servicing X-ray equipment and other workers and the general public in the vicinity of areas where X-ray equipment is in operation. It specifies general safety features of design, construction and functioning of X-ray equipment and facilities; describes the responsibilities of the user, operator and maintenance personnel; contains recommendations to ensure that the X-ray equipment is used and maintained in accordance with the ALARA principle; and describes a program of personnel monitoring and radiation safety surveys. ( 6 refs., 5 tabs., 4 figs.)

  11. Development of coherent x-ray lasers

    International Nuclear Information System (INIS)

    Proposed x-ray laser applications such as interferometry and holography require coherent radiation. The fact that x-ray laser media are short-lived high-temperature plasmas leads to very different coherence properties from those of ordinary lasers. Research aimed at developing theoretical models and experimentally characterizing and improving x-ray laser coherence is discussed. Longitudinal coherence is already sufficient for several applications due to the narrow linewidths. However, transverse coherence is estimated to be poor for most current x-ray lasers. To quantify these estimates and to design better lasers, both wave and geometric optics propagation and coherence theories have been developed. These theories and resulting predictions of the coherence length are presented and compared. Measurements of x-ray laser beam patterns and coherence lengths are presented and compared to detailed theoretical simulations. Designs for more coherent lasers are given

  12. Perspectives of medical X-ray imaging

    Science.gov (United States)

    Freudenberger, J.; Hell, E.; Knüpfer, W.

    2001-06-01

    While X-ray image intensifiers (XII), storage phosphor screens and film-screen systems are still the work horses of medical imaging, large flat panel solid state detectors using either scintillators and amorphous silicon photo diode arrays (FD-Si), or direct X-ray conversion in amorphous selenium are reaching maturity. The main advantage with respect to image quality and low patient dose of the XII and FD-Si systems is caused by the rise of the Detector Quantum Efficiency originating from the application of thick needle-structured phosphor X-ray absorbers. With the detectors getting closer to an optimal state, further progress in medical X-ray imaging requires an improvement of the usable source characteristics. The development of clinical monochromatic X-ray sources of high power would not only allow an improved contrast-to-dose ratio by allowing smaller average photon energies in applications but would also lead to new imaging techniques.

  13. Perspectives of medical X-ray imaging

    International Nuclear Information System (INIS)

    While X-ray image intensifiers (XII), storage phosphor screens and film-screen systems are still the work horses of medical imaging, large flat panel solid state detectors using either scintillators and amorphous silicon photo diode arrays (FD-Si), or direct X-ray conversion in amorphous selenium are reaching maturity. The main advantage with respect to image quality and low patient dose of the XII and FD-Si systems is caused by the rise of the Detector Quantum Efficiency originating from the application of thick needle-structured phosphor X-ray absorbers. With the detectors getting closer to an optimal state, further progress in medical X-ray imaging requires an improvement of the usable source characteristics. The development of clinical monochromatic X-ray sources of high power would not only allow an improved contrast-to-dose ratio by allowing smaller average photon energies in applications but would also lead to new imaging techniques

  14. Perspectives of medical X-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Freudenberger, J. E-mail: joerg.freudenberger@med.siemens.de; Hell, E.; Knuepfer, W

    2001-06-21

    While X-ray image intensifiers (XII), storage phosphor screens and film-screen systems are still the work horses of medical imaging, large flat panel solid state detectors using either scintillators and amorphous silicon photo diode arrays (FD-Si), or direct X-ray conversion in amorphous selenium are reaching maturity. The main advantage with respect to image quality and low patient dose of the XII and FD-Si systems is caused by the rise of the Detector Quantum Efficiency originating from the application of thick needle-structured phosphor X-ray absorbers. With the detectors getting closer to an optimal state, further progress in medical X-ray imaging requires an improvement of the usable source characteristics. The development of clinical monochromatic X-ray sources of high power would not only allow an improved contrast-to-dose ratio by allowing smaller average photon energies in applications but would also lead to new imaging techniques.

  15. Computer radiography-X-ray with vision

    International Nuclear Information System (INIS)

    Computer radiography describes an entire process of creating a digital image including acquiring, processing, presenting and managing the image data. the cassettes are special in that they use an imaging plate instead of films. the imaging plate is coated with storage phosphors which captures x-ray as they pass through the patient. the imaging plate is read with a bar code reader and the imaging plate number recorded in the computer. The cassette is then loaded in the reader unit where it is read using infra-red light which excites the particles on the plate which in turn illuminates and picked by photo-sensors which converts the signal into digital pulses. the pulses then run through a board which converts it into an image which is then displayed on the control console. The plate then runs through the erasure section where it is exposed to yellow light, which erases the plate. The IP is then put back in the cassette and locked and can be reused for the next episode

  16. Design considerations for soft X-ray television imaging detectors

    International Nuclear Information System (INIS)

    Television sensors for X-rays can be coupled to converters and image intensifiers to obtain active areas, high flux capabilities, quantum efficiency, high time resolution, or ease of construction and operation that may not be obtained with a directly illuminated sensor. A general purpose system which makes use of these capabilities for a number of applications is decribed. Some of the performance characteristics of this type of system are examined, and the expected future developments for such systems are briefly addressed. 19 refs

  17. MEASURING OF X-RAY SOURCE SIZE BY USING COMPOUND REFRACTIVE X-RAY LENS

    Directory of Open Access Journals (Sweden)

    Yu. V. Dudchik

    2015-04-01

    Full Text Available Compound refractive lens was used for measuring size of 2-3 beamline Standford synchrotron radiation source and a size of microfocus X-ray tube. X-ray beam from the source was focused by the lens and parameters of the beam at image plane were measured. Scanning diaphragm and X-ray CCD-camera were used for measuring X-ray beam. It was found that the vertical size of synchrotron source is equal to 0,6 mm and the size of the X-ray tube focal spot is equal to 60 micrometers. 

  18. Large area soft x-ray collimator to facilitate x-ray optics testing

    Science.gov (United States)

    Espy, Samuel L.

    1994-01-01

    The first objective of this program is to design a nested conical foil x-ray optic which will collimate x-rays diverging from a point source. The collimator could then be employed in a small, inexpensive x-ray test stand which would be used to test various x-ray optics and detector systems. The second objective is to demonstrate the fabrication of the x-ray reflectors for this optic using lacquer-smoothing and zero-stress electroforming techniques.

  19. First X-ray fluorescence CT experimental results at the SSRF X-ray imaging beamline

    Institute of Scientific and Technical Information of China (English)

    DENG Biao; YANG Qun; XIE Hong-Lan; DU Guo-Hao; XIAO Wi-Qiao

    2011-01-01

    X-ray fluorescence CT is a non-destructive technique for detecting elemental composition and distribution inside a specimen. In this paper, the first experimental results of X-ray fluorescence CT obtained at the SSRF X-ray imaging beamline (BL13W1) are described. The test samples were investigated and the 2D elemental image was reconstructed using a filtered back-projection algorithm. In the sample the element Cd was observed. Up to now, the X-ray fluorescence CT could be carried out at the SSRF X-ray imaging beamline.

  20. Laser plasma x-ray source for ultrafast time-resolved x-ray absorption spectroscopy

    OpenAIRE

    Miaja-Avila, L.; G. C. O'Neil; Uhlig, J.; C. L. Cromer; Dowell, M. L.; Jimenez, R.; Hoover, A. S.; Silverman, K. L.; Ullom, J. N.

    2015-01-01

    We describe a laser-driven x-ray plasma source designed for ultrafast x-ray absorption spectroscopy. The source is comprised of a 1 kHz, 20 W, femtosecond pulsed infrared laser and a water target. We present the x-ray spectra as a function of laser energy and pulse duration. Additionally, we investigate the plasma temperature and photon flux as we vary the laser energy. We obtain a 75 μm FWHM x-ray spot size, containing ∼106 photons/s, by focusing the produced x-rays with a polycapillary opti...

  1. X-ray Spectral Variation of Eta Carinae through the 2003 X-ray Minimum

    OpenAIRE

    Hamaguchi, Kenji; Corcoran, Michael F.; Gull, Theodore; Ishibashi, Kazunori; Pittard, Julian M.; Hillier, D. John; Damineli, Augusto; Davidson, Kris; Nielsen, Krister E.; Kober, Gladys Vieira

    2007-01-01

    We report the results of an X-ray observing campaign on the massive, evolved star Eta Carinae, concentrating on the 2003 X-ray minimum as seen by the XMM-Newton observatory. These are the first spatially-resolved X-ray monitoring observations of the stellar X-ray spectrum during the minimum. The hard X-ray emission, believed to be associated with the collision of Eta Carinae's wind with the wind from a massive companion star, varied strongly in flux on timescales of days, but not significantl...

  2. Minimalist coupled evolution model for stellar x-ray activity, rotation, mass loss, and magnetic field

    CERN Document Server

    Blackman, Eric G

    2015-01-01

    Late-type main sequence stars exhibit an x-ray to bolometric flux that depends on the Corolis number $Co$ (product of convective turnover time and angular rotation speed) as $Co^{\\zeta}$ with $2\\le \\zeta \\le 3$ for $Co > 1$. Stars in the unsaturated regime also obey the Skumanich law--- their rotation speeds scale inversely with square root of their age. The associated stellar magnetic field strengths follow a similar decrease with age. While the connection between faster rotators, stronger fields, and higher activity has been well established observationally, a basic theory for the time evolution of x-ray luminosity, rotation, magnetic field and mass loss been lacking. Here we offer a minimalist model for the time evolution of these quantities built from combining a Parker wind with several new ingredients: (1) explicit sourcing of both the thermal energy launching the wind and the x-ray luminosity via dynamo produced magnetic fields; (2) explicit coupling of x-ray activity and mass loss saturation to dynamo...

  3. Detection of X-ray Emission from the Very Old Pulsar J0108-1431

    CERN Document Server

    Pavlov, G G; Wong, J A; Garmire, G P

    2008-01-01

    PSR J0108-1431 is a nearby, 170 Myr old, very faint radio pulsar near the ``pulsar death line'' in the P-Pdot diagram. We observed the pulsar with the Chandra X-ray Observatory and detected 53 counts in a 30 ks exposure, which corresponds to the source flux of 7\\times 10^{-15} ergs cm^{-2} s^{-1} in the 0.3-6 keV band. The pulsar spectrum can be described by a power-law model with photon index Gamma \\approx 2.2 and luminosity L_{0.3-8 keV} \\sim 2\\times 10^{28} d_{130}^2 ergs s^{-1}, or by a blackbody model with the temperature kT\\approx 0.28 keV and bolometric luminosity L_{bol} \\sim 1.3\\times 10^{28} d_{130}^2 ergs s^{-1}, for a plausible hydrogen column density NH = 7.3\\times 10^{19} cm^{-2} (d_{130}=d/130 pc). The pulsar converts \\sim 0.4% of its spin-down power into the X-ray luminosity, i.e., its X-ray efficiency is higher than for most younger pulsars. From the comparison of the X-ray position with the previously measured radio positions, we estimated the pulsar proper motion of 0.2 arcsec yr^{-1} (V_\\p...

  4. BAT AGN Spectroscopic Survey II: X-ray Emission and High Ionization Optical Emission Lines

    CERN Document Server

    Berney, Simon; Trakhtenbrot, Benny; Ricci, Claudio; Lamperti, Isabella; Schawinski, Kevin; Balokovic, Mislav; Crenshaw, D Michael; Fischer, Travis; Gehrels, Neil; Harrison, Fiona; Hashimoto, Yasuhiro; Ichikawa, Kohei; Mushotzky, Richard; Oh, Kyuseok; Stern, Daniel; Treister, Ezequiel; Ueda, Yoshihiro; Veilleux, Sylvain; Winter, Lisa

    2015-01-01

    We investigate the relationship between X-ray and optical line emission in 340 nearby AGN selected above 10 keV using Swift BAT. We find a weak correlation between the extinction corrected [O III] and hard X-ray luminosity (14-195 keV) with a [OIII] large scatter (R_Pear = 0.64, sigma = 0.62 dex) and a similarly large scatter with the intrinsic 2-10 keV to [O III] luminosities (RPear=0.63, sigma = 0.63 dex). Correlations of the hard X-ray fluxes with the fluxes of high-ionization narrow lines ([O III], He II, [Ne III] and [Ne V]) are not significantly better than with the low ionization lines (Halpha, [SII]). Factors like obscuration or physical slit size are not found to be a significant part of the large scatter. In contrast, the optical emission lines show much better correlations with each other (sigma = 0.3 dex) than with the X-ray flux. The inherent large scatter questions the common usage of narrow emission lines as AGN bolometric luminosity indicators and suggests that other issues such as geometrical...

  5. X-ray diagnostic developments in the perspective of DEMO

    Energy Technology Data Exchange (ETDEWEB)

    Pacella, D.; Romano, A.; Gabellieri, L.; Causa, F. [Euratom-ENEA Association, C.R. Frascati, Via E. Fermi, 45 - 00044 Frascati, Rome (Italy); Murtas, F.; Claps, G. [Istituto Nazionale di Fisica Nucleare, Via E. Fermi 40, 00044 Frascati, Rome (Italy); Choe, W.; Lee, S. H.; Jang, S.; Jang, J.; Hong, J.; Jeon, T.; Lee, H. [Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

    2014-08-21

    Soft X-ray diagnostics at present are not adequate for a burning plasma experiment, neither in term of hardware nor as diagnostic conception. Detectors have to be radiation tolerant, easily shielded, with low sensitivity to neutrons and gammas and with energy discrimination. Layout and viewing capability should be more flexible, thanks to the use also of optical devices, going toward a configuration intermediate between discrete tomography and pure imaging. The general conception of these diagnostics should therefore evolve in the direction of pattern recognition for a real time feedback. This work is focused on the diagnostic developments undertaken at the ENEA- Frascati X-ray Laboratory, following in particular three directions: gas detector for fast and advanced high density tomography, C-MOS solid state imaging detectors for slow control and X-ray polycapillary optics. GEM gas detectors in photon counting mode (noise free) were developed in the range 1-30 keV having high efficiency, high time resolution (up to microseconds), energy discrimination in bands and optical flexibility. Discrimination of X-rays, neutrons and gammas has been demonstrated, thanks to the combination of intrinsic gain and discrimination thresholds, at neutron fluxes (10{sup 7} n/s*cm{sup 2}) comparable with the expected ones at the ports of ITER. GEM detectors are also extremely flexible in the design, allowing optimization of the measurements and solutions for shielding or minimization of the effect of background radiation. Two solid state C-MOS imagers working in photon counting mode, one based on Si semiconductor (Medipix-2, range 5-30 keV) and the other one having a CdTe sensor (Pixirad, range 2-100 keV) have been characterized in laboratory. C-MOS imagers have features and performances thoroughly complementary to the GEM detector and, thanks to their higher pixel density, could be used as remote imaging detectors coupled to optics. X-ray polycapillary lenses have been therefore

  6. X-ray diagnostic developments in the perspective of DEMO

    International Nuclear Information System (INIS)

    Soft X-ray diagnostics at present are not adequate for a burning plasma experiment, neither in term of hardware nor as diagnostic conception. Detectors have to be radiation tolerant, easily shielded, with low sensitivity to neutrons and gammas and with energy discrimination. Layout and viewing capability should be more flexible, thanks to the use also of optical devices, going toward a configuration intermediate between discrete tomography and pure imaging. The general conception of these diagnostics should therefore evolve in the direction of pattern recognition for a real time feedback. This work is focused on the diagnostic developments undertaken at the ENEA- Frascati X-ray Laboratory, following in particular three directions: gas detector for fast and advanced high density tomography, C-MOS solid state imaging detectors for slow control and X-ray polycapillary optics. GEM gas detectors in photon counting mode (noise free) were developed in the range 1-30 keV having high efficiency, high time resolution (up to microseconds), energy discrimination in bands and optical flexibility. Discrimination of X-rays, neutrons and gammas has been demonstrated, thanks to the combination of intrinsic gain and discrimination thresholds, at neutron fluxes (107 n/s*cm2) comparable with the expected ones at the ports of ITER. GEM detectors are also extremely flexible in the design, allowing optimization of the measurements and solutions for shielding or minimization of the effect of background radiation. Two solid state C-MOS imagers working in photon counting mode, one based on Si semiconductor (Medipix-2, range 5-30 keV) and the other one having a CdTe sensor (Pixirad, range 2-100 keV) have been characterized in laboratory. C-MOS imagers have features and performances thoroughly complementary to the GEM detector and, thanks to their higher pixel density, could be used as remote imaging detectors coupled to optics. X-ray polycapillary lenses have been therefore studied in the

  7. Dual-energy X-ray CT and the extension to polychromatic X-ray CT

    International Nuclear Information System (INIS)

    We have developed dual energy X-ray CT using monochromatic X-ray beams. From the dual-energy X-ray CT, we can obtain distributions of an electron density and an effective atomic number in a human body. Especially, the electron density is very important for the heavy ion radiotherapy. Now, we adopted new array-detector to know the energy of incident photons as well as detect the position and the number of photons. We carry out the experiment of the dual-energy X-ray CT at the beamline of KEK and SPring-8 as a fundamental study for the polychromatic X-ray CT. We will show the preliminary result of this experiments and the feasibility of a quantitative polychromatic X-ray CT as an advanced method of monochromatic X-ray CT in this study. (author)

  8. X-ray Imaging Spectroscopy for Planetary Science

    Science.gov (United States)

    Kraft, Ralph P.; Kenter, A.; Murray, S.; Elvis, M.; Branduardi-Raymont, G.; Garcia, M.; Forman, W.; Geary, J.; McCoy, T.; Smith, R.

    2012-10-01

    We are developing monolithic backside illuminated CMOS detectors as soft X-ray imaging spectrometers for high energy astrophysics missions. These devices represent a significant advance over CCD technology and have unique properties that would make them ideal sensors for various planetary mission concepts. The benefits of CMOS include higher levels of integration which provide maximum pixel gain and therefore very low noise, very fast parallel output signal chains for high frame rates. CMOS imaging detectors have zero or one charge transfer so that they can withstand many orders of magnitude more radiation than conventional CCDs before degradation. The capability of high read rates provides dynamic range and temporal resolution. Additionally, the rapid read rates minimize shot noise from thermal dark current and optical light. CMOS detectors can therefore run at warmer temperatures and with ultra-thin optical blocking filters. Thin OBFs provide near unity quantum efficiency below 1 keV, thus maximizing response at the C and O lines. Possible mission concepts for these sensors include X-ray fluorescence studies of rocky bodies, and investigation of the magnetospheres of the gas giants and their moons. In this presentation, we discuss the current state of our technology development and outline its scientific potential for planetary physics with particular emphasis on studies of the Jovian magnetosphere. We contrast the capabilities of our instrument with that which has been achieved by the current generation of Earth-orbiting X-ray observatories.

  9. Toward Adaptive X-Ray Telescopes

    Science.gov (United States)

    O'Dell, Stephen L.; Atkins, Carolyn; Button, Tim W.; Cotroneo, Vincenzo; Davis, William N.; Doel, Peer; Feldman, Charlotte H.; Freeman, Mark D.; Gubarev, Mikhail V.; Kolodziejczak, Jeffrey J.; Michette, Alan G.; Ramsey, Brian D.; Reid, Paul B.; Rodriguez Sanmartin, Daniel; Saha, Timo T.; Schwartz, Daniel A.; Trolier-McKinstry, Susan; Wilke, Rudeger H. T.; Willingale, Richard; Zhang, William W.

    2011-01-01

    Future x-ray observatories will require high-resolution (less than 1 inch) optics with very-large-aperture (greater than 25 square meter) areas. Even with the next generation of heavy-lift launch vehicles, launch-mass constraints and aperture-area requirements will limit the surface areal density of the grazing-incidence mirrors to about 1 kilogram per square meter or less. Achieving sub-arcsecond x-ray imaging with such lightweight mirrors will require excellent mirror surfaces, precise and stable alignment, and exceptional stiffness or deformation compensation. Attaining and maintaining alignment and figure control will likely involve adaptive (in-space adjustable) x-ray optics. In contrast with infrared and visible astronomy, adaptive optics for x-ray astronomy is in its infancy. In the middle of the past decade, two efforts began to advance technologies for adaptive x-ray telescopes: The Generation-X (Gen-X) concept studies in the United States, and the Smart X-ray Optics (SXO) Basic Technology project in the United Kingdom. This paper discusses relevant technological issues and summarizes progress toward adaptive x-ray telescopes.

  10. Toward active x-ray telescopes

    Science.gov (United States)

    O'Dell, Stephen L.; Atkins, Carolyn; Button, Timothy W.; Cotroneo, Vincenzo; Davis, William N.; Doel, Peter; Feldman, Charlotte H.; Freeman, Mark D.; Gubarev, Mikhail V.; Kolodziejczak, Jeffery J.; Michette, Alan G.; Ramsey, Brian D.; Reid, Paul B.; Rodriguez Sanmartin, Daniel; Saha, Timo T.; Schwartz, Daniel A.; Trolier-McKinstry, Susan; Wilke, Rudeger H. T.; Willingale, Richard; Zhang, William W.

    2011-09-01

    Future x-ray observatories will require high-resolution ( 25 m2) areas. Even with the next generation of heavy-lift launch vehicles, launch-mass constraints and aperture-area requirements will limit the areal density of the grazing-incidence mirrors to about 1 kg/m2 or less. Achieving sub-arcsecond x-ray imaging with such lightweight mirrors will require excellent mirror surfaces, precise and stable alignment, and exceptional stiffness or deformation compensation. Attaining and maintaining alignment and figure control will likely involve active (in-space adjustable) x-ray optics. In contrast with infrared and visible astronomy, active optics for x-ray astronomy is in its infancy. In the middle of the past decade, two efforts began to advance technologies for adaptive x-ray telescopes: The Smart X-ray Optics (SXO) Basic Technology project in the United Kingdom (UK) and the Generation-X (Gen-X) concept studies in the United States (US). This paper discusses relevant technological issues and summarizes progress toward active x-ray telescopes.

  11. Stellar coronas, X-rays, and Einstein

    International Nuclear Information System (INIS)

    Observations of the sun at ultraviolet and X-ray wavelengths reveal a structure connected with the configuration of the solar magnetic field. The Einstein Observatory (HEAO 2), the first satellite to use an imaging X-ray telescope, searched for faint coronas on the basis of visual brightness and their proximity to the sun. Observed temperatures of transition regions between the chromosphere and the corona exceed 1,000,000 K. A possible correlation between X-ray luminosity and rotation rate has been observed and Einstein observations also indicated that stellar coronas showed changes in X-ray brightness during the most stable period of a star's life. Solar flares and transients, which generate substantial amounts of X-rays, radio waves and charged particles, are believed to be other properties of stellar coronas which change with age. Future missions such as NASA's Extreme Ultraviolet Explorer, the Advanced X-ray Astrophysics Facility and Space Telescope will enable astronomers to greatly increase their sampling of stellar coronas available for study. Observations also suggest the early development of a strong stellar dynamo due to X-ray activity in pre-main-sequence objects. It is hoped that the study of activity cycles in other stars will yield a greater understanding of the dynamo theory

  12. Cell survival studies using ultrasoft x rays

    International Nuclear Information System (INIS)

    Cell survival was studied for V79 hamster, 10T1/2 mouse, and human skin fibroblast cell lines, using carbon K (0.28 keV), copper K (8.0 keV), and 250 kVp x rays. Because of the rapid attenuation of the carbon x rays, cellular dimensions at the time of exposure were measured using optical and electron microscopy, and frequency distributions of mean dose absorbed by the cell nucleus were obtained. The results indicate that the differences in cell killing between ultra-soft and hard x rays may depend on the nuclear thickness of the cells. Studies of the effects of hypoxia on V79 and 10T1/2 cells using carbon K, aluminum K (1.5 keV), and copper K x rays show decreasing OER values with decreasing x-ray energy and no difference between the two cell lines. Age response studies with V79 cells show similar cell-cycle variation of survival for carbon K and aluminum K x rays as for hard x rays

  13. X-ray diffraction imaging and analysis

    International Nuclear Information System (INIS)

    The first papers dealing with the very important application of x-ray diffraction to crystal structure analysis were also published in 1912 by W.L. Bragg, while a student at Cambridge. Bragg performed an analysis of the Laue diffraction pattern of zinc blend and determined the correct structure of the crystal lattice. There have been many practical applications for x-ray diffraction techniques. Historically conventional x-ray machines were used as generators and film used as the recording medium. Prior to 1966, all attempts to directly image x-ray diffraction patterns used a large format x-ray image intensifier tube of the same type as conventionally used for medical and industrial fluoroscopy. Since the 1960's numerous electro-optical systems have been developed which are far better suited for real-time viewing and recording of x-ray diffraction patterns. Modern x-ray diffraction imaging systems incorporating rotating anode and pulsed x-ray generators, synchrotron x-ray sources, and optimized electro-optical systems have been used to orient single crystals, to study crystal lattice rotation accompanying plastic deformation, to measure the rate of grain boundary migration during recrystallization annealing of cold-worked metals, to determine the physical state of exploding metals, to rapidly measure residual stress (strain), to study the dynamics of structural phase transitions in ferroelectric crystals, to monitor the amorphous to crystalline phase transformation of rapidly solidified metals, and to record topographic images of lattice defects in quartz, gallium arsenide and nickel alloy turbine blade crystals

  14. Laboratory x-ray CCD camera electronics: a test bed for the Swift X-Ray Telescope

    Science.gov (United States)

    Hill, Joanne E.; Zugger, Michael E.; Shoemaker, Jason; Witherite, Mark E.; Koch, T. Scott; Chou, Lester L.; Case, Traci; Burrows, David N.

    2000-12-01

    The Penn State University Department of Astronomy and Astrophysics has been active in the design of X-ray CCD cameras for astronomy for over two decades, including sounding rocket systems, the CUBIC instrument on the SAC-B satellite and the ACIS camera on the Chandra satellite. Currently the group is designing and building an X-ray telescope (XRT), which will comprise part of the Swift Gamma-Ray Burst Explorer satellite. The Swift satellite, selected in October 1999 as one of two winners of NASA Explorer contracts, will -- within one minute -- detect, locate, and observe gamma-ray bursts simultaneously in the optical, ultraviolet, X-ray, and gamma- ray wavelengths using three co-aligned telescopes. The XRT electronics is required to read out the telescope's CCD sensor in a number of different ways depending on the observing mode selected. Immediately after the satellite re-orients to observe a newly detected burst, the XRT will enter an imaging mode to determine the exact position of the burst. The location will then be transmitted to the ground, and the XRT will autonomously enter other modes as the X-ray intensity of the burst waxes and wanes. This paper will discuss the electronics for a laboratory X-ray CCD camera, which serves as a test bed for development of the Swift XRT camera. It will also touch upon the preliminary design of the flight camera, which is closely related. A major challenge is achieving performance and reliability goals within the cost constraints of an Explorer mission.

  15. Nustar Reveals an Intrinsically X-ray Weak Broad Absorption Line Quasar in the Ultraluminous Infrared Galaxy Markarian 231

    Science.gov (United States)

    Teng, Stacy H.; Brandt. W. N.; Harrison, F. A.; Luo, B.; Alexander, D. M.; Bauer, F. E.; Boggs, S. E.; Christensen, F. E.; Comastri, A.; Craig, W. W.; Fabian, A. C.; Farrah, D.; Fiore, F.; Gandhi, P.; Grefenstette, B. W.; Hailey, C. J.; Hickox, R. C.; Madsen, K. K.; Ptak, A. F.; Rigby, Jane Rebecca; Risaliti, G.; Saz, C.; Stern, D.; Veilleux, S.; Walton, D. J.; Wik, D. R.; Zhang, W. W.

    2014-01-01

    We present high-energy (3-30 keV) NuSTAR observations of the nearest quasar, the ultraluminous infrared galaxy (ULIRG) Markarian 231 (Mrk 231), supplemented with new and simultaneous low-energy (0.5-8 keV) data from Chandra. The source was detected, though at much fainter levels than previously reported, likely due to contamination in the large apertures of previous non-focusing hard X-ray telescopes. The full band (0.5-30 keV) X-ray spectrum suggests the active galactic nucleus (AGN) in Mrk 231 is absorbed by a patchy and Compton-thin N(sub H) approx. 1.2(sup +0.3) sub-0.3) x 10(exp 23) / sq cm) column. The intrinsic X-ray luminosity L(sub 0.5-30 Kev) approx. 1.0 x 10(exp 43) erg /s) is extremely weak relative to the bolometric luminosity where the 2-10 keV to bolometric luminosity ratio is approx. 0.03% compared to the typical values of 2-15%. Additionally, Mrk 231 has a low X-ray-to-optical power law slope alpha(sub 0X) approx. -1.7. It is a local example of a low-ionization broad absorption line (LoBAL) quasar that is intrinsically X-ray weak. The weak ionizing continuum may explain the lack of mid-infrared [O IV], [Ne V], and [Ne VI] fine-structure emission lines which are present in sources with otherwise similar AGN properties. We argue that the intrinsic X-ray weakness may be a result of the super-Eddington accretion occurring in the nucleus of this ULIRG, and may also be naturally related to the powerful wind event seen in Mrk 231, a merger remnant escaping from its dusty cocoon.

  16. X-ray hazards - diagnostic and therapeutic

    International Nuclear Information System (INIS)

    The subject is covered in sections, entitled: introduction; nature of X-rays; X-rays - effect on biological materials; X-ray measurement; radiation dosages to exposed groups; organizational structure of radiological protection; duties of the Radiological Safety Officer; general measures for radiological protection; protection of staff; protection of patients; safety measures in radiotherapy work - sealed sources laboratory -general safety rules; radiotherapy - duties of the Radiological Safety Officer (Radiotherapy); the custodian of sealed sources -duties and relevant radiological protection information; external beam therapy - radionuclide source unit - emergency procedure in the event of technical failure; safety aspects of brachytherapy in the patient's vicinity; diagnostic radiology; conclusion. (U.K.)

  17. X-ray microscopy using synchrotron radiation

    International Nuclear Information System (INIS)

    The system for x-ray microscopy now being developed at the X-26 beam line of the Brookhaven National Synchrotron Light Source (NSLS) is described here. Examples of the use of x-ray microscopy for trace element geochemistry, biology and medicine, and materials investigations are given to emphasize the scientific applications of the technique. Future directions for the improvement and further development of the X-26 microscope and of the x-ray microscopy field in general are discussed. 11 refs., 7 figs

  18. Two-dimensional x-ray diffraction

    CERN Document Server

    He, Bob B

    2009-01-01

    Written by one of the pioneers of 2D X-Ray Diffraction, this useful guide covers the fundamentals, experimental methods and applications of two-dimensional x-ray diffraction, including geometry convention, x-ray source and optics, two-dimensional detectors, diffraction data interpretation, and configurations for various applications, such as phase identification, texture, stress, microstructure analysis, crystallinity, thin film analysis and combinatorial screening. Experimental examples in materials research, pharmaceuticals, and forensics are also given. This presents a key resource to resea

  19. X-ray Variability of Blazars

    OpenAIRE

    Pian, Elena

    2002-01-01

    Critical progress in our understanding of high energy emission from AGN has been determined in the last 10 years by X-ray monitoring campaigns with many space missions, notably ROSAT, ASCA, RXTE, BeppoSAX, and XMM, often in conjunction with observations at other frequencies. The emphasis of the present review is on recent findings about X-ray variability of blazars. Among AGN, these exhibit the largest amplitude variations of the X-ray emission, often well correlated with variations at higher...

  20. Imaging Cellular Architecture with X-rays

    OpenAIRE

    Larabell, Carolyn A.; Nugent, Keith A.

    2010-01-01

    X-ray imaging of biological samples is progressing rapidly. In this paper we review the progress to date in high resolution imaging of cellular architecture. In particular we survey the progress in soft X-ray tomography and argue that the field is coming of age and that important biological insights are starting to emerge. We then review the new ideas based on coherent diffraction. These methods are at a much earlier stage of development but, as they eliminate the need for X-ray optics, have ...

  1. Large Area X-Ray Spectroscopy Mission

    Science.gov (United States)

    Tananbaum, H.

    1997-01-01

    The Large Area X-ray Spectroscopy (LAXS) mission concept study continues to evolve strongly following the merging of the LAXS mission with the Next Generation X-ray Observatory (NGXO, PI: Nick White) into the re-named High Throughput X-ray Spectroscopy (HTXS) Mission. HTXS retains key elements of the LAXS proposal, including the use of multiple satellites for risk-reduction and cost savings. A key achievement of the program has been the recommendation by the Structure and Evolution of the Universe (SEUS) (April 1997) for a new start for the HTXS mission in the 2000-2004 timeframe.

  2. The Future of X-Ray Optics

    Science.gov (United States)

    Weisskopf, Martin C.

    2013-01-01

    The most important next step is the development of X-ray optics comparable to (or better than) Chandra in angular resolution that far exceed Chandra s effective area. Use the long delay to establish an adequately funded, competitive technology program along the lines I have recommended. Don't be diverted from this objective, except for Explorer-class missions. Progress in X-ray optics, with emphasis on the angular resolution, is central to the paradigm-shifting discoveries and the contributions of X-ray astronomy to multiwavelength astrophysics over the past 51 years.

  3. X-ray emission from Centaurus A

    Energy Technology Data Exchange (ETDEWEB)

    Terrell, N.J.

    1981-01-01

    Observations of 3 to 12 keV x-ray emission from NGC 5128 (Cen A) were made by Vela spacecraft over the period 1969 to 1979. These data are in good agreement with previously reported data, but are much more complete. Numerous peaks of x-ray intensity occurred during the period 1973 to 1975, characterized by rapid increases and equally rapid decreases (in less than 10 days). Thus it seems probable that most of the x-ray flux from the nucleus of Cen A came from a single source of small size.

  4. X-rays from jets and lobes

    Science.gov (United States)

    Feigelson, E. D.

    1983-01-01

    The current status of X-ray detections (and non-detections) of radio jets and lobes is presented. High resolution images obtained with the Einstein Observatory reveal X-ray emission associated with jet and lobe components of Virgo A, Centaurus A, 3C273, and possibly other radio structures. The Vir A and Cen A jet emission is probably s ynchrotron in origin, requiring in situ particle acceleration to extremely high energies. Inverse Compton emission is the likely cause of asymmetrical X-ray features in the halo of Vir A, supporting the assumption of equipartition.

  5. X-rays from jets and lobes

    International Nuclear Information System (INIS)

    The current status of X-ray detections (and non-detections) of radio jets and lobes is reviewed. The author summarizes the findings and interpretation of several detections of jet and lobe X-ray emission made with the EINSTEIN observatory in Virgo A, Centaurus A, 3C273, and possibly other radio structures. The Vir A (=M27) and Cen A jet emission is probably synchrotron in origin, requiring in situ particle acceleration to extremely high energies. Inverse Compton emission is the likely cause of asymmetrical X-ray features in the halo of Vir A, supporting the assumption of equipartition. (Auth.)

  6. Nonlinear X-ray Compton Scattering

    OpenAIRE

    Fuchs, Matthias; Trigo, Mariano; Chen, Jian; Ghimire, Shambhu; Shwartz, Sharon; Kozina, Michael; Jiang, Mason; Henighan, Thomas; Bray, Crystal; Ndabashimiye, Georges; Bucksbaum, P. H.; Feng, Yiping; Herrmann, Sven; Carini, Gabriella; Pines, Jack

    2015-01-01

    X-ray scattering is a weak linear probe of matter. It is primarily sensitive to the position of electrons and their momentum distribution. Elastic X-ray scattering forms the basis of atomic structural determination while inelastic Compton scattering is often used as a spectroscopic probe of both single-particle excitations and collective modes. X-ray free-electron lasers (XFELs) are unique tools for studying matter on its natural time and length scales due to their bright and coherent ultrash...

  7. Advances in x-ray analysis

    International Nuclear Information System (INIS)

    This book presents papers given at the 1982 Denver Conference on the Applications of X-ray Analysis. Focus is on recent developments in measurement accuracy of two-theta and intensity. Topics include accuracy in x-ray powder diffraction (the theme of the conference); search/match procedures (Powder Diffraction File); quantitative XRD analysis; XRD application and automation; x-ray stress determination (position sensitive detectors, fatigue and fracture characterization); new XRF instrumentation and techniques; XRF computer systems and mathematical corrections; and XRF general applications

  8. Streaked, x-ray-transmission-grating spectrometer

    International Nuclear Information System (INIS)

    A free standing x-ray transmission grating has been coupled with a soft x-ray streak camera to produce a time resolved x-ray spectrometer. The instrument has a temporal resolution of approx. 20 psec, is capable of covering a broad spectral range, 2 to 120 A, has high sensitivity, and is simple to use requiring no complex alignment procedure. In recent laser fusion experiments the spectrometer successfully recorded time resolved spectra over the range 10 to 120 A with a spectral resolving power, lambda/Δlambda of 4 to 50, limited primarily by source size and collimation effects

  9. X-ray lenses with large aperture

    International Nuclear Information System (INIS)

    Up to now, most X-ray imaging setups are based on absorption contrast imaging. There is a demand for focused X-rays in many X-ray analysis applications, either to increase the resolution of an imaging system, or, to reduce the time effort of an experiment through higher photon flux. For photon energies higher than 15 keV refractive X-ray optics are more efficient in comparison to non-refractive X-ray optics. The aim of this work was to develop X-ray lenses with large apertures and high transparency. By increasing the number of refracting surfaces while removing unnecessary lens material such lenses have been developed. Utilizing this approach the overall beam deflection angle is large with respect to the lens material it propagates through and so the transparency of the lens is increased. Within this work, X-ray lenses consisting of several thousands of prisms with an edge length in the range of micrometers have been developed and fabricated by deep X-ray lithography. Deep X-ray lithography enables high precision microstrucures with smooth sidewalls and large aspect ratios. The aperture of high-transparency X-ray lenses made this way is greater than 1 mm. They are suitable for photon energies in the range of 8 keV to 24 keV and offer a focal width of smaller than 10 μm at a transparency of around 40%. Furthermore, rolled X-ray lenses have been developed, that are made out of a microstructured polyimide film, which is cut according to the requirements regarding focal length and photon energy. The microstructured film is fabricated by molding, using an anisotropically etched silicon wafer as molding tool. Its mean roughness is in the range of nanometers. The film features prismatic structures, its surface topology is similar to an asparagus field. The measured diameter of the point focus was 18 μm to 31 μm, the calculated opticla efficiency was 37%. Future work will concentrate on increasing the aspect ratio of Prism Lenses and on increasing the rolling accuracy

  10. Ten years of X-ray interferometry

    International Nuclear Information System (INIS)

    X-ray interferometers were the first optical instruments which utilized many Bragg reflecting components in monolithic blocks of perfect crystal. They have made important contributions to our knowledge of fundamental constants, of Bragg reflection x-ray optics, of strains and defects in crystals and of the optical constants of materials in the x-ray region of the electromagnetic spectrum. Based on an oversimplified optical analogue, their mode of operation is described in detail. Current applications of crystal interferometers and future work is briefly reviewed. (author)

  11. Transient Extremely Soft X-ray Emission from the Unusually Bright CV in the Globular Cluster M3: a New CV X-ray Luminosity Record?

    CERN Document Server

    Stacey, W S; Elsner, R F; Edmonds, P D; Weisskopf, M C; Grindlay, J E

    2011-01-01

    We observed the accreting white dwarf 1E1339.8+2837 (1E1339) in the globular cluster M3 in Nov. 2003, May 2004 and Jan. 2005, using the Chandra ACIS-S detector. The source was observed in 1992 to possess traits of a supersoft X-ray source (SSS), with a 0.1-2.4 keV luminosity as large as 2x10^{35} erg/s, after which time the source's luminosity fell by roughly two orders of magnitude, adopting a hard X-ray spectrum more typical of CVs. Our observations confirm 1E1339's hard CV-like spectrum, with photon index Gamma=1.3+-0.2. We found 1E1339 to be highly variable, with a 0.5-10 keV luminosity ranging from 1.4+-0.3x10^{34} erg/s to 8.5+4.9-4.6x10^{32} erg/s, with 1E1339's maximum luminosity being perhaps the highest yet recorded for hard X-ray emission onto a white dwarf. In Jan. 2005, 1E1339 displayed substantial low-energy emission below 0.3 keV. Although current Chandra responses cannot properly model this emission, its bolometric luminosity appears comparable to or greater than that of the hard spectral comp...

  12. Contrast optimization in X-ray radiography with single photon counting imagers of Medipix type

    Czech Academy of Sciences Publication Activity Database

    Jandejsek, Ivan; Dammer, J.; Jakůbek, J.; Vavřík, Daniel; Žemlička, J.

    2012-01-01

    Roč. 7, C12011 (2012), s. 1-5. ISSN 1748-0221. [International Workshop on Radiation Imaging Detectors /14./. Figueira da Foz, Coimbra, 01.07.2012-05.07.2012] R&D Projects: GA ČR GAP105/11/1551 Grant ostatní: GA MKO(CZ) DF12P01OVV048 Institutional support: RVO:68378297 Keywords : X-ray detectors * X-ray radiography and digital radiography * inspection with x-rays Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 1.869, year: 2011 http://iopscience.iop.org/1748-0221/7/12/C12011/

  13. Charge diffusion measurement in fully depleted CCD using 55Fe X-rays

    Czech Academy of Sciences Publication Activity Database

    Kotov, I.V.; Kotov, A.I.; Frank, J.; Kubánek, Petr; O´Connor, P.; Radeka, V.; Takacs, P.

    Bellingham : SPIE, 2012 - (Holland, A.; Beletic, J.), 84531B/1-84531B/6 ISBN 9780819491541. ISSN 0277-786X. - (Proceedings of SPIE. 8453). [High Energy, Optical, and Infrared Detectors for Astronomy V. Amsterdam (NL), 01.07.2012-04.07.2012] Institutional research plan: CEZ:AV0Z10100502 Keywords : diffusion * photons * point spread functions * sensors * X-ray sources * X-rays Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  14. MBI: Millimetre-wave bolometric interferometer

    Science.gov (United States)

    Ali, S.; Rossinot, P.; Piccirillo, L.; Gear, W. K.; Mauskopf, P.; Ade, P.; Haynes, V.; Timbie, P.

    2002-05-01

    We present the design of the prototype of a millimeter-wave bolometric interferometer (MBI). This interferometer uses two arrays bolometers as detectors. The combination of high sensitivity bolometers and interferometric imaging appears to be well suited for precision measurements in observational cosmology. .

  15. Laser plasma x-ray source for ultrafast time-resolved x-ray absorption spectroscopy

    Directory of Open Access Journals (Sweden)

    L. Miaja-Avila

    2015-03-01

    Full Text Available We describe a laser-driven x-ray plasma source designed for ultrafast x-ray absorption spectroscopy. The source is comprised of a 1 kHz, 20 W, femtosecond pulsed infrared laser and a water target. We present the x-ray spectra as a function of laser energy and pulse duration. Additionally, we investigate the plasma temperature and photon flux as we vary the laser energy. We obtain a 75 μm FWHM x-ray spot size, containing ∼106 photons/s, by focusing the produced x-rays with a polycapillary optic. Since the acquisition of x-ray absorption spectra requires the averaging of measurements from >107 laser pulses, we also present data on the source stability, including single pulse measurements of the x-ray yield and the x-ray spectral shape. In single pulse measurements, the x-ray flux has a measured standard deviation of 8%, where the laser pointing is the main cause of variability. Further, we show that the variability in x-ray spectral shape from single pulses is low, thus justifying the combining of x-rays obtained from different laser pulses into a single spectrum. Finally, we show a static x-ray absorption spectrum of a ferrioxalate solution as detected by a microcalorimeter array. Altogether, our results demonstrate that this water-jet based plasma source is a suitable candidate for laboratory-based time-resolved x-ray absorption spectroscopy experiments.

  16. X-ray diffraction contrast tomography (DCT) system, and an X-ray diffraction contrast tomography (DCT) method

    DEFF Research Database (Denmark)

    2012-01-01

    Source: US2012008736A An X-ray diffraction contrast tomography system (DCT) comprising a laboratory X-ray source (2), a staging device (5) rotating a polycrystalline material sample in the direct path of the X-ray beam, a first X-ray detector (6) detecting the direct X-ray beam being transmitted...

  17. A new method for estimating the bolometric properties of Ibc SNe

    CERN Document Server

    Cano, Zach

    2013-01-01

    The bolometric properties (nickel mass, ejecta mass and kinetic energies) of 61 Ibc supernovae (SNe), including 20 Gamma-Ray Burst and X-Ray Flash (GRB/XRF), 19 Ib, 13 Ic and 9 Ic-BL (broad-lined) SNe are presented. All of the available $BVRI$ photometry in the literature have been collected and used in a new method that utilizes a template supernova (SN 1998bw) and an analytical model based on Arnett (1982) to accurately estimate the bolometric properties of each SN. A statistical analysis of the bolometric properties is then performed, where it is found that GRB/XRF SNe are the most energetic, and eject more mass (including nickel content) than Ib, Ic and Ic-BL SNe. The results are then compared to the existing progenitor models of Ibc SNe, where it is concluded that it is highly likely that at least two progenitor channels exist for producing a Ibc SN: most Ibc SNe arise via binary interactions, where the mass of the stellar progenitor is less than what is attributed to a Wolf Rayet star. Conversely, the p...

  18. Non-LTE Luminosity and Abundance Diagnostics of Classical Novae in X-rays

    CERN Document Server

    Németh, Péter

    2013-01-01

    Classical novae are significant sources of interstellar material, especially carbon, nitrogen and oxygen. These standard candles are only behind supernovae and $\\gamma$-ray bursts as the third brightest objects in the sky, and the most probable progenitors of type Ia supernovae. After a nova outburst the system enters into the constant bolometric luminosity phase and the nova maintains a stable hydrogen burning in the surface layers of the white dwarf. As the expanding shell around the nova attenuates, progressively deeper and hotter layers become visible. At the end of the constant bolometric luminosity phase, the hottest layers are exposed and novae radiate X-rays. This work uses the static, plane-parallel model atmosphere code TLUSTY to calculate atmospheric structure and SYNSPEC to calculate synthetic X-ray spectra. It was necessary to incorporate atomic data for the highest ionization stages of elements ranging from hydrogen to iron in both programs. Atomic data on energy levels, bound-free, bound-bound ...

  19. Panoramic dental X-ray machine

    International Nuclear Information System (INIS)

    A panoramic dental X-ray machine is described possessing mechanical and electronic simplicity for providing both continuous and discontinuous radiographs of a dental arch area. The machine includes an excursion mechanism which causes a tubehead-camera assembly to uninterruptedly circularly orbit the patient's head at a constant speed. A drive mechanism is employed which controls the shifting or transport of the patient along an X-axis only, when either continuous or discontinuous images are desired. The kVp and milliamperes remain constant during the entire exposure of the patient to the X-rays as well as the rotational speed of the tubehead-camera assembly, and no attenuating members are required in the X-ray path for varying intensity of the X-ray beam. (Auth.)

  20. Future X-ray timing missions

    CERN Document Server

    Barret, D; Staubert, R; Stella, L

    2000-01-01

    Thanks to the Rossi X-ray Timing Explorer (RXTE), it is now widely recognized that fast X-ray timing can be used to probe strong gravity fields around collapsed objects and constrain the equation of state of dense matter in neutron stars. We first discuss some of the outstanding issues which could be solved with an X-ray timing mission building on the great successes of RXTE and providing an order of magnitude better sensitivity. Then we briefly describe the 'Experiment for X-ray timing and Relativistic Astrophysics' (EXTRA) recently proposed to the European Space Agency as a follow-up to RXTE and the related US mission 'Relativistic Astrophysics Explorer' (RAE).