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Sample records for medical compton cameras

  1. Silicon detector for a Compton Camera in Nuclear Medical Imaging

    CERN Document Server

    Meier, D; Jalocha, P; Sowicki, B; Kowal, M; Dulinski, W; Maehlum, G; Nygård, E; Yoshioka, K; Fuster, J A; Lacasta, C; Mikuz, M; Roe, S; Weilhammer, Peter; Hua, C H; Park, S J; Wilderman, S J; Zhang, L; Clinthorne, N H; Rogers, W L

    2001-01-01

    Electronically collimated gamma ca\\-me\\-ras based on Com\\-pton scattering in silicon pad sensors may improve imaging in nuclear medicine and bio-medical research. The work described here concentrates on the silicon pad detector developed for a prototype Compton camera. The silicon pad sensors are read out using low noise VLSI CMOS chips and novel fast triggering chips. Depending on the application a light weight and dense packaging of sensors and its readout electronics on a hybrid is required. We describe the silicon pad sensor and their readout with the newly designed hybrid. %The silicon detector of a Compton camera %may contain up to $10^5$~analogue channels requiring %a fast and low cost data acquisition system. We also describe a modular and low-cost data acquisition system (CCDAQ) based on a digital signal processor which is interfaced to the EPP port of personal computers. Using the CCDAQ and the hybrids energy spectra of gamma-ray photons from technetium ($^{\\rm 99m}_{43}$Tc) and americium ($^{241}_{...

  2. A Compton camera prototype for prompt gamma medical imaging

    Directory of Open Access Journals (Sweden)

    Thirolf P.G.

    2016-01-01

    Full Text Available Compton camera prototype for a position-sensitive detection of prompt γ rays from proton-induced nuclear reactions is being developed in Garching. The detector system allows to track the Comptonscattered electrons. The camera consists of a monolithic LaBr3:Ce scintillation absorber crystal, read out by a multi-anode PMT, preceded by a stacked array of 6 double-sided silicon strip detectors acting as scatterers. The LaBr3:Ce crystal has been characterized with radioactive sources. Online commissioning measurements were performed with a pulsed deuteron beam at the Garching Tandem accelerator and with a clinical proton beam at the OncoRay facility in Dresden. The determination of the interaction point of the photons in the monolithic crystal was investigated.

  3. Medical Compton cameras based on semiconductor detectors design and experimental development

    CERN Document Server

    Scannavini, M G

    2001-01-01

    The work presented in this thesis is aimed at the study of Compton scatter as an alternative method of collimating gamma-rays in nuclear medicine applications. Conventional approaches to radioisotope medical imaging and their current limitations are examined. The theory of electronic collimation based on Compton scatter is introduced and it is shown that in principle its application could provide an advantageous imaging method, with both high spatial resolution and high sensitivity. The current status of research in the field, of Compton cameras is assessed and potential niches for applications of clinical interest are suggested. The criteria for the design of a Compton scatter camera are examined. A variety of semiconductors are considered for the construction of an electronic collimator and results from Monte Carlo computer simulations are presented for photon energies of clinical interest. It is concluded that the most viable approach is to design a silicon collimator for the imaging of high-energy (511 ke...

  4. Optimization of a single-phase liquid xenon Compton camera for 3γ medical imaging

    OpenAIRE

    Gallego Manzano, Lucia

    2016-01-01

    The work described in this thesis is focused on the characterization and optimization of a single-phaseliquid xenon Compton camera for medical imaging applications. The detector has been conceived to exploit the advantages of an innovative medical imaging technique called 3γ imaging, which aims to obtain aprecise 3D location of a radioactive source with high sensitivity and an important reduction of the dose administered to the patient. The 3γ imaging technique is based on the detection in co...

  5. The Compton Camera - medical imaging with higher sensitivity Exhibition LEPFest 2000

    CERN Multimedia

    2000-01-01

    The Compton Camera reconstructs the origin of Compton-scattered X-rays using electronic collimation with Silicon pad detectors instead of the heavy conventional lead collimators in Anger cameras - reaching up to 200 times better sensitivity and a factor two improvement in resolution. Possible applications are in cancer diagnosis, neurology neurobiology, and cardiology.

  6. A Gaseous Compton Camera using a 2D-sensitive gaseous photomultiplier for Nuclear Medical Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, C.D.R., E-mail: cdazevedo@ua.pt; Pereira, F.A.; Lopes, T.; Correia, P.M.M.; Silva, A.L.M.; Carramate, L.F.N.D.; Covita, D.S.; Veloso, J.F.C.A.

    2013-12-21

    A new Compton Camera (CC) concept based on a High Pressure Scintillation Chamber coupled to a position-sensitive Gaseous PhotoMultiplier for Nuclear Medical Imaging applications is proposed. The main goal of this work is to describe the development of a ϕ25×12cm{sup 3} cylindrical prototype, which will be suitable for scintimammography and for small-animal imaging applications. The possibility to scale it to an useful human size device is also in study. The idea is to develop a device capable to compete with the standard Anger Camera. Despite the large success of the Anger Camera, it still presents some limitations, such as: low position resolution and fair energy resolutions for 140 keV. The CC arises a different solution as it provides information about the incoming photon direction, avoiding the use of a collimator, which is responsible for a huge reduction (10{sup −4}) of the sensitivity. The main problem of the CC's is related with the Doppler Broadening which is responsible for the loss of angular resolution. In this work, calculations for the Doppler Broadening in Xe, Ar, Ne and their mixtures are presented. Simulations of the detector performance together with discussion about the gas choice are also included.

  7. Data acquisition and analysis for the energy-subtraction Compton scatter camera for medical imaging

    Science.gov (United States)

    Khamzin, Murat Kamilevich

    In response to the shortcomings of the Anger camera currently being used in conventional SPECT, particularly the trade-off between sensitivity and spatial resolution, a novel energy-subtraction Compton scatter camera, or the ESCSC, has been proposed. A successful clinical implementation of the ESCSC could revolutionize the field of SPECT. Features of this camera include utilization of silicon and CdZnTe detectors in primary and secondary detector systems, list-mode time stamping data acquisition, modular architecture, and post-acquisition data analysis. Previous ESCSC studies were based on Monte Carlo modeling. The objective of this work is to test the theoretical framework developed in previous studies by developing the data acquisition and analysis techniques necessary to implement the ESCSC. The camera model working in list-mode with time stamping was successfully built and tested thus confirming potential of the ESCSC that was predicted in previous simulation studies. The obtained data were processed during the post-acquisition data analysis based on preferred event selection criteria. Along with the construction of a camera model and proving the approach, the post-acquisition data analysis was further extended to include preferred event weighting based on the likelihood of a preferred event to be a true preferred event. While formulated to show ESCSC capabilities, the results of this study are important for any Compton scatter camera implementation as well as for coincidence data acquisition systems in general.

  8. Crystal Compton Camera

    Energy Technology Data Exchange (ETDEWEB)

    Ziock, Klaus-Peter [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Braverman, Joshua B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Harrison, Mark J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hornback, Donald Eric [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Fabris, Lorenzo [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Newby, Jason [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2013-09-26

    Stand-off detection is one of the most important radiation detection capabilities for arms control and the control of illicit nuclear materials. For long range passive detection one requires a large detector and a means of “seeing through” the naturally occurring and varying background radiation, i.e. imaging. Arguably, Compton imaging is the best approach over much of the emission band suitable for long range detection. It provides not only imaging, but more information about the direction of incidence of each detected gamma-ray than the alternate approach of coded-aperture imaging. The directional information allows one to reduce the background and hence improve the sensitivity of a measurement. However, to make an efficient Compton imager requires localizing and measuring the simultaneous energy depositions when gamma-rays Compton scatter and are subsequently captured within a single, large detector volume. This concept has been demonstrated in semi-conductor detectors (HPGe, CZT, Si) but at ~ $1k/cm3 these materials are too expensive to build the large systems needed for standoff detection. Scintillator detectors, such as NaI(Tl), are two orders of magnitude less expensive and possess the energy resolution required to make such an imager. However, they do not currently have the ability to localize closely spaced, simultaneous energy depositions in a single large crystal. In this project we are applying a new technique that should, for the first time ever, allow cubic-millimeter event localization in a bulk scintillator crystal.

  9. SU-E-I-63: Performance Study of An Electron-Tracking Compton Camera for Medical Imaging.

    Science.gov (United States)

    Kabuki, S; Kimura, H; Kubo, H; Ogawa, K; Kunieda, E; Tanimori, T

    2012-06-01

    Conventional gamma-ray detector, PET and SPECT, have the limitation of energy and field of view. These limitations are major problems of studying for a new medical imaging. Therefore, we have developed the new imaging detector which is an electron-tracking Compton camera (ETCC). A reconstruction method of Compton camera (CC) is using the physics principle. Because of using physics principle, CC can have a wide energy dynamic range and wide field of view. Conventional CC, however, cannot catch Compton recoil electron tracks, and this is one of the reasons of low imaging power. We have developed a time projection chamber (TPC) using micro pixel chamber (μPIC) as the new detector for ETCC. The μPIC is 2-dimensional gaseous detector and this position resolution is less than 400 μm. Using this detector, ETCC can get electron tracks which are generated from Compton scattering. In this paper, we show the prototype ETCC performance and imaging results. ETCC achieved a wide energy dynamic range (200-1300keV) and wide field of view (3 steradian). Also we succeeded in imaging new imaging reagents using mice as follows; (1) F-18-FDG (511 keV) and I-131-MIBG (364 keV) simultaneous imaging for double clinical tracer imaging, (2) Zn-65- porphyrin (1116 keV) imaging for high energy gamma-ray imaging and, (3) imaging of some minerals (Mn-54, Zn-65) in mice and so on. And we succeeded in 3-D imaging which has imaged only one direction using one head camera. We have developed the ETCC for new medical imaging device and succeeded in imaging the some imaging reagents. We started to develop the new ETCC which can image the mouse within 30 min. Thus, this detector has the possibility of new medical imaging. © 2012 American Association of Physicists in Medicine.

  10. Development of a Compton camera for medical applications based on silicon strip and scintillation detectors

    Science.gov (United States)

    Krimmer, J.; Ley, J.-L.; Abellan, C.; Cachemiche, J.-P.; Caponetto, L.; Chen, X.; Dahoumane, M.; Dauvergne, D.; Freud, N.; Joly, B.; Lambert, D.; Lestand, L.; Létang, J. M.; Magne, M.; Mathez, H.; Maxim, V.; Montarou, G.; Morel, C.; Pinto, M.; Ray, C.; Reithinger, V.; Testa, E.; Zoccarato, Y.

    2015-07-01

    A Compton camera is being developed for the purpose of ion-range monitoring during hadrontherapy via the detection of prompt-gamma rays. The system consists of a scintillating fiber beam tagging hodoscope, a stack of double sided silicon strip detectors (90×90×2 mm3, 2×64 strips) as scatter detectors, as well as bismuth germanate (BGO) scintillation detectors (38×35×30 mm3, 100 blocks) as absorbers. The individual components will be described, together with the status of their characterization.

  11. Development of a Compton camera for medical applications based on silicon strip and scintillation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Krimmer, J., E-mail: j.krimmer@ipnl.in2p3.fr [Institut de Physique Nucléaire de Lyon, Université de Lyon, Université Lyon 1, CNRS/IN2P3 UMR 5822, 69622 Villeurbanne cedex (France); Ley, J.-L. [Institut de Physique Nucléaire de Lyon, Université de Lyon, Université Lyon 1, CNRS/IN2P3 UMR 5822, 69622 Villeurbanne cedex (France); Abellan, C.; Cachemiche, J.-P. [Aix-Marseille Université, CNRS/IN2P3, CPPM UMR 7346, 13288 Marseille (France); Caponetto, L.; Chen, X.; Dahoumane, M.; Dauvergne, D. [Institut de Physique Nucléaire de Lyon, Université de Lyon, Université Lyon 1, CNRS/IN2P3 UMR 5822, 69622 Villeurbanne cedex (France); Freud, N. [Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA - Lyon, Université Lyon 1, Centre Léon Bérard (France); Joly, B.; Lambert, D.; Lestand, L. [Clermont Université, Université Blaise Pascal, CNRS/IN2P3, Laboratoire de Physique Corpusculaire, BP 10448, F-63000 Clermont-Ferrand (France); Létang, J.M. [Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA - Lyon, Université Lyon 1, Centre Léon Bérard (France); Magne, M. [Clermont Université, Université Blaise Pascal, CNRS/IN2P3, Laboratoire de Physique Corpusculaire, BP 10448, F-63000 Clermont-Ferrand (France); and others

    2015-07-01

    A Compton camera is being developed for the purpose of ion-range monitoring during hadrontherapy via the detection of prompt-gamma rays. The system consists of a scintillating fiber beam tagging hodoscope, a stack of double sided silicon strip detectors (90×90×2 mm{sup 3}, 2×64 strips) as scatter detectors, as well as bismuth germanate (BGO) scintillation detectors (38×35×30 mm{sup 3}, 100 blocks) as absorbers. The individual components will be described, together with the status of their characterization.

  12. SPEIR: A Ge Compton Camera

    Energy Technology Data Exchange (ETDEWEB)

    Mihailescu, L; Vetter, K M; Burks, M T; Hull, E L; Craig, W W

    2004-02-11

    The SPEctroscopic Imager for {gamma}-Rays (SPEIR) is a new concept of a compact {gamma}-ray imaging system of high efficiency and spectroscopic resolution with a 4-{pi} field-of-view. The system behind this concept employs double-sided segmented planar Ge detectors accompanied by the use of list-mode photon reconstruction methods to create a sensitive, compact Compton scatter camera.

  13. First coincidences in pre-clinical Compton camera prototype for medical imaging

    Science.gov (United States)

    Studen, A.; Burdette, D.; Chesi, E.; Cindro, V.; Clinthorne, N. H.; Dulinski, W.; Fuster, J.; Han, L.; Kagan, H.; Lacasta, C.; Llosá, G.; Marques, A. C.; Malakhov, N.; Meier, D.; Mikuž, M.; Park, S. J.; Roe, S.; Rogers, W. L.; Steinberg, J.; Weilhammer, P.; Wilderman, S. J.; Zhang, L.; Žontar, D.

    2004-09-01

    Compton collimated imaging may improve the detection of gamma rays emitted by radioisotopes used in single photon emission computed tomography (SPECT). We present a crude prototype consisting of a single 500μm thick, 256 pad silicon detector with pad size of 1.4×1.4mm2, combined with a 15×15×1cm3 NaI scintillator crystal coupled to a set of 20 photo multipliers. Emphasis is placed on the performance of the silicon detector and the associated read-out electronics, which has so far proved to be the most challenging part of the set-up. Results were obtained using the VATAGP3, 128 channel low-noise self-triggering ASIC as the silicon detector's front-end. The noise distribution (σ) of the spectroscopic outputs gave an equivalent noise charge (ENC) with a mean value of =137e with a spread of 10e, corresponding to an energy resolution of 1.15keV FWHM for the scattered electron energy. Threshold settings above 8.2keV were required for stable operation of the trigger. Coincident Compton scatter events in both modules were observed for photons emitted by 57Co source with principal gamma ray energies of 122 and 136keV.

  14. Submillimeter nuclear medical imaging with a Compton Camera using triple coincidences of collinear \\beta+ annihilation photons and \\gamma-rays

    OpenAIRE

    Lang, C.; Habs, D.; Thirolf, P. G.; Zoglauer, A.

    2012-01-01

    Modern PET systems reach a spatial resolution of 3-10 mm. A disadvantage of this technique is the diffusion of the positron before its decay with a typical range of ca. 1 mm (depending on its energy). This motion and Compton scattering of the 511 keV photons within the patient limit the performance of PET. We present a nuclear medical imaging technique, able to reach submillimeter spatial resolution in 3 dimensions with a reduced activity application compared to conventional PET. This 'gamma-...

  15. Submillimeter nuclear medical imaging with a Compton Camera using triple coincidences of collinear \\beta+ annihilation photons and \\gamma-rays

    CERN Document Server

    Lang, C; Thirolf, P G; Zoglauer, A

    2012-01-01

    Modern PET systems reach a spatial resolution of 3-10 mm. A disadvantage of this technique is the diffusion of the positron before its decay with a typical range of ca. 1 mm (depending on its energy). This motion and Compton scattering of the 511 keV photons within the patient limit the performance of PET. We present a nuclear medical imaging technique, able to reach submillimeter spatial resolution in 3 dimensions with a reduced activity application compared to conventional PET. This 'gamma-PET' technique draws on specific positron sources simultaneously emitting an additional photon with the \\beta+ decay. Exploiting the triple coincidence between the positron annihilation and the third photon, it is possible to separate the reconstructed 'true' events from background. In order to test the feasibility of this technique, Monte-Carlo simulations and image reconstruction has been performed. The spatial resolution amounts to 0.2 mm (FWHM) in each direction, surpassing the performance of conventional PET by about...

  16. Gamma-ray imaging with compton cameras: recent years development

    CERN Document Server

    Hirasawa, M; Shibata, S; Enomoto, S; Yano, Y

    2002-01-01

    Compton cameras can image the distribution of gamma-ray sources with electronic collimation instead of mechanical collimators. It consists of at least two position sensitive detectors. The first detector measures the position and the recoil electron energy of Compton scattering process and the second detector working in coincidence with the first measures the position of the scattered ray. This camera was proposed in the 1970s and since then has been improved in moderate pace until recently. This paper reviews the recent years development on Compton cameras technology. (author)

  17. Noise evaluation of Compton camera imaging for proton therapy

    CERN Document Server

    Ortega, P G; Cerutti, F; Ferrari, A; Gillam, J E; Lacasta, C; Llosá, G; Oliver, J F; Sala, P R; Solevi, P; Rafecas, M

    2015-01-01

    Compton Cameras emerged as an alternative for real-time dose monitoring techniques for Particle Therapy (PT), based on the detection of prompt-gammas. As a consequence of the Compton scattering process, the gamma origin point can be restricted onto the surface of a cone (Compton cone). Through image reconstruction techniques, the distribution of the gamma emitters can be estimated, using cone-surfaces backprojections of the Compton cones through the image space, along with more sophisticated statistical methods to improve the image quality. To calculate the Compton cone required for image reconstruction, either two interactions, the last being photoelectric absorption, or three scatter interactions are needed. Because of the high energy of the photons in PT the first option might not be adequate, as the photon is not absorbed in general. However, the second option is less efficient. That is the reason to resort to spectral reconstructions, where the incoming γ energy is considered as a variable in the recons...

  18. Development of silicon pad detectors and readout electronics for a Compton camera

    Science.gov (United States)

    Studen, A.; Cindro, V.; Clinthorne, N. H.; Czermak, A.; Dulinski, W.; Fuster, J.; Han, L.; Jalocha, P.; Kowal, M.; Kragh, T.; Lacasta, C.; Llosá, G.; Meier, D.; Mikuž, M.; Nygård, E.; Park, S. J.; Roe, S.; Rogers, W. L.; Sowicki, B.; Weilhammer, P.; Wilderman, S. J.; Yoshioka, K.; Zhang, L.

    2003-03-01

    Applications in nuclear medicine and bio-medical engineering may profit using a Compton camera for imaging distributions of radio-isotope labelled tracers in organs and tissues. These applications require detection of photons using thick position-sensitive silicon sensors with the highest possible energy and good spatial resolution. In this paper, research and development on silicon pad sensors and associated readout electronics for a Compton camera are presented. First results with low-noise, self-triggering VATAGP ASIC's are reported. The measured energy resolution was 1.1 keV FWHM at room temperature for the 241Am photo-peak at 59.5 keV.

  19. Evaluation of two Compton camera models for scintimammography

    Science.gov (United States)

    Uche, C. Z.; Round, W. H.; Cree, M. J.

    2012-01-01

    We study the performance of a Si/LaBr 3:Ce Compton camera model for scintimammography, and compare it with a Si/NaI(Tl) model of similar geometry. The GEANT4 simulation toolkit was used to study the behaviour of the cameras at 511 keV. Certain simulation steps, such as the modelling of radionuclide decay times, scintillation photon transport and interactions with photomultipliers, as well as detector dead time corrections were included to make the modelling of the cameras more realistic than previous studies. The Si/LaBr 3:Ce Compton camera shows superior efficiency of 2.0×10 -3 and resolution of 5.3 mm over the Si/NaI(Tl) Compton camera model which has the efficiency of 1.6×10 -3 and resolution of 6.9 mm at a source-to-scatterer distance of interest, 2.5 cm. A similar result sequence is obtained for two breast tumours of 5 mm diameter embedded in the medial region of an average-size breast phantom of thickness 5 cm. Notably, the signal-to-noise ratios (SNR) obtained for the Si/LaBr 3:Ce camera are 9.7 and 3.4 for tumour/background radiation uptakes of 10:1 and 6:1, whereas 6.8 and 2.4 were obtained for the Si/NaI(Tl) camera model for the same tumour/background radiation uptakes respectively. It is therefore envisioned that with lower cost, LaBr 3:Ce could replace NaI(Tl) as the Compton camera absorber.

  20. Evaluation of two Compton camera models for scintimammography

    Energy Technology Data Exchange (ETDEWEB)

    Uche, C.Z., E-mail: czu1@waikato.ac.nz [School of Engineering, University of Waikato, Private Bag 3105 Hamilton (New Zealand); Round, W.H., E-mail: h.round@waikato.ac.nz [School of Engineering, University of Waikato, Private Bag 3105 Hamilton (New Zealand); Cree, M.J., E-mail: cree@waikato.ac.nz [School of Engineering, University of Waikato, Private Bag 3105 Hamilton (New Zealand)

    2012-01-11

    We study the performance of a Si/LaBr{sub 3}:Ce Compton camera model for scintimammography, and compare it with a Si/NaI(Tl) model of similar geometry. The GEANT4 simulation toolkit was used to study the behaviour of the cameras at 511 keV. Certain simulation steps, such as the modelling of radionuclide decay times, scintillation photon transport and interactions with photomultipliers, as well as detector dead time corrections were included to make the modelling of the cameras more realistic than previous studies. The Si/LaBr{sub 3}:Ce Compton camera shows superior efficiency of 2.0 Multiplication-Sign 10{sup -3} and resolution of 5.3 mm over the Si/NaI(Tl) Compton camera model which has the efficiency of 1.6 Multiplication-Sign 10{sup -3} and resolution of 6.9 mm at a source-to-scatterer distance of interest, 2.5 cm. A similar result sequence is obtained for two breast tumours of 5 mm diameter embedded in the medial region of an average-size breast phantom of thickness 5 cm. Notably, the signal-to-noise ratios (SNR) obtained for the Si/LaBr{sub 3}:Ce camera are 9.7 and 3.4 for tumour/background radiation uptakes of 10:1 and 6:1, whereas 6.8 and 2.4 were obtained for the Si/NaI(Tl) camera model for the same tumour/background radiation uptakes respectively. It is therefore envisioned that with lower cost, LaBr{sub 3}:Ce could replace NaI(Tl) as the Compton camera absorber.

  1. 3D Image Reconstruction from Compton camera data

    CERN Document Server

    Kuchment, Peter

    2016-01-01

    In this paper, we address analytically and numerically the inversion of the integral transform (\\emph{cone} or \\emph{Compton} transform) that maps a function on $\\mathbb{R}^3$ to its integrals over conical surfaces. It arises in a variety of imaging techniques, e.g. in astronomy, optical imaging, and homeland security imaging, especially when the so called Compton cameras are involved. Several inversion formulas are developed and implemented numerically in $3D$ (the much simpler $2D$ case was considered in a previous publication).

  2. 4π FOV compact Compton camera for nuclear material investigations

    Science.gov (United States)

    Lee, Wonho; Lee, Taewoong

    2011-10-01

    A compact Compton camera with a 4π field of view (FOV) was manufactured using the design parameters optimized with the effective choice of gamma-ray interaction order determined from a Monte Carlo simulation. The camera consisted of six CsI(Na) planar scintillators with a pixelized structure that was coupled to position sensitive photomultiplier tubes (H8500) consisting of multiple anodes connected to custom-made circuits. The size of the scintillator and each pixel was 4.4×4.4×0.5 and 0.2×0.2×0.5 cm, respectively. The total size of each detection module was only 5×5×6 cm and the distance between the detector modules was approximately 10 cm to maximize the camera performance, as calculated by the simulation. Therefore, the camera is quite portable for examining nuclear materials in areas, such as harbors or nuclear power plants. The non-uniformity of the multi-anode PMTs was corrected using a novel readout circuit. Amplitude information of the signals from the electronics attached to the scintillator-coupled multi-anode PMTs was collected using a data acquisition board (cDAQ-9178), and the timing information was sent to a FPGA (SPARTAN3E). The FPGA picked the rising edges of the timing signals, and compared the edges of the signals from six detection modules to select the coincident signal from a Compton pair only. The output of the FPGA triggered the DAQ board to send the effective Compton events to a computer. The Compton image was reconstructed, and the performance of the 4π FOV Compact camera was examined.

  3. Optimization of the performance of a pixellated germanium Compton camera

    OpenAIRE

    Ghoggali, W.

    2015-01-01

    A planar HPGe Compton camera for nuclear medicine applications that contains 177 pixels of 4 × 4mm2, of which 25 are at the back detector, is being used to image point sources of Cs137, line sources and clinical-like shape distributed sources. Experimental results are obtained to study the e ffects of energy resolution, position sensitivity, and reconstruction algorithms on camera images. Preamplifi ed pulses are digitized for pulse shape analysis using gamma ray tracking GRT4s data acquisiti...

  4. EGS5 simulations to design a Ce:GAGG scintillator based Compton camera.

    Science.gov (United States)

    Malik, Azhar H; Shimazoe, Kenji; Takahashi, Hiroyuki

    2013-01-01

    Ce(+3): Gd3Al2Ga3O12 (Ce:GAGG) is expected to be promising scintillator for PET, SPECT, and gamma camera applications because of its attractive properties. We designed a Compton camera based on Ce:GAGG, both as scatterer and absorber, for imaging and radioactivity measurement of point sources. The two important parameters sensitivity and spatial resolution are determined for 4 × 4 pixels, each pixel of size 1 × 1 cm(2), for both scatterer and absorber. Our main focus in this paper is to image a distant source for which sensitivity is of prime importance. High sensitivity and light weight are two important advantages of Compton camera for distant source imaging and the availability of Ce:GAGG 3 × 3 mm(2) pixel size is expected to give a spatial resolution of ~ 5 mm for medical applications as well.

  5. Performance evaluation of MACACO: a multilayer Compton camera

    Science.gov (United States)

    Muñoz, Enrique; Barrio, John; Etxebeste, Ane; Ortega, Pablo G.; Lacasta, Carlos; Oliver, Josep F.; Solaz, Carles; Llosá, Gabriela

    2017-09-01

    Compton imaging devices have been proposed and studied for a wide range of applications. We have developed a Compton camera prototype which can be operated with two or three detector layers based on monolithic lanthanum bromide (LaBr3 ) crystals coupled to silicon photomultipliers (SiPMs), to be used for proton range verification in hadron therapy. In this work, we present the results obtained with our prototype in laboratory tests with radioactive sources and in simulation studies. Images of a 22 Na and an 88 Y radioactive sources have been successfully reconstructed. The full width half maximum of the reconstructed images is below 4 mm for a 22 Na source at a distance of 5 cm.

  6. Performance evaluation of MACACO: a multilayer Compton camera.

    Science.gov (United States)

    Muñoz, Enrique; Barrio, John; Etxebeste, Ane; Ortega, Pablo G; Lacasta, Carlos; Oliver, Josep F; Solaz, Carles; Llosá, Gabriela

    2017-08-22

    Compton imaging devices have been proposed and studied for a wide range of applications. We have developed a Compton camera prototype which can be operated with two or three detector layers based on monolithic lanthanum bromide ([Formula: see text]) crystals coupled to silicon photomultipliers (SiPMs), to be used for proton range verification in hadron therapy. In this work, we present the results obtained with our prototype in laboratory tests with radioactive sources and in simulation studies. Images of a [Formula: see text]Na and an [Formula: see text]Y radioactive sources have been successfully reconstructed. The full width half maximum of the reconstructed images is below 4 mm for a [Formula: see text]Na source at a distance of 5 cm.

  7. Noise evaluation of Compton camera imaging for proton therapy

    Science.gov (United States)

    Ortega, P. G.; Torres-Espallardo, I.; Cerutti, F.; Ferrari, A.; Gillam, J. E.; Lacasta, C.; Llosá, G.; Oliver, J. F.; Sala, P. R.; Solevi, P.; Rafecas, M.

    2015-02-01

    Compton Cameras emerged as an alternative for real-time dose monitoring techniques for Particle Therapy (PT), based on the detection of prompt-gammas. As a consequence of the Compton scattering process, the gamma origin point can be restricted onto the surface of a cone (Compton cone). Through image reconstruction techniques, the distribution of the gamma emitters can be estimated, using cone-surfaces backprojections of the Compton cones through the image space, along with more sophisticated statistical methods to improve the image quality. To calculate the Compton cone required for image reconstruction, either two interactions, the last being photoelectric absorption, or three scatter interactions are needed. Because of the high energy of the photons in PT the first option might not be adequate, as the photon is not absorbed in general. However, the second option is less efficient. That is the reason to resort to spectral reconstructions, where the incoming γ energy is considered as a variable in the reconstruction inverse problem. Jointly with prompt gamma, secondary neutrons and scattered photons, not strongly correlated with the dose map, can also reach the imaging detector and produce false events. These events deteriorate the image quality. Also, high intensity beams can produce particle accumulation in the camera, which lead to an increase of random coincidences, meaning events which gather measurements from different incoming particles. The noise scenario is expected to be different if double or triple events are used, and consequently, the reconstructed images can be affected differently by spurious data. The aim of the present work is to study the effect of false events in the reconstructed image, evaluating their impact in the determination of the beam particle ranges. A simulation study that includes misidentified events (neutrons and random coincidences) in the final image of a Compton Telescope for PT monitoring is presented. The complete chain of

  8. Noise evaluation of Compton camera imaging for proton therapy.

    Science.gov (United States)

    Ortega, P G; Torres-Espallardo, I; Cerutti, F; Ferrari, A; Gillam, J E; Lacasta, C; Llosá, G; Oliver, J F; Sala, P R; Solevi, P; Rafecas, M

    2015-03-07

    Compton Cameras emerged as an alternative for real-time dose monitoring techniques for Particle Therapy (PT), based on the detection of prompt-gammas. As a consequence of the Compton scattering process, the gamma origin point can be restricted onto the surface of a cone (Compton cone). Through image reconstruction techniques, the distribution of the gamma emitters can be estimated, using cone-surfaces backprojections of the Compton cones through the image space, along with more sophisticated statistical methods to improve the image quality. To calculate the Compton cone required for image reconstruction, either two interactions, the last being photoelectric absorption, or three scatter interactions are needed. Because of the high energy of the photons in PT the first option might not be adequate, as the photon is not absorbed in general. However, the second option is less efficient. That is the reason to resort to spectral reconstructions, where the incoming γ energy is considered as a variable in the reconstruction inverse problem. Jointly with prompt gamma, secondary neutrons and scattered photons, not strongly correlated with the dose map, can also reach the imaging detector and produce false events. These events deteriorate the image quality. Also, high intensity beams can produce particle accumulation in the camera, which lead to an increase of random coincidences, meaning events which gather measurements from different incoming particles. The noise scenario is expected to be different if double or triple events are used, and consequently, the reconstructed images can be affected differently by spurious data. The aim of the present work is to study the effect of false events in the reconstructed image, evaluating their impact in the determination of the beam particle ranges. A simulation study that includes misidentified events (neutrons and random coincidences) in the final image of a Compton Telescope for PT monitoring is presented. The complete chain of

  9. Development of silicon pad detectors and readout electronics for a Compton camera

    CERN Document Server

    Studen, A; Clinthorne, N H; Czermak, A; Dulinski, W; Fuster, J A; Han, L; Jalocha, P; Kowal, M; Kragh, T; Lacasta, C; Llosa, G; Meier, D; Mikuz, M; Nygård, E; Park, S J; Roe, S; Rogers, W L; Sowicki, B; Weilhammer, P; Wilderman, S J; Yoshioka, K; Zhang, L

    2003-01-01

    Applications in nuclear medicine and bio-medical engineering may profit using a Compton camera for imaging distributions of radio-isotope labelled tracers in organs and tissues. These applications require detection of photons using thick position-sensitive silicon sensors with the highest possible energy and good spatial resolution. In this paper, research and development on silicon pad sensors and associated readout electronics for a Compton camera are presented. First results with low-noise, self-triggering VATAGP ASIC's are reported. The measured energy resolution was 1.1 keV FWHM at room temperature for the sup 2 sup 4 sup 1 Am photo-peak at 59.5 keV.

  10. Prototype of a single probe Compton camera for laparoscopic surgery

    Science.gov (United States)

    Koyama, A.; Nakamura, Y.; Shimazoe, K.; Takahashi, H.; Sakuma, I.

    2017-02-01

    Image-guided surgery (IGS) is performed using a real-time surgery navigation system with three-dimensional (3D) position tracking of surgical tools. IGS is fast becoming an important technology for high-precision laparoscopic surgeries, in which the field of view is limited. In particular, recent developments in intraoperative imaging using radioactive biomarkers may enable advanced IGS for supporting malignant tumor removal surgery. In this light, we develop a novel intraoperative probe with a Compton camera and a position tracking system for performing real-time radiation-guided surgery. A prototype probe consisting of Ce :Gd3 Al2 Ga3 O12 (GAGG) crystals and silicon photomultipliers was fabricated, and its reconstruction algorithm was optimized to enable real-time position tracking. The results demonstrated the visualization capability of the radiation source with ARM = ∼ 22.1 ° and the effectiveness of the proposed system.

  11. FPGA-based data acquisition system for a Compton camera

    Science.gov (United States)

    Nurdan, K.; Çonka-Nurdan, T.; Besch, H. J.; Freisleben, B.; Pavel, N. A.; Walenta, A. H.

    2003-09-01

    A data acquisition (DAQ) system with custom back-plane and custom readout boards has been developed for a Compton camera prototype. The DAQ system consists of two layers. The first layer has units for parallel high-speed analog-to-digital conversion and online data pre-processing. The second layer has a central board to form a general event trigger and to build the data structure for the event. This modularity and the use of field programmable gate arrays make the whole DAQ system highly flexible and adaptable to modified experimental setups. The design specifications, the general architecture of the Trigger and DAQ system and the implemented readout protocols are presented in this paper.

  12. Development of a readout electronic for a Si-pixeldetector for application in a Compton camera

    OpenAIRE

    Ibragimov, Iskander

    2005-01-01

    Compton cameras are very promising gamma-ray imaging systems, which have already found their application in astrophysics. Their use in nuclear medicine could offer higher sensitivity and better spatial resolution than existing mechanically-collimated gamma cameras, leading to a reduction of the radiation dose given to a patient. A Comp- ton camera consists basically of two detectors: a scatter detector, where Compton scatter- ing takes place, and a photoabsorber, where the scat...

  13. Development of a Compton Camera for Online Range Monitoring of Laser-Accelerated Proton Beams via Prompt-Gamma Detection

    Directory of Open Access Journals (Sweden)

    Thirolf P.G.

    2014-03-01

    Full Text Available Presently large efforts are conducted in Munich towards the development of proton beams for bio-medical applications, generated via the technique of particle acceleration from high-power, short-pulse lasers. While so far mostly offline diagnostics tools are used in this context, we aim at developing a reliable and accurate online range monitoring technique, based on the position-sensitive detection of prompt γ rays emitted from nuclear reactions between the proton beam and the biological sample. For this purpose, we develop a Compton camera, designed to be able to track not only the Compton scattering of the primary photon, but also to detect the secondary Compton electron, thus reducing the Compton cone to an arc segment and by this increasing the source reconstruction efficiency. Design specifications and the status of the protype system are discussed.

  14. A Compton camera application for the GAMOS GEANT4-based framework

    Energy Technology Data Exchange (ETDEWEB)

    Harkness, L.J., E-mail: ljh@ns.ph.liv.ac.uk [Oliver Lodge Laboratory, The University of Liverpool, Liverpool L69 7ZE (United Kingdom); Arce, P. [Department of Basic Research, CIEMAT, Madrid (Spain); Judson, D.S.; Boston, A.J.; Boston, H.C.; Cresswell, J.R.; Dormand, J.; Jones, M.; Nolan, P.J.; Sampson, J.A.; Scraggs, D.P.; Sweeney, A. [Oliver Lodge Laboratory, The University of Liverpool, Liverpool L69 7ZE (United Kingdom); Lazarus, I.; Simpson, J. [STFC Daresbury Laboratory, Daresbury, Warrington WA4 4AD (United Kingdom)

    2012-04-11

    Compton camera systems can be used to image sources of gamma radiation in a variety of applications such as nuclear medicine, homeland security and nuclear decommissioning. To locate gamma-ray sources, a Compton camera employs electronic collimation, utilising Compton kinematics to reconstruct the paths of gamma rays which interact within the detectors. The main benefit of this technique is the ability to accurately identify and locate sources of gamma radiation within a wide field of view, vastly improving the efficiency and specificity over existing devices. Potential advantages of this imaging technique, along with advances in detector technology, have brought about a rapidly expanding area of research into the optimisation of Compton camera systems, which relies on significant input from Monte-Carlo simulations. In this paper, the functionality of a Compton camera application that has been integrated into GAMOS, the GEANT4-based Architecture for Medicine-Oriented Simulations, is described. The application simplifies the use of GEANT4 for Monte-Carlo investigations by employing a script based language and plug-in technology. To demonstrate the use of the Compton camera application, simulated data have been generated using the GAMOS application and acquired through experiment for a preliminary validation, using a Compton camera configured with double sided high purity germanium strip detectors. Energy spectra and reconstructed images for the data sets are presented.

  15. High resolution measurements with silicon drift detectors for Compton camera applications

    OpenAIRE

    Çonka Nurdan, Tuba

    2006-01-01

    The accurate and rapid location of the radionuclide distribution in radioactively labeled tissue or organs is the goal of nuclear medicine. The Compton camera, in principle, can improve the spatial resolution and effiency with respect to today's PET and SPECT techniques. Since it is necessary to reconstruct a full scattering event in the Compton camera, the detector technology is very demanding. Useful detectors have not been available in the past. However, a new detector type, the Silicon Dr...

  16. Optimizing a three-stage Compton camera for measuring prompt gamma rays emitted during proton radiotherapy.

    Science.gov (United States)

    Peterson, S W; Robertson, D; Polf, J

    2010-11-21

    In this work, we investigate the use of a three-stage Compton camera to measure secondary prompt gamma rays emitted from patients treated with proton beam radiotherapy. The purpose of this study was (1) to develop an optimal three-stage Compton camera specifically designed to measure prompt gamma rays emitted from tissue and (2) to determine the feasibility of using this optimized Compton camera design to measure and image prompt gamma rays emitted during proton beam irradiation. The three-stage Compton camera was modeled in Geant4 as three high-purity germanium detector stages arranged in parallel-plane geometry. Initially, an isotropic gamma source ranging from 0 to 15 MeV was used to determine lateral width and thickness of the detector stages that provided the optimal detection efficiency. Then, the gamma source was replaced by a proton beam irradiating a tissue phantom to calculate the overall efficiency of the optimized camera for detecting emitted prompt gammas. The overall calculated efficiencies varied from ∼ 10(-6) to 10(-3) prompt gammas detected per proton incident on the tissue phantom for several variations of the optimal camera design studied. Based on the overall efficiency results, we believe it feasible that a three-stage Compton camera could detect a sufficient number of prompt gammas to allow measurement and imaging of prompt gamma emission during proton radiotherapy.

  17. Development of a low noise integrated readout electronic for pixel detectors in CMOS technology for a Compton camera

    OpenAIRE

    Hausmann, Joachim

    2006-01-01

    Semiconductor detectors are very popular, particularly for their good energy resolution and their easy handling. Combined with a two dimensional spatial resolution such a detector is predestined to realise an active collimation in a Compton camera for medical applications. To measure the deposited energy in each channel (pixel), a self-triggering integrated electronic has been developed, which is directly bonded on top of the detector. The design of the low noise readout ele...

  18. Hybrid Compton camera/coded aperture imaging system

    Science.gov (United States)

    Mihailescu, Lucian [Livermore, CA; Vetter, Kai M [Alameda, CA

    2012-04-10

    A system in one embodiment includes an array of radiation detectors; and an array of imagers positioned behind the array of detectors relative to an expected trajectory of incoming radiation. A method in another embodiment includes detecting incoming radiation with an array of radiation detectors; detecting the incoming radiation with an array of imagers positioned behind the array of detectors relative to a trajectory of the incoming radiation; and performing at least one of Compton imaging using at least the imagers and coded aperture imaging using at least the imagers. A method in yet another embodiment includes detecting incoming radiation with an array of imagers positioned behind an array of detectors relative to a trajectory of the incoming radiation; and performing Compton imaging using at least the imagers.

  19. Coded-Aperture Compton Camera for Gamma-Ray Imaging

    Directory of Open Access Journals (Sweden)

    Farber Aaron M.

    2016-01-01

    Full Text Available A novel gamma-ray imaging system is demonstrated, by means of Monte Carlo simulation. Previous designs have used either a coded aperture or Compton scattering system to image a gamma-ray source. By taking advantage of characteristics of each of these systems a new design can be implemented that does not require a pixelated stopping detector. Use of the system is illustrated for a simulated radiation survey in a decontamination and decommissioning operation.

  20. Imaging multi-energy gamma-ray fields with a Compton scatter camera

    Science.gov (United States)

    Martin, J. B.; Dogan, N.; Gormley, J. E.; Knoll, G. F.; O'Donnell, M.; Wehe, D. K.

    1994-08-01

    Multi-energy gamma-ray fields have been imaged with a ring Compton scatter camera (RCC). The RCC is intended for industrial applications, where there is a need to image multiple gamma-ray lines from spatially extended sources. To our knowledge, the ability of a Compton scatter camera to perform this task had not previously been demonstrated. Gamma rays with different incident energies are distinguished based on the total energy deposited in the camera elements. For multiple gamma-ray lines, separate images are generated for each line energy. Random coincidences and other interfering interactions have been investigated. Camera response has been characterized for energies from 0.511 to 2.75 MeV. Different gamma-ray lines from extended sources have been measured and images reconstructed using both direct and iterative algorithms.

  1. A portable Si/CdTe Compton camera and its applications to the visualization of radioactive substances

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Shin' ichiro, E-mail: takeda@astro.isas.jaxa.jp [Institute of Space and Astronautical Science (ISAS)/JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Harayama, Atsushi [Institute of Space and Astronautical Science (ISAS)/JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Ichinohe, Yuto [Institute of Space and Astronautical Science (ISAS)/JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan); Odaka, Hirokazu [Institute of Space and Astronautical Science (ISAS)/JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Watanabe, Shin; Takahashi, Tadayuki [Institute of Space and Astronautical Science (ISAS)/JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan); Tajima, Hiroyasu [Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601 (Japan); Genba, Kei; Matsuura, Daisuke; Ikebuchi, Hiroshi; Kuroda, Yoshikatsu [Mitsubishi Heavy Industries, 1200 Higashi-Tanaka, Komaki, Aichi 485-8561 (Japan); Tomonaka, Tetsuya [Mitsubishi Heavy Industry, 2-1-1 Shinhama, Arai-cho, Takasago, Hyogo 676-8686 (Japan)

    2015-07-01

    Gamma-ray imagers with the potential for visualizing the distribution of radioactive materials are required in the fields of astrophysics, medicine, nuclear applications, and homeland security. Based on the technology of the Si/CdTe Compton camera, we have manufactured the first commercial Compton camera for practical use. Through field tests in Fukushima, we demonstrated that the camera is capable of hot spot detection and the evaluation of radioactive decontamination.

  2. Development of a Compton camera for online ion beam range verification via prompt γ detection

    Energy Technology Data Exchange (ETDEWEB)

    Aldawood, Saad [Ludwig-Maximilians-Universitaet Muenchen (Germany); King Saud University, Riyadh (Saudi Arabia); Lang, Christian; Lutter, Rudolf; Bortfeldt, Jonathan; Parodi, Katia; Thirolf, Peter G. [Ludwig-Maximilians-Universitaet Muenchen (Germany); Kolff, Hugh van der [Ludwig-Maximilians-Universitaet Muenchen (Germany); Delft University of Technology (Netherlands); Maier, Ludwig [Technische Universitaet Muenchen (Germany)

    2014-07-01

    Precise and preferably online ion beam range verification is a mandatory prerequisite to fully exploit the advantages of hadron-therapy in cancer treatment. Our aim is to develop an imaging system based on a Compton camera designed to detect prompt γ rays induced by nuclear reactions between ion beam and biological tissue. The Compton camera prototype consists of a stack of double-sided Si-strip detectors (DSSSD) acting as scatterers, while the absorber is formed by a LaBr{sub 3} scintillator crystal read out by a position-sensitive multi-anode photomultiplier. The LaBr{sub 3} detector was characterized with both absorptive and reflective side-face wrapping materials. Comparative studies of energy and time resolution, photopeak detection efficiency and spatial resolution are presented together with first tests of the complete camera system.

  3. Development of a Compton camera for online ion beam range verification via prompt γ detection

    Energy Technology Data Exchange (ETDEWEB)

    Aldawood, S. [LMU Munich, Garching (Germany); King Saud University, Riyadh (Saudi Arabia); Liprandi, S.; Marinsek, T.; Bortfeldt, J.; Lang, C.; Lutter, R.; Dedes, G.; Parodi, K.; Thirolf, P.G. [LMU Munich, Garching (Germany); Maier, L.; Gernhaeuser, R. [TU Munich, Garching (Germany); Kolff, H. van der [LMU Munich, Garching (Germany); TU Delft (Netherlands); Castelhano, I. [LMU Munich, Garching (Germany); University of Lisbon, Lisbon (Portugal); Schaart, D.R. [TU Delft (Netherlands)

    2015-07-01

    Precise and preferably online ion beam range verification is a mandatory prerequisite to fully exploit the advantages of hadron therapy in cancer treatment. An imaging system is being developed in Garching aiming to detect promptγ rays induced by nuclear reactions between the ion beam and biological tissue. The Compton camera prototype consists of a stack of six customized double-sided Si-strip detectors (DSSSD, 50 x 50 mm{sup 2}, 0.5 mm thick, 128 strips/side) acting as scatterer, while the absorber is formed by a monolithic LaBr{sub 3}:Ce scintillator crystal (50 x 50 x 30 mm{sup 3}) read out by a position-sensitive multi-anode photomultiplier (Hamamatsu H9500). The on going characterization of the Compton camera properties and its individual components both offline in the laboratory as well as online using proton beam are presented.

  4. Data acquisition, event building and signal reconstruction for Compton camera imaging

    OpenAIRE

    Nurdan, Kivanc

    2006-01-01

    Nurdan, Kıvanç Die Compton-Camera ist ein neues Detektorsystem zur bildlichen Darstellung von radioaktiven Markierungssubstanzen im Bereich der Gammastrahlung, das prinzipiell eine besonders gute Ortsauflösung und hohe Empfindlichkeit liefern kann. Die ist von grosser Bedeutung für die moderne bio-medizinische Forschung oder für darauf basierende diagnostische Verfahren. Dafür ist ein neues Konzept einer software-basierten Koinzidenzmessung entwickelt worden, das auf den b...

  5. Evaluation of Compton gamma camera prototype based on pixelated CdTe detectors

    OpenAIRE

    Y Calderón; Chmeissani, M.; Kolstein, M.; De Lorenzo, G.

    2014-01-01

    A proposed Compton camera prototype based on pixelated CdTe is simulated and evaluated in order to establish its feasibility and expected performance in real laboratory tests. The system is based on module units containing a 2×4 array of square CdTe detectors of 10×10 mm2 area and 2 mm thickness. The detectors are pixelated and stacked forming a 3D detector with voxel sizes of 2 × 1 × 2 mm3. The camera performance is simulated with Geant4-based Architecture for Medicine-Oriented Simulations(G...

  6. Design of a Compton camera for 3D prompt-{gamma} imaging during ion beam therapy

    Energy Technology Data Exchange (ETDEWEB)

    Roellinghoff, F., E-mail: roelling@ipnl.in2p3.fr [Universite de Lyon, F-69622 Lyon (France); Universite Lyon 1 and CNRS/IN2P3, UMR 5822, IPNL, F-69622 Villeurbanne (France); INSA-Lyon Laboratory of Nondestructive Testing using Ionizing Radiation (CNDRI), F-69621 Villeurbanne Cedex (France); Richard, M.-H., E-mail: mrichard@ipnl.in2p3.fr [Universite de Lyon, F-69622 Lyon (France); Universite Lyon 1 and CNRS/IN2P3, UMR 5822, IPNL, F-69622 Villeurbanne (France); INSA-Lyon Laboratory of Nondestructive Testing using Ionizing Radiation (CNDRI), F-69621 Villeurbanne Cedex (France); Chevallier, M.; Constanzo, J.; Dauvergne, D. [Universite de Lyon, F-69622 Lyon (France); Universite Lyon 1 and CNRS/IN2P3, UMR 5822, IPNL, F-69622 Villeurbanne (France); Freud, N. [INSA-Lyon Laboratory of Nondestructive Testing using Ionizing Radiation (CNDRI), F-69621 Villeurbanne Cedex (France); Henriquet, P.; Le Foulher, F. [Universite de Lyon, F-69622 Lyon (France); Universite Lyon 1 and CNRS/IN2P3, UMR 5822, IPNL, F-69622 Villeurbanne (France); Letang, J.M. [INSA-Lyon Laboratory of Nondestructive Testing using Ionizing Radiation (CNDRI), F-69621 Villeurbanne Cedex (France); Montarou, G. [LPC, CNRS/IN2P3, Clermont-F. University (France); Ray, C.; Testa, E.; Testa, M. [Universite de Lyon, F-69622 Lyon (France); Universite Lyon 1 and CNRS/IN2P3, UMR 5822, IPNL, F-69622 Villeurbanne (France); Walenta, A.H. [Uni-Siegen, FB Physik, Emmy-Noether Campus, D-57068 Siegen (Germany)

    2011-08-21

    We investigate, by means of Geant4 simulations, a real-time method to control the position of the Bragg peak during ion therapy, based on a Compton camera in combination with a beam tagging device (hodoscope) in order to detect the prompt gamma emitted during nuclear fragmentation. The proposed set-up consists of a stack of 2 mm thick silicon strip detectors and a LYSO absorber detector. The {gamma} emission points are reconstructed analytically by intersecting the ion trajectories given by the beam hodoscope and the Compton cones given by the camera. The camera response to a polychromatic point source in air is analyzed with regard to both spatial resolution and detection efficiency. Various geometrical configurations of the camera have been tested. In the proposed configuration, for a typical polychromatic photon point source, the spatial resolution of the camera is about 8.3 mm FWHM and the detection efficiency 2.5x10{sup -4} (reconstructable photons/emitted photons in 4{pi}). Finally, the clinical applicability of our system is considered and possible starting points for further developments of a prototype are discussed.

  7. High-resolution Compton cameras based on Si/CdTe double-sided strip detectors

    Energy Technology Data Exchange (ETDEWEB)

    Odaka, Hirokazu, E-mail: odaka@astro.isas.jaxa.jp [Department of High Energy Astrophysics, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa 252-5210 (Japan); Ichinohe, Yuto [Department of High Energy Astrophysics, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa 252-5210 (Japan); Department of Physics, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo, Tokyo 113-0033 (Japan); Takeda, Shin' ichiro [Department of High Energy Astrophysics, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa 252-5210 (Japan); Fukuyama, Taro; Hagino, Koichi; Saito, Shinya; Sato, Tamotsu [Department of High Energy Astrophysics, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa 252-5210 (Japan); Department of Physics, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo, Tokyo 113-0033 (Japan); Sato, Goro; Watanabe, Shin; Kokubun, Motohide [Department of High Energy Astrophysics, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa 252-5210 (Japan); Takahashi, Tadayuki [Department of High Energy Astrophysics, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa 252-5210 (Japan); Department of Physics, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo, Tokyo 113-0033 (Japan); Yamaguchi, Mitsutaka [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency (JAEA), 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); and others

    2012-12-11

    We have developed a new Compton camera based on silicon (Si) and cadmium telluride (CdTe) semiconductor double-sided strip detectors (DSDs). The camera consists of a 500-{mu}m-thick Si-DSD and four layers of 750-{mu}m-thick CdTe-DSDs all of which have common electrode configuration segmented into 128 strips on each side with pitches of 250{mu}m. In order to realize high angular resolution and to reduce size of the detector system, a stack of DSDs with short stack pitches of 4 mm is utilized to make the camera. Taking advantage of the excellent energy and position resolutions of the semiconductor devices, the camera achieves high angular resolutions of 4.5 Degree-Sign at 356 keV and 3.5 Degree-Sign at 662 keV. To obtain such high resolutions together with an acceptable detection efficiency, we demonstrate data reduction methods including energy calibration using Compton scattering continuum and depth sensing in the CdTe-DSD. We also discuss imaging capability of the camera and show simultaneous multi-energy imaging.

  8. Feasibility study of Compton cameras for x-ray fluorescence computed tomography with humans.

    Science.gov (United States)

    Vernekohl, Don; Ahmad, Moiz; Chinn, Garry; Xing, Lei

    2016-12-21

    X-ray fluorescence imaging is a promising imaging technique able to depict the spatial distributions of low amounts of molecular agents in vivo. Currently, the translation of the technique to preclinical and clinical applications is hindered by long scanning times as objects are scanned with flux-limited narrow pencil beams. The study presents a novel imaging approach combining x-ray fluorescence imaging with Compton imaging. Compton cameras leverage the imaging performance of XFCT and abolish the need for pencil beam excitation. The study examines the potential of this new imaging approach on the base of Monte-Carlo simulations. In the work, it is first presented that the particular option of slice/fan-beam x-ray excitation has advantages in image reconstruction in regard of processing time and image quality compared to traditional volumetric Compton imaging. In a second experiment, the feasibility of the approach for clinical applications with tracer agents made from gold nano-particles is examined in a simulated lung scan scenario. The high energy of characteristic x-ray photons from gold is advantageous for deep tissue penetration and has lower angular blurring in the Compton camera. It is found that Doppler broadening in the first detector stage of the Compton camera adds the largest contribution on the angular blurring; physically limiting the spatial resolution. Following the analysis of the results from the spatial resolution test, resolutions in the order of one centimeter are achievable with the approach in the center of the lung. The concept of Compton imaging allows one to distinguish to some extent between scattered photons and x-ray fluorescent photons based on their difference in emission position. The results predict that molecular sensitivities down to 240 pM l(-1) for 5 mm diameter lesions at 15 mGy for 50 nm diameter gold nano-particles are achievable. A 45-fold speed up time for data acquisition compared to traditional pencil beam XFCT could

  9. Feasibility study of Compton cameras for x-ray fluorescence computed tomography with humans

    Science.gov (United States)

    Vernekohl, Don; Ahmad, Moiz; Chinn, Garry; Xing, Lei

    2016-12-01

    X-ray fluorescence imaging is a promising imaging technique able to depict the spatial distributions of low amounts of molecular agents in vivo. Currently, the translation of the technique to preclinical and clinical applications is hindered by long scanning times as objects are scanned with flux-limited narrow pencil beams. The study presents a novel imaging approach combining x-ray fluorescence imaging with Compton imaging. Compton cameras leverage the imaging performance of XFCT and abolish the need for pencil beam excitation. The study examines the potential of this new imaging approach on the base of Monte-Carlo simulations. In the work, it is first presented that the particular option of slice/fan-beam x-ray excitation has advantages in image reconstruction in regard of processing time and image quality compared to traditional volumetric Compton imaging. In a second experiment, the feasibility of the approach for clinical applications with tracer agents made from gold nano-particles is examined in a simulated lung scan scenario. The high energy of characteristic x-ray photons from gold is advantageous for deep tissue penetration and has lower angular blurring in the Compton camera. It is found that Doppler broadening in the first detector stage of the Compton camera adds the largest contribution on the angular blurring; physically limiting the spatial resolution. Following the analysis of the results from the spatial resolution test, resolutions in the order of one centimeter are achievable with the approach in the center of the lung. The concept of Compton imaging allows one to distinguish to some extent between scattered photons and x-ray fluorescent photons based on their difference in emission position. The results predict that molecular sensitivities down to 240 pM l-1 for 5 mm diameter lesions at 15 mGy for 50 nm diameter gold nano-particles are achievable. A 45-fold speed up time for data acquisition compared to traditional pencil beam XFCT could

  10. A Compton camera for spectroscopic imaging from 100keV to 1MeV

    Science.gov (United States)

    Earnhart, Jonathan Raby Dewitt

    The objective of this work is to investigate Compton camera technology for spectroscopic imaging of gamma rays in the 100keV to 1MeV range. An efficient, specific purpose Monte Carlo code was developed to investigate the image formation process in Compton cameras. The code is based on a pathway sampling technique with extensive use of variance reduction techniques. The code includes detailed Compton scattering physics, including incoherent scattering functions, Doppler broadening, and multiple scattering. Experiments were performed with two different camera configurations for a scene containing a 75Se source and a 137Cs source. The first camera was based on a fixed silicon detector in the front plane and a CdZnTe detector mounted in the stage. The second camera configuration was based on two CdZnTe detectors. Both systems were able to reconstruct images of 75Se, using the 265keV line, and 137Cs, using the 662keV line. Only the silicon-CdZnTe camera was able to resolve the low intensity 400keV line of 75Se. Neither camera was able to reconstruct the 75Se source location using the 136keV line. The energy resolution of the silicon-CdZnTe camera system was 4% at 662keV. This camera reproduced the location of the 137Cs source by event circle image reconstruction with angular resolutions of 10° for a source on the camera axis and 14° for a source 30° off axis. Typical detector pair efficiencies were measured as 3 x 10-11 at 662keV. The dual CdZnTe camera had an energy resolution of 3.2% at 662keV. This camera reproduced the location of the 137Cs source by event circle image reconstruction with angular resolutions of 8° for a source on the camera axis and 12° for a source 20° off axis. Typical detector pair efficiencies were measured as 7 x 10-11 at 662keV. Of the two prototype camera configurations tested, the silicon-CdZnTe configuration had superior imaging characteristics. This configuration is less sensitive to effects caused by source decay cascades and random

  11. OMC camera experiment for INTEGRAL and search for Compton GRO BATSE LOCBURST optical transients

    Science.gov (United States)

    Rezek, Tomáš; Hudec, René; Hroch, Filip; Soldán, Jan; Mas-Hesse, Miguel; Giménez, Alvaro

    1998-05-01

    The test camera of the Optical Monitoring Camera (OMC) experiment for INTEGRAL spacecraft achieving an angular pixel size of 18 arcsec and a field of view 7.5°×5.1° has been successfully developed and tested at the Astronomical Institute Ondřejov. The test camera is able to provide imaging down to 15 mag over the whole field of view within one exposure of 300 seconds. Although developed primarily to test the OMC performance and help with software development, this device is ideally suited for use as a ground-based camera for sites where Compton Gamma Ray Observatory BATSE Locburst triggers are followed-up in the optical waveband and also for wide-field sky monitoring in general. The low cost of this camera makes it possible to duplicate the system at a number of observing sites. A chart and a corresponding CCD-image for the BACODINE Locburst Position 6368 taken with the OMC test camera at Ondřejov observatory are also presented. The image taken 18 hours after the trigger was computer-blinked with the frame taken 30 days later. No optical activity has been found down to 13.5 mag.

  12. The Si/CdTe semiconductor Compton camera of the ASTRO-H Soft Gamma-ray Detector (SGD)

    CERN Document Server

    Watanabe, Shin; Fukazawa, Yasushi; Ichinohe, Yuto; Takeda, Shin'ichiro; Enoto, Teruaki; Fukuyama, Taro; Furui, Shunya; Genba, Kei; Hagino, Kouichi; Harayama, Astushi; Kuroda, Yoshikatsu; Matsuura, Daisuke; Nakamura, Ryo; Nakazawa, Kazuhiro; Noda, Hirofumi; Odaka, Hirokazu; Ohta, Masayuki; Onishi, Mitsunobu; Saito, Shinya; Sato, Goro; Sato, Tamotsu; Takahashi, Tadayuki; Tanaka, Takaaki; Togo, Atsushi; Tomizuka, Shinji

    2015-01-01

    The Soft Gamma-ray Detector (SGD) is one of the instrument payloads onboard ASTRO-H, and will cover a wide energy band (60--600 keV) at a background level 10 times better than instruments currently in orbit. The SGD achieves low background by combining a Compton camera scheme with a narrow field-of-view active shield. The Compton camera in the SGD is realized as a hybrid semiconductor detector system which consists of silicon and cadmium telluride (CdTe) sensors. The design of the SGD Compton camera has been finalized and the final prototype, which has the same configuration as the flight model, has been fabricated for performance evaluation. The Compton camera has overall dimensions of 12 cm x 12 cm x 12 cm, consisting of 32 layers of Si pixel sensors and 8 layers of CdTe pixel sensors surrounded by 2 layers of CdTe pixel sensors. The detection efficiency of the Compton camera reaches about 15% and 3% for 100 keV and 511 keV gamma rays, respectively. The pixel pitch of the Si and CdTe sensors is 3.2 mm, and ...

  13. A double photomultiplier Compton camera and its readout system for mice imaging

    Science.gov (United States)

    Fontana, Cristiano Lino; Atroshchenko, Kostiantyn; Baldazzi, Giuseppe; Bello, Michele; Uzunov, Nikolay; Di Domenico, Giovanni Di

    2013-04-01

    We have designed a Compton Camera (CC) to image the bio-distribution of gamma-emitting radiopharmaceuticals in mice. A CC employs the "electronic collimation", i.e. a technique that traces the gamma-rays instead of selecting them with physical lead or tungsten collimators. To perform such a task, a CC measures the parameters of the Compton interaction that occurs in the device itself. At least two detectors are required: one (tracker), where the primary gamma undergoes a Compton interaction and a second one (calorimeter), in which the scattered gamma is completely absorbed. Eventually the polar angle and hence a "cone" of possible incident directions are obtained (event with "incomplete geometry"). Different solutions for the two detectors are proposed in the literature: our design foresees two similar Position Sensitive Photomultipliers (PMT, Hamamatsu H8500). Each PMT has 64 output channels that are reduced to 4 using a charge multiplexed readout system, i.e. a Series Charge Multiplexing net of resistors. Triggering of the system is provided by the coincidence of fast signals extracted at the last dynode of the PMTs. Assets are the low cost and the simplicity of design and operation, having just one type of device; among drawbacks there is a lower resolution with respect to more sophisticated trackers and full 64 channels Readout. This paper does compare our design of our two-Hamamatsu CC to other solutions and shows how the spatial and energy accuracy is suitable for the inspection of radioactivity in mice.

  14. Development of Signal Processing Circuit for Side-absorber of Dual-mode Compton Camera

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Hee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Park, Jong Hoon; Kim, Young Su; Kim, Chan Hyeong [Dept. of Nuclear Engineering, Hanyang University, Seoul (Korea, Republic of); Lee, Ju Hahn; Lee, Chun Sik [Dept. of Physics, Chung-Ang University, Seoul (Korea, Republic of)

    2012-03-15

    In the present study, a gamma-ray detector and associated signal processing circuit was developed for a side-absorber of a dual-mode Compton camera. The gamma-ray detector was made by optically coupling a CsI(Tl) scintillation crystal to a silicon photodiode. The developed signal processing circuit consists of two parts, i.e., the slow part for energy measurement and the fast part for timing measurement. In the fast part, there are three components: (1) fast shaper, (2) leading-edge discriminator, and (3) TTL-to-NIM logic converter. AC coupling configuration between the detector and front-end electronics (FEE) was used. Because the noise properties of FEE can significantly affect the overall performance of the detection system, some design criteria were presented. The performance of the developed system was evaluated in terms of energy and timing resolutions. The evaluated energy resolution was 12.0% and 15.6% FWHM for 662 and 511 keV peaks, respectively. The evaluated timing resolution was 59.0 ns. In the conclusion, the methods to improve the performance were discussed because the developed gamma-ray detection system showed the performance that could be applicable but not satisfactory in Compton camera application.

  15. Characterization of Compton camera LaBr{sub 3} absorber detector

    Energy Technology Data Exchange (ETDEWEB)

    Marinsek, T.; Liprandi, S.; Bortfeldt, J.; Lang, C.; Lutter, R.; Dedes, G.; Parodi, K.; Thirolf, P.G. [LMU Munich, Garching (Germany); Aldawood, S. [LMU Munich, Garching (Germany); King Saud University, Riyadh (Saudi Arabia); Maier, L.; Gernhaeuser, R. [TU Munich, Garching (Germany); Kolff, H. van der [LMU Munich, Garching (Germany); TU Delft (Netherlands); Castelhano, I. [LMU Munich, Garching (Germany); University of Lisbon, Lisbon (Portugal); Schaart, D.R. [TU Delft (Netherlands)

    2015-07-01

    Detection of prompt γ rays from nuclear interactions between a particle beam and organic tissue using a Compton camera to determine the Bragg peak position is a promising way of ion-beam range verification in hadron therapy. The Compton camera consists of a stack of six double-sided Si-strip detectors acting as scatterers, while the other essential part - the absorber - is made of a LaBr{sub 3} monolithic scintillator crystal (50 x 50 x 30 mm{sup 3}) with reflective side-surface wrapping, offering excellent time and energy resolution. Scintillation light induced in the crystal is detected by a 256-fold segmented multi-anode PMT. Prerequisite to reconstruct the γ source position is the determination of the photon interaction position in the crystal by applying ''k-nearest neighbors'' algorithm (van Dam et al., Nuclear Science (2011)) using the reference library of light distributions, obtained by performing a 2D scan of the detector using a strong collimated {sup 137}Cs source. The status of the spatial resolution characterization is presented.

  16. Requirements for a Compton camera for in vivo range verification of proton therapy

    Science.gov (United States)

    Rohling, H.; Priegnitz, M.; Schoene, S.; Schumann, A.; Enghardt, W.; Hueso-González, F.; Pausch, G.; Fiedler, F.

    2017-04-01

    To ensure the optimal outcome of proton therapy, in vivo range verification is highly desired. Prompt γ-ray imaging (PGI) is a possible approach for in vivo range monitoring. For PGI, dedicated detection systems, e.g. Compton cameras, are currently under investigation. The presented paper deals with substantial requirements regarding hardware and software that a Compton camera used in clinical routine has to meet. By means of GEANT4 simulations, we investigate the load on the detectors and the percentage of background expected in a realistic irradiation and we simulate γ-ray detections subsequently used as input data for the reconstruction. By reconstructing events from simulated sources of well-defined geometry, we show that large-area detectors are favourable. We investigate reconstruction results in dependence of the number of events. Finally, an end-to-end test for a realistic patient scenario is presented: starting with a treatment plan, the γ-ray emissions are calculated, the detector response is modelled, and the image reconstruction is performed. By this, the complexity of the system is shown, and requirements and limitations regarding precision and costs are determined.

  17. The first demonstration of the concept of "narrow-FOV Si/CdTe semiconductor Compton camera"

    OpenAIRE

    Ichinohe, Yuto; Uchida, Yuusuke; Watanabe, Shin; Edahiro, Ikumi; Hayashi, Katsuhiro; Kawano, Takafumi; Ohno, Masanori; Ohta, Masayuki; Takeda, Shin'ichiro; Fukazawa, Yasushi; Katsuragawa, Miho; Nakazawa, Kazuhiro; Odaka, Hirokazu; Tajima, Hiroyasu; Takahashi, Hiromitsu

    2015-01-01

    The Soft Gamma-ray Detector (SGD), to be deployed onboard the {\\it ASTRO-H} satellite, has been developed to provide the highest sensitivity observations of celestial sources in the energy band of 60-600~keV by employing a detector concept which uses a Compton camera whose field-of-view is restricted by a BGO shield to a few degree (narrow-FOV Compton camera). In this concept, the background from outside the FOV can be heavily suppressed by constraining the incident direction of the gamma ray...

  18. A double photomultiplier Compton camera and its readout system for mice imaging

    Energy Technology Data Exchange (ETDEWEB)

    Fontana, Cristiano Lino [Physics Department Galileo Galilei, University of Padua, Via Marzolo 8, Padova 35131 (Italy) and INFN Padova, Via Marzolo 8, Padova 35131 (Italy); Atroshchenko, Kostiantyn [Physics Department Galileo Galilei, University of Padua, Via Marzolo 8, Padova 35131 (Italy) and INFN Legnaro, Viale dell' Universita 2, Legnaro PD 35020 (Italy); Baldazzi, Giuseppe [Physics Department, University of Bologna, Viale Berti Pichat 6/2, Bologna 40127, Italy and INFN Bologna, Viale Berti Pichat 6/2, Bologna 40127 (Italy); Bello, Michele [INFN Legnaro, Viale dell' Universita 2, Legnaro PD 35020 (Italy); Uzunov, Nikolay [Department of Natural Sciences, Shumen University, 115 Universitetska str., Shumen 9712, Bulgaria and INFN Legnaro, Viale dell' Universita 2, Legnaro PD 35020 (Italy); Di Domenico, Giovanni [Physics Department, University of Ferrara, Via Saragat 1, Ferrara 44122 (Italy) and INFN Ferrara, Via Saragat 1, Ferrara 44122 (Italy)

    2013-04-19

    We have designed a Compton Camera (CC) to image the bio-distribution of gamma-emitting radiopharmaceuticals in mice. A CC employs the 'electronic collimation', i.e. a technique that traces the gamma-rays instead of selecting them with physical lead or tungsten collimators. To perform such a task, a CC measures the parameters of the Compton interaction that occurs in the device itself. At least two detectors are required: one (tracker), where the primary gamma undergoes a Compton interaction and a second one (calorimeter), in which the scattered gamma is completely absorbed. Eventually the polar angle and hence a 'cone' of possible incident directions are obtained (event with 'incomplete geometry'). Different solutions for the two detectors are proposed in the literature: our design foresees two similar Position Sensitive Photomultipliers (PMT, Hamamatsu H8500). Each PMT has 64 output channels that are reduced to 4 using a charge multiplexed readout system, i.e. a Series Charge Multiplexing net of resistors. Triggering of the system is provided by the coincidence of fast signals extracted at the last dynode of the PMTs. Assets are the low cost and the simplicity of design and operation, having just one type of device; among drawbacks there is a lower resolution with respect to more sophisticated trackers and full 64 channels Readout. This paper does compare our design of our two-Hamamatsu CC to other solutions and shows how the spatial and energy accuracy is suitable for the inspection of radioactivity in mice.

  19. Evaluation of Compton gamma camera prototype based on pixelated CdTe detectors.

    Science.gov (United States)

    Calderón, Y; Chmeissani, M; Kolstein, M; De Lorenzo, G

    2014-06-01

    A proposed Compton camera prototype based on pixelated CdTe is simulated and evaluated in order to establish its feasibility and expected performance in real laboratory tests. The system is based on module units containing a 2×4 array of square CdTe detectors of 10×10 mm(2) area and 2 mm thickness. The detectors are pixelated and stacked forming a 3D detector with voxel sizes of 2 × 1 × 2 mm(3). The camera performance is simulated with Geant4-based Architecture for Medicine-Oriented Simulations(GAMOS) and the Origin Ensemble(OE) algorithm is used for the image reconstruction. The simulation shows that the camera can operate with up to 10(4) Bq source activities with equal efficiency and is completely saturated at 10(9) Bq. The efficiency of the system is evaluated using a simulated (18)F point source phantom in the center of the Field-of-View (FOV) achieving an intrinsic efficiency of 0.4 counts per second per kilobecquerel. The spatial resolution measured from the point spread function (PSF) shows a FWHM of 1.5 mm along the direction perpendicular to the scatterer, making it possible to distinguish two points at 3 mm separation with a peak-to-valley ratio of 8.

  20. First demonstration of real-time gamma imaging by using a handheld Compton camera for particle therapy

    Energy Technology Data Exchange (ETDEWEB)

    Taya, T., E-mail: taka48138@ruri.waseda.jp [Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan); Kataoka, J.; Kishimoto, A.; Iwamoto, Y.; Koide, A. [Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan); Nishio, T. [Graduate School of Biomedical and Health Science, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima-shi, Hiroshima (Japan); Kabuki, S. [School of Medicine, Tokai University, 143 Shimokasuya, Isehara-shi, Kanagawa (Japan); Inaniwa, T. [National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba (Japan)

    2016-09-21

    The use of real-time gamma imaging for cancer treatment in particle therapy is expected to improve the accuracy of the treatment beam delivery. In this study, we demonstrated the imaging of gamma rays generated by the nuclear interactions during proton irradiation, using a handheld Compton camera (14 cm×15 cm×16 cm, 2.5 kg) based on scintillation detectors. The angular resolution of this Compton camera is ∼8° at full width at half maximum (FWHM) for a {sup 137}Cs source. We measured the energy spectra of the gamma rays using a LaBr{sub 3}(Ce) scintillator and photomultiplier tube, and using the handheld Compton camera, performed image reconstruction when using a 70 MeV proton beam to irradiate a water, Ca(OH){sub 2}, and polymethyl methacrylate (PMMA) phantom. In the energy spectra of all three phantoms, we found an obvious peak at 511 keV, which was derived from annihilation gamma rays, and in the energy spectrum of the PMMA phantom, we found another peak at 718 keV, which contains some of the prompt gamma rays produced from {sup 10}B. Therefore, we evaluated the peak positions of the projection from the reconstructed images of the PMMA phantom. The differences between the peak positions and the Bragg peak position calculated using simulation are 7 mm±2 mm and 3 mm±8 mm, respectively. Although we could quickly acquire online gamma imaging of both of the energy ranges during proton irradiation, we cannot arrive at a clear conclusion that prompt gamma rays sufficiently trace the Bragg peak from these results because of the uncertainty given by the spatial resolution of the Compton camera. We will develop a high-resolution Compton camera in the near future for further study. - Highlights: • Gamma imaging during proton irradiation by a handheld Compton camera is demonstrated. • We were able to acquire the online gamma-ray images quickly. • We are developing a high resolution Compton camera for range verification.

  1. A BASIC CAMERA UNIT FOR MEDICAL PHOTOGRAPHY.

    Science.gov (United States)

    SMIALOWSKI, A; CURRIE, D J

    1964-08-22

    A camera unit suitable for most medical photographic purposes is described. The unit comprises a single-lens reflex camera, an electronic flash unit and supplementary lenses. Simple instructions for use of th's basic unit are presented. The unit is entirely suitable for taking fine-quality photographs of most medical subjects by persons who have had little photographic training.

  2. First demonstration of real-time gamma imaging by using a handheld Compton camera for particle therapy

    Science.gov (United States)

    Taya, T.; Kataoka, J.; Kishimoto, A.; Iwamoto, Y.; Koide, A.; Nishio, T.; Kabuki, S.; Inaniwa, T.

    2016-09-01

    The use of real-time gamma imaging for cancer treatment in particle therapy is expected to improve the accuracy of the treatment beam delivery. In this study, we demonstrated the imaging of gamma rays generated by the nuclear interactions during proton irradiation, using a handheld Compton camera (14 cm×15 cm×16 cm, 2.5 kg) based on scintillation detectors. The angular resolution of this Compton camera is ∼8° at full width at half maximum (FWHM) for a 137Cs source. We measured the energy spectra of the gamma rays using a LaBr3(Ce) scintillator and photomultiplier tube, and using the handheld Compton camera, performed image reconstruction when using a 70 MeV proton beam to irradiate a water, Ca(OH)2, and polymethyl methacrylate (PMMA) phantom. In the energy spectra of all three phantoms, we found an obvious peak at 511 keV, which was derived from annihilation gamma rays, and in the energy spectrum of the PMMA phantom, we found another peak at 718 keV, which contains some of the prompt gamma rays produced from 10B. Therefore, we evaluated the peak positions of the projection from the reconstructed images of the PMMA phantom. The differences between the peak positions and the Bragg peak position calculated using simulation are 7 mm±2 mm and 3 mm±8 mm, respectively. Although we could quickly acquire online gamma imaging of both of the energy ranges during proton irradiation, we cannot arrive at a clear conclusion that prompt gamma rays sufficiently trace the Bragg peak from these results because of the uncertainty given by the spatial resolution of the Compton camera. We will develop a high-resolution Compton camera in the near future for further study.

  3. Effects of energy threshold and dead time on Compton camera performance

    Energy Technology Data Exchange (ETDEWEB)

    Uche, C.Z., E-mail: czu1@waikato.ac.nz [Department of Engineering, University of Waikato, Private Bag 3105 Hamilton (New Zealand); Round, W.H., E-mail: h.round@waikato.ac.nz [Department of Engineering, University of Waikato, Private Bag 3105 Hamilton (New Zealand); Cree, M.J., E-mail: cree@waikato.ac.nz [Department of Engineering, University of Waikato, Private Bag 3105 Hamilton (New Zealand)

    2011-06-11

    We study the effects of energy threshold and dead time on the sensitivity and image resolution of the Compton camera. The simulation model includes the decay times, detection time jitters, energy threshold and detector dead time as well as basic detector parameters such as Doppler broadening, energy resolution and finite detector resolution. The GEANT4 toolkit was used to model the camera geometry and performance for two common nuclear medicine energies that correspond to {sup 99m}Tc (140.5 keV) and {sup 18}F (511 keV) radiotracers. Results without the energy threshold and time effects show good agreement with previous studies. For 140.5 keV, the inclusion of energy threshold improved image resolution from 10.7 to 9.5 mm with a source-to-detector distance of 5 cm, while the inclusion of time effects made no further difference on resolution. The energy threshold reduced the sensitivity by 48%, and subsequent inclusion of time effects further reduced the sensitivity by 17%. At 511 keV, the application of energy threshold reduced the sensitivity by 6%, while the time effects dominated count rate losses with further reduction of 13%. However, the inclusion of the two effects had negligible impact on the resolution.

  4. Effects of energy threshold and dead time on Compton camera performance

    Science.gov (United States)

    Uche, C. Z.; Round, W. H.; Cree, M. J.

    2011-06-01

    We study the effects of energy threshold and dead time on the sensitivity and image resolution of the Compton camera. The simulation model includes the decay times, detection time jitters, energy threshold and detector dead time as well as basic detector parameters such as Doppler broadening, energy resolution and finite detector resolution. The GEANT4 toolkit was used to model the camera geometry and performance for two common nuclear medicine energies that correspond to 99mTc (140.5 keV) and 18F (511 keV) radiotracers. Results without the energy threshold and time effects show good agreement with previous studies. For 140.5 keV, the inclusion of energy threshold improved image resolution from 10.7 to 9.5 mm with a source-to-detector distance of 5 cm, while the inclusion of time effects made no further difference on resolution. The energy threshold reduced the sensitivity by 48%, and subsequent inclusion of time effects further reduced the sensitivity by 17%. At 511 keV, the application of energy threshold reduced the sensitivity by 6%, while the time effects dominated count rate losses with further reduction of 13%. However, the inclusion of the two effects had negligible impact on the resolution.

  5. The first demonstration of the concept of "narrow-FOV Si/CdTe semiconductor Compton camera"

    CERN Document Server

    Ichinohe, Yuto; Watanabe, Shin; Edahiro, Ikumi; Hayashi, Katsuhiro; Kawano, Takafumi; Ohno, Masanori; Ohta, Masayuki; Takeda, Shin'ichiro; Fukazawa, Yasushi; Katsuragawa, Miho; Nakazawa, Kazuhiro; Odaka, Hirokazu; Tajima, Hiroyasu; Takahashi, Hiromitsu; Takahashi, Tadayuki; Yuasa, Takayuki

    2015-01-01

    The Soft Gamma-ray Detector (SGD), to be deployed onboard the {\\it ASTRO-H} satellite, has been developed to provide the highest sensitivity observations of celestial sources in the energy band of 60-600~keV by employing a detector concept which uses a Compton camera whose field-of-view is restricted by a BGO shield to a few degree (narrow-FOV Compton camera). In this concept, the background from outside the FOV can be heavily suppressed by constraining the incident direction of the gamma ray reconstructed by the Compton camera to be consistent with the narrow FOV. We, for the first time, demonstrate the validity of the concept using background data taken during the thermal vacuum test and the low-temperature environment test of the flight model of SGD on ground. We show that the measured background level is suppressed to less than 10\\% by combining the event rejection using the anti-coincidence trigger of the active BGO shield and by using Compton event reconstruction techniques. More than 75\\% of the signal...

  6. The first demonstration of the concept of "narrow-FOV Si/CdTe semiconductor Compton camera"

    Science.gov (United States)

    Ichinohe, Yuto; Uchida, Yuusuke; Watanabe, Shin; Edahiro, Ikumi; Hayashi, Katsuhiro; Kawano, Takafumi; Ohno, Masanori; Ohta, Masayuki; Takeda, Shin`ichiro; Fukazawa, Yasushi; Katsuragawa, Miho; Nakazawa, Kazuhiro; Odaka, Hirokazu; Tajima, Hiroyasu; Takahashi, Hiromitsu; Takahashi, Tadayuki; Yuasa, Takayuki

    2016-01-01

    The Soft Gamma-ray Detector (SGD), to be deployed on board the ASTRO-H satellite, has been developed to provide the highest sensitivity observations of celestial sources in the energy band of 60-600 keV by employing a detector concept which uses a Compton camera whose field-of-view is restricted by a BGO shield to a few degree (narrow-FOV Compton camera). In this concept, the background from outside the FOV can be heavily suppressed by constraining the incident direction of the gamma ray reconstructed by the Compton camera to be consistent with the narrow FOV. We, for the first time, demonstrate the validity of the concept using background data taken during the thermal vacuum test and the low-temperature environment test of the flight model of SGD on ground. We show that the measured background level is suppressed to less than 10% by combining the event rejection using the anti-coincidence trigger of the active BGO shield and by using Compton event reconstruction techniques. More than 75% of the signals from the field-of-view are retained against the background rejection, which clearly demonstrates the improvement of signal-to-noise ratio. The estimated effective area of 22.8 cm2 meets the mission requirement even though not all of the operational parameters of the instrument have been fully optimized yet.

  7. Test of Compton camera components for prompt gamma imaging at the ELBE bremsstrahlung beam

    Science.gov (United States)

    Hueso-González, F.; Golnik, C.; Berthel, M.; Dreyer, A.; Enghardt, W.; Fiedler, F.; Heidel, K.; Kormoll, T.; Rohling, H.; Schöne, S.; Schwengner, R.; Wagner, A.; Pausch, G.

    2014-05-01

    In the context of ion beam therapy, particle range verification is a major challenge for the quality assurance of the treatment. One approach is the measurement of the prompt gamma rays resulting from the tissue irradiation. A Compton camera based on several position sensitive gamma ray detectors, together with an imaging algorithm, is expected to reconstruct the prompt gamma ray emission density map, which is correlated with the dose distribution. At OncoRay and Helmholtz-Zentrum Dresden-Rossendorf (HZDR), a Compton camera setup is being developed consisting of two scatter planes: two CdZnTe (CZT) cross strip detectors, and an absorber consisting of one Lu2SiO5 (LSO) block detector. The data acquisition is based on VME electronics and handled by software developed on the ROOT framework. The setup has been tested at the linear electron accelerator ELBE at HZDR, which is used in this experiment to produce bunched bremsstrahlung photons with up to 12.5 MeV energy and a repetition rate of 13 MHz. Their spectrum has similarities with the shape expected from prompt gamma rays in the clinical environment, and the flux is also bunched with the accelerator frequency. The charge sharing effect of the CZT detector is studied qualitatively for different energy ranges. The LSO detector pixel discrimination resolution is analyzed and it shows a trend to improve for high energy depositions. The time correlation between the pulsed prompt photons and the measured detector signals, to be used for background suppression, exhibits a time resolution of 3 ns FWHM for the CZT detector and of 2 ns for the LSO detector. A time walk correction and pixel-wise calibration is applied for the LSO detector, whose resolution improves up to 630 ps. In conclusion, the detector setup is suitable for time-resolved background suppression in pulsed clinical particle accelerators. Ongoing tasks are the quantitative comparison with simulations and the test of imaging algorithms. Experiments at proton

  8. Commissioning of the scatter component of a Compton camera consisting of a stack of Si strip detectors

    Energy Technology Data Exchange (ETDEWEB)

    Liprandi, S.; Marinsek, T.; Bortfeldt, J.; Lang, C.; Lutter, R.; Dedes, G.; Parodi, K.; Thirolf, P.G. [LMU Munich, Garching (Germany); Aldawood, S. [LMU Munich, Garching (Germany); King Saud University, Riyadh (Saudi Arabia); Maier, L.; Gernhaeuser, R. [TU Munich, Garching (Germany); Kolff, H. van der [LMU Munich, Garching (Germany); TU Delft (Netherlands); Castelhano, I. [LMU Munich, Garching (Germany); University of Lisbon, Lisbon (Portugal); Schaart, D.R. [TU Delft (Netherlands)

    2015-07-01

    At LMU Munich in Garching a Compton camera is presently being developed aiming at the range verification of proton (or ion) beams for hadron therapy via imaging of prompt γ rays from nuclear reactions in the tissue. The poster presentation focuses on the characterization of the scatter component of the Compton camera, consisting of a stack of six double-sided Si strip detectors (50 x 50 mm{sup 2}, 0.5 mm thick, 128 strips/side). The overall 1536 electronics channels are processed by a readout system based on the GASSIPLEX ASIC chip, feeding into a VME-based data acquisition system. The status of the offline and online characterization studies is presented.

  9. Study of the Polarimetric Performance of a Si/CdTe Semiconductor Compton Camera for the Hitomi Satellite

    CERN Document Server

    Katsuta, Junichiro; Watanabe, Shin; Odaka, Hirokazu; Uchida, Yusuke; Uchida, Nagomi; Mizuno, Tsunefumi; Fukazawa, Yasushi; Hayashi, Katsuhiro; Habata, Sho; Ichinohe, Yuto; Kitaguchi, Takao; Ohno, Masanori; Ohta, Masayuki; Takahashi, Hiromitsu; Takahashi, Tadayuki; Takeda, Shin'ichiro; Tajima, Hiroyasu; Yuasa, Takayuki; Itou, Masayoshi

    2016-01-01

    Gamma-ray polarization offers a unique probes into the geometry of the gamma-ray emission process in celestial objects. The Soft Gamma-ray Detector (SGD) onboard the X-ray observatory Hitomi is a Si/CdTe Compton camera and is expected to be an excellent polarimeter, as well as a highly sensitive spectrometer due to its good angular coverage and resolution for Compton scattering. A beam test of the final-prototype for the SGD Compton camera was conducted to demonstrate its polarimetric capability and to verify and calibrate the Monte Carlo simulation of the instrument. The modulation factor of the SGD prototype camera, evaluated for the inner and outer parts of the CdTe sensors as absorbers, was measured to be 0.649--0.701 (inner part) and 0.637--0.653 (outer part) at 122.2 keV and 0.610--0.651 (inner part) and 0.564--0.592 (outer part) at 194.5 keV at varying polarization angles with respect to the detector. This indicates that the relative systematic uncertainty of the modulation factor is as small as ~3%.

  10. Study of the polarimetric performance of a Si/CdTe semiconductor Compton camera for the Hitomi satellite

    Science.gov (United States)

    Katsuta, Junichiro; Edahiro, Ikumi; Watanabe, Shin; Odaka, Hirokazu; Uchida, Yusuke; Uchida, Nagomi; Mizuno, Tsunefumi; Fukazawa, Yasushi; Hayashi, Katsuhiro; Habata, Sho; Ichinohe, Yuto; Kitaguchi, Takao; Ohno, Masanori; Ohta, Masayuki; Takahashi, Hiromitsu; Takahashi, Tadayuki; Takeda, Shin'ichiro; Tajima, Hiroyasu; Yuasa, Takayuki; Itou, Masayoshi

    2016-12-01

    Gamma-ray polarization offers a unique probe into the geometry of the γ-ray emission process in celestial objects. The Soft Gamma-ray Detector (SGD) onboard the X-ray observatory Hitomi is a Si/CdTe Compton camera and is expected to be an excellent polarimeter, as well as a highly sensitive spectrometer due to its good angular coverage and resolution for Compton scattering. A beam test of the final-prototype for the SGD Compton camera was conducted to demonstrate its polarimetric capability and to verify and calibrate the Monte Carlo simulation of the instrument. The modulation factor of the SGD prototype camera, evaluated for the inner and outer parts of the CdTe sensors as absorbers, was measured to be 0.649-0.701 (inner part) and 0.637-0.653 (outer part) at 122.2 keV and 0.610-0.651 (inner part) and 0.564-0.592 (outer part) at 194.5 keV at varying polarization angles with respect to the detector. This indicates that the relative systematic uncertainty of the modulation factor is as small as ∼ 3 % .

  11. Portable mini gamma camera for medical applications

    CERN Document Server

    Porras, E; Benlloch, J M; El-Djalil-Kadi-Hanifi, M; López, S; Pavon, N; Ruiz, J A; Sánchez, F; Sebastiá, A

    2002-01-01

    A small, portable and low-cost gamma camera for medical applications has been developed and clinically tested. This camera, based on a scintillator crystal and a Position Sensitive Photo-Multiplier Tube, has a useful field of view of 4.6 cm diameter and provides 2.2 mm of intrinsic spatial resolution. Its mobility and light weight allow to reach the patient from any desired direction. This camera images small organs with high efficiency and so addresses the demand for devices of specific clinical applications. In this paper, we present the camera and briefly describe the procedures that have led us to choose its configuration and the image reconstruction method. The clinical tests and diagnostic capability are also presented and discussed.

  12. Inversion of the conical Radon transform with vertices on a surface of revolution arising in an application of a Compton camera

    Science.gov (United States)

    Moon, Sunghwan

    2017-06-01

    A Compton camera has been introduced for use in single photon emission computed tomography to improve the low efficiency of a conventional gamma camera. In general, a Compton camera brings about the conical Radon transform. Here we consider a conical Radon transform with the vertices on a rotation symmetric set with respect to a coordinate axis. We show that this conical Radon transform can be decomposed into two transforms: the spherical sectional transform and the weighted fan beam transform. After finding inversion formulas for these two transforms, we provide an inversion formula for the conical Radon transform.

  13. Evaluation of a multistage CdZnTe Compton camera for prompt γ imaging for proton therapy

    Science.gov (United States)

    McCleskey, M.; Kaye, W.; Mackin, D. S.; Beddar, S.; He, Z.; Polf, J. C.

    2015-06-01

    A new detector system, Polaris J from H3D, has been evaluated for its potential application as a Compton camera (CC) imaging device for prompt γ rays (PGs) emitted during proton radiation therapy (RT) for the purpose of dose range verification. This detector system consists of four independent CdZnTe detector stages and a coincidence module, allowing the user to construct a Compton camera in different geometrical configurations and to accept both double and triple scatter events. Energy resolution for the 662 keV line from 137Cs was found to be 9.7 keV FWHM. The raw absolute efficiencies for double and triple scatter events were 2.2 ×10-5 and 5.8 ×10-7, respectively, for γs from a 60Co source. The position resolution for the reconstruction of a point source from the measured CC data was about 2 mm. Overall, due to the low efficiency of the Polaris J CC, the current system was deemed not viable for imaging PGs emitted during proton RT treatment delivery. However, using a validated Monte Carlo model of the CC, we found that by increasing the size of the detectors and placing them in a two stage configuration, the efficiency could be increased to a level to make PG imaging possible during proton RT.

  14. A performance study of an electron-tracking Compton camera with a compact system for environmental gamma-ray observation

    CERN Document Server

    Mizumoto, Tetsuya; Takada, Atsushi; Tanimori, Toru; Komura, Shotaro; Kubo, Hidetoshi; Matsuoka, Yoshihiro; Mizumura, Yoshitaka; Nakamura, Kiseki; Nakamura, Shogo; Oda, Makoto; Parker, Joseph D; Sawano, Tatsuya; Bando, Naoto; Nabetani, Akira

    2015-01-01

    An electron-tracking Compton camera (ETCC) is a detector that can determine the arrival direction and energy of incident sub-MeV/MeV gamma-ray events on an event-by-event basis. It is a hybrid detector consisting of a gaseous time projection chamber (TPC), that is the Compton-scattering target and the tracker of recoil electrons, and a position-sensitive scintillation camera that absorbs of the scattered gamma rays, to measure gamma rays in the environment from contaminated soil. To measure of environmental gamma rays from soil contaminated with radioactive cesium (Cs), we developed a portable battery-powered ETCC system with a compact readout circuit and data-acquisition system for the SMILE-II experiment. We checked the gamma-ray imaging ability and ETCC performance in the laboratory by using several gamma-ray point sources. The performance test indicates that the field of view (FoV) of the detector is about 1$\\;$sr and that the detection efficiency and angular resolution for 662$\\;$keV gamma rays from the ...

  15. Development of a liquid xenon Compton telescope dedicated to functional medical imaging; Etude et developpement d'un telescope compton au xenon liquide dedie a l'imagerie medicale fonctionnelle

    Energy Technology Data Exchange (ETDEWEB)

    Grignon, C

    2007-12-15

    Functional imaging is a technique used to locate in three dimensions the position of a radiotracer previously injected in a patient. The two main modalities used for a clinical application to detect tumors, the SPECT and the PET, use solid scintillators as a detection medium. The objective of this thesis was to investigate the possibility of using liquid xenon in order to benefit from the intrinsic properties of this medium in functional imaging. The feasibility study of such a device has been performed by taking into account the technical difficulties specific to the liquid xenon. First of all, simulations of a liquid xenon PET has been performed using Monte-Carlo methods. The results obtained with a large liquid xenon volume are promising : we can expect a reduction of the injected activity of radiotracer, an improvement of the spatial resolution of the image and a parallax free camera. The second part of the thesis was focused on the development of a new concept of medical imaging, the three gamma imaging, based on the use of a new emitter: the 44 scandium. Associated to a classical PET camera, the Compton telescope is used to infer the incoming direction of the third gamma ray by triangulation. Therefore, it is possible to reconstruct the position of each emitter in three dimensions. This work convinced the scientific community to support the construction and characterization of a liquid xenon Compton telescope. The first camera dedicated to small animal imaging should then be operational in 2009. (author)

  16. Evaluation of list-mode ordered subset expectation maximization image reconstruction for pixelated solid-state compton gamma camera with large number of channels

    Science.gov (United States)

    Kolstein, M.; De Lorenzo, G.; Chmeissani, M.

    2014-04-01

    The Voxel Imaging PET (VIP) Pathfinder project intends to show the advantages of using pixelated solid-state technology for nuclear medicine applications. It proposes designs for Positron Emission Tomography (PET), Positron Emission Mammography (PEM) and Compton gamma camera detectors with a large number of signal channels (of the order of 106). For Compton camera, especially with a large number of readout channels, image reconstruction presents a big challenge. In this work, results are presented for the List-Mode Ordered Subset Expectation Maximization (LM-OSEM) image reconstruction algorithm on simulated data with the VIP Compton camera design. For the simulation, all realistic contributions to the spatial resolution are taken into account, including the Doppler broadening effect. The results show that even with a straightforward implementation of LM-OSEM, good images can be obtained for the proposed Compton camera design. Results are shown for various phantoms, including extended sources and with a distance between the field of view and the first detector plane equal to 100 mm which corresponds to a realistic nuclear medicine environment.

  17. Development of a novel handheld intra-operative laparoscopic Compton camera for 18F-Fluoro-2-deoxy-2-D-glucose-guided surgery

    Science.gov (United States)

    Nakamura, Y.; Shimazoe, K.; Takahashi, H.; Yoshimura, S.; Seto, Y.; Kato, S.; Takahashi, M.; Momose, T.

    2016-08-01

    As well as pre-operative roadmapping by 18F-Fluoro-2-deoxy-2-D-glucose (FDG) positron emission tomography, intra-operative localization of the tracer is important to identify local margins for less-invasive surgery, especially FDG-guided surgery. The objective of this paper is to develop a laparoscopic Compton camera and system aimed at use for intra-operative FDG imaging for accurate and less-invasive dissections. The laparoscopic Compton camera consists of four layers of a 12-pixel cross-shaped array of GFAG crystals (2× 2× 3 mm3) and through silicon via multi-pixel photon counters and dedicated individual readout electronics based on a dynamic time-over-threshold method. Experimental results yielded a spatial resolution of 4 mm (FWHM) for a 10 mm working distance and an absolute detection efficiency of 0.11 cps kBq-1, corresponding to an intrinsic detection efficiency of  ˜0.18%. In an experiment using a NEMA-like well-shaped FDG phantom, a φ 5× 10 mm cylindrical hot spot was clearly obtained even in the presence of a background distribution surrounding the Compton camera and the hot spot. We successfully obtained reconstructed images of a resected lymph node and primary tumor ex vivo after FDG administration to a patient having esophageal cancer. These performance characteristics indicate a new possibility of FDG-directed surgery by using a Compton camera intra-operatively.

  18. Optimization of a multiple-scattering Compton camera as a photon-tracking imager for 6-MV photon therapy

    Science.gov (United States)

    Lee, Taewoong; Yoon, Changyeon; Lee, Wonho

    2014-06-01

    During radiation therapy, the irradiated position and the energy deposited in a patient must be monitored. In general, calculations before photon exposure or 2D measurements of the transmitted photons have been widely used for making dose estimates. In this paper, we propose a real-time 3D dose measurement using Compton imaging technology. On the basis of the Monte-Carlo method, we designed a multiple-scattering Compton camera system (MSCC) with semiconductor and scintillation detectors. The MSCC was constructed with two semiconductor detectors as scattering detectors and a cadmium-tungstate (CWO) scintillator detector as an absorber detector. The two planar semiconductor arrays, and the CWO array consisted of 40 × 40 pixels, each with a size of 1 × 1 × ɛ mm3, where ɛ is the variable thickness of the detectors. The design parameters, such as the types of semiconductors, detector thicknesses and distances between detectors, were optimized on the basis of the detection efficiency and angular resolution of reconstructed images for a point source. Under the optimized conditions, uncertainty factors in geometry and energy were estimated for various inter-detector distances. We used a source corresponding to photons scattered from a water phantom exposed to 6-MeV peak X-rays. According to our simulation results, the figure of merit, reached its maximum value when the inter-detector distance was 3 cm. In order to achieve a high FOM, we chose 1 cm as the optimum thickness for the scattering and absorbed detectors. A cadmium-zinc-telluride (CZT) detector showed the best performance among the simulated semiconductors. The position uncertainty caused by the pixelization effect was the major factor in degrading the angular resolution of the reconstructed images, and the degradation caused by energy broadening was less than expected. The angular uncertainties caused by Doppler broadening and incorrect sequencing were minimal compared with that of pixelization. Our

  19. Gamma-ray detection and Compton camera image reconstruction with application to hadron therapy; Detection des rayons gamma et reconstruction d'images pour la camera Compton: Application a l'hadrontherapie

    Energy Technology Data Exchange (ETDEWEB)

    Frandes, M.

    2010-09-15

    A novel technique for radiotherapy - hadron therapy - irradiates tumors using a beam of protons or carbon ions. Hadron therapy is an effective technique for cancer treatment, since it enables accurate dose deposition due to the existence of a Bragg peak at the end of particles range. Precise knowledge of the fall-off position of the dose with millimeters accuracy is critical since hadron therapy proved its efficiency in case of tumors which are deep-seated, close to vital organs, or radio-resistant. A major challenge for hadron therapy is the quality assurance of dose delivery during irradiation. Current systems applying positron emission tomography (PET) technologies exploit gamma rays from the annihilation of positrons emitted during the beta decay of radioactive isotopes. However, the generated PET images allow only post-therapy information about the deposed dose. In addition, they are not in direct coincidence with the Bragg peak. A solution is to image the complete spectrum of the emitted gamma rays, including nuclear gamma rays emitted by inelastic interactions of hadrons to generated nuclei. This emission is isotropic, and has a spectrum ranging from 100 keV up to 20 MeV. However, the measurement of these energetic gamma rays from nuclear reactions exceeds the capability of all existing medical imaging systems. An advanced Compton scattering detection method with electron tracking capability is proposed, and modeled to reconstruct the high-energy gamma-ray events. This Compton detection technique was initially developed to observe gamma rays for astrophysical purposes. A device illustrating the method was designed and adapted to Hadron Therapy Imaging (HTI). It consists of two main sub-systems: a tracker where Compton recoiled electrons are measured, and a calorimeter where the scattered gamma rays are absorbed via the photoelectric effect. Considering a hadron therapy scenario, the analysis of generated data was performed, passing trough the complete

  20. Development of a low-cost-high-sensitivity Compton camera using CsI (Tl) scintillators (γI)

    Energy Technology Data Exchange (ETDEWEB)

    Kagaya, M., E-mail: 13nd401n@vc.ibaraki.ac.jp [College of Science, Ibaraki University, 2-1-1 Bunkyo, Mito City, Ibaraki 310-8512 (Japan); Open-It consortium (Japan); Katagiri, H. [College of Science, Ibaraki University, 2-1-1 Bunkyo, Mito City, Ibaraki 310-8512 (Japan); Open-It consortium (Japan); Enomoto, R. [Institute for Cosmic Ray Research, University of Tokyo, 5-1-5 Kashiwa-no-Ha, Kashiwa City, Chiba 277-8582 (Japan); Open-It consortium (Japan); Hanafusa, R.; Hosokawa, M.; Itoh, Y. [Fuji Electric, 1 Fujimachi, Hino City, Tokyo 191-8502 (Japan); Muraishi, H. [School of Allied Health Science, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara City, Kanagawa 252-0373 (Japan); Open-It consortium (Japan); Nakayama, K. [College of Science, Ibaraki University, 2-1-1 Bunkyo, Mito City, Ibaraki 310-8512 (Japan); Open-It consortium (Japan); Satoh, K. [Shinsei Corporation, 4-9-1 Nihonbashi-honcho, Chuo-ku, Tokyo 103-0023 (Japan); Takeda, T. [School of Allied Health Science, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara City, Kanagawa 252-0373 (Japan); Tanaka, M.M.; Uchida, T. [High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba City, Ibaraki 305-0801 (Japan); Open-It consortium (Japan); Watanabe, T. [School of Allied Health Science, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara City, Kanagawa 252-0373 (Japan); Open-It consortium (Japan); Yanagita, S.; Yoshida, T.; Umehara, K. [College of Science, Ibaraki University, 2-1-1 Bunkyo, Mito City, Ibaraki 310-8512 (Japan); Open-It consortium (Japan)

    2015-12-21

    We have developed a novel low-cost gamma-ray imaging Compton camera γI that has a high detection efficiency. Our motivation for the development of this detector was to measure the arrival directions of gamma rays produced by radioactive nuclides that were released by the Fukushima Daiichi nuclear power plant accident in 2011. The detector comprises two arrays of inorganic scintillation detectors, which act as a scatterer and an absorber. Each array has eight scintillation detectors, each comprising a large CsI (Tl) scintillator cube of side 3.5 cm, which is inexpensive and has a good energy resolution. Energies deposited by the Compton scattered electrons and subsequent photoelectric absorption, measured by each scintillation counter, are used for image reconstruction. The angular resolution was found to be 3.5° after using an image-sharpening technique. With this angular resolution, we can resolve a 1 m{sup 2} radiation hot spot that is located at a distance of 10 m from the detector with a wide field of view of 1 sr. Moreover, the detection efficiency 0.68 cps/MBq at 1 m for 662 keV (7.6 cps/μSv/h) is sufficient for measuring low-level contamination (i.e., less than 1 μSv/h) corresponding to typical values in large areas of eastern Japan. In addition to the laboratory tests, the imaging capability of our detector was verified in various regions with dose rates less than 1 μSv/h (e.g., Fukushima city).

  1. Development of a low-cost-high-sensitivity Compton camera using CsI (Tl) scintillators (γI)

    Science.gov (United States)

    Kagaya, M.; Katagiri, H.; Enomoto, R.; Hanafusa, R.; Hosokawa, M.; Itoh, Y.; Muraishi, H.; Nakayama, K.; Satoh, K.; Takeda, T.; Tanaka, M. M.; Uchida, T.; Watanabe, T.; Yanagita, S.; Yoshida, T.; Umehara, K.

    2015-12-01

    We have developed a novel low-cost gamma-ray imaging Compton camera γI that has a high detection efficiency. Our motivation for the development of this detector was to measure the arrival directions of gamma rays produced by radioactive nuclides that were released by the Fukushima Daiichi nuclear power plant accident in 2011. The detector comprises two arrays of inorganic scintillation detectors, which act as a scatterer and an absorber. Each array has eight scintillation detectors, each comprising a large CsI (Tl) scintillator cube of side 3.5 cm, which is inexpensive and has a good energy resolution. Energies deposited by the Compton scattered electrons and subsequent photoelectric absorption, measured by each scintillation counter, are used for image reconstruction. The angular resolution was found to be 3.5° after using an image-sharpening technique. With this angular resolution, we can resolve a 1 m2 radiation hot spot that is located at a distance of 10 m from the detector with a wide field of view of 1 sr. Moreover, the detection efficiency 0.68 cps/MBq at 1 m for 662 keV (7.6 cps/μSv/h) is sufficient for measuring low-level contamination (i.e., less than 1 μSv/h) corresponding to typical values in large areas of eastern Japan. In addition to the laboratory tests, the imaging capability of our detector was verified in various regions with dose rates less than 1 μSv/h (e.g., Fukushima city).

  2. Development of a Compton camera for online ion beam range verification via prompt γ detection. Session: HK 12.6 Mo 18:30

    Energy Technology Data Exchange (ETDEWEB)

    Aldawood, S. [LMU Munich, Garching (Germany); King Saud University, Riyadh (Saudi Arabia); Liprandi, S.; Marinsek, T.; Bortfeldt, J.; Lang, C.; Lutter, R.; Dedes, G.; Parodi, K.; Thirolf, P.G. [LMU Munich, Garching (Germany); Maier, L.; Gernhaeuser, R. [TU Munich, Garching (Germany); Kolff, H. van der; Schaart, D. [TU Delft (Netherlands); Castelhano, I. [University of Lisbon, Lisbon (Portugal)

    2015-07-01

    A real-time ion beam verification in hadron-therapy is playing a major role in cancer treatment evaluation. This will make the treatment interuption possible if the planned and actual ion range are mismatched. An imaging system is being developed in Garching aiming to detect prompt γ rays induced by nuclear reactions between the ion beam and biological tissue. The Compton camera prototype consists of a stack of six customized double-sided Si-strip detectors (DSSSD, 50 x 50 mm{sup 2}, 128 strips/side) acting as scatterer, while the absorber is formed by a monolithic LaBr{sub 3}:Ce scintillator crystal (50 x 50 x 30 mm{sup 3}) read out by a position-sensitive multi-anode photomultiplier (Hamamatsu H9500). The study of the Compton camera properties and its individual component are in progress both in the laboratory as well as at the online facilities.

  3. Characterization of a module with pixelated CdTe detectors for possible PET, PEM and compton camera applications

    Science.gov (United States)

    Ariño-Estrada, G.; Chmeissani, M.; de Lorenzo, G.; Puigdengoles, C.; Martínez, R.; Cabruja, E.

    2014-05-01

    We present the measurement of the energy resolution and the impact of charge sharing for a pixel CdTe detector. This detector will be used in a novel conceptual design for diagnostic systems in the field of nuclear medicine such as positron emission tomography (PET), positron emission mammography (PEM) and Compton camera. The detector dimensions are 10 mm × 10 mm × 2 mm and with a pixel pitch of 1 mm × 1 mm. The pixel CdTe detector is a Schottky diode and it was tested at a bias of -1000 V. The VATAGP7.1 frontend ASIC was used for the readout of the pixel detector and the corresponding single channel electronic noise was found to be σ < 2 keV for all the pixels. We have achieved an energy resolution, FWHM/Epeak, of 7.1%, 4.5% and 0.98% for 59.5, 122 and 511 keV respectively. The study of the charge sharing shows that 16% of the events deposit part of their energy in the adjacent pixel.

  4. Performance of a new electron-tracking Compton camera under intense radiations from a water target irradiated with a proton beam

    CERN Document Server

    Matsuoka, Yatsuoka; Kubo, H; Takada, A; Parker, J D; Mizumoto, T; Mizumura, Y; Iwaki, S; Sawano, T; Komura, S; Kishimoto, T; Oda, M; Takemura, T; Miyamoto, S; Sonoda, S; Tomono, D; Miuchi, K; Kabuki, S; Kurosawa, S

    2014-01-01

    We have developed an electron-tracking Compton camera (ETCC) for use in next-generation MeV gamma ray telescopes. An ETCC consists of a gaseous time projection chamber (TPC) and pixel scintillator arrays (PSAs). Since the TPC measures the three dimensional tracks of Compton-recoil electrons, the ETCC can completely reconstruct the incident gamma rays. Moreover, the ETCC demonstrates efficient background rejection power in Compton-kinematics tests, identifies particle from the energy deposit rate (dE/dX) registered in the TPC, and provides high quality imaging by completely reconstructing the Compton scattering process. We are planning the "Sub-MeV gamma ray Imaging Loaded-on-balloon Experiment" (SMILE) for our proposed all-sky survey satellite. Performance tests of a mid-sized 30 cm-cubic ETCC, constructed for observing the Crab nebula, are ongoing. However, observations at balloon altitudes or satellite orbits are obstructed by radiation background from the atmosphere and the detector itself. The background ...

  5. Compton scattered imaging based on the V-line radon transform and its medical imaging applications.

    Science.gov (United States)

    Nguyen, M K; Regniery, R; Truong, T T; Zaidi, H

    2010-01-01

    The Radon transform (RT) on straight lines deals as mathematical foundation for many tomographic modalities (e.g. Xray scanner, Positron Emission Tomography), using only primary radiation. In this paper, we consider a new RT defined on a pair of half-lines forming a letter V, arising from the modeling a two-dimensional emission imaging process by Compton scattered gamma rays. We establish its analytic inverse, which is shown to support the feasibility of the reconstruction of a two-dimensional image from scattered radiation collected on a one-dimensional collimated camera. Moreover, a filtered back-projection inversion method is also constructed. Its main advantages are algorithmic efficiency and computational rapidity. We present numerical simulations to illustrate the working. To sum up, the V-line RT leads not only to a new imaging principle, but also to a new concept of detector with high energetic resolution capable to collect the scattered radiation.

  6. Observational Possibility of the Early GRBs using a Gaseous Electron Tracking Compton Camera in sub-MeV and MeV regions

    Science.gov (United States)

    Tanimori, Toru

    2010-10-01

    GRBs have been recently known as a unique probe to catch the highest z galaxies and stars. Here I propose the new trigger method to catch high-z GRBs with z>10 efficiently by imaging sub-MeV gamma rays from GRBs. We have developed the Electron Tracking Compton Camera (ETCC) with reconstructing tracks of the recoil electron in Compton process to explore the MeV gamma-ray astronomy. By measuring the track of a recoil electron, the direction of the incident gamma ray is determined for each photon, which enables us to reconstruct the direction of GRBs by detecting only several ten photons (>100 keV). Ability of the large ETCC (100 cm2 effective area) to detect GRBs with z~20 is revealed, based on the results of the balloon experiment and laboratory imaging test using the small ETCC.

  7. A wide-acceptance Compton spectrometer for spectral characterization of a medical x-ray source

    Science.gov (United States)

    Espy, Michelle A.; Gehring, A.; Belian, A.; Haines, T.; Hunter, J.; James, M.; Klasky, M.; Mendez, J.; Moir, D.; Sedillo, R.; Shurter, R.; Stearns, J.; Van Syoc, K.; Volegov, P.

    2016-03-01

    Accurate knowledge of the x-ray spectra used in medical treatment and radiography is important for dose calculations and material decomposition analysis. Indirect measurements via transmission through materials are possible. However, such spectra are challenging to measure directly due to the high photon fluxes. One method of direct measurement is via a Compton spectrometer (CS) method. In this approach, the x-rays are converted to a much lower flux of electrons via Compton scattering on a converter foil (typically beryllium or aluminum). The electrons are then momentum selected by bending in a magnetic field. With tight angular acceptance of electrons into the magnet of ~ 1 deg, there is a linear correlation between incident photon energy and electron position recorded on an image plate. Here we present measurements of Bremsstrahlung spectrum from a medical therapy machine, a Scanditronix M22 Microtron. Spectra with energy endpoints from 6 to 20 MeV are directly measured, using a CS with a wide energy range from 0.5 to 20 MeV. We discuss the sensitivity of the device and the effects of converter material and collimation on the accuracy of the reconstructed spectra. Approaches toward improving the sensitivity, including the use of coded apertures, and potential future applications to characterization of spectra are also discussed.

  8. Probabilistic models and numerical calculation of system matrix and sensitivity in list-mode MLEM 3D reconstruction of Compton camera images.

    Science.gov (United States)

    Maxim, Voichita; Lojacono, Xavier; Hilaire, Estelle; Krimmer, Jochen; Testa, Etienne; Dauvergne, Denis; Magnin, Isabelle; Prost, Rémy

    2016-01-01

    This paper addresses the problem of evaluating the system matrix and the sensitivity for iterative reconstruction in Compton camera imaging. Proposed models and numerical calculation strategies are compared through the influence they have on the three-dimensional reconstructed images. The study attempts to address four questions. First, it proposes an analytic model for the system matrix. Second, it suggests a method for its numerical validation with Monte Carlo simulated data. Third, it compares analytical models of the sensitivity factors with Monte Carlo simulated values. Finally, it shows how the system matrix and the sensitivity calculation strategies influence the quality of the reconstructed images.

  9. Medical Thermography with a Pyroelectric Vidicon Camera.

    Science.gov (United States)

    1981-03-01

    thermal picture. The scab at the centre of the ulcer has no blood flow to it and is cooler than its surroundings. The good sign of the positive...temperature gradient towards the ulcer is evident. Again however, a better medical judgement may be made from more quantified data. The contouring unit was...were again set to 0.50, From the numbers below the pictures the temgerature difference between the scene edges and the edge of the ulcer is 4 C. This

  10. New readout and data-acquisition system in an Electron-Tracking Compton Camera for MeV Gamma-Ray Astronomy (SMILE-II)

    CERN Document Server

    Mizumoto, Tetsuya; Mizumura, Yoshitaka; Tanimori, Toru; Kubo, Hidetoshi; Takada, Atsushi; Iwaki, Satoru; Sawano, Tatsuya; Nakamura, Kiseki; Komura, Shotaro; Nakamura, Shogo; Kishimoto, Tetsuro; Oda, Makoto; Miyamoto, Shohei; Takemura, Taito; Parker, Joseph D; Tomono, Dai; Sonoda, Shinya; Miuchi, Kentaro; Kurosawa, Shunsuke

    2015-01-01

    For MeV gamma-ray astronomy, we have developed an electron-tracking Compton camera (ETCC) as a MeV gamma-ray telescope capable of rejecting the radiation background and attaining the high sensitivity of near 1 mCrab in space. Our ETCC comprises a gaseous time-projection chamber (TPC) with a micro pattern gas detector for tracking recoil electrons and a position-sensitive scintillation camera for detecting scattered gamma rays. After the success of a first balloon experiment in 2006 with a small ETCC (using a 10$\\times$10$\\times$15 cm$^3$ TPC) for measuring diffuse cosmic and atmospheric sub-MeV gamma rays (Sub-MeV gamma-ray Imaging Loaded-on-balloon Experiment I; SMILE-I), a (30 cm)$^{3}$ medium-sized ETCC was developed to measure MeV gamma-ray spectra from celestial sources, such as the Crab Nebula, with single-day balloon flights (SMILE-II). To achieve this goal, a 100-times-larger detection area compared with that of SMILE-I is required without changing the weight or power consumption of the detector syste...

  11. New high spatial resolution portable camera in medical imaging

    Science.gov (United States)

    Trotta, C.; Massari, R.; Palermo, N.; Scopinaro, F.; Soluri, A.

    2007-07-01

    In the last years, many studies have been carried out on portable gamma cameras in order to optimize a device for medical imaging. In this paper, we present a new type of gamma camera, for low energies detection, based on a position sensitive photomultiplier tube Hamamatsu Flat Panel H8500 and an innovative technique based on CsI(Tl) scintillation crystals inserted into the square holes of a tungsten collimator. The geometrical features of this collimator-scintillator structure, which affect the camera spatial resolution and sensitivity, were chosen to offer optimal performances in clinical functional examinations. Detector sensitivity, energy resolution and spatial resolution were measured and the acquired image quality was evaluated with particular attention to the pixel identification capability. This low weight (about 2 kg) portable gamma camera was developed thanks to a miniaturized resistive chain electronic readout, combined with a dedicated compact 4 channel ADC board. This data acquisition board, designed by our research group, showed excellent performances, with respect to a commercial PCI 6110E card (National Intruments), in term of sampling period and additional on board operation for data pre-processing.

  12. Two new macro-stereo cameras for medical photography with special reference to the eye.

    Science.gov (United States)

    AandeKerk, A L

    1991-04-01

    Information is given on two new macro-stereo cameras for simultaneous stereo photography designed by members of the Dutch Stereo Society. These cameras can be used for medical photography. The first camera takes half frame stereo pictures and utilizes frames for positioning and focusing. The second camera takes full frame stereo pictures and utilizes spots projection for positioning and focusing. Examples are shown.

  13. New readout and data-acquisition system in an electron-tracking Compton camera for MeV gamma-ray astronomy (SMILE-II)

    Energy Technology Data Exchange (ETDEWEB)

    Mizumoto, T., E-mail: mizumoto@cr.scphys.kyoto-u.ac.jp [Department of Physics, Kyoto University, 606-8502 Kyoto (Japan); Matsuoka, Y. [Department of Physics, Kyoto University, 606-8502 Kyoto (Japan); Mizumura, Y. [Unit of Synergetic Studies for Space, Kyoto University, 606-8502 Kyoto (Japan); Department of Physics, Kyoto University, 606-8502 Kyoto (Japan); Tanimori, T. [Department of Physics, Kyoto University, 606-8502 Kyoto (Japan); Unit of Synergetic Studies for Space, Kyoto University, 606-8502 Kyoto (Japan); Kubo, H.; Takada, A.; Iwaki, S.; Sawano, T.; Nakamura, K.; Komura, S.; Nakamura, S.; Kishimoto, T.; Oda, M.; Miyamoto, S.; Takemura, T.; Parker, J.D.; Tomono, D.; Sonoda, S. [Department of Physics, Kyoto University, 606-8502 Kyoto (Japan); Miuchi, K. [Department of Physics, Kobe University, 658-8501 Kobe (Japan); Kurosawa, S. [Institute for Materials Research, Tohoku University, 980-8577 Sendai (Japan)

    2015-11-11

    For MeV gamma-ray astronomy, we have developed an electron-tracking Compton camera (ETCC) as a MeV gamma-ray telescope capable of rejecting the radiation background and attaining the high sensitivity of near 1 mCrab in space. Our ETCC comprises a gaseous time-projection chamber (TPC) with a micro pattern gas detector for tracking recoil electrons and a position-sensitive scintillation camera for detecting scattered gamma rays. After the success of a first balloon experiment in 2006 with a small ETCC (using a 10×10×15 cm{sup 3} TPC) for measuring diffuse cosmic and atmospheric sub-MeV gamma rays (Sub-MeV gamma-ray Imaging Loaded-on-balloon Experiment I; SMILE-I), a (30 cm){sup 3} medium-sized ETCC was developed to measure MeV gamma-ray spectra from celestial sources, such as the Crab Nebula, with single-day balloon flights (SMILE-II). To achieve this goal, a 100-times-larger detection area compared with that of SMILE-I is required without changing the weight or power consumption of the detector system. In addition, the event rate is also expected to dramatically increase during observation. Here, we describe both the concept and the performance of the new data-acquisition system with this (30 cm){sup 3} ETCC to manage 100 times more data while satisfying the severe restrictions regarding the weight and power consumption imposed by a balloon-borne observation. In particular, to improve the detection efficiency of the fine tracks in the TPC from ~10% to ~100%, we introduce a new data-handling algorithm in the TPC. Therefore, for efficient management of such large amounts of data, we developed a data-acquisition system with parallel data flow.

  14. Development of a Compton Camera for Online Range Monitoring of Laser-Accelerated Proton Beams via Prompt-Gamma Detection

    NARCIS (Netherlands)

    Thirolf, P.G.; Lang, C.; Aldawood, S.; Van der Kolff, H.G.; Maier, L.; Schaart, D.R.; Parodi, K.

    2014-01-01

    Presently large efforts are conducted in Munich towards the development of proton beams for bio-medical applications, generated via the technique of particle acceleration from high-power, short-pulse lasers. While so far mostly offline diagnostics tools are used in this context, we aim at developing

  15. Imaging of prompt gamma rays emitted during delivery of clinical proton beams with a Compton camera: feasibility studies for range verification.

    Science.gov (United States)

    Polf, Jerimy C; Avery, Stephen; Mackin, Dennis S; Beddar, Sam

    2015-09-21

    The purpose of this paper is to evaluate the ability of a prototype Compton camera (CC) to measure prompt gamma rays (PG) emitted during delivery of clinical proton pencil beams for prompt gamma imaging (PGI) as a means of providing in vivo verification of the delivered proton radiotherapy beams. A water phantom was irradiated with clinical 114 MeV and 150 MeV proton pencil beams. Up to 500 cGy of dose was delivered per irradiation using clinical beam currents. The prototype CC was placed 15 cm from the beam central axis and PGs from 0.2 MeV up to 6.5 MeV were measured during irradiation. From the measured data (2D) images of the PG emission were reconstructed. (1D) profiles were extracted from the PG images and compared to measured depth dose curves of the delivered proton pencil beams. The CC was able to measure PG emission during delivery of both 114 MeV and 150 MeV proton beams at clinical beam currents. 2D images of the PG emission were reconstructed for single 150 MeV proton pencil beams as well as for a 5   ×   5 cm mono-energetic layer of 114 MeV pencil beams. Shifts in the Bragg peak (BP) range were detectable on the 2D images. 1D profiles extracted from the PG images show that the distal falloff of the PG emission profile lined up well with the distal BP falloff. Shifts as small as 3 mm in the beam range could be detected from the 1D PG profiles with an accuracy of 1.5 mm or better. However, with the current CC prototype, a dose of 400 cGy was required to acquire adequate PG signal for 2D PG image reconstruction. It was possible to measure PG interactions with our prototype CC during delivery of proton pencil beams at clinical dose rates. Images of the PG emission could be reconstructed and shifts in the BP range were detectable. Therefore PGI with a CC for in vivo range verification during proton treatment delivery is feasible. However, improvements in the prototype CC detection efficiency and reconstruction algorithms are necessary

  16. Electron Pattern Recognition using trigger mode SOI pixel sensor for Advanced Compton Imaging

    Science.gov (United States)

    Shimazoe, K.; Yoshihara, Y.; Fairuz, A.; Koyama, A.; Takahashi, H.; Takeda, A.; Tsuru, T.; Arai, Y.

    2016-02-01

    Compton imaging is a useful method for localizing sub MeV to a few MeV gamma-rays and widely used for environmental and medical applications. The direction of recoiled electrons in Compton scattering process provides the additional information to limit the Compton cones and increases the sensitivity in the system. The capability of recoiled electron tracking using trigger-mode Silicon-On-Insulator (SOI) sensor is investigated with various radiation sources. The trigger-mode SOI sensor consists of 144 by 144 active pixels with 30 μm cells and the thickness of sensor is 500 μm. The sensor generates the digital output when it is hit by gamma-rays and 25 by 25 pixel pattern of surrounding the triggered pixel is readout to extract the recoiled electron track. The electron track is successfully observed for 60Co and 137Cs sources, which provides useful information for future electron tracking Compton camera.

  17. Monitoring the distribution of prompt gamma rays in boron neutron capture therapy using a multiple-scattering Compton camera: A Monte Carlo simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Taewoong; Lee, Hyounggun; Lee, Wonho, E-mail: wonhol@korea.ac.kr

    2015-10-21

    This study evaluated the use of Compton imaging technology to monitor prompt gamma rays emitted by {sup 10}B in boron neutron capture therapy (BNCT) applied to a computerized human phantom. The Monte Carlo method, including particle-tracking techniques, was used for simulation. The distribution of prompt gamma rays emitted by the phantom during irradiation with neutron beams is closely associated with the distribution of the boron in the phantom. Maximum likelihood expectation maximization (MLEM) method was applied to the information obtained from the detected prompt gamma rays to reconstruct the distribution of the tumor including the boron uptake regions (BURs). The reconstructed Compton images of the prompt gamma rays were combined with the cross-sectional images of the human phantom. Quantitative analysis of the intensity curves showed that all combined images matched the predetermined conditions of the simulation. The tumors including the BURs were distinguishable if they were more than 2 cm apart.

  18. Design Of A Multiformat Camera For Medical Fluoroscopy

    Science.gov (United States)

    Edmonds, Ernest W.; Hynes, David M.; Baranoski, Dennis; Rowlands, John; Krametz, Karl R.

    1981-07-01

    For a number of years multi-format or multi-image cameras have been used in radiology departments to record images for ultrasound, nuclear medicine and computerized tomography. The authors have described in previous papers the development of a total low dose fluoroscopy system, using a Siemens Videomed H 1023 line 25 MHz television system, a V.A.S. video disc recorder for pulsed fluoroscopy, and a modified Matrix Videoimager to record the spot film images. This approach has provided images of high quality with dose and cost reductions of the order of 90% for the total examination. The particular problems involved with the modification of a multi-image camera for fluoroscopic or radiographic procedures, can be minimised by appropriate choice of monitor phosphor and correct control of the exposure sequence.

  19. Development of tunable Fabry-Perot spectral camera and light source for medical applications

    Science.gov (United States)

    Kaarre, M.; Kivi, S.; Panouillot, P. E.; Saari, H.; Mäkynen, J.; Sorri, I.; Juuti, M.

    2013-05-01

    VTT has developed a fast, tunable Fabry-Perot (FP) filter component and applied it in making small, lightweight spectral cameras and light sources. One application field where this novel technology is now tested is medical field. A demonstrator has been made to test the applicability of FP based spectral filtering in the imaging of retina in visible light wavelength area.

  20. Compton imaging with the PorGamRays spectrometer

    Science.gov (United States)

    Judson, D. S.; Boston, A. J.; Coleman-Smith, P. J.; Cullen, D. M.; Hardie, A.; Harkness, L. J.; Jones, L. L.; Jones, M.; Lazarus, I.; Nolan, P. J.; Pucknell, V.; Rigby, S. V.; Seller, P.; Scraggs, D. P.; Simpson, J.; Slee, M.; Sweeney, A.; PorGamRays Collaboration

    2011-10-01

    The PorGamRays project aims to develop a portable gamma-ray detection system with both spectroscopic and imaging capabilities. The system is designed around a stack of thin Cadmium Zinc Telluride (CZT) detectors. The imaging capability utilises the Compton camera principle. Each detector is segmented into 100 pixels which are read out through custom designed Application Specific Integrated Circuits (ASICs). This device has potential applications in the security, decommissioning and medical fields. This work focuses on the near-field imaging performance of a lab-based demonstrator consisting of two pixelated CZT detectors, each of which is bonded to a NUCAM II ASIC. Measurements have been made with point 133Ba and 57Co sources located ˜35 mm from the surface of the scattering detector. Position resolution of ˜20 mm FWHM in the x and y planes is demonstrated.

  1. Compton imaging with the PorGamRays spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Judson, D.S., E-mail: dsj@ns.ph.liv.ac.uk [Department of Physics, University of Liverpool, Liverpool L697ZE (United Kingdom); Boston, A.J. [Department of Physics, University of Liverpool, Liverpool L697ZE (United Kingdom); Coleman-Smith, P.J. [STFC Daresbury Laboratory, Daresbury, Warrington WA4 4AD (United Kingdom); Cullen, D.M. [Schuster Laboratory, University of Manchester, Manchester M13 9PL (United Kingdom); Hardie, A. [STFC Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot OX11 0QX (United Kingdom); Harkness, L.J. [Department of Physics, University of Liverpool, Liverpool L697ZE (United Kingdom); Jones, L.L. [STFC Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot OX11 0QX (United Kingdom); Jones, M. [Department of Physics, University of Liverpool, Liverpool L697ZE (United Kingdom); Lazarus, I. [STFC Daresbury Laboratory, Daresbury, Warrington WA4 4AD (United Kingdom); Nolan, P.J. [Department of Physics, University of Liverpool, Liverpool L697ZE (United Kingdom); Pucknell, V. [STFC Daresbury Laboratory, Daresbury, Warrington WA4 4AD (United Kingdom); Rigby, S.V. [Department of Physics, University of Liverpool, Liverpool L697ZE (United Kingdom); Seller, P. [STFC Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot OX11 0QX (United Kingdom); Scraggs, D.P. [Department of Physics, University of Liverpool, Liverpool L697ZE (United Kingdom); Simpson, J. [STFC Daresbury Laboratory, Daresbury, Warrington WA4 4AD (United Kingdom); Slee, M.; Sweeney, A. [Department of Physics, University of Liverpool, Liverpool L697ZE (United Kingdom)

    2011-10-01

    The PorGamRays project aims to develop a portable gamma-ray detection system with both spectroscopic and imaging capabilities. The system is designed around a stack of thin Cadmium Zinc Telluride (CZT) detectors. The imaging capability utilises the Compton camera principle. Each detector is segmented into 100 pixels which are read out through custom designed Application Specific Integrated Circuits (ASICs). This device has potential applications in the security, decommissioning and medical fields. This work focuses on the near-field imaging performance of a lab-based demonstrator consisting of two pixelated CZT detectors, each of which is bonded to a NUCAM II ASIC. Measurements have been made with point {sup 133}Ba and {sup 57}Co sources located {approx}35mm from the surface of the scattering detector. Position resolution of {approx}20mm FWHM in the x and y planes is demonstrated.

  2. Feasibility of monitoring patient motion with opposed stereo infrared cameras during supine medical imaging

    Science.gov (United States)

    Beach, Richard D.; McNamara, Joseph E.; Terlecki, George; King, Michael A.

    2006-10-01

    Patient motion during single photon emission computed tomographic (SPECT) acquisition causes inconsistent projection data and reconstruction artifacts which can significantly affect diagnostic accuracy. We have investigated use of the Polaris stereo infrared motion-tracking system to track 6-Degrees-of-Freedom (6-DOF) motion of spherical reflectors (markers) on stretchy bands about the patient's chest and abdomen during cardiac SPECT imaging. The marker position information, obtained by opposed stereo infrared-camera systems, requires processing to correctly record tracked markers, and map Polaris co-ordinate data into the SPECT co-ordinate system. One stereo camera views the markers from the patient's head direction, and the other from the patient's foot direction. The need for opposed cameras is to overcome anatomical and geometrical limitations which sometimes prevent all markers from being seen by a single stereo camera. Both sets of marker data are required to compute rotational and translational 6-DOF motion of the patient which ultimately will be used for SPECT patient-motion corrections. The processing utilizes an algorithm involving least-squares fitting, to each other, of two 3-D point sets using singular value decomposition (SVD) resulting in the rotation matrix and translation of the rigid body centroid. We have previously demonstrated the ability to monitor multiple markers for twelve patients viewing from the foot end, and employed a neural network to separate the periodic respiratory motion component of marker motion from aperiodic body motion. We plan to initiate routine 6-DOF tracking of patient motion during SPECT imaging in the future, and are herein evaluating the feasibility of employing opposed stereo cameras.

  3. Unified ab initio treatment of attosecond photoionization and Compton scattering

    Science.gov (United States)

    Yudin, G. L.; Bondar, D. I.; Patchkovskii, S.; Corkum, P. B.; Bandrauk, A. D.

    2009-10-01

    We present a new theoretical approach to attosecond laser-assisted photo- and Compton ionization. Attosecond x-ray absorption and scattering are described by \\hat{\\mathscr{S}}^{(1,2)} -matrices, which are coherent superpositions of 'monochromatic' \\skew{3}\\hat{S}^{(1,2)} -matrices in a laser-modified Furry representation. Besides refining the existing theory of the soft x-ray photoelectron attosecond streak camera and spectral phase interferometry (ASC and ASPI), we formulate a theory of hard x-ray photoelectron and Compton ASC and ASPI. The resulting scheme has a simple structure and leads to closed-form expressions for ionization amplitudes. We investigate Compton electron interference in the separable Coulomb-Volkov continuum with both Coulomb and laser fields treated non-perturbatively. We find that at laser-field intensities below 1013 Wcm-2 normalized Compton lines almost coincide with the lines obtained in the laser-free regime. At higher intensities, attosecond interferences survive integration over electron momenta, and feature prominently in the Compton lines themselves. We define a regime where the electron ground-state density can be measured with controllable accuracy in an attosecond time interval. The new theory provides a firm basis for extracting photo- and Compton electron phases and atomic and molecular wavefunctions from experimental data.

  4. The high resolution gamma imager (HRGI): a CCD based camera for medical imaging

    Science.gov (United States)

    Lees, John. E.; Fraser, George. W.; Keay, Adam; Bassford, David; Ott, Robert; Ryder, William

    2003-11-01

    We describe the High Resolution Gamma Imager (HRGI): a Charge Coupled Device (CCD) based camera for imaging small volumes of radionuclide uptake in tissues. The HRGI is a collimated, scintillator-coated, low cost, high performance imager using low noise CCDs that will complement whole-body imaging Gamma Cameras in nuclear medicine. Using 59.5 keV radiation from a 241Am source we have measured the spatial resolution and relative efficiency of test CCDs from E2V Technologies (formerly EEV Ltd.) coated with Gadox (Gd 2O 2S(Tb)) layers of varying thicknesses. The spatial resolution degrades from 0.44 to 0.6 mm and the detection efficiency increases (×3) as the scintillator thickness increases from 100 to 500 μm. We also describe our first image using the clinically important isotope 99mTc. The final HRGI will have intrinsic sub-mm spatial resolution (˜0.7 mm) and good energy resolution over the energy range 30-160 keV.

  5. Preliminary Results on Compton Electrons in Silicon Drift Detector

    Science.gov (United States)

    Conka-Nurdan, T.; Nurdan, K.; Laihem, K.; Walenta, A. H.; Fiorini, C.; Freisleben, B.; Hornel, N.; Pavel, N. A.; Struder, L.

    2004-10-01

    Silicon drift detectors (SDD) with on-chip electronics have found many applications in different fields. A detector system has recently been designed and built to study the electrons from Compton scatter events in such a detector. The reconstruction of the Compton electrons is a crucial issue for Compton imaging. The equipment consists of a monolithic array of 19 channel SDDs and an Anger camera. Photons emitted from a finely collimated source undergo Compton scattering within the SDD where the recoil electron is absorbed. The scattered photon is subsequently observed by photoelectric absorption in the second detector. The coincidence events are used to get the energy, position, and direction of the Compton electrons. Because the on-chip transistors provide the first stage amplification, the SDDs provide outstanding noise performance and fast shaping, so that very good energy resolution can be obtained even at room temperature. The drift detectors require a relatively low number of readout channels for large detector areas. Custom-designed analog and digital electronics provide fast readout of the SDDs. The equipment is designed such that the measurements can be done in all detector orientations and kinematical conditions. The first results obtained with this detector system will be presented in this paper.

  6. Determining patient 6-degrees-of-freedom motion from stereo infrared cameras during supine medical imaging

    Science.gov (United States)

    Beach, Richard D.; Feng, Bing; Shazeeb, Mohammed S.; King, Michael A.

    2006-03-01

    Patient motion during SPECT acquisition causes inconsistent projection data and reconstruction artifacts which can significantly affect the diagnostic accuracy of SPECT. The tracking of motion by infrared monitoring spherical reflectors (markers) on the patient's surface can provide 6-Degrees-of-Freedom (6-DOF) motion information capable of providing clinically robust correction. Object rigid-body motion can be described by 3 translational DOF and 3 rotational DOF. Polaris marker position information obtained by stereo infrared cameras requires algorithmic processing to correctly record the tracked markers, and to calibrate and map Polaris co-ordinate data into the SPECT co-ordinate system. Marker data then requires processing to determine the rotational and translational 6-DOF motion to ultimately be used for SPECT image corrections. This processing utilizes an algorithm involving least-squares fitting, to each other, of two 3-D point sets using singular value decomposition (SVD) resulting in the rotation matrix and translation of the rigid body centroid. We have demonstrated the ability to monitor 12 clinical patients as well as 7 markers on 2 elastic belts worn by a volunteer while intentionally moving, and determined the 3 axis Euclidian rotation angles and centroid translations. An anthropomorphic phantom with Tc-99m added to the heart, liver, and body was simultaneously SPECT imaged and motion tracked using 4 rigidly mounted markers. The determined rotation matrix and translation information was used to correct the image resulting in virtually identical "no motion" and "corrected" images. We plan to initiate routine 6-DOF tracking of patient motion during SPECT imaging in the future.

  7. Breast Imaging Utilizing Dedicated Gamma Camera and (99m)Tc-MIBI: Experience at the Tel Aviv Medical Center and Review of the Literature Breast Imaging.

    Science.gov (United States)

    Even-Sapir, Einat; Golan, Orit; Menes, Tehillah; Weinstein, Yuliana; Lerman, Hedva

    2016-07-01

    The scope of the current article is the clinical role of gamma cameras dedicated for breast imaging and (99m)Tc-MIBI tumor-seeking tracer, as both a screening modality among a healthy population and as a diagnostic modality in patients with breast cancer. Such cameras are now commercially available. The technology utilizing a camera composed of a NaI (Tl) detector is termed breast-specific gamma imaging. The technology of dual-headed camera composed of semiconductor cadmium zinc telluride detectors that directly converts gamma-ray energy into electronic signals is termed molecular breast imaging. Molecular breast imaging system has been installed at the Department of Nuclear medicine at the Tel Aviv Sourasky Medical Center, Tel Aviv in 2009. The article reviews the literature well as our own experience. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Compton polarimetry revisited

    CERN Document Server

    Bernard, Denis

    2015-01-01

    I compute the average polarisation asymmetry from the Klein-Nishina differential cross section on free electrons at rest. As expected from the expression for the asymmetry, the average asymmetry is found to decrease like the inverse of the incident photon energy asymptotically at high energy. I then compute a simple estimator of the polarisation fraction that makes optimal use of all the kinematic information present in an event final state, by the use of "moments" method, and I compare its statistical power to that of a simple fit of the azimuthal distribution. In contrast to polarimetry with pair creation, for which I obtained an improvement by a factor of larger than two in a previous work, here for Compton scattering the improvement is only of 10-20 %.

  9. Compton polarimetry revisited

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, D.

    2015-11-01

    We compute the average polarisation asymmetry from the Klein–Nishina differential cross-section on free electrons at rest. As expected from the expression for the asymmetry, the average asymmetry is found to decrease like the inverse of the incident photon energy asymptotically at high energy. We then compute a simple estimator of the polarisation fraction that makes optimal use of all the kinematic information present in an event final state, by the use of “moments” method, and we compare its statistical power to that of a simple fit of the azimuthal distribution. In contrast to polarimetry with pair creation, for which we obtained an improvement by a factor of larger than two in a previous work, here for Compton scattering the improvement is only of 10–20%.

  10. Compton imager using room temperature silicon detectors

    Science.gov (United States)

    Kurfess, James D.; Novikova, Elena I.; Phlips, Bernard F.; Wulf, Eric A.

    2007-08-01

    We have been developing a multi-layer Compton Gamma Ray Imager using position-sensitive, intrinsic silicon detectors. Advantages of this approach include room temperature operation, reduced Doppler broadening, and use of conventional silicon fabrication technologies. We have obtained results on the imaging performance of a multi-layer instrument where each layer consists of a 2×2 array of double-sided strip detectors. Each detector is 63 mm×63 mm×2 mm thick and has 64 strips providing a strip pitch of approximately 0.9 mm. The detectors were fabricated by SINTEF ICT (Oslo Norway) from 100 mm diameter wafers. The use of large arrays of silicon detectors appears especially advantageous for applications that require excellent sensitivity, spectral resolution and imaging such as gamma ray astrophysics, detection of special nuclear materials, and medical imaging. The multiple Compton interactions (three or more) in the low-Z silicon enable the energy and direction of the incident gamma ray to be determined without full deposition of the incident gamma-ray energy in the detector. The performance of large volume instruments for various applications are presented, including an instrument under consideration for NASA's Advanced Compton Telescope (ACT) mission and applications to Homeland Security. Technology developments that could further extend the sensitivity and performance of silicon Compton Imagers are presented, including the use of low-energy (few hundred keV) electron tracking within novel silicon detectors and the potential for a wafer-bonding approach to produce thicker, position-sensitive silicon detectors with an associated reduction of required electronics and instrument cost.

  11. Richard Compton, University of Oxford.

    Science.gov (United States)

    2006-07-01

    The Analyst profiles Richard Compton, Professor of Chemistry at the University of Oxford and the first and only recipient of both the RSC Medals in Electrochemistry and in Electroanalytical Chemistry.

  12. Performance of MACACO Compton telescope for ion-beam therapy monitoring: first test with proton beams

    Science.gov (United States)

    Solevi, Paola; Muñoz, Enrique; Solaz, Carles; Trovato, Marco; Dendooven, Peter; Gillam, John E.; Lacasta, Carlos; Oliver, Josep F.; Rafecas, Magdalena; Torres-Espallardo, Irene; Llosá, Gabriela

    2016-07-01

    In order to exploit the advantages of ion-beam therapy in a clinical setting, delivery verification techniques are necessary to detect deviations from the planned treatment. Efforts are currently oriented towards the development of devices for real-time range monitoring. Among the different detector concepts proposed, Compton cameras are employed to detect prompt gammas and represent a valid candidate for real-time range verification. We present the first on-beam test of MACACO, a Compton telescope (multi-layer Compton camera) based on lanthanum bromide crystals and silicon photo-multipliers. The Compton telescope was first characterized through measurements and Monte Carlo simulations. The detector linearity was measured employing 22Na and Am-Be sources, obtaining about 10% deviation from linearity at 3.44 MeV. A spectral image reconstruction algorithm was tested on synthetic data. Point-like sources emitting gamma rays with energy between 2 and 7 MeV were reconstructed with 3-5 mm resolution. The two-layer Compton telescope was employed to measure radiation emitted from a beam of 150 MeV protons impinging on a cylindrical PMMA target. Bragg-peak shifts were achieved via adjustment of the PMMA target location and the resulting measurements used during image reconstruction. Reconstructed Bragg peak profiles proved sufficient to observe peak-location differences within 10 mm demonstrating the potential of the MACACO Compton Telescope as a monitoring device for ion-beam therapy.

  13. Observation of Nonlinear Compton Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Kotseroglou, T.

    2003-12-19

    This experiment tests Quantum Electrodynamics in the strong field regime. Nonlinear Compton scattering has been observed during the interaction of a 46.6 GeV electron beam with a 10{sup 18} W/cm{sup 2} laser beam. The strength of the field achieved was measured by the parameter {eta} = e{var_epsilon}{sub rms}/{omega}mc = 0.6. Data were collected with infrared and green laser photons and circularly polarized laser light. The timing stabilization achieved between the picosecond laser and electron pulses has {sigma}{sub rms} = 2 ps. A strong signal of electrons that absorbed up to 4 infrared photons (or up to 3 green photons) at the same point in space and time, while emitting a single gamma ray, was observed. The energy spectra of the scattered electrons and the nonlinear dependence of the electron yield on the field strength agreed with the simulation over 3 orders of magnitude. The detector could not resolve the nonlinear Compton scattering from the multiple single Compton scattering which produced rates of scattered electrons of the same order of magnitude. Nevertheless, a simulation has studied this difference and concluded that the scattered electron rates observed could not be accounted for only by multiple ordinary Compton scattering; nonlinear Compton scattering processes are dominant for n {ge} 3.

  14. The Mathematical Foundations of 3D Compton Scatter Emission Imaging

    Directory of Open Access Journals (Sweden)

    T. T. Truong

    2007-01-01

    Full Text Available The mathematical principles of tomographic imaging using detected (unscattered X- or gamma-rays are based on the two-dimensional Radon transform and many of its variants. In this paper, we show that two new generalizations, called conical Radon transforms, are related to three-dimensional imaging processes based on detected Compton scattered radiation. The first class of conical Radon transform has been introduced recently to support imaging principles of collimated detector systems. The second class is new and is closely related to the Compton camera imaging principles and invertible under special conditions. As they are poised to play a major role in future designs of biomedical imaging systems, we present an account of their most important properties which may be relevant for active researchers in the field.

  15. Turbulent Comptonization in Relativistic Accretion Disks

    CERN Document Server

    Socrates, A; Blaes, Omer M; Socrates, Aristotle; Davis, Shane W.; Blaes, Omer

    2006-01-01

    Turbulent Comptonization, a potentially important damping and radiation mechanism in relativistic accretion flows, is discussed. Particular emphasis is placed on the physical basis, relative importance, and thermodynamics of turbulent Comptonization. The effects of metal-absorption opacity on the spectral component resulting from turbulent Comptonization is considered as well.

  16. Spectral properties of Compton inverse radiation: Application of Compton beams

    CERN Document Server

    Bulyak, Eugene

    2013-01-01

    Compton inverse radiation emitted due to backscattering of laser pulses off the relativistic electrons possesses high spectral density and high energy of photons - in hard x-ray up to gamma-ray energies - because of short wavelength of laser radiation as compared with the classical electromagnetic devices such as undulators. In this report, the possibility of such radiation to monochromatization by means of collimation is studied. Two approaches have been considered for the description of the spectral-angular density of Compton radiation based on the classical field theory and on the quantum electrodynamics. As is shown, both descriptions produce similar total spectra. On the contrary, angular distribution of the radiation is different: the classical approach predicted a more narrow radiation cone. Also proposed and estimated is a method of the `electronic' monochromatization based on the electronic subtraction of the two images produced by the electron beams with slightly different energies. A `proof-of-prin...

  17. Filtered back-projection algorithm for Compton telescopes

    Science.gov (United States)

    Gunter, Donald L.

    2008-03-18

    A method for the conversion of Compton camera data into a 2D image of the incident-radiation flux on the celestial sphere includes detecting coincident gamma radiation flux arriving from various directions of a 2-sphere. These events are mapped by back-projection onto the 2-sphere to produce a convolution integral that is subsequently stereographically projected onto a 2-plane to produce a second convolution integral which is deconvolved by the Fourier method to produce an image that is then projected onto the 2-sphere.

  18. Compton Sources of Electromagnetic Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Geoffrey Krafft,Gerd Priebe

    2011-01-01

    When a relativistic electron beam interacts with a high-field laser beam, intense and highly collimated electromagnetic radiation will be generated through Compton scattering. Through relativistic upshifting and the relativistic Doppler effect, highly energetic polarized photons are radiated along the electron beam motion when the electrons interact with the laser light. For example, X-ray radiation can be obtained when optical lasers are scattered from electrons of tens-of-MeV beam energy. Because of the desirable properties of the radiation produced, many groups around the world have been designing, building, and utilizing Compton sources for a wide variety of purposes. In this review article, we discuss the generation and properties of the scattered radiation, the types of Compton source devices that have been constructed to date, and the prospects of radiation sources of this general type. Due to the possibilities of producing hard electromagnetic radiation in a device that is small compared to the alternative storage ring sources, it is foreseen that large numbers of such sources may be constructed in the future.

  19. Bulk Comptonization by Turbulence in Accretion Disks

    CERN Document Server

    Kaufman, J

    2016-01-01

    Radiation pressure dominated accretion discs around compact objects may have turbulent velocities that greatly exceed the electron thermal velocities within the disc. Bulk Comptonization by the turbulence may therefore dominate over thermal Comptonization in determining the emergent spectrum. Bulk Comptonization by divergenceless turbulence is due to radiation viscous dissipation only. It can be treated as thermal Comptonization by solving the Kompaneets equation with an equivalent "wave" temperature, which is a weighted sum over the power present at each scale in the turbulent cascade. Bulk Comptonization by turbulence with non-zero divergence is due to both pressure work and radiation viscous dissipation. Pressure work has negligible effect on photon spectra in the limit of optically thin turbulence, and in this limit radiation viscous dissipation alone can be treated as thermal Comptonization with a temperature equivalent to the full turbulent power. In the limit of extremely optically thick turbulence, ra...

  20. Giant Compton Shifts in Hyperbolic Metamaterial

    CERN Document Server

    Iorsh, Ivan; Ginzburg, Pavel; Belov, Pavel; Kivshar, Yuri

    2014-01-01

    We study the Compton scattering of light by free electrons inside a hyperbolic medium. We demonstrate that the unconventional dispersion and local density of states of the electromagnetic modes in such media can lead to a giant Compton shift and dramatic enhancement of the scattering cross section. We develop an universal approach for the study of coupled multi-photon processes in nanostructured media and derive the spectral intensity function of the scattered radiation for realistic metamaterial structures. We predict the Compton shift of the order of a few meVs for the infrared spectrum that is at least one order of magnitude larger than the Compton shift in any other system.

  1. Compton Scattering on the Proton

    CERN Document Server

    Scholten, O

    2002-01-01

    A microscopic coupled-channels model for Compton and pion scattering off the nucleon is introduced which is applicable at the lowest energies (polarizabilities) as well as at GeV energies. To introduce the model first the conventional K-matrix approach is discussed to extend this in a following chapter to the "Dressed K-Matrix" model. The latter approach restores causality, or analyticity, of the amplitude to a large extent. In particular, crossing symmetry, gauge invariance and unitarity are satisfied. The extent of violation of analyticity (causality) is used as an expansion parameter.

  2. The Advanced Compton Telescope Mission

    CERN Document Server

    Boggs, S E; Ryan, J; Aprile, E; Gehrels, N; Kippen, M; Leising, M; Oberlack, U; Wunderer, C; Zych, A; Bloser, P; Harris, M; Hoover, A; Klimenk, A; Kocevski, D; McConnell, M; Milne, P; Novikova, E I; Phlips, B; Polsen, M; Sturner, S; Tournear, D; Weidenspointner, G; Wulf, E; Zoglauer, A; Baring, M; Beacom, J; Bildsten, L; Dermer, C; Hartmann, D; Hernanz, M; Smith, D; Starrfield, S; Boggs, Steven E.; Kurfess, James; Ryan, James; Aprile, Elena; Gehrels, Neil; Kippen, Marc; Leising, Mark; Oberlack, Uwe; Wunderer, Cornelia; Zych, Allen; Bloser, Peter; Harris, Michael; Hoover, Andrew; Klimenk, Alexei; Kocevski, Dan; Connell, Mark Mc; Milne, Peter; Novikova, Elena I.; Phlips, Bernard; Polsen, Mark; Sturner, Steven; Tournear, Derek; Weidenspointner, Georg; Wulf, Eric; Zoglauer, Andreas; Baring, Matthew; Beacom, John; Bildsten, Lars; Dermer, Charles; Hartmann, Dieter; Hernanz, Margarita; Smith, David; Starrfield, Sumner

    2006-01-01

    The Advanced Compton Telescope (ACT), the next major step in gamma-ray astronomy, will probe the fires where chemical elements are formed by enabling high-resolution spectroscopy of nuclear emission from supernova explosions. During the past two years, our collaboration has been undertaking a NASA mission concept study for ACT. This study was designed to (1) transform the key scientific objectives into specific instrument requirements, (2) to identify the most promising technologies to meet those requirements, and (3) to design a viable mission concept for this instrument. We present the results of this study, including scientific goals and expected performance, mission design, and technology recommendations.

  3. X-ray Compton line scan tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kupsch, Andreas; Lange, Axel; Jaenisch, Gerd-Ruediger [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany). Fachgruppe 8.5 - Mikro-ZfP; Hentschel, Manfred P. [Technische Univ. Berlin (Germany); Kardjilov, Nikolay; Markoetter, Henning; Hilger, Andre; Manke, Ingo [Helmholtz-Zentrum Berlin (HZB) (Germany); Toetzke, Christian [Potsdam Univ. (Germany)

    2015-07-01

    The potentials of incoherent X-ray scattering (Compton) computed tomography (CT) are investigated. The imaging of materials of very different atomic number or density at once is generally a perpetual challenge for X-ray tomography or radiography. In a basic laboratory set-up for simultaneous perpendicular Compton scattering and direct beam attenuation tomography are conducted by single channel photon counting line scans. This results in asymmetric distortions of the projection profiles of the scattering CT data set. In a first approach, corrections of Compton scattering data by taking advantage of rotational symmetry yield tomograms without major geometric artefacts. A cylindrical sample composed of PE, PA, PVC, glass and wood demonstrates similar Compton contrast for all the substances, while the conventional absorption tomogram only reveals the two high order materials. Comparison to neutron tomography reveals astonishing similarities except for the glass component (without hydrogen). Therefore, Compton CT offers the potential to replace neutron tomography, which requires much more efforts.

  4. Compton scatter correction for planner scintigraphic imaging

    Energy Technology Data Exchange (ETDEWEB)

    Vaan Steelandt, E.; Dobbeleir, A.; Vanregemorter, J. [Algemeen Ziekenhuis Middelheim, Antwerp (Belgium). Dept. of Nuclear Medicine and Radiotherapy

    1995-12-01

    A major problem in nuclear medicine is the image degradation due to Compton scatter in the patient. Photons emitted by the radioactive tracer scatter in collision with electrons of the surrounding tissue. Due to the resulting loss of energy and change in direction, the scattered photons induce an object dependant background on the images. This results in a degradation of the contrast of warm and cold lesions. Although theoretically interesting, most of the techniques proposed in literature like the use of symmetrical photopeaks can not be implemented on the commonly used gamma camera due to the energy/linearity/sensitivity corrections applied in the detector. A method for a single energy isotope based on existing methods with adjustments towards daily practice and clinical situations is proposed. It is assumed that the scatter image, recorded from photons collected within a scatter window adjacent to the photo peak, is a reasonable close approximation of the true scatter component of the image reconstructed from the photo peak window. A fraction `k` of the image using the scatter window is subtracted from the image recorded in the photo peak window to produce the compensated image. The principal matter of the method is the right value for the factor `k`, which is determined in a mathematical way and confirmed by experiments. To determine `k`, different kinds of scatter media are used and are positioned in different ways in order to simulate a clinical situation. For a secondary energy window from 100 to 124 keV below a photo peak window from 126 to 154 keV, a value of 0.7 is found. This value has been verified using both an antropomorph thyroid phantom and the Rollo contrast phantom.

  5. Tower Camera

    Data.gov (United States)

    Oak Ridge National Laboratory — The tower camera in Barrow provides hourly images of ground surrounding the tower. These images may be used to determine fractional snow cover as winter arrives, for...

  6. Cardiac cameras.

    Science.gov (United States)

    Travin, Mark I

    2011-05-01

    Cardiac imaging with radiotracers plays an important role in patient evaluation, and the development of suitable imaging instruments has been crucial. While initially performed with the rectilinear scanner that slowly transmitted, in a row-by-row fashion, cardiac count distributions onto various printing media, the Anger scintillation camera allowed electronic determination of tracer energies and of the distribution of radioactive counts in 2D space. Increased sophistication of cardiac cameras and development of powerful computers to analyze, display, and quantify data has been essential to making radionuclide cardiac imaging a key component of the cardiac work-up. Newer processing algorithms and solid state cameras, fundamentally different from the Anger camera, show promise to provide higher counting efficiency and resolution, leading to better image quality, more patient comfort and potentially lower radiation exposure. While the focus has been on myocardial perfusion imaging with single-photon emission computed tomography, increased use of positron emission tomography is broadening the field to include molecular imaging of the myocardium and of the coronary vasculature. Further advances may require integrating cardiac nuclear cameras with other imaging devices, ie, hybrid imaging cameras. The goal is to image the heart and its physiological processes as accurately as possible, to prevent and cure disease processes.

  7. Hidden baryons: The physics of Compton composites

    Science.gov (United States)

    Mayer, Frederick J.

    2016-06-01

    A large fraction of the mass-energy of the Universe appears to be composed of Compton composites. How is it then that these composites are not frequently observed in experiments? This paper addresses this question, and others, by reviewing recent publications that: 1) introduced Compton composites, 2) showed how and where they are formed and 3) explained how they interact with other systems. Though ubiquitous in many physical situations, Compton composites are almost completely hidden in experiments due to their unique interaction characteristics. Still, their presence has been indirectly observed, though not interpreted as such until recently. Looking to the future, direct-detection experiments are proposed that could verify the composites' components. It is with deep sadness that I dedicate this paper to my mentor, collaborator, and friend, Dr. John R. Reitz, who passed away within days of the publication of our paper “Compton Composites Late in the Early Universe”.

  8. Relativistic Accretion Mediated by Turbulent Comptonization

    CERN Document Server

    Socrates, Aristotle

    2008-01-01

    Black hole and neutron star accretion flows display unusually high levels of hard coronal emission in comparison to all other optically thick, gravitationally bound, turbulent astrophysical systems. Since these flows sit in deep relativistic gravitational potentials, their random bulk motions approach the speed of light, therefore allowing turbulent Comptonization to be an important effect. We show that the inevitable production of hard X-ray photons results from turbulent Comptonization in the limit where the turbulence is trans-sonic and the accretion power approaches the Eddington Limit. In this regime, the turbulent Compton y-parameter approaches unity and the turbulent Compton temperature is a significant fraction of the electron rest mass energy, in agreement with the observed phenomena.

  9. The first demonstration of the concept of “narrow-FOV Si/CdTe semiconductor Compton camera”

    Energy Technology Data Exchange (ETDEWEB)

    Ichinohe, Yuto, E-mail: ichinohe@astro.isas.jaxa.jp [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa 252-5210 (Japan); University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan); Uchida, Yuusuke; Watanabe, Shin [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa 252-5210 (Japan); University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan); Edahiro, Ikumi [Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Hayashi, Katsuhiro [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa 252-5210 (Japan); Kawano, Takafumi; Ohno, Masanori [Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Ohta, Masayuki [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa 252-5210 (Japan); Takeda, Shin' ichiro [Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa 904-0495 (Japan); Fukazawa, Yasushi [Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Katsuragawa, Miho [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa 252-5210 (Japan); University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan); Nakazawa, Kazuhiro [University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan); Odaka, Hirokazu [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa 252-5210 (Japan); Tajima, Hiroyasu [Solar-Terrestrial Environment Laboratory, Nagoya University, Furo-cho, Chikusa, Nagoya, Aichi 464-8601 (Japan); Takahashi, Hiromitsu [Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); and others

    2016-01-11

    The Soft Gamma-ray Detector (SGD), to be deployed on board the ASTRO-H satellite, has been developed to provide the highest sensitivity observations of celestial sources in the energy band of 60–600 keV by employing a detector concept which uses a Compton camera whose field-of-view is restricted by a BGO shield to a few degree (narrow-FOV Compton camera). In this concept, the background from outside the FOV can be heavily suppressed by constraining the incident direction of the gamma ray reconstructed by the Compton camera to be consistent with the narrow FOV. We, for the first time, demonstrate the validity of the concept using background data taken during the thermal vacuum test and the low-temperature environment test of the flight model of SGD on ground. We show that the measured background level is suppressed to less than 10% by combining the event rejection using the anti-coincidence trigger of the active BGO shield and by using Compton event reconstruction techniques. More than 75% of the signals from the field-of-view are retained against the background rejection, which clearly demonstrates the improvement of signal-to-noise ratio. The estimated effective area of 22.8 cm{sup 2} meets the mission requirement even though not all of the operational parameters of the instrument have been fully optimized yet.

  10. CCD Camera

    Science.gov (United States)

    Roth, Roger R.

    1983-01-01

    A CCD camera capable of observing a moving object which has varying intensities of radiation eminating therefrom and which may move at varying speeds is shown wherein there is substantially no overlapping of successive images and wherein the exposure times and scan times may be varied independently of each other.

  11. Using Compton scattering for random coincidence rejection

    Science.gov (United States)

    Kolstein, M.; Chmeissani, M.

    2016-12-01

    The Voxel Imaging PET (VIP) project presents a new approach for the design of nuclear medicine imaging devices by using highly segmented pixel CdTe sensors. CdTe detectors can achieve an energy resolution of ≈ 1% FWHM at 511 keV and can be easily segmented into submillimeter sized voxels for optimal spatial resolution. These features help in rejecting a large part of the scattered events from the PET coincidence sample in order to obtain high quality images. Another contribution to the background are random events, i.e., hits caused by two independent gammas without a common origin. Given that 60% of 511 keV photons undergo Compton scattering in CdTe (i.e. 84% of all coincidence events have at least one Compton scattering gamma), we present a simulation study on the possibility to use the Compton scattering information of at least one of the coincident gammas within the detector to reject random coincidences. The idea uses the fact that if a gamma undergoes Compton scattering in the detector, it will cause two hits in the pixel detectors. The first hit corresponds to the Compton scattering process. The second hit shall correspond to the photoelectric absorption of the remaining energy of the gamma. With the energy deposition of the first hit, one can calculate the Compton scattering angle. By measuring the hit location of the coincident gamma, we can construct the geometric angle, under the assumption that both gammas come from the same origin. Using the difference between the Compton scattering angle and the geometric angle, random events can be rejected.

  12. Inverse Compton γ-ray source for nuclear physics and related applications

    Science.gov (United States)

    O'Shea, P. G.; Litvinenko, V. N.; Madey, J. M. J.; Roberson, N. R.; Schreiber, E. C.; Straub, K. D.; Weeks, K. J.; Weller, H. R.; Wu, Y.

    1996-02-01

    The development of intense, short-wavelength FEL light sources has opened opportunities for new applications of high-energy Compton-backscattered photons. These applications range from medical imaging with X-rays to high energy physics with photon colliders. In this paper we discuss the practical aspects applications using polarized Compton backscattered γ-rays in the 5-150 MeV range from the Duke storage-ring-driven FEL. Such applications include: nuclear physics, cancer therapy, radiographic imaging, radiation effects testing, and positron production for material science studies.

  13. Compton imaging with a highly-segmented, position-sensitive HPGe detector

    Science.gov (United States)

    Steinbach, T.; Hirsch, R.; Reiter, P.; Birkenbach, B.; Bruyneel, B.; Eberth, J.; Gernhäuser, R.; Hess, H.; Lewandowski, L.; Maier, L.; Schlarb, M.; Weiler, B.; Winkel, M.

    2017-02-01

    A Compton camera based on a highly-segmented high-purity germanium (HPGe) detector and a double-sided silicon-strip detector (DSSD) was developed, tested, and put into operation; the origin of γ radiation was determined successfully. The Compton camera is operated in two different modes. Coincidences from Compton-scattered γ-ray events between DSSD and HPGe detector allow for best angular resolution; while the high-efficiency mode takes advantage of the position sensitivity of the highly-segmented HPGe detector. In this mode the setup is sensitive to the whole 4π solid angle. The interaction-point positions in the 36-fold segmented large-volume HPGe detector are determined by pulse-shape analysis (PSA) of all HPGe detector signals. Imaging algorithms were developed for each mode and successfully implemented. The angular resolution sensitively depends on parameters such as geometry, selected multiplicity and interaction-point distances. Best results were obtained taking into account the crosstalk properties, the time alignment of the signals and the distance metric for the PSA for both operation modes. An angular resolution between 13.8° and 19.1°, depending on the minimal interaction-point distance for the high-efficiency mode at an energy of 1275 keV, was achieved. In the coincidence mode, an increased angular resolution of 4.6° was determined for the same γ-ray energy.

  14. The Design of Diamond Compton Telescope

    CERN Document Server

    Hibino, Kinya; Okuno, Shoji; Yajima, Kaori; Uchihori, Yukio; Kitamura, Hisashi; Takashima, Takeshi; Yokota, Mamoru; Yoshida, Kenji

    2007-01-01

    We have developed radiation detectors using the new synthetic diamonds. The diamond detector has an advantage for observations of "low/medium" energy gamma rays as a Compton telescope. The primary advantage of the diamond detector can reduce the photoelectric effect in the low energy range, which is background noise for tracking of the Compton recoil electron. A concept of the Diamond Compton Telescope (DCT) consists of position sensitive layers of diamond-striped detector and calorimeter layer of CdTe detector. The key part of the DCT is diamond-striped detectors with a higher positional resolution and a wider energy range from 10 keV to 10 MeV. However, the diamond-striped detector is under development. We describe the performance of prototype diamond detector and the design of a possible DCT evaluated by Monte Carlo simulations.

  15. Compton scattering in the Endpoint Model

    CERN Document Server

    Dagaonkar, Sumeet

    2016-01-01

    We use the Endpoint model for exclusive hadronic processes to study Compton scattering of the proton. The parameters of the Endpoint model are fixed using the data for $F_1$ and the ratio of Pauli and Dirac form factors ($F_2/F_1$) and then used to get numerical predictions for the differential scattering cross section. We studied the Compton scattering at fixed $\\theta_{CM}$ in the $s \\sim t \\gg \\Lambda_{QCD}$ limit and at fixed $s$ much larger than $t$ limit. We observed that the calculations in the Endpoint Model give a good fit with experimental data in both regions.

  16. Compton scattering and nonforward parton distributions

    CERN Document Server

    Radyushkin, A V

    1998-01-01

    The hard exclusive electroproduction processes provide new information about hadronic structure accumulated in nonforward parton distributions. The NFPD's are universal hybrid functions having the properties of parton densities, hadronic form factors and distribution amplitudes. They give a unified description of various hard exclusive and inclusive reactions. The basic supplier of information about nonforward parton distributions is deeply virtual Compton scattering which offers a remarkable example of Bjorken scaling phenomena in exclusive processes. Wide-angle real Compton scattering is an ideal tool to test angle-dependent scaling laws characteristic for soft overlap mechanism. Hard meson electroproduction is the best candidate to see pQCD hard gluon exchange in exclusive reactions.

  17. Sensitivity booster for DOI-PET scanner by utilizing Compton scattering events between detector blocks

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Eiji, E-mail: rush@nirs.go.jp; Tashima, Hideaki; Yamaya, Taiga

    2014-11-01

    In a conventional PET scanner, coincidence events are measured with a limited energy window for detection of photoelectric events in order to reject Compton scatter events that occur in a patient, but Compton scatter events caused in detector crystals are also rejected. Scatter events within the patient causes scatter coincidences, but inter crystal scattering (ICS) events have useful information for determining an activity distribution. Some researchers have reported the feasibility of PET scanners based on a Compton camera for tracing ICS into the detector. However, these scanners require expensive semiconductor detectors for high-energy resolution. In the Anger-type block detector, single photons interacting with multiple detectors can be obtained for each interacting position and complete information can be gotten just as for photoelectric events in the single detector. ICS events in the single detector have been used to get coincidence, but single photons interacting with multiple detectors have not been used to get coincidence. In this work, we evaluated effect of sensitivity improvement using Compton kinetics in several types of DOI-PET scanners. The proposed method promises to improve the sensitivity using coincidence events of single photons interacting with multiple detectors, which are identified as the first interaction (FI). FI estimation accuracy can be improved to determine FI validity from the correlation between Compton scatter angles calculated on the coincidence line-of-response. We simulated an animal PET scanner consisting of 42 detectors. Each detector block consists of three types of scintillator crystals (LSO, GSO and GAGG). After the simulation, coincidence events are added as information for several depth-of-interaction (DOI) resolutions. From the simulation results, we concluded the proposed method promises to improve the sensitivity considerably when effective atomic number of a scintillator is low. Also, we showed that FI estimate

  18. Sensitivity booster for DOI-PET scanner by utilizing Compton scattering events between detector blocks

    Science.gov (United States)

    Yoshida, Eiji; Tashima, Hideaki; Yamaya, Taiga

    2014-11-01

    In a conventional PET scanner, coincidence events are measured with a limited energy window for detection of photoelectric events in order to reject Compton scatter events that occur in a patient, but Compton scatter events caused in detector crystals are also rejected. Scatter events within the patient causes scatter coincidences, but inter crystal scattering (ICS) events have useful information for determining an activity distribution. Some researchers have reported the feasibility of PET scanners based on a Compton camera for tracing ICS into the detector. However, these scanners require expensive semiconductor detectors for high-energy resolution. In the Anger-type block detector, single photons interacting with multiple detectors can be obtained for each interacting position and complete information can be gotten just as for photoelectric events in the single detector. ICS events in the single detector have been used to get coincidence, but single photons interacting with multiple detectors have not been used to get coincidence. In this work, we evaluated effect of sensitivity improvement using Compton kinetics in several types of DOI-PET scanners. The proposed method promises to improve the sensitivity using coincidence events of single photons interacting with multiple detectors, which are identified as the first interaction (FI). FI estimation accuracy can be improved to determine FI validity from the correlation between Compton scatter angles calculated on the coincidence line-of-response. We simulated an animal PET scanner consisting of 42 detectors. Each detector block consists of three types of scintillator crystals (LSO, GSO and GAGG). After the simulation, coincidence events are added as information for several depth-of-interaction (DOI) resolutions. From the simulation results, we concluded the proposed method promises to improve the sensitivity considerably when effective atomic number of a scintillator is low. Also, we showed that FI estimate

  19. Neutron Compton scattering studies of stretched polyethylene

    CERN Document Server

    Gabrys, B J; Mayers, J; Kalhoro, M S

    2002-01-01

    The mean kinetic energy of hydrogen and carbon atoms in unstretched and stretched polyethylene samples has been measured by neutron Compton scattering. The vibrational frequencies of the ground state and torsional energies have been calculated and compared with the existing data and calculations. The results obtained on deuterated and non-deuterated samples are compared. (orig.)

  20. Compton scattering and the complementarity principle

    CERN Document Server

    Sastry, G P

    1993-01-01

    We explain briefly why Compton scattering from a crystal gives a featureless continuous x-ray background while Bragg scattering from the same crystal produces sharp diffraction peaks. It is shown that the answer lies at the heart of quantum mechanics, namely the uncertainty and the complementarity principles. (author)

  1. Proton Tomography Through Deeply Virtual Compton Scattering

    CERN Document Server

    Ji, Xiangdong

    2016-01-01

    In this prize talk, I recall some of the history surrounding the discovery of deeply virtual Compton scattering, and explain why it is an exciting experimental tool to obtain novel tomographic pictures of the nucleons at Jefferson Lab 12 GeV facility and the planned Electron-Ion Collider in the United States.

  2. Investigation of the Compton Rescue technique

    Energy Technology Data Exchange (ETDEWEB)

    Stevenson, Alexander W.; Williams, Christopher S.; Burggraf, Larry W.; Kowash, Benjamin R.

    2015-05-15

    This paper summarizes an investigation of a process to improve the efficiency of position-sensitive gamma-radiation measurements from thin, planar semiconductor detectors. The method entails the use of a second, more efficient coaxial bulk detector placed behind a position-sensitive planar detector to collect Compton scattered photons that escape the volume of the position-sensitive detector. The technique is termed Compton rescue. The investigation consisted of two phases. First, a Monte-Carlo simulation was conducted to test feasibility of employing the technique. The simulation predicted the increase in detection efficiency by directly counting the number of photons added to the data set by Compton rescue and comparing to the number detected without the use of the technique. The simulation indicated that the technique could improve detection efficiency by approximately doubling the number of full-energy photons detected. The technique was tested in a laboratory setting using a coaxial semiconductor detector in coincidence with a thin, planar position-sensitive semiconductor detector. An efficiency improvement of approximately 20% was measured. The effect of Compton rescue data on the energy resolution of the position-sensitive detector was also determined.

  3. Design Study for Direction Variable Compton Scattering Gamma Ray

    Science.gov (United States)

    Kii, T.; Omer, M.; Negm, H.; Choi, Y. W.; Kinjo, R.; Yoshida, K.; Konstantin, T.; Kimura, N.; Ishida, K.; Imon, H.; Shibata, M.; Shimahashi, K.; Komai, T.; Okumura, K.; Zen, H.; Masuda, K.; Hori, T.; Ohgaki, H.

    2013-03-01

    A monochromatic gamma ray beam is attractive for isotope-specific material/medical imaging or non-destructive inspection. A laser Compton scattering (LCS) gamma ray source which is based on the backward Compton scattering of laser light on high-energy electrons can generate energy variable quasi-monochromatic gamma ray. Due to the principle of the LCS gamma ray, the direction of the gamma beam is limited to the direction of the high-energy electrons. Then the target object is placed on the beam axis, and is usually moved if spatial scanning is required. In this work, we proposed an electron beam transport system consisting of four bending magnets which can stick the collision point and control the electron beam direction, and a laser system consisting of a spheroidal mirror and a parabolic mirror which can also stick the collision point. Then the collision point can be placed on one focus of the spheroid. Thus gamma ray direction and collision angle between the electron beam and the laser beam can be easily controlled. As the results, travelling direction of the LCS gamma ray can be controlled under the limitation of the beam transport system, energy of the gamma ray can be controlled by controlling incident angle of the colliding beams, and energy spread can be controlled by changing the divergence of the laser beam.

  4. Application of Two Phase (Liquid/Gas) Xenon Gamma-Camera for the Detection of Special Nuclear Material and PET Medical Imaging

    Energy Technology Data Exchange (ETDEWEB)

    McKinsey, Daniel Nicholas [Yale University

    2013-08-27

    The McKinsey group at Yale has been awarded a grant from DTRA for the building of a Liquid Xenon Gamma Ray Color Camera (LXe-GRCC), which combines state-of-the-art detection of LXe scintillation light and time projection chamber (TPC) charge readout. The DTRA application requires a movable detector and hence only a single phase (liquid) xenon detector can be considered in this case. We propose to extend the DTRA project to applications that allow a two phase (liquid/gas) xenon TPC. This entails additional (yet minimal) hardware and extension of the research effort funded by DTRA. The two phase detector will have better energy and angular resolution. Such detectors will be useful for PET medical imaging and detection of special nuclear material in stationary applications (e.g. port of entry). The expertise of the UConn group in gas phase TPCs will enhance the capabilities of the Yale group and the synergy between the two groups will be very beneficial for this research project as well as the education and research projects of the two universities. The LXe technology to be used in this project has matured rapidly over the past few years, developed for use in detectors for nuclear physics and astrophysics. This technology may now be applied in a straightforward way to the imaging of gamma rays. According to detailed Monte Carlo simulations recently performed at Yale University, energy resolution of 1% and angular resolution of 3 degrees may be obtained for 1.0 MeV gamma rays, using existing technology. With further research and development, energy resolution of 0.5% and angular resolution of 1.3 degrees will be possible at 1.0 MeV. Because liquid xenon is a high density, high Z material, it is highly efficient for scattering and capturing gamma rays. In addition, this technology scales elegantly to large detector areas, with several square meter apertures possible. The Yale research group is highly experienced in the development and use of noble liquid detectors for

  5. From asymmetric window to spectral constrained factor analysis: A review of the methods of Compton scatter correction in radioisotope imaging. De la fenetre asymetrique a l'analyse factorielle sous contrainte spectrale: une revue des methodes de correction de la diffusion Compton en imagerie isotopique

    Energy Technology Data Exchange (ETDEWEB)

    Mas, J.; Hannequin, P.; Ben Younes, R.; Pousse, A.; Bidet, R. (Centre Hospitalier Universitaire Jean Minjoz, 25 - Besancon (FR))

    1990-01-01

    The quality of nuclear images is degraded by the poor spatial resolution of the gamma-camera, the attenuation, the statistical noise and the Compton scattered photons included within the pulseheight window centred on the radionuclide peak. A +- 10% window is needed if all the photopeak photons have to be detected, because of the low gamma-camera energy resolution, thus including a lot of scattered photons in this acquisition window. This last problem has received little attention in the literature, whereas attenuation and spatial resolution have been more extensively studied. Nevertheless, the use of refined techniques to achieve more accurate reconstruction of the true radioactivity distribution implies to address the problem of Compton scatter. We review in this paper all the methods of Compton scatter correction suggested during the eighties, presenting the main results, advantages and limits of each. 49 refs.

  6. Kinematics of Compton backscattering x-ray source for angiography

    Energy Technology Data Exchange (ETDEWEB)

    Blumberg, L.N.

    1992-05-01

    Calculations of X-Ray production rates, energy spread, and spectrum of Compton-backscattered photons from a Free Electron Laser on an electron beam in a low energy (136-MeV) compact (8.5-m circumference) storage ring indicate that an X-Ray intensity of 34.6 10{sup 7} X-Ray photons per 0.5-mm {times} 0.5-mm pixel for Coronary Angiography near the 33.169-keV iodine K-absorption edge can be achieved in a 4-msec pulse within a scattering cone of 1-mrad half angle. This intensity, at 10-m from the photon-electron interaction point to the patient is about a factor of 10 larger than presently achieved from a 4.5-T superconducting wiggler source in the NSLS 2.5-GeV storage ring and over an area about 5 times larger. The 2.2-keV energy spread of the Compton-backscattered beam is, however, much larger than the 70-eV spread presently attained form the wiggler source and use of a monochromator. The beam spot at the 10-m interaction point-to-patient distance is 20-mm diameter; larger spots are attainable at larger distances but with a corresponding reduction in X-Ray flux. Such a facility could be an inexpensive clinical alternative to present methods of non-invasive Digital Subtraction Angiography (DSA), small enough to be deployed in an urban medical center, and could have other medical, industrial and aerospace applications. Problems with the Compton backscattering source include laser beam heating of the mirror in the FEL oscillator optical cavity, achieving a large enough X-Ray beam spot at the patient, and obtaining radiation damping of the transverse oscillations and longitudinal emittance dilution of the storage ring electron beam resulting from photon-electron collisions without going to higher electron energy where the X-Ray energy spread becomes excessive for DSA. 38 refs.

  7. Using triple gamma coincidences with a pixelated semiconductor Compton-PET scanner: a simulation study

    Science.gov (United States)

    Kolstein, M.; Chmeissani, M.

    2016-01-01

    The Voxel Imaging PET (VIP) Pathfinder project presents a novel design using pixelated semiconductor detectors for nuclear medicine applications to achieve the intrinsic image quality limits set by physics. The conceptual design can be extended to a Compton gamma camera. The use of a pixelated CdTe detector with voxel sizes of 1 × 1 × 2 mm3 guarantees optimal energy and spatial resolution. However, the limited time resolution of semiconductor detectors makes it impossible to use Time Of Flight (TOF) with VIP PET. TOF is used in order to improve the signal to noise ratio (SNR) by using only the most probable portion of the Line-Of-Response (LOR) instead of its entire length. To overcome the limitation of CdTe time resolution, we present in this article a simulation study using β+-γ emitting isotopes with a Compton-PET scanner. When the β+ annihilates with an electron it produces two gammas which produce a LOR in the PET scanner, while the additional gamma, when scattered in the scatter detector, provides a Compton cone that intersects with the aforementioned LOR. The intersection indicates, within a few mm of uncertainty along the LOR, the origin of the beta-gamma decay. Hence, one can limit the part of the LOR used by the image reconstruction algorithm.

  8. AXIS: an instrument for imaging Compton radiographs using the Advanced Radiography Capability on the NIF.

    Science.gov (United States)

    Hall, G N; Izumi, N; Tommasini, R; Carpenter, A C; Palmer, N E; Zacharias, R; Felker, B; Holder, J P; Allen, F V; Bell, P M; Bradley, D; Montesanti, R; Landen, O L

    2014-11-01

    Compton radiography is an important diagnostic for Inertial Confinement Fusion (ICF), as it provides a means to measure the density and asymmetries of the DT fuel in an ICF capsule near the time of peak compression. The AXIS instrument (ARC (Advanced Radiography Capability) X-ray Imaging System) is a gated detector in development for the National Ignition Facility (NIF), and will initially be capable of recording two Compton radiographs during a single NIF shot. The principal reason for the development of AXIS is the requirement for significantly improved detection quantum efficiency (DQE) at high x-ray energies. AXIS will be the detector for Compton radiography driven by the ARC laser, which will be used to produce Bremsstrahlung X-ray backlighter sources over the range of 50 keV-200 keV for this purpose. It is expected that AXIS will be capable of recording these high-energy x-rays with a DQE several times greater than other X-ray cameras at NIF, as well as providing a much larger field of view of the imploded capsule. AXIS will therefore provide an image with larger signal-to-noise that will allow the density and distribution of the compressed DT fuel to be measured with significantly greater accuracy as ICF experiments are tuned for ignition.

  9. Comptonization signatures in the prompt emission of gamma-ray bursts

    Energy Technology Data Exchange (ETDEWEB)

    Frontera, F.; Farinelli, R.; Dichiara, S.; Guidorzi, C.; Titarchuk, L. [Dipartimento di Fisicae Scienze della Terra, Università di Ferrara, Via Saragat 1, I-44100 Ferrara (Italy); Amati, L.; Landi, R., E-mail: frontera@fe.infn.it [INAF, Istituto di Astrofisica Spaziale e Fisica Cosmica, Bologna, Via Gobetti 101, I-40129 Bologna (Italy)

    2013-12-20

    We report results of a systematic study of the broadband (2-2000 keV) time-resolved prompt emission spectra of a sample of gamma-ray bursts (GRBs) detected with both Wide Field Cameras (WFCs) on board the BeppoSAX satellite and the Burst and Transient Source Experiment (BATSE) on board the Compton Gamma Ray Observatory. The main goal of this paper is to test spectral models of the GRB prompt emission that have recently been proposed. In particular, we test a recent photospheric model proposed, i.e., blackbody plus power law, the addition of a blackbody emission to the Band function in the cases in which this function does not fit the data, and a recent Comptonization model. By considering the few spectra for which the simple Band function does not provide a fully acceptable fit to the data, we find a statistically significant better fit by adding a blackbody to this function only in one case. We confirm earlier results found fitting the BATSE spectra alone with a blackbody plus power law. Instead, when the BATSE GRB spectra are joined to those obtained with WFCs (2-28 keV), this model becomes unacceptable in most time intervals in which we subdivide the GRB light curves. We find instead that the Comptonization model is always acceptable, even in the few cases in which the Band function is inconsistent with the data. We discuss the implications of these results.

  10. AXIS: An instrument for imaging Compton radiographs using the Advanced Radiography Capability on the NIF

    Energy Technology Data Exchange (ETDEWEB)

    Hall, G. N., E-mail: hall98@llnl.gov; Izumi, N.; Tommasini, R.; Carpenter, A. C.; Palmer, N. E.; Zacharias, R.; Felker, B.; Holder, J. P.; Allen, F. V.; Bell, P. M.; Bradley, D.; Montesanti, R.; Landen, O. L. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States)

    2014-11-15

    Compton radiography is an important diagnostic for Inertial Confinement Fusion (ICF), as it provides a means to measure the density and asymmetries of the DT fuel in an ICF capsule near the time of peak compression. The AXIS instrument (ARC (Advanced Radiography Capability) X-ray Imaging System) is a gated detector in development for the National Ignition Facility (NIF), and will initially be capable of recording two Compton radiographs during a single NIF shot. The principal reason for the development of AXIS is the requirement for significantly improved detection quantum efficiency (DQE) at high x-ray energies. AXIS will be the detector for Compton radiography driven by the ARC laser, which will be used to produce Bremsstrahlung X-ray backlighter sources over the range of 50 keV–200 keV for this purpose. It is expected that AXIS will be capable of recording these high-energy x-rays with a DQE several times greater than other X-ray cameras at NIF, as well as providing a much larger field of view of the imploded capsule. AXIS will therefore provide an image with larger signal-to-noise that will allow the density and distribution of the compressed DT fuel to be measured with significantly greater accuracy as ICF experiments are tuned for ignition.

  11. Theory of Compton scattering by anisotropic electrons

    CERN Document Server

    Poutanen, Juri

    2010-01-01

    Compton scattering plays an important role in various astrophysical objects such as accreting black holes and neutron stars, pulsars, and relativistic jets, clusters of galaxies as well as the early Universe. In most of the calculations it is assumed that the electrons have isotropic angular distribution in some frame. However, there are situations where the anisotropy may be significant due to the bulk motions, or anisotropic cooling by synchrotron radiation, or anisotropic source of seed soft photons. We develop here an analytical theory of Compton scattering by anisotropic distribution of electrons that can simplify significantly the calculations. Assuming that the electron angular distribution can be represented by a second order polynomial over cosine of some angle (dipole and quadrupole anisotropy), we integrate the exact Klein-Nishina cross-section over the angles. Exact analytical and approximate formulae valid for any photon and electron energies are derived for the redistribution functions describin...

  12. Dispersion Properties of TIRPCF under Compton Scattering

    Institute of Scientific and Technical Information of China (English)

    HAO Dong-shan; YU Ding-chen

    2006-01-01

    The dispersion properties in the short wavelength region of total internal reflective photonic crystal fiber(TIRPCF) in Compton scattering have been studied by using the model of the equivalent twin waveguide soliton coupling,dispersion management solitons and effective refractive index. It is shown that the positive dispersion of the cladding waveguide of TIRPCF and the negative dispersion of its core waveguide are quickly increased by the square of the collision non-elastic composition between the electron and photons,and they are lessened by the increase of the electron absorption photon number. Under the one-photon nonlinear Compton scattering,the method of the compensated probing laser diffraction by the phase hole induced by the stationary pumping laser in the cladding waveguide enables the average dispersion value of TIRPCF to be close to zero,and the zero dispersion point quickly shifts to the short wavelength region.

  13. Turbulent Comptonization in Black Hole Accretion Disks

    CERN Document Server

    Socrates, A; Blaes, Omer M; Socrates, Aristotle; Davis, Shane W.; Blaes, Omer

    2004-01-01

    In the inner-most regions of radiation pressure supported accretion disks, the turbulent magnetic pressure may greatly exceed that of the gas. If this is the case, it is possible for bulk Alfvenic motions driven by the magnetorotational instability (MRI) to surpass the electron thermal velocity. Bulk rather than thermal Comptonization may then be the dominant radiative process which mediates gravitational energy release. For sufficiently large turbulent stresses, we show that turbulent Comptonization produces a significant contribution to the far-UV and X-ray emission of black hole accretion disks. The existence of this spectral component provides a means of obtaining direct observational constraints on the nature of the turbulence itself. We describe how this component may affect the spectral energy distributions and variability properties of X-ray binaries and active galactic nuclei.

  14. Supernova Science with an Advanced Compton Telescope

    Science.gov (United States)

    2000-12-04

    advanced Compton telescope would be a powerful astrophysical tool. KEYWORDS: gamma rays:observations - Galaxy: center - supernoae: genearl - ISM: general 1...Radionuclei produced in SNe decay to stable nuclei on various time-scales, generating gamma- and x-ray photons, electrons and positrons. These decay products...Older SNRs must be galactic, but the emission can be detected on decadal- millenial time-scales. SNR studies thus concentrate upon 57Co(122 keV), 22Na

  15. Resonant Compton Physics for Magnetar Astrophysics

    Science.gov (United States)

    Ickes, Jesse; Gonthier, Peter L.; Eiles, Matthew; Baring, Matthew G.

    2016-01-01

    Various telescopes including RXTE, INTEGRAL, Suzaku, and Fermi have detected steady non-thermal X-ray emission in the 10 - 200 keV band from strongly magnetic neutron stars known as magnetars. Magnetic inverse Compton scattering is believed to be the leading candidate for the production of this intense X-ray radiation. Scattering at ultra-relativistic energies leads to attractive simplifications in the analytics of the magnetic Compton cross section. We have recently addressed such a case by developing compact analytic expressions using correct spin-dependent widths acquired through the implementation of Sokolov & Ternov basis states, focusing specifically on ground-state-ground-state scattering. Compton scattering in magnetar magnetospheres can cool electrons down to mildly relativistic energies. Moreover, soft gamma-ray flaring in magnetars may involve strong Comptonization in expanding clouds of mildly relativistic pairs. Such environs necessitate the development of more general magnetic scattering cross sections, in which the incoming photons acquire substantial incident angles relative to the field in the rest frame of the electron leading to arbitrary Landau excitations of the intermediate and final states. Due to the rapid transitions of the excited-state to the ground-state, the initial electron is still assumed to be in the ground state. The cross sections treat the plethora of harmonic resonances associated with various cyclotron transitions between Landau states. Polarization and spin dependence of the cross section for the four scattering modes is compared to the cross section obtained with spin-averaged widths. We present numerical results to show the comparisons to highlight the role of the spin-dependent widths of the resonances. The findings presented here will have applications to various neutron star problems, including computation of Eddington luminosities and polarization mode-switching rates in transient magnetar fireballs.

  16. High-Energy Compton Scattering Light Sources

    CERN Document Server

    Hartemann, Fred V; Barty, C; Crane, John; Gibson, David J; Hartouni, E P; Tremaine, Aaron M

    2005-01-01

    No monochromatic, high-brightness, tunable light sources currently exist above 100 keV. Important applications that would benefit from such new hard x-ray sources include: nuclear resonance fluorescence spectroscopy, time-resolved positron annihilation spectroscopy, and MeV flash radiography. The peak brightness of Compton scattering light sources is derived for head-on collisions and found to scale with the electron beam brightness and the drive laser pulse energy. This gamma 2

  17. Pre-clinical and Clinical Evaluation of High Resolution, Mobile Gamma Camera and Positron Imaging Devices

    Science.gov (United States)

    2010-10-01

    S. Majewski, R. Wojcik, A.G. Weisenberger, B. Kross, V. Popov, “Correction for the Effects of Accidental Coincidences , Compton Scatter and Object... Coincidence Imaging with a Gamma Camera ”, IEEE Transactions on Nuclear Science, Vol. 48, No. 1, Feb. 2001, Pg. 98-105. [14] R.S. Miyaoka, S.K...Coleman, “Attenuation Effects in Gamma Camera Coincidence Imaging”, IEEE Transactions on Nuclear Science, Vol. 45, No. 6, Dec. 1998, Pg. 3115-3121

  18. Theoretical Compton profile anisotropies in molecules and solids. VI. Compton profile anisotropies and chemical binding

    Energy Technology Data Exchange (ETDEWEB)

    Matcha, R.L.; Pettitt, B.M.

    1979-03-15

    An interesting empirical relationship between zero point Compton profile anisotropies ..delta..J (0) and nuclear charges is noted. It is shown that, for alkali halide molecules AB, to a good approximation ..delta..J (0) =N ln(Z/sub b//Z/sub a/).

  19. Compton profile of tantalum

    Indian Academy of Sciences (India)

    Thomas Varghese; K M Balakrishna; K Siddappa

    2003-03-01

    The Compton profile of tantalum (Ta) has been measured using IGP type coaxial photon detector. The target atoms were excited by means of 59.54 keV -rays from Am-241. The measurements were carried out on a high purity thin elemental foil. The data were recoreded in a 4 K multichannel analyzer. These data duly corrected for various effects are presented and compared with theoretical and measured values. Best agreement with experiment is found for the 5d36s2 electron configuration.

  20. Cork quality estimation by using Compton tomography

    CERN Document Server

    Brunetti, A; Golosio, B; Luciano, P; Ruggero, A

    2002-01-01

    The quality control of cork stoppers is mandatory in order to guarantee the perfect conservation of the wine. Several techniques have been developed but until now the quality control was essentially related to the status of the external surface. Thus possible cracks or holes inside the stopper will be hidden. In this paper a new technique based on X-ray Compton tomography is described. It is a non-destructive technique that allows one to reconstruct and visualize the cross-section of the cork stopper analyzed, and so to put in evidence the presence of internal imperfections. Some results are reported and compared with visual classification.

  1. Deeply Virtual Compton Scattering off the neutron

    Energy Technology Data Exchange (ETDEWEB)

    M. Mazouz; A. Camsonne; C. Munoz Camacho; C. Ferdi; G. Gavalian; E. Kuchina; M. Amarian; K. A. Aniol; M. Beaumel; H. Benaoum; P. Bertin; M. Brossard; J.-P. Chen; E. Chudakov; B. Craver; F. Cusanno; C.W. de Jager; A. Deur; R. Feuerbach; J.-M. Fieschi; S. Frullani; M. Garcon; F. Garibaldi; O. Gayou; R. Gilman; J. Gomez; P. Gueye; P.A.M. Guichon; B. Guillon; O. Hansen; D. Hayes; D. Higinbotham; T. Holmstrom; C.E. Hyde; H. Ibrahim; R. Igarashi; X. Jiang; H.S. Jo; L.J. Kaufman; A. Kelleher; A. Kolarkar; G. Kumbartzki; G. Laveissiere; J.J. LeRose; R. Lindgren; N. Liyanage; H.-J. Lu; D.J. Margaziotis; Z.-E. Meziani; K. McCormick; R. Michaels; B. Michel; B. Moffit; P. Monaghan; S. Nanda; V. Nelyubin; M. Potokar; Y. Qiang; R.D. Ransome; J.-S. Real; B. Reitz; Y. Roblin; J. Roche; F. Sabatie; A. Saha; S. Sirca; K. Slifer; P. Solvignon; R. Subedi; V. Sulkosky; P.E. Ulmer; E. Voutier; K. Wang; L.B. Weinstein; B. Wojtsekhowski; X. Zheng; L. Zhu

    2007-12-01

    The present experiment exploits the interference between the Deeply Virtual Compton Scattering (DVCS) and the Bethe-Heitler processes to extract the imaginary part of DVCS amplitudes on the neutron and on the deuteron from the helicity-dependent D$({\\vec e},e'\\gamma)X$ cross section measured at $Q^2$=1.9 GeV$^2$ and $x_B$=0.36. We extract a linear combination of generalized parton distributions (GPDs) particularly sensitive to $E_q$, the least constrained GPD. A model dependent constraint on the contribution of the up and down quarks to the nucleon spin is deduced.

  2. Deeply Virtual Compton Scattering off the neutron

    CERN Document Server

    Mazouz, M; Ferdi, C; Gavalian, G; Kuchina, E; Amarian, M; Aniol, K A; Beaumel, M; Benaoum, H; Bertin, P; Brossard, M; Chen, J P; Chudakov, E; Craver, B; Cusanno, F; De Jager, C W; Deur, A; Feuerbach, R; Fieschi, J M; Frullani, S; Garçon, M; Garibaldi, F; Gayou, O; Gilman, R; Gómez, J; Gueye, P; Guichon, P A M; Guillon, B; Hansen, O; Hayes, D; Higinbotham, D; Holmstrom, T; Hyde, C E; Ibrahim, H; Igarashi, R; Jiang, X; Jo, H S; Kaufman, L J; Kelleher, A; Kolarkar, A; Kumbartzki, G; Laveissière, G; Le Rose, J J; Lindgren, R; Liyanage, N; Lu, H J; Margaziotis, D J; Meziani, Z E; McCormick, K; Michaels, R; Michel, B; Moffit, B; Monaghan, P; Nanda, S; Nelyubin, V; Potokar, M; Qiang, Y; Ransome, R D; Real, J S; Reitz, B; Roblin, Y; Roche, J; Sabatie, F; Saha, A; Sirca, S; Slifer, K; Solvignon, P; Subedi, R; Sulkosky, V; Ulmer, P E; Voutier, E; Wang, K; Weinstein, L B; Wojtsekhowski, B; Zheng, X; Zhu, L

    2007-01-01

    The present experiment exploits the interference between the Deeply Virtual Compton Scattering (DVCS) and the Bethe-Heitler processes to extract the imaginary part of DVCS amplitudes on the neutron and on the deuteron from the helicity-dependent D$({\\vec e},e'\\gamma)X$ cross section measured at $Q^2$=1.9 GeV$^2$ and $x_B$=0.36. We extract a linear combination of generalized parton distributions (GPDs) particularly sensitive to $E_q$, the least constrained GPD. A model dependent constraint on the contribution of the up and down quarks to the nucleon spin is deduced.

  3. Advanced Laser-Compton Gamma-Ray Sources for Nuclear Materials Detection, Assay and Imaging

    Science.gov (United States)

    Barty, C. P. J.

    2015-10-01

    Highly-collimated, polarized, mono-energetic beams of tunable gamma-rays may be created via the optimized Compton scattering of pulsed lasers off of ultra-bright, relativistic electron beams. Above 2 MeV, the peak brilliance of such sources can exceed that of the world's largest synchrotrons by more than 15 orders of magnitude and can enable for the first time the efficient pursuit of nuclear science and applications with photon beams, i.e. Nuclear Photonics. Potential applications are numerous and include isotope-specific nuclear materials management, element-specific medical radiography and radiology, non-destructive, isotope-specific, material assay and imaging, precision spectroscopy of nuclear resonances and photon-induced fission. This review covers activities at the Lawrence Livermore National Laboratory related to the design and optimization of mono-energetic, laser-Compton gamma-ray systems and introduces isotope-specific nuclear materials detection and assay applications enabled by them.

  4. Simulation of Laser-Compton Cooling of Electron Beams

    OpenAIRE

    Ohgaki, T.

    2000-01-01

    We study a method of laser-Compton cooling of electron beams. Using a Monte Carlo code, we evaluate the effects of the laser-electron interaction for transverse cooling. The optics with and without chromatic correction for the cooling are examined. The laser-Compton cooling for JLC/NLC at E_0=2 GeV is considered.

  5. 21 CFR 878.4160 - Surgical camera and accessories.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Surgical camera and accessories. 878.4160 Section... (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4160 Surgical camera and accessories. (a) Identification. A surgical camera and accessories is a device intended to be...

  6. 21 CFR 892.1100 - Scintillation (gamma) camera.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Scintillation (gamma) camera. 892.1100 Section 892...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1100 Scintillation (gamma) camera. (a) Identification. A scintillation (gamma) camera is a device intended to image the distribution of radionuclides...

  7. Laser pulsing in linear Compton scattering

    Science.gov (United States)

    Krafft, G. A.; Johnson, E.; Deitrick, K.; Terzić, B.; Kelmar, R.; Hodges, T.; Melnitchouk, W.; Delayen, J. R.

    2016-12-01

    Previous work on calculating energy spectra from Compton scattering events has either neglected considering the pulsed structure of the incident laser beam, or has calculated these effects in an approximate way subject to criticism. In this paper, this problem has been reconsidered within a linear plane wave model for the incident laser beam. By performing the proper Lorentz transformation of the Klein-Nishina scattering cross section, a spectrum calculation can be created which allows the electron beam energy spread and emittance effects on the spectrum to be accurately calculated, essentially by summing over the emission of each individual electron. Such an approach has the obvious advantage that it is easily integrated with a particle distribution generated by particle tracking, allowing precise calculations of spectra for realistic particle distributions "in collision." The method is used to predict the energy spectrum of radiation passing through an aperture for the proposed Old Dominion University inverse Compton source. Many of the results allow easy scaling estimates to be made of the expected spectrum.

  8. Ground calibrations of Nuclear Compton Telescope

    Science.gov (United States)

    Chiu, Jeng-Lun; Liu, Zhong-Kai; Bandstra, Mark S.; Bellm, Eric C.; Liang, Jau-Shian; Perez-Becker, Daniel; Zoglauer, Andreas; Boggs, Steven E.; Chang, Hsiang-Kuang; Chang, Yuan-Hann; Huang, Minghuey A.; Amman, Mark; Chiang, Shiuan-Juang; Hung, Wei-Che; Lin, Chih-Hsun; Luke, Paul N.; Run, Ray-Shine; Wunderer, Cornelia B.

    2010-07-01

    The Nuclear Compton Telescope (NCT) is a balloon-borne soft gamma ray (0.2-10 MeV) telescope designed to study astrophysical sources of nuclear line emission and polarization. The heart of NCT is an array of 12 cross-strip germanium detectors, designed to provide 3D positions for each photon interaction with full 3D position resolution to imaging, effectively reduces background, and enables the measurement of polarization. The keys to Compton imaging with NCT's detectors are determining the energy deposited in the detector at each strip and tracking the gamma-ray photon interaction within the detector. The 3D positions are provided by the orthogonal X and Y strips, and by determining the interaction depth using the charge collection time difference (CTD) between the anode and cathode. Calibrations of the energy as well as the 3D position of interactions have been completed, and extensive calibration campaigns for the whole system were also conducted using radioactive sources prior to our flights from Ft. Sumner, New Mexico, USA in Spring 2009, and from Alice Springs, Australia in Spring 2010. Here we will present the techniques and results of our ground calibrations so far, and then compare the calibration results of the effective area throughout NCT's field of view with Monte Carlo simulations using a detailed mass model.

  9. Nonlinear X-ray Compton Scattering

    CERN Document Server

    Fuchs, Matthias; 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; Hart, Philip; Kenney, Christopher; Guillet, Serge; Boutet, Sebastien; Williams, Garth; Messerschmidt, Marc; Seibert, Marvin; Moeller, Stefan; Hastings, Jerome B; Reis, David A

    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 ultrashort pulses. However, in the focus of an XFEL the assumption of a weak linear probe breaks down, and nonlinear light-matter interactions can become ubiquitous. The field can be sufficiently high that even non-resonant multiphoton interactions at hard X-rays wavelengths become relevant. Here we report the observation of one of the most fundamental nonlinear X-ray-matter interactions, the simultaneous Compton scattering of two identical photons producing a single photon at nearly twice the photon energy. We measure scattered...

  10. Deeply virtual Compton scattering at Jefferson Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Biselli, Angela S. [Fairfield University - Department of Physics 1073 North Benson Road, Fairfield, CT 06430, USA; Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-08-01

    The generalized parton distributions (GPDs) have emerged as a universal tool to describe hadrons in terms of their elementary constituents, the quarks and the gluons. Deeply virtual Compton scattering (DVCS) on a proton or neutron ($N$), $e N \\rightarrow e' N' \\gamma$, is the process more directly interpretable in terms of GPDs. The amplitudes of DVCS and Bethe-Heitler, the process where a photon is emitted by either the incident or scattered electron, can be accessed via cross-section measurements or exploiting their interference which gives rise to spin asymmetries. Spin asymmetries, cross sections and cross-section differences can be connected to different combinations of the four leading-twist GPDs (${H}$, ${E}$, ${\\tilde{H}}$, ${\\tilde{E}}$) for each quark flavors, depending on the observable and on the type of target. This paper gives an overview of recent experimental results obtained for DVCS at Jefferson Laboratory in the halls A and B. Several experiments have been done extracting DVCS observables over large kinematics regions. Multiple measurements with overlapping kinematic regions allow to perform a quasi-model independent extraction of the Compton form factors, which are GPDs integrals, revealing a 3D image of the nucleon.

  11. Compton scattering measurements from dense plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Glenzer, S H; Neumayer, P; Doeppner, T; Landen, L; Lee, R W; Wallace, R; Weber, S; Lee, H J; Kritcher, A L; Falcone, R; Regan, S P; Sawada, H; Meyerhofer, D D; Gregori, G; Fortmann, C; Schwarz, V; Redmer, R

    2007-10-02

    Compton scattering has been developed for accurate measurements of densities and temperatures in dense plasmas. One future challenge is the application of this technique to characterize compressed matter on the National Ignition Facility where hydrogen and beryllium will approach extremely dense states of matter of up to 1000 g/cc. In this regime, the density, compressibility, and capsule fuel adiabat may be directly measured from the Compton scattered spectrum of a high-energy x-ray line source. Specifically, the scattered spectra directly reflect the electron velocity distribution. In non-degenerate plasmas, the width provides an accurate measure of the electron temperatures, while in partially Fermi degenerate systems that occur in laser-compressed matter it provides the Fermi energy and hence the electron density. Both of these regimes have been accessed in experiments at the Omega laser by employing isochorically heated solid-density beryllium and moderately compressed beryllium foil targets. In the latter experiment, compressions by a factor of 3 at pressures of 40 Mbar have been measured in excellent agreement with radiation hydrodynamic modeling.

  12. Compton scattering measurements from dense plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Glenzer, S H; Neumayer, P; Doeppner, T; Landen, O L; Lee, R W; Wallace, R J; Weber, S [Lawrence Livermore National Laboratory, Livermore, CA (United States); Lee, H J; Kritcher, A L; Falcone, R [University of California Berkeley, Berkeley, CA 94709 (United States); Regan, S P; Sawada, H; Meyerhofer, D D [Laboratory for Laser Energetics, Rochester, NY (United States); Gregori, G [Clarendon Laboratory, University of Oxford, Oxford OX1 3PU (United Kingdom); Fortmann, C; Schwarz, V; Redmer, R [Institut fuer Physik, Universitaet Rostock, D-18051 Rostock (Germany)], E-mail: glenzer1@llnl.gov

    2008-05-15

    Compton scattering techniques have been developed for accurate measurements of densities and temperatures in dense plasmas. One future challenge is the application of this technique to characterize compressed matter on the National Ignition Facility where hydrogen and beryllium will approach extremely dense states of matter of up to 1000 g/cc. In this regime, the density, compressibility, and capsule fuel adiabat may be directly measured from the Compton scattered spectrum of a high-energy x-ray line source. Specifically, the scattered spectra directly reflect the electron velocity distribution. In non-degenerate plasmas, the width provides an accurate measure of the electron temperatures, while in partially Fermi degenerate systems that occur in laser-compressed matter it provides the Fermi energy and hence the electron density. Both of these regimes have been accessed in experiments at the Omega laser by employing isochorically heated solid-density beryllium and moderately compressed beryllium foil targets. In the latter experiment, compressions by a factor of 3 at pressures of 40 Mbar have been measured in excellent agreement with radiation hydrodynamic modeling.

  13. Gravitationally induced electromagnetism at the Compton scale

    CERN Document Server

    Rosquist, K

    2004-01-01

    It is shown that Einstein gravity tends to modify the electric and magnetic fields appreciably at distances of the order of the Compton wavelength. At that distance the gravitational field becomes spin dominated rather than mass dominated. The gravitational field couples to the electromagnetic field via the Einstein-Maxwell equations which in the simplest model causes the electrostatic field of charged spinning particles to acquire an oblate structure relative to the spin direction. A pure Coulomb field is therefore likely to be incompatible with general relativity at the Compton scale. In the simplest model, the magnetic dipole corresponds to the Dirac g-factor, $g=2$. Also, it follows from the form of the electric field that the electric dipole moment vanishes, in agreement with current experimental limits for the electron. Quantitatively, the classical Einstein-Maxwell theory predicts the magnetic and electric dipoles of the electron to an accuracy of about one part in $10^{-3}$ or better. Going to the nex...

  14. A dual purpose Compton suppression spectrometer

    CERN Document Server

    Parus, J; Raab, W; Donohue, D

    2003-01-01

    A gamma-ray spectrometer with a passive and an active shield is described. It consists of a HPGe coaxial detector of 42% efficiency and 4 NaI(Tl) detectors. The energy output pulses of the Ge detector are delivered into the 3 spectrometry chains giving the normal, anti- and coincidence spectra. From the spectra of a number of sup 1 sup 3 sup 7 Cs and sup 6 sup 0 Co sources a Compton suppression factor, SF and a Compton reduction factor, RF, as the parameters characterizing the system performance, were calculated as a function of energy and source activity and compared with those given in literature. The natural background is reduced about 8 times in the anticoincidence mode of operation, compared to the normal spectrum which results in decreasing the detection limits for non-coincident gamma-rays up to a factor of 3. In the presence of other gamma-ray activities, in the range from 5 to 11 kBq, non- and coincident, the detection limits can be decreased for some nuclides by a factor of 3 to 5.7.

  15. Gamma-ray imaging with a large micro-TPC and a scintillation camera

    Energy Technology Data Exchange (ETDEWEB)

    Hattori, K. [Graduate School of Science, Department of Physics, Kyoto University Kitashirakawa, Sakyo, Kyoto 606-8502 (Japan)], E-mail: hattori@cr.scphys.kyoto-u.ac.jp; Kabuki, S.; Kubo, H.; Kurosawa, S.; Miuchi, K. [Graduate School of Science, Department of Physics, Kyoto University Kitashirakawa, Sakyo, Kyoto 606-8502 (Japan); Nagayoshi, T. [Advanced Research Institute for Science and Engineering, Waseda University, 17 Kikui-cho, Shinjuku 162-0044, Tokyo (Japan); Nishimura, H.; Okada, Y. [Graduate School of Science, Department of Physics, Kyoto University Kitashirakawa, Sakyo, Kyoto 606-8502 (Japan); Orito, R. [Graduate School of Science and Technology, Department of Physics, Kobe University, 1-1 Rokkoudai, Nada, Kobe 657-8501 (Japan); Sekiya, H.; Takada, A. [Graduate School of Science, Department of Physics, Kyoto University Kitashirakawa, Sakyo, Kyoto 606-8502 (Japan); Takeda, A. [Kamioka Observatory, ICRR, University of Tokyo, 456 Higashi-mozumi, Hida-shi, Gifu 505-1205 (Japan); Tanimori, T.; Ueno, K. [Graduate School of Science, Department of Physics, Kyoto University Kitashirakawa, Sakyo, Kyoto 606-8502 (Japan)

    2007-10-21

    We report on the development of a large Compton camera with the full reconstruction of the Compton process based on a prototype. This camera consists of two kinds of detectors. One is a gaseous time projection chamber (micro-TPC) for measuring the energy and the track of a Compton recoil electron. The micro-TPC is based on a {mu}-PIC and a GEM, which are micro-pattern gas detectors (MPGDs). The size of the micro-TPC was 10cmx10cmx8cm in the case of the prototype, and we enlarged it to 23cmx28cmx15cm. The other detector part is a NaI (Tl) Anger camera for measuring the scattered gamma-ray. With these informations, we can completely reconstruct a Compton event, and determine the direction of the incident gamma-ray, event by event. We succeeded in reconstructing events of incident 662 keV gamma-rays. The measured angular resolutions of the 'angular resolution measure' (ARM) and the 'scatter plane deviation' (SPD) were 9.3{sup 0} and 158{sup 0} (FWHM), respectively.

  16. Interconnected network of cameras

    Science.gov (United States)

    Hosseini Kamal, Mahdad; Afshari, Hossein; Leblebici, Yusuf; Schmid, Alexandre; Vandergheynst, Pierre

    2013-02-01

    The real-time development of multi-camera systems is a great challenge. Synchronization and large data rates of the cameras adds to the complexity of these systems as well. The complexity of such system also increases as the number of their incorporating cameras increases. The customary approach to implementation of such system is a central type, where all the raw stream from the camera are first stored then processed for their target application. An alternative approach is to embed smart cameras to these systems instead of ordinary cameras with limited or no processing capability. Smart cameras with intra and inter camera processing capability and programmability at the software and hardware level will offer the right platform for distributed and parallel processing for multi- camera systems real-time application development. Inter camera processing requires the interconnection of smart cameras in a network arrangement. A novel hardware emulating platform is introduced for demonstrating the concept of the interconnected network of cameras. A methodology is demonstrated for the interconnection network of camera construction and analysis. A sample application is developed and demonstrated.

  17. A compact neutron scatter camera for field deployment

    CERN Document Server

    Goldsmith, John E M; Brennan, James S

    2016-01-01

    We describe a very compact (0.9 m high, 0.4 m diameter, 40 kg) battery operable neutron scatter camera designed for field deployment. Unlike most other systems, the configuration of the sixteen liquid-scintillator detection cells are arranged to provide omnidirectional (4{\\pi}) imaging with sensitivity comparable to a conventional two-plane system. Although designed primarily to operate as a neutron scatter camera for localizing energetic neutron sources, it also functions as a Compton camera for localizing gamma sources. In addition to describing the radionuclide source localization capabilities of this system, we demonstrate how it provides neutron spectra that can distinguish plutonium metal from plutonium oxide sources, in addition to the easier task of distinguishing AmBe from fission sources.

  18. Making Ceramic Cameras

    Science.gov (United States)

    Squibb, Matt

    2009-01-01

    This article describes how to make a clay camera. This idea of creating functional cameras from clay allows students to experience ceramics, photography, and painting all in one unit. (Contains 1 resource and 3 online resources.)

  19. Making Ceramic Cameras

    Science.gov (United States)

    Squibb, Matt

    2009-01-01

    This article describes how to make a clay camera. This idea of creating functional cameras from clay allows students to experience ceramics, photography, and painting all in one unit. (Contains 1 resource and 3 online resources.)

  20. Vacuum Camera Cooler

    Science.gov (United States)

    Laugen, Geoffrey A.

    2011-01-01

    Acquiring cheap, moving video was impossible in a vacuum environment, due to camera overheating. This overheating is brought on by the lack of cooling media in vacuum. A water-jacketed camera cooler enclosure machined and assembled from copper plate and tube has been developed. The camera cooler (see figure) is cup-shaped and cooled by circulating water or nitrogen gas through copper tubing. The camera, a store-bought "spy type," is not designed to work in a vacuum. With some modifications the unit can be thermally connected when mounted in the cup portion of the camera cooler. The thermal conductivity is provided by copper tape between parts of the camera and the cooled enclosure. During initial testing of the demonstration unit, the camera cooler kept the CPU (central processing unit) of this video camera at operating temperature. This development allowed video recording of an in-progress test, within a vacuum environment.

  1. Constrained space camera assembly

    Science.gov (United States)

    Heckendorn, Frank M.; Anderson, Erin K.; Robinson, Casandra W.; Haynes, Harriet B.

    1999-01-01

    A constrained space camera assembly which is intended to be lowered through a hole into a tank, a borehole or another cavity. The assembly includes a generally cylindrical chamber comprising a head and a body and a wiring-carrying conduit extending from the chamber. Means are included in the chamber for rotating the body about the head without breaking an airtight seal formed therebetween. The assembly may be pressurized and accompanied with a pressure sensing means for sensing if a breach has occurred in the assembly. In one embodiment, two cameras, separated from their respective lenses, are installed on a mounting apparatus disposed in the chamber. The mounting apparatus includes means allowing both longitudinal and lateral movement of the cameras. Moving the cameras longitudinally focuses the cameras, and moving the cameras laterally away from one another effectively converges the cameras so that close objects can be viewed. The assembly further includes means for moving lenses of different magnification forward of the cameras.

  2. COMPACT CdZnTe-BASED GAMMA CAMERA FOR PROSTATE CANCER IMAGING

    Energy Technology Data Exchange (ETDEWEB)

    CUI, Y.; LALL, T.; TSUI, B.; YU, J.; MAHLER, G.; BOLOTNIKOV, A.; VASKA, P.; DeGERONIMO, G.; O' CONNOR, P.; MEINKEN, G.; JOYAL, J.; BARRETT, J.; CAMARDA, G.; HOSSAIN, A.; KIM, K.H.; YANG, G.; POMPER, M.; CHO, S.; WEISMAN, K.; SEO, Y.; BABICH, J.; LaFRANCE, N.; AND JAMES, R.B.

    2011-10-23

    In this paper, we discuss the design of a compact gamma camera for high-resolution prostate cancer imaging using Cadmium Zinc Telluride (CdZnTe or CZT) radiation detectors. Prostate cancer is a common disease in men. Nowadays, a blood test measuring the level of prostate specific antigen (PSA) is widely used for screening for the disease in males over 50, followed by (ultrasound) imaging-guided biopsy. However, PSA tests have a high false-positive rate and ultrasound-guided biopsy has a high likelihood of missing small cancerous tissues. Commercial methods of nuclear medical imaging, e.g. PET and SPECT, can functionally image the organs, and potentially find cancer tissues at early stages, but their applications in diagnosing prostate cancer has been limited by the smallness of the prostate gland and the long working distance between the organ and the detectors comprising these imaging systems. CZT is a semiconductor material with wide band-gap and relatively high electron mobility, and thus can operate at room temperature without additional cooling. CZT detectors are photon-electron direct-conversion devices, thus offering high energy-resolution in detecting gamma rays, enabling energy-resolved imaging, and reducing the background of Compton-scattering events. In addition, CZT material has high stopping power for gamma rays; for medical imaging, a few-mm-thick CZT material provides adequate detection efficiency for many SPECT radiotracers. Because of these advantages, CZT detectors are becoming popular for several SPECT medical-imaging applications. Most recently, we designed a compact gamma camera using CZT detectors coupled to an application-specific-integrated-circuit (ASIC). This camera functions as a trans-rectal probe to image the prostate gland from a distance of only 1-5 cm, thus offering higher detection efficiency and higher spatial resolution. Hence, it potentially can detect prostate cancers at their early stages. The performance tests of this camera

  3. Compact CdZnTe-based gamma camera for prostate cancer imaging

    Science.gov (United States)

    Cui, Yonggang; Lall, Terry; Tsui, Benjamin; Yu, Jianhua; Mahler, George; Bolotnikov, Aleksey; Vaska, Paul; De Geronimo, Gianluigi; O'Connor, Paul; Meinken, George; Joyal, John; Barrett, John; Camarda, Giuseppe; Hossain, Anwar; Kim, Ki Hyun; Yang, Ge; Pomper, Marty; Cho, Steve; Weisman, Ken; Seo, Youngho; Babich, John; LaFrance, Norman; James, Ralph B.

    2011-06-01

    In this paper, we discuss the design of a compact gamma camera for high-resolution prostate cancer imaging using Cadmium Zinc Telluride (CdZnTe or CZT) radiation detectors. Prostate cancer is a common disease in men. Nowadays, a blood test measuring the level of prostate specific antigen (PSA) is widely used for screening for the disease in males over 50, followed by (ultrasound) imaging-guided biopsy. However, PSA tests have a high falsepositive rate and ultrasound-guided biopsy has a high likelihood of missing small cancerous tissues. Commercial methods of nuclear medical imaging, e.g. PET and SPECT, can functionally image the organs, and potentially find cancer tissues at early stages, but their applications in diagnosing prostate cancer has been limited by the smallness of the prostate gland and the long working distance between the organ and the detectors comprising these imaging systems. CZT is a semiconductor material with wide band-gap and relatively high electron mobility, and thus can operate at room temperature without additional cooling. CZT detectors are photon-electron direct-conversion devices, thus offering high energy-resolution in detecting gamma rays, enabling energy-resolved imaging, and reducing the background of Compton-scattering events. In addition, CZT material has high stopping power for gamma rays; for medical imaging, a few-mm-thick CZT material provides adequate detection efficiency for many SPECT radiotracers. Because of these advantages, CZT detectors are becoming popular for several SPECT medical-imaging applications. Most recently, we designed a compact gamma camera using CZT detectors coupled to an application-specific-integratedcircuit (ASIC). This camera functions as a trans-rectal probe to image the prostate gland from a distance of only 1-5 cm, thus offering higher detection efficiency and higher spatial resolution. Hence, it potentially can detect prostate cancers at their early stages. The performance tests of this camera

  4. Instrumentation developments for production and characterisation of Inverse Compton Scattering X-rays and first results with a 17 MeV electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Chauchat, A.S., E-mail: anne-sophie.chauchat@cea.f [CEA, DAM, DIF, F-91297 Arpajon (France); Le Flanchec, V.; Negre, J.P.; Binet, A.; Balleyguier, P. [CEA, DAM, DIF, F-91297 Arpajon (France); Brasile, J.P. [THALES Communication, 160 Bd de Valmy, F-92700 Colombes (France); Ortega, J.M. [CLIO/LCP, Batiment 201, Universite Paris-Sud, F-91405 Orsay (France)

    2010-10-01

    An X-ray Compton source is under development at the ELSA facility. The electron beam coming from the ELSA linear accelerator interacts with a laser beam to generate an X-ray flux in the direction of the electron beam. With a 17 MeV electron beam and a 532 nm laser, the resulting X-ray maximal energy is around 11 keV. The beams visualization at the interaction point is achieved via an aluminum retractable bevel-edge with an OTR surface on one side and a slightly roughened surface on the other. Thanks to an optical beamsplitter, beam images are both transmitted to a CCD camera and to a streak camera to manage the spatial and temporal overlap of the bunches. Careful beam management and electron background noise minimization were both required to observe the first Inverse Compton Scattering X-ray profile of this source on radio-luminescent imaging plates.

  5. Evaluating intensified camera systems

    Energy Technology Data Exchange (ETDEWEB)

    S. A. Baker

    2000-07-01

    This paper describes image evaluation techniques used to standardize camera system characterizations. Key areas of performance include resolution, noise, and sensitivity. This team has developed a set of analysis tools, in the form of image processing software used to evaluate camera calibration data, to aid an experimenter in measuring a set of camera performance metrics. These performance metrics identify capabilities and limitations of the camera system, while establishing a means for comparing camera systems. Analysis software is used to evaluate digital camera images recorded with charge-coupled device (CCD) cameras. Several types of intensified camera systems are used in the high-speed imaging field. Electro-optical components are used to provide precise shuttering or optical gain for a camera system. These components including microchannel plate or proximity focused diode image intensifiers, electro-static image tubes, or electron-bombarded CCDs affect system performance. It is important to quantify camera system performance in order to qualify a system as meeting experimental requirements. The camera evaluation tool is designed to provide side-by-side camera comparison and system modeling information.

  6. Adapting Virtual Camera Behaviour

    DEFF Research Database (Denmark)

    Burelli, Paolo

    2013-01-01

    In a three-dimensional virtual environment aspects such as narrative and interaction completely depend on the camera since the camera defines the player’s point of view. Most research works in automatic camera control aim to take the control of this aspect from the player to automatically gen...

  7. Digital Pinhole Camera

    Science.gov (United States)

    Lancor, Rachael; Lancor, Brian

    2014-01-01

    In this article we describe how the classic pinhole camera demonstration can be adapted for use with digital cameras. Students can easily explore the effects of the size of the pinhole and its distance from the sensor on exposure time, magnification, and image quality. Instructions for constructing a digital pinhole camera and our method for…

  8. 搭载摄像功能的数码单反相机在临床医学教学中的应用%Application of Digital Single Lens Reflex Camera with Digital Video Function in Clinical Medical Teaching

    Institute of Scientific and Technical Information of China (English)

    陈敏; 刘珺; 王玲

    2012-01-01

    目的:探讨兼具视频短片拍摄功能的数码单反相机的使用以及动静态影像在临床医疗、诊断以及医学教学中的应用.方法:选择搭载具备摄像功能的高品质数码单反相机如佳能EOS 5DMarkⅡ或EOS 550D等,应用于临床带教的病例及标本等医学影像的拍摄,并针对临床医学摄影的特点辅之相应的基本操作的指导.结果:相对普及型便携式数码相机,搭载具备摄像功能的数码单反相机除了可以拍摄静止医学图像外,还能够拍摄动态的较高质量的短片视频,用以制作医学教学多媒体课件、培训教材或构建网络化的图文工作站等.结论:搭载摄像功能的数码单反相机的应用,提高了临床医师以及带教实习医学生们记录临床病例资料的灵活性以及多样性,丰富了医学影像资料的采录收集,在临床教学中是一个轻便易携带且具备多功能、不可缺少的资料记录工具.%Objective To discuss the usage of digital single lens reflex (DSLR) camera with digital video (DV) function and its static and dynamic images in clinical medicine, teaching and diagnosis. Methods The high quality DSLR camera such as Cannon EOS5DMark Ⅱ or EOS550D was chosen to record video and lake medical photograph, and also some guidance for the basic operation was provided according to the characteristics of clinical medical photography. Results Compared with the simple digital camera, except for taking medical photograph, the DSLR camera with DV function also could record a high quality video or movie which would be used for multi-media, training texts and photography network station and so on. Conclusion It is convenient for doctors and students who study the medicine to apply the DSLR with DV function in clinical medical teaching and diagnosis due to its flexibility and variety on recording the clinical cases and documents. [Chinese Medical Equipment Journal.2012,33(4) :94-95,108

  9. Laser Pulsing in Linear Compton Scattering

    CERN Document Server

    Krafft, Geoffrey; Deitrick, Kirsten; Terzic, Balsa; Kelmar, R; Hodges, Todd; Melnitchouk, W; Delayen, Jean

    2016-01-01

    Previous work on calculating energy spectra from Compton scattering events has either neglected considering the pulsed structure of the incident laser beam, or has calculated these effects in an approximate way subject to criticism. In this paper, this problem has been reconsidered within a linear plane wave model for the incident laser beam. By performing the proper Lorentz transformation of the Klein-Nishina scattering cross section, a spectrum calculation can be created which allows the electron beam energy spread and emittance effects on the spectrum to be accurately calculated, essentially by summing over the emission of each individual electron. Such an approach has the obvious advantage that it is easily integrated with a particle distribution generated by particle tracking, allowing precise calculations of spectra for realistic particle distributions in collision. The method is used to predict the energy spectrum of radiation passing through an aperture for the proposed Old Dominion University inverse...

  10. Compton Radiation for Nuclear Waste Management and Transmutation

    Science.gov (United States)

    Bulyak, E.; Urakawa, J.

    2015-10-01

    Compton inverse radiation is emitted in the process of backscattering of the laser pulses off the relativistic electrons. This radiation possesses high spectral density and high energy of photons--in hard x-ray up to gammaray energy range--with moderate electron energies (hundreds of MeV up to 1 GeV) due to short wavelength of the laser radiation. The Compton radiation is well collimated: emitting within a narrow cone along the electron beam. A distinct property of the Compton inverse radiation is a steep high-energy cutoff of the spectrum and the maximal intensity just below the cutoff. The Compton sources can attain: spectral density up to 1014 gammas/(s 0.1%bandwidth) in MeV range of energies, and spectral brightness up to 1020 gammas/(smm2mr2 0.1% bw). Applicability of Compton sources for nuclear waste management and detection of radioisotopes and fissionable nuclides are discussed in the report. Also application limits of Compton gamma sources for transmutation of radioactive isotopes are estimated. A recently proposed subtracting method, in which two sets of data obtained by irradiating the object by the Compton beams with slightly different maximal energies are compared, will enhance resolution of detection radioactive elements at the 'atomic' (hundreds of keV) and the 'nuclear' (a few MeV) photon energies.

  11. Gravitationally induced electromagnetism at the Compton scale

    Energy Technology Data Exchange (ETDEWEB)

    Rosquist, Kjell [Department of Physics, AlbaNova University Center, Stockholm University, 106 91 Stockholm (Sweden)

    2006-05-07

    It is shown that Einstein gravity tends to modify the electric and magnetic fields appreciably at length scales of the order of the Compton wavelength. At that scale the gravitational field becomes spin dominated rather than mass dominated. The gravitational field couples to the electromagnetic field via the Einstein-Maxwell equations which in the simplest model (Kerr-Newman) causes the electrostatic field of charged spinning particles to acquire an oblate structure relative to the spin direction. For electrons and protons, the Coulomb field is therefore likely to be modified by general relativity at the Compton scale. In the Kerr-Newman model, the magnetic dipole is known to correspond to the Dirac g-factor, g 2. Also, the electric dipole moment vanishes, in agreement with current experimental limits for the electron. Quantitatively, the classical Einstein-Maxwell field represented by the Kerr-Newman solution models the magnetic and electric dipoles of the electron to an accuracy of about one part in 10{sup -3} or better taking into account also the anomalous magnetic moment. Going to the next multipole order, one finds for the Kerr-Newman model that the first non-vanishing higher multipole is the electric quadrupole moment which acquires the value -124 b for the electron. Any non-zero value of the electric quadrupole moment for the electron or the proton would be a clear sign of curvature due to the implied violation of rotation invariance. There is also a possible spherical modification of the Coulomb force proportional to r{sup -4}. However, the size of this effect is well below current experimental limits. The corrections to the hydrogen spectrum are expected to be small but possibly detectable.

  12. Compton Positron Emission Tomography with a Liquid Xenon Time Projection Chamber

    CERN Document Server

    Giboni, K; Doke, T; Suzuki,, S; Fernandes, L M P; Lopes, J A M; Dos Santos, J M F

    2007-01-01

    Most background noise in medical Positron Emission Tomography (PET) imaging originates from photons which Compton scatter before they leave the body of the patient. In only 4% of total events do both photons leave the body un-scattered and are therefore useful for current PET imaging. In an additional 8% of the events one of the photons scatters only once. This class of events can be analyzed correctly with Compton reconstruction. A detector with sufficiently good energy, position, and multiple hit resolution can recognize these events and process them properly. By virtue of recent technological progress, Liquid Xenon Time Projection Chambers (LXeTPCs) match these requirements. A ring of small LXeTPCs can measure the energy with better than 4% FWHM and the position with less than 1 mm RMS. It also has the capability to reconstruct all interaction points. These data are required for Compton imaging. With an improved energy resolution over existing crystal scintillators (LSO/LYSO,BGO and GSO), more of the remai...

  13. Measurement of Compton edge position in low-Z scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Swiderski, Lukasz, E-mail: l.swiderski@ipj.gov.p [Department of Nuclear Detectors and Electronics, Soltan Institute for Nuclear Studies, Otwock-Swierk (Poland); Moszynski, Marek; Czarnacki, Wieslaw; Iwanowska, Joanna; Syntfeld-Kazuch, Agnieszka; Szczesniak, Tomasz [Department of Nuclear Detectors and Electronics, Soltan Institute for Nuclear Studies, Otwock-Swierk (Poland); Pausch, Guntram; Plettner, Cristina; Roemer, Katja [ICx Technologies GmbH, Piepersberg 12, Solingen (Germany)

    2010-03-15

    A method based on a Compton coincidence technique was applied to measure in a wide energy range the position of Compton edge in organic scintillators. The experimental setup comprised a High Purity Germanium (HPGe) detector and a tested scintillator coupled to a PMT. The detectors were set in a face-to-face geometry and the source was placed between them. Thus gating on events backscattered in the tested scintillator and detected in HPGe allowed measuring of Compton edge position for a given {gamma}-ray energy. The presented method provides a valuable tool for energy calibration of low-Z scintillators.

  14. Electronic properties and Compton profiles of silver iodide

    Indian Academy of Sciences (India)

    Alpa Dashora; Ambica Marwal; K R Soni; B L Ahuja

    2010-06-01

    We have carried out an extensive study of electronic properties of silver iodide in - and -phases. The theoretical Compton profiles, energy bands, density of states and anisotropies in momentum densities are computed using density functional theories. We have also employed full-potential linearized augmented plane-wave method to derive the energy bands and the density of states. To compare our theoretical data, isotropic Compton profile measurement on -AgI using 137Cs Compton spectrometer at an intermediate resolution of 0.38 a.u. has been undertaken. The theoretical anisotropies are also interpreted on the basis of energy bands.

  15. A Compton-thick active galactic nucleus powering the hyperluminous infrared galaxy IRAS 00182-7112

    Science.gov (United States)

    Nandra, K.; Iwasawa, K.

    2007-11-01

    We present X-ray observations of the hyperluminous infrared galaxy (HLIRG) IRAS 00182- 7112 obtained using the XMM-Newton EPIC camera. A luminous hard X-ray source coincident with the nucleus is revealed, along with weaker soft X-ray emission which may be extended or offset from the hard emission. The EPIC spectrum is extremely flat and shows Fe Kα emission with very high equivalent width: both are typical characteristics of a buried, Compton-thick active galactic nucleus (AGN) which is seen only in scattered light. Perhaps the most remarkable characteristic of the spectrum is that the Fe Kα line energy is that of He-like iron, making IRAS 00182-7112 the first hidden AGN known to be dominated by ionized, Compton-thick reflection. Taking an appropriate bolometric correction, we find that this AGN could easily dominate the far-infrared (FIR) energetics. The nuclear reflection spectrum is seen through a relatively cold absorber with column density consistent with recent Spitzer observations. The soft X-ray emission, which may be thermal in nature and associated with star-forming activity, is seen unabsorbed. The soft X-rays and weak polycyclic aromatic hydrocarbon features both give estimates of the star formation rate ~300Msolar yr-1, insufficient to power the FIR emission and supportive of the idea that this HLIRG is AGN-dominated.

  16. An optical inverse-Compton hotspot in 3C196?

    CERN Document Server

    Hardcastle, M J

    2001-01-01

    Several hotspots of FRII radio sources have previously been detected in the X-ray at a flux level consistent with the X-rays being due to inverse-Compton scattering of radio synchrotron photons (`synchrotron self-Compton'), if the magnetic fields in the hotspots are close to their equipartition values. However, the number of hotspots compact and bright enough to exhibit detectable X-ray emission is small, so it is worth searching for synchrotron self-Compton emission in the optical, in spite of the obvious observational difficulties of such an approach. In this note I report on a possible detection of an optical inverse-Compton hotspot in a deep Hubble Space Telescope observation of the distant quasar 3C196, at a level which implies a hotspot magnetic field strength close to equipartition if the electrons have a low-energy cutoff around gamma ~ 500.

  17. An optical inverse-Compton hotspot in 3C 196?

    Science.gov (United States)

    Hardcastle, M. J.

    2001-07-01

    Several hotspots of FRII radio sources have previously been detected in the X-ray at a flux level consistent with the X-rays being due to inverse-Compton scattering of radio ``synchrotron photons synchrotron self-Compton'', if the magnetic fields in the hotspots are close to their equipartition values. However, the number of hotspots compact and bright enough to exhibit detectable X-ray emission is small, so it is worth searching for synchrotron self-Compton emission in the optical, in spite of the obvious observational difficulties of such an approach. In this note I report on a possible detection of an optical inverse-Compton hotspot in a deep Hubble Space Telescope observation of the distant quasar 3C 196, at a level which implies a hotspot magnetic field strength close to equipartition if the electrons have a low-energy cutoff around gamma ~ 500.

  18. Investigation of Compton profiles of molecular methane and ethane

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Xiao-Li; Xu, Long-Quan; Kang, Xu; Liu, Ya-Wei; Ni, Dong-Dong; Zhu, Lin-Fan, E-mail: lfzhu@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics,University of Science and Technology of China, Hefei, Anhui 230026 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Yang, Ke, E-mail: yangke@sinap.ac.cn; Ma, Yong-Peng; Yan, Shuai [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204 (China)

    2015-02-28

    The Compton profiles of methane and ethane molecules have been determined at an incident photon energy of 20 keV based on the third generation synchrotron radiation, and the statistical accuracy of 0.2% is achieved near p{sub z} = 0. The density functional theory with aug-cc-pVTZ basis set was used to calculate the Compton profiles of methane and ethane. The present experimental Compton profiles are in better agreement with the theoretical calculations in the whole p{sub z} region than the previous experimental results, which indicates that the present experimental Compton profiles are accurate enough to serve as the benchmark data for methane and ethane molecules.

  19. Compton scatter imaging: A tool for historical exploration

    Energy Technology Data Exchange (ETDEWEB)

    Harding, G. [GE Security Germany GmbH, Heselstuecken 3, D-22453 Hamburg (Germany)], E-mail: Geoffrey.Harding@ge.com; Harding, E. [University of Muenster, Interdisciplinary Research Training Group ' Societal symbolism in mediaeval and early modern times' (German Research Foundation, DFG), Pferdegasse 3/D-48143 Muenster (Germany)

    2010-06-15

    This review discusses the principles and technological realisation of a technique, termed Compton scatter imaging (CSI), which is based on spatially resolved detection of Compton scattered X-rays. The applicational focus of this review is to objects of historical interest. Following a historical survey of CSI, a description is given of the major characteristics of Compton X-ray scatter. In particular back-scattered X-rays allow massive objects to be imaged, which would otherwise be too absorbing for the conventional transmission X-ray technique. The ComScan (an acronym for Compton scatter scanner) is a commercially available backscatter imaging system, which is discussed here in some detail. ComScan images from some artefacts of historical interest, namely a fresco, an Egyptian mummy and a mediaeval clasp are presented and their use in historical analysis is indicated. The utility of scientific and technical advance for not only exploring history, but also restoring it, is briefly discussed.

  20. Design, development, and modeling of a compton camera tomographer based on room temperature solid statepixel detector

    OpenAIRE

    Calderón, Yonatán; Casado, Pilar

    2014-01-01

    Desde el descubrimiento de los rayos X en 1895 y su primera aplicación médica un año después, se han desarrollado diferentes técnicas de imagen médica. La tomografía por emisión es una rama de las imágenes médicas que permite a los médicos realizar un seguimiento de los procesos fisiológicos en el paciente. Un compuesto radiactivo llamado radiotrazador se inyecta en el cuerpo del paciente. La molécula radiotrazador se elige para cumplir una tarea específica en el organismo que permite el segu...

  1. Design, development, and modeling of a compton camera tomographer based on room temperature solid statepixel detector

    OpenAIRE

    Calderón, Yonatán

    2014-01-01

    Desde el descubrimiento de los rayos X en 1895 y su primera aplicación médica un año después, se han desarrollado diferentes técnicas de imagen médica. La tomografía por emisión es una rama de las imágenes médicas que permite a los médicos realizar un seguimiento de los procesos fisiológicos en el paciente. Un compuesto radiactivo llamado radiotrazador se inyecta en el cuerpo del paciente. La molécula radiotrazador se elige para cumplir una tarea específica en el organismo que permite el seg...

  2. Effect of position resolution on LoR discrimination for a dual-head Compton camera

    Science.gov (United States)

    Gillam, John E.; Beveridge, Toby E.; Boston, Andrew J.; Boston, Helen C.; Cooper, Reynold J.; Hall, Chris J.; Mather, Andrew R.; Nolan, Paul J.; Lewis, Rob A.

    2007-04-01

    With the current increase in effective germanium semiconductor detection technology, a positron emission tomography system comprising two opposing HPGe detectors is under development. This type of detection offers not only improvement to some aspects of PET, but also the ability to record single-photon information in the detection process. This information can be used in stand-alone imaging, and also as an additional information source in the PET process. Discrimination based on this single-photon information was proposed; however, the effectiveness of this discrimination is dependent on the resolution of the single-photon information. Simulations of the detection system, in which the positional resolution of the interaction information is variable, was conducted. The single-photon information has then been used in the PET imaging process and its effect on image improvement shown. Much like mechanical collimation, electronic collimation may be used to remove false LoRs from an image, at the expense of efficiency. Moreover, unlike mechanical collimation, this trade off may be dynamically adjusted post data acquisition.

  3. Complete O(. cap alpha. ) corrections to polarized Compton scattering

    Energy Technology Data Exchange (ETDEWEB)

    Gongora-T, A.; Stuart, R.G.

    1989-04-01

    General expressions for Compton scattering and its O(..cap alpha..) real and virtual corrections are given for electron and photon beams with arbitrary polarization. The expressions obtained are suitable for use in Monte Carlo simulations of Compton polarimeters planned for polarized e/sup +/e/sup -/ colliders. The basis for the calculation are the spinor techniques recently applied to photon and gluon bremsstrahlung. The practical application of these techniques for massive fermions is discussed.

  4. Validation of Compton Scattering Monte Carlo Simulation Models

    CERN Document Server

    Weidenspointner, Georg; Hauf, Steffen; Hoff, Gabriela; Kuster, Markus; Pia, Maria Grazia; Saracco, Paolo

    2014-01-01

    Several models for the Monte Carlo simulation of Compton scattering on electrons are quantitatively evaluated with respect to a large collection of experimental data retrieved from the literature. Some of these models are currently implemented in general purpose Monte Carlo systems; some have been implemented and evaluated for possible use in Monte Carlo particle transport for the first time in this study. Here we present first and preliminary results concerning total and differential Compton scattering cross sections.

  5. Timelike Compton Scattering - New Theoretical Results and Experimental Possibilities

    CERN Document Server

    Pire, Bernard; Wagner, Jakub

    2012-01-01

    We review recent progress in the study of timelike Compton scattering (TCS), the crossed process of deeply virtual Compton scattering. We emphasize the need to include NLO corrections to any phenomenological program to extract Generalized Parton Distributions (GPDs) from near future experimental data. We point out that TCS at high energy should be available through a study of ultraperipheral collisions at RHIC and LHC, opening a window on quark and gluon GPDs at very small skewness.

  6. Microchannel plate streak camera

    Science.gov (United States)

    Wang, Ching L.

    1989-01-01

    An improved streak camera in which a microchannel plate electron multiplier is used in place of or in combination with the photocathode used in prior streak cameras. The improved streak camera is far more sensitive to photons (UV to gamma-rays) than the conventional x-ray streak camera which uses a photocathode. The improved streak camera offers gamma-ray detection with high temporal resolution. It also offers low-energy x-ray detection without attenuation inside the cathode. Using the microchannel plate in the improved camera has resulted in a time resolution of about 150 ps, and has provided a sensitivity sufficient for 1000 KeV x-rays.

  7. Solid state video cameras

    CERN Document Server

    Cristol, Y

    2013-01-01

    Solid State Video Cameras reviews the state of the art in the field of solid-state television cameras as compiled from patent literature. Organized into 10 chapters, the book begins with the basic array types of solid-state imagers and appropriate read-out circuits and methods. Documents relating to improvement of picture quality, such as spurious signal suppression, uniformity correction, or resolution enhancement, are also cited. The last part considerssolid-state color cameras.

  8. LSST Camera Optics Design

    Energy Technology Data Exchange (ETDEWEB)

    Riot, V J; Olivier, S; Bauman, B; Pratuch, S; Seppala, L; Gilmore, D; Ku, J; Nordby, M; Foss, M; Antilogus, P; Morgado, N

    2012-05-24

    The Large Synoptic Survey Telescope (LSST) uses a novel, three-mirror, telescope design feeding a camera system that includes a set of broad-band filters and three refractive corrector lenses to produce a flat field at the focal plane with a wide field of view. Optical design of the camera lenses and filters is integrated in with the optical design of telescope mirrors to optimize performance. We discuss the rationale for the LSST camera optics design, describe the methodology for fabricating, coating, mounting and testing the lenses and filters, and present the results of detailed analyses demonstrating that the camera optics will meet their performance goals.

  9. Ringfield lithographic camera

    Science.gov (United States)

    Sweatt, William C.

    1998-01-01

    A projection lithography camera is presented with a wide ringfield optimized so as to make efficient use of extreme ultraviolet radiation from a large area radiation source (e.g., D.sub.source .apprxeq.0.5 mm). The camera comprises four aspheric mirrors optically arranged on a common axis of symmetry with an increased etendue for the camera system. The camera includes an aperture stop that is accessible through a plurality of partial aperture stops to synthesize the theoretical aperture stop. Radiation from a mask is focused to form a reduced image on a wafer, relative to the mask, by reflection from the four aspheric mirrors.

  10. Compton Composites Late in the Early Universe

    Directory of Open Access Journals (Sweden)

    Frederick Mayer

    2014-07-01

    Full Text Available Beginning roughly two hundred years after the big-bang, a tresino phase transition generated Compton-scale composite particles and converted most of the ordinary plasma baryons into new forms of dark matter. Our model consists of ordinary electrons and protons that have been bound into mostly undetectable forms. This picture provides an explanation of the composition and history of ordinary to dark matter conversion starting with, and maintaining, a critical density Universe. The tresino phase transition started the conversion of ordinary matter plasma into tresino-proton pairs prior to the the recombination era. We derive the appropriate Saha–Boltzmann equilibrium to determine the plasma composition throughout the phase transition and later. The baryon population is shown to be quickly modified from ordinary matter plasma prior to the transition to a small amount of ordinary matter and a much larger amount of dark matter after the transition. We describe the tresino phase transition and the origin, quantity and evolution of the dark matter as it takes place from late in the early Universe until the present.

  11. New Compton densitometer for measuring pulmonary edema

    Energy Technology Data Exchange (ETDEWEB)

    Loo, B.W.; Goulding, F.S.; Simon, D.S.

    1985-10-01

    Pulmonary edema is the pathological increase of extravascular lung water found most often in patients with congestive heart failure and other critically ill patients who suffer from intravenous fluid overload. A non-invasive lung density monitor that is accurate, easily portable, safe and inexpensive is needed for clinical evaluation of pulmonary edema. Other researchers who have employed Compton scattering techniques generally used systems of extended size and detectors with poor energy resolution. This has resulted in significant systematic biases from multiply-scattered photons and larger errors in counting statistics at a given radiation dose to the patient. We are proposing a patented approach in which only backscattered photons are measured with a high-resolution HPGe detector in a compact system geometry. By proper design and a unique data extraction scheme, effects of the variable chest wall on lung density measurements are minimized. Preliminary test results indicate that with a radioactive source of under 30 GBq, it should be possible to make an accurate lung density measurement in one minute, with a risk of radiation exposure to the patient a thousand times smaller than that from a typical chest x-ray. The ability to make safe, frequent lung density measurements could be very helpful for monitoring the course of P.E. at the hospital bedside or outpatient clinics, and for evaluating the efficacy of therapy in clinical research. 6 refs., 5 figs.

  12. CCD Luminescence Camera

    Science.gov (United States)

    Janesick, James R.; Elliott, Tom

    1987-01-01

    New diagnostic tool used to understand performance and failures of microelectronic devices. Microscope integrated to low-noise charge-coupled-device (CCD) camera to produce new instrument for analyzing performance and failures of microelectronics devices that emit infrared light during operation. CCD camera also used to indentify very clearly parts that have failed where luminescence typically found.

  13. Camera as Cultural Critique

    DEFF Research Database (Denmark)

    Suhr, Christian

    2015-01-01

    What does the use of cameras entail for the production of cultural critique in anthropology? Visual anthropological analysis and cultural critique starts at the very moment a camera is brought into the field or existing visual images are engaged. The framing, distances, and interactions between...... to establish analysis as a continued, iterative movement of transcultural dialogue and critique....

  14. Camera Operator and Videographer

    Science.gov (United States)

    Moore, Pam

    2007-01-01

    Television, video, and motion picture camera operators produce images that tell a story, inform or entertain an audience, or record an event. They use various cameras to shoot a wide range of material, including television series, news and sporting events, music videos, motion pictures, documentaries, and training sessions. Those who film or…

  15. Virtual compton scattering at low energy; Diffusion compton virtuelle a basse energie

    Energy Technology Data Exchange (ETDEWEB)

    Lhuillier, D

    1997-09-01

    The work described in this PhD is a study of the Virtual Compton scattering (VCS) off the proton at low energy, below pion production threshold. Our experiment has been carried out at MAMI in the collaboration with the help of two high resolution spectrometers. Experimentally, the VCS process is the electroproduction of photons off a liquid hydrogen target. First results of data analysis including radiative corrections are presented and compared with low energy theorem prediction. VCS is an extension of the Real Compton Scattering. The virtuality of the incoming photon allows us to access new observables of the nucleon internal structure which are complementarity to the elastic form factors: the generalized polarizabilities (GP). They are function of the squared invariant mass of the virtual photo. The mass limit of these observables restore the usual electric and magnetic polarizabilities. Our experiment is the first measurement of the VCS process at a virtual photon mass equals 0.33 Ge V square. The experimental development presents the analysis method. The high precision needed in the absolute cross-section measurement required an accurate estimate of radiative corrections to the VCS. This new calculation, which has been performed in the dimensional regulation scheme, composes the theoretical part of this thesis. At low q', preliminary results agree with low energy theorem prediction. At higher q', substraction of low energy theorem contribution to extract GP is discussed. (author)

  16. Thermal Cameras and Applications

    DEFF Research Database (Denmark)

    Gade, Rikke; Moeslund, Thomas B.

    2014-01-01

    Thermal cameras are passive sensors that capture the infrared radiation emitted by all objects with a temperature above absolute zero. This type of camera was originally developed as a surveillance and night vision tool for the military, but recently the price has dropped, significantly opening up...... a broader field of applications. Deploying this type of sensor in vision systems eliminates the illumination problems of normal greyscale and RGB cameras. This survey provides an overview of the current applications of thermal cameras. Applications include animals, agriculture, buildings, gas detection......, industrial, and military applications, as well as detection, tracking, and recognition of humans. Moreover, this survey describes the nature of thermal radiation and the technology of thermal cameras....

  17. Dry imaging cameras

    Directory of Open Access Journals (Sweden)

    I K Indrajit

    2011-01-01

    Full Text Available Dry imaging cameras are important hard copy devices in radiology. Using dry imaging camera, multiformat images of digital modalities in radiology are created from a sealed unit of unexposed films. The functioning of a modern dry camera, involves a blend of concurrent processes, in areas of diverse sciences like computers, mechanics, thermal, optics, electricity and radiography. Broadly, hard copy devices are classified as laser and non laser based technology. When compared with the working knowledge and technical awareness of different modalities in radiology, the understanding of a dry imaging camera is often superficial and neglected. To fill this void, this article outlines the key features of a modern dry camera and its important issues that impact radiology workflow.

  18. Compton spectra of atoms at high x-ray intensity

    Science.gov (United States)

    Son, Sang-Kil; Geffert, Otfried; Santra, Robin

    2017-03-01

    Compton scattering is the nonresonant inelastic scattering of an x-ray photon by an electron and has been used to probe the electron momentum distribution in gas-phase and condensed-matter samples. In the low x-ray intensity regime, Compton scattering from atoms dominantly comes from bound electrons in neutral atoms, neglecting contributions from bound electrons in ions and free (ionized) electrons. In contrast, in the high x-ray intensity regime, the sample experiences severe ionization via x-ray multiphoton multiple ionization dynamics. Thus, it becomes necessary to take into account all the contributions to the Compton scattering signal when atoms are exposed to high-intensity x-ray pulses provided by x-ray free-electron lasers (XFELs). In this paper, we investigate the Compton spectra of atoms at high x-ray intensity, using an extension of the integrated x-ray atomic physics toolkit, xatom. As the x-ray fluence increases, there is a significant contribution from ionized electrons to the Compton spectra, which gives rise to strong deviations from the Compton spectra of neutral atoms. The present study provides not only understanding of the fundamental XFEL-matter interaction but also crucial information for single-particle imaging experiments, where Compton scattering is no longer negligible. , which features invited work from the best early-career researchers working within the scope of J. Phys. B. This project is part of the Journal of Physics series’ 50th anniversary celebrations in 2017. Sang-Kil Son was selected by the Editorial Board of J. Phys. B as an Emerging Leader.

  19. Compact stereo endoscopic camera using microprism arrays.

    Science.gov (United States)

    Yang, Sung-Pyo; Kim, Jae-Jun; Jang, Kyung-Won; Song, Weon-Kook; Jeong, Ki-Hun

    2016-03-15

    This work reports a microprism array (MPA) based compact stereo endoscopic camera with a single image sensor. The MPAs were monolithically fabricated by using two-step photolithography and geometry-guided resist reflow to form an appropriate prism angle for stereo image pair formation. The fabricated MPAs were transferred onto a glass substrate with a UV curable resin replica by using polydimethylsiloxane (PDMS) replica molding and then successfully integrated in front of a single camera module. The stereo endoscopic camera with MPA splits an image into two stereo images and successfully demonstrates the binocular disparities between the stereo image pairs for objects with different distances. This stereo endoscopic camera can serve as a compact and 3D imaging platform for medical, industrial, or military uses.

  20. Vacuum compatible miniature CCD camera head

    Science.gov (United States)

    Conder, Alan D.

    2000-01-01

    A charge-coupled device (CCD) camera head which can replace film for digital imaging of visible light, ultraviolet radiation, and soft to penetrating x-rays, such as within a target chamber where laser produced plasmas are studied. The camera head is small, capable of operating both in and out of a vacuum environment, and is versatile. The CCD camera head uses PC boards with an internal heat sink connected to the chassis for heat dissipation, which allows for close(0.04" for example) stacking of the PC boards. Integration of this CCD camera head into existing instrumentation provides a substantial enhancement of diagnostic capabilities for studying high energy density plasmas, for a variety of military industrial, and medical imaging applications.

  1. Nuclear medical imaging using β+γ coincidences from 44Sc radio-nuclide with liquid xenon as detection medium

    Science.gov (United States)

    Grignon, C.; Barbet, J.; Bardiès, M.; Carlier, T.; Chatal, J. F.; Couturier, O.; Cussonneau, J. P.; Faivre, A.; Ferrer, L.; Girault, S.; Haruyama, T.; Le Ray, P.; Luquin, L.; Lupone, S.; Métivier, V.; Morteau, E.; Servagent, N.; Thers, D.

    2007-02-01

    We report on a new nuclear medical imaging technique based on the measurement of the emitter location in the three dimensions with a few mm spatial resolution using β+γ emitters. Such measurement could be realized thanks to a new kind of radio-nuclides which emit a γ-ray quasi-simultaneously with the β+ decay. The most interesting radio-nuclide candidate, namely 44Sc, will be potentially produced at the Nantes cyclotron ARRONAX. The principle is to reconstruct the intersection of the classical line of response (obtained with a standard PET camera) with the direction cone defined by the third γ-ray. The emission angle measurement of this additional γ-ray involves the use of a Compton telescope for which a new generation of camera based on a liquid xenon (LXe) time projection chamber is considered. GEANT3 simulations of a large acceptance LXe Compton telescope combined with a commercial micro-PET (LSO crystals) have been performed and the obtained results will be presented. They demonstrate that a good image can be obtained from the accumulation of each three-dimensional measured position. A spatial resolution of 2.3 mm has been reached with an injected activity of 0.5 MBq for a 44Sc point source emitter.

  2. Compton Thick AGN in the COSMOS field

    Science.gov (United States)

    Lanzuisi, Giorgio; Cosmos Collaboration

    2015-09-01

    I will present the results we published in a couple of recent papers (Lanzuisi et al. 2015, A&A 573A 137, Lanzuisi et al. 2015, arXiv 1505.01153) on the properties of X-ray selected Compton Thick (CT, NH>10^24 cm^-2) AGN, in the COSMOS survey. We exploited the rich multi-wavelength dataset available in this field, to show that CT AGN tend to harbor smaller, rapidly growing SMBH with respect to unobscured AGN, and have a higher chance of being hosted by star-forming, merging and post-merger systems.We also demonstrated the detectability of even more heavily obscured AGN (NH>10^25 cm^-2), thanks to a truly multi-wavelength approach in the same field. The extreme source detected in this way shows strong evidences of ongoing powerful AGN feedback, detected as blue-shifted wings of high ionization optical emission lines such as [NeV] and [FeVII], as well as of the [OIII] emission line.The results obtained from these works point toward a scenario in which highly obscured AGN occupy a peculiar place in the galaxy-AGN co-evolution process, in which both the host and the SMBH rapidly evolve toward the local relations.We will also present estimates on the detectability of such extreme sources up to redshift ~6-7 with Athena. Combining the most up to date models for the Luminosity Function of CT AGN at high z, aggressive data analysis techniques on faint sources, and the current Athena survey design, we demonstrate that we will detect, and recognize as such, a small (few to ten) but incredibly valuable sample of CT AGN at such high redshift.

  3. Polarization observables in Virtual Compton Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Doria, Luca

    2007-10-15

    Virtual Compton Scattering (VCS) is an important reaction for understanding nucleon structure at low energies. By studying this process, the generalized polarizabilities of the nucleon can be measured. These observables are a generalization of the already known polarizabilities and will permit theoretical models to be challenged on a new level. More specifically, there exist six generalized polarizabilities and in order to disentangle them all, a double polarization experiment must be performed. Within this work, the VCS reaction p(e,e'p){gamma} was measured at MAMI using the A1 Collaboration three spectrometer setup with Q{sup 2}=0.33 (GeV/c){sup 2}. Using the highly polarized MAMI beam and a recoil proton polarimeter, it was possible to measure both the VCS cross section and the double polarization observables. Already in 2000, the unpolarized VCS cross section was measured at MAMI. In this new experiment, we could confirm the old data and furthermore the double polarization observables were measured for the first time. The data were taken in five periods between 2005 and 2006. In this work, the data were analyzed to extract the cross section and the proton polarization. For the analysis, a maximum likelihood algorithm was developed together with the full simulation of all the analysis steps. The experiment is limited by the low statistics due mainly to the focal plane proton polarimeter efficiency. To overcome this problem, a new determination and parameterization of the carbon analyzing power was performed. The main result of the experiment is the extraction of a new combination of the generalized polarizabilities using the double polarization observables. (orig.)

  4. Vision Sensors and Cameras

    Science.gov (United States)

    Hoefflinger, Bernd

    Silicon charge-coupled-device (CCD) imagers have been and are a specialty market ruled by a few companies for decades. Based on CMOS technologies, active-pixel sensors (APS) began to appear in 1990 at the 1 μm technology node. These pixels allow random access, global shutters, and they are compatible with focal-plane imaging systems combining sensing and first-level image processing. The progress towards smaller features and towards ultra-low leakage currents has provided reduced dark currents and μm-size pixels. All chips offer Mega-pixel resolution, and many have very high sensitivities equivalent to ASA 12.800. As a result, HDTV video cameras will become a commodity. Because charge-integration sensors suffer from a limited dynamic range, significant processing effort is spent on multiple exposure and piece-wise analog-digital conversion to reach ranges >10,000:1. The fundamental alternative is log-converting pixels with an eye-like response. This offers a range of almost a million to 1, constant contrast sensitivity and constant colors, important features in professional, technical and medical applications. 3D retino-morphic stacking of sensing and processing on top of each other is being revisited with sub-100 nm CMOS circuits and with TSV technology. With sensor outputs directly on top of neurons, neural focal-plane processing will regain momentum, and new levels of intelligent vision will be achieved. The industry push towards thinned wafers and TSV enables backside-illuminated and other pixels with a 100% fill-factor. 3D vision, which relies on stereo or on time-of-flight, high-speed circuitry, will also benefit from scaled-down CMOS technologies both because of their size as well as their higher speed.

  5. Do Speed Cameras Reduce Collisions?

    OpenAIRE

    Skubic, Jeffrey; Johnson, Steven B.; Salvino, Chris; Vanhoy, Steven; Hu, Chengcheng

    2013-01-01

    We investigated the effects of speed cameras along a 26 mile segment in metropolitan Phoenix, Arizona. Motor vehicle collisions were retrospectively identified according to three time periods – before cameras were placed, while cameras were in place and after cameras were removed. A 14 mile segment in the same area without cameras was used for control purposes. Five cofounding variables were eliminated. In this study, the placement or removal of interstate highway speed cameras did not indepe...

  6. Do speed cameras reduce collisions?

    Science.gov (United States)

    Skubic, Jeffrey; Johnson, Steven B; Salvino, Chris; Vanhoy, Steven; Hu, Chengcheng

    2013-01-01

    We investigated the effects of speed cameras along a 26 mile segment in metropolitan Phoenix, Arizona. Motor vehicle collisions were retrospectively identified according to three time periods - before cameras were placed, while cameras were in place and after cameras were removed. A 14 mile segment in the same area without cameras was used for control purposes. Five cofounding variables were eliminated. In this study, the placement or removal of interstate highway speed cameras did not independently affect the incidence of motor vehicle collisions.

  7. WPOL, a future space Compton wide field polarimeter: Optimization for polarimetry

    Energy Technology Data Exchange (ETDEWEB)

    Khalil, M., E-mail: mkhalil@in2p3.fr [APC Laboratory, 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13 (France); Laurent, P.; Lebrun, F. [APC Laboratory, 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13 (France); CEA, Centre de Saclay, 91191 Gif-Sur-Yvette Cedex (France); Dolgorouky, Y. [APC Laboratory, 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13 (France); Limousin, O. [CEA, Centre de Saclay, 91191 Gif-Sur-Yvette Cedex (France); Bertoli, W.; Breelle, E. [APC Laboratory, 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13 (France)

    2015-07-01

    Polarimetry in the hard X-ray/soft gamma-ray domain (20–1000 keV) is a new area of astrophysics that started to unveil in the past few years, mainly with the ESA/INTEGRAL mission results. Following these pioneering observations, it is appropriate to prepare a new concept which will allow the astronomers to map the X-ray/gamma-ray polarized sources in our Galaxy. WPOL is a wide field polarimeter which aims at monitoring the X-ray and gamma-ray sources and measuring their polarimetric properties. This camera will be used in space to map our Galaxy and also to alert a main instrument in case of transient events such as gamma-ray bursts, black hole binaries state transition, supernovae. It will be proposed, as an accompanying instrument, within the context of the next medium mission ESA call (M4) in January 2015. This concept is based upon coded mask imaging, with a detector unit composed of two layers of Silicon Double Sided Strip Detectors (DSSD) and a tungsten mask. In this article, we will present the key scientific drivers and the instrumental concept for WPOL (imaging technique, energy reconstitution and polarimetric measurements). Then, we will present an optimization of the thickness of the first detection layer performed through MEGALIB Monte-Carlo simulations. Finally, we will present a MEGALIB simulation of WPOL's observation of a source at 100 keV to compute the minimum detectable polarization reached by the instrument. - Highlights: • WPOL will operate in the horizon of 2020 where no other wide field monitor in the 2–200 keV is planned to be operational. • Thickness of the first detection layer in the Compton camera is optimized by using the thickest detector available (2000 μm). • Thickness of the first detection layer in the Compton camera is optimized for polarimetry. • by using the thickest detector available (2000 μm). • The polarization modulation factor of WPOL was found to 8% at 100 keV. • The minimum detectable polarization

  8. Rosseland and flux mean opacities for Compton scattering

    CERN Document Server

    Poutanen, Juri

    2016-01-01

    Rosseland mean opacity plays an important role in theories of stellar evolution and X-ray burst models. In the high-temperature regime, when most of the gas is completely ionized, the opacity is dominated by Compton scattering. Our aim here is to critically evaluate previous works on this subject and to compute exact Rosseland mean opacity for Compton scattering in a broad range of temperatures and electron degeneracy parameter. We use relativistic kinetic equations for Compton scattering and compute the photon mean free path as a function of photon energy by solving the corresponding integral equation in the diffusion limit. As a byproduct we also demonstrate the way to compute photon redistribution functions in case of degenerate electrons. We then compute the Rosseland mean opacity as a function of temperature and electron degeneracy. We compare our results to the previous calculations and find a significant difference in the low-temperature regime and strong degeneracy. We find useful analytical expressio...

  9. Pulsar high energy emission due to inverse Compton scattering

    Energy Technology Data Exchange (ETDEWEB)

    Lyutikov, Maxim

    2013-06-15

    We discuss growing evidence that pulsar high energy is emission is generated via Inverse Compton mechanism. We reproduce the broadband spectrum of Crab pulsar, from UV to very high energy gamma-rays - nearly ten decades in energy, within the framework of the cyclotron-self-Compton model. Emission is produced by two counter-streaming beams within the outer gaps, at distances above ∼ 20 NS radii. The outward moving beam produces UV-X-ray photons via Doppler-booster cyclotron emission, and GeV photons by Compton scattering the cyclotron photons produced by the inward going beam. The scattering occurs in the deep Klein-Nishina regime, whereby the IC component provides a direct measurement of particle distribution within the magnetosphere. The required plasma multiplicity is high, ∼10{sup 6} – 10{sup 7}, but is consistent with the average particle flux injected into the pulsar wind nebula.

  10. Inclusive and Exclusive Compton Processes in Quantum Chromodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Psaker, Ales [Old Dominion Univ., Norfolk, VA (United States)

    2005-12-01

    In our work, we describe two types of Compton processes. As an example of an inclusive process, we consider the high-energy photoproduction of massive muon pairs off the nucleon. We analyze the process in the framework of the QCD parton model, in which the usual parton distributions emerge as a tool to describe the nucleon in terms of quark and gluonic degrees of freedom. To study its exclusive version, a new class of phenomenological functions is required, namely, generalized parton distributions. They can be considered as a generalization of the usual parton distributions measured in deeply inelastic lepton-nucleon scattering. Generalized parton distributions (GPDs) may be observed in hard exclusive reactions such as deeply virtual Compton scattering. We develop an extension of this particular process into the weak interaction sector. We also investigate a possible application of the GPD formalism to wide-angle real Compton scattering.

  11. Electronic structure of CaCO₃: a Compton scattering study.

    Science.gov (United States)

    Mohammed, S F; Mohammad, F M; Sahariya, Jagrati; Mund, H S; Bhamu, K C; Ahuja, B L

    2013-02-01

    In the present work, we have studied electron momentum density of CaCO₃ using a Compton scattering technique. The experiment has been performed using a 100 mCi (241)Am (59.54 keV) Compton spectrometer. The experimental data have been interpreted in terms of theoretical Compton profiles. To compute the theoretical momentum densities, energy bands and density of states, we have used linear combination of atomic orbitals method as embodied in CRYSTAL09 code. We have used local density approximation, generalized gradient approximation (GGA) and second order GGA (SOGGA) within the frame work of density functional theory. It is seen that the GGA gives a better agreement with the experimental data than other approximations. We have also discussed the energy bands and density of states of CaCO₃.

  12. A nonlinear plasma retroreflector for single pulse Compton backscattering

    CERN Document Server

    Palastro, J P; Gordon, D; Hafizi, B; Helle, M; Penano, J; Ting, A

    2014-01-01

    Compton scattered x-rays can be generated using a configuration consisting of a single, ultra-intense laser pulse, and a shaped gas target. The gas target incorporates a hydrodynamically formed density spike, which nonlinearly scatters the incident pump radiation, to produce a counter-propagating electromagnetic wiggler. This self-generated wiggler field Compton scatters from electrons accelerated in the laser wakefield of the pump radiation. The nonlinear scattering mechanism in the density spike is examined theoretically and numerically in order to optimize the Compton scattered radiation. It is found that narrow-band x-rays are produced by moderate intensity pump radiation incident on the quarter-critical surface of the density spike, while high fluence, broadband x-rays are produced by high intensity pump radiation reflected near the critical surface.

  13. Nonlinear single Compton scattering of an electron wave-packet

    CERN Document Server

    Angioi, A; Di Piazza, A

    2016-01-01

    In the presence of a sufficiently intense electromagnetic laser field, an electron can absorb on average a large number of photons from the laser and emit a high-energy one (nonlinear single Compton scattering). The case of nonlinear single Compton scattering by an electron with definite initial momentum has been thoroughly investigated in the literature. Here, we consider a more general initial state of the electron and use a wave-packet obtained as a superposition of Volkov wave functions. In particular, we investigate the energy spectrum of the emitted radiation at fixed observation direction and show that in typical experimental situations the sharply peaked structure of nonlinear single Compton scattering spectra of an electron with definite initial energy is almost completely washed out. Moreover, we show that at comparable uncertainties, the one in the momentum of the incoming electron has a larger impact on the photon spectra at a fixed observation direction than the one on the laser frequency, relate...

  14. Imaging the gamma-ray sky with Compton telescopes

    Energy Technology Data Exchange (ETDEWEB)

    von Ballmoos, P.; Diehl, R.; Schoenfelder, V. (Max-Planck-Institut fuer Physik and Astrophysik, Garching (DE). Inst. fuer. Extraterrestrische Physik); von Ballmoos, P. (New Hampshire Univ., Durham (UK). Space Science Center); von Ballmoos, P. (Toulouse-3 Univ., 31 (FR). Centre d' Etude spatiale des Rayonnements)

    1989-09-01

    Compton telescopes can overcome the difficulties that so far delayed mapping of the low energy gamma ray sky. Since these instruments are ideally matched to the MeV energy range they have a unique potential to produce images of it. However, the multi-coincidence nature of photon detection results in complex data analysis. This paper describes the imaging characteristics of Compton telescopes, and it presents an algorithm for the generation of skymaps which has been successfully applied to data from different Compton telescopes. The algorithm generates maps of likelihood ratios by taking advantage of background symmetries of the instrument and its environment. The resulting skymaps have been found to indicate source positions reliably.

  15. Measurement of radiative Bhabha and quasi-real Compton scattering

    CERN Document Server

    Acciarri, M; Aguilar-Benítez, M; Ahlen, S P; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Baksay, L; Banerjee, S; Banerjee, Sw; Banicz, K; Barczyk, A; Barillère, R; Barone, L; Bartalini, P; Baschirotto, A; Basile, M; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Bhattacharya, S; Biasini, M; Biland, A; Bilei, G M; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böck, R K; Böhm, A; Boldizsar, L; Borgia, B; Bourilkov, D; Bourquin, Maurice; Braccini, S; Branson, J G; Brigljevic, V; Brock, I C; Buffini, A; Buijs, A; Burger, J D; Burger, W J; Busenitz, J K; Cai, X D; Campanelli, M; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada-Canales, M; Cesaroni, F; Chamizo-Llatas, M; Chang, Y H; Chaturvedi, U K; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chéreau, X J; Chiefari, G; Chien, C Y; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Coignet, G; Colijn, A P; Colino, N; Costantini, S; Cotorobai, F; de la Cruz, B; Csilling, Akos; Dai, T S; D'Alessandro, R; De Asmundis, R; Degré, A; Deiters, K; Della Volpe, D; Denes, P; De Notaristefani, F; Diemoz, M; Van Dierendonck, D N; Di Lodovico, F; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dova, M T; Duchesneau, D; Duinker, P; Durán, I; Easo, S; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Ernenwein, J P; Extermann, Pierre; Fabre, M; Faccini, R; Falagán, M A; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Ferguson, T; Ferroni, F; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Fisk, I; Forconi, G; Fredj, L; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gataullin, M; Gau, S S; Gentile, S; Gheordanescu, N; Giagu, S; Goldfarb, S; Goldstein, J; Gong, Z F; Gougas, Andreas; Gratta, Giorgio; Grünewald, M W; van Gulik, R; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hartmann, B; Hasan, A; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hidas, P; Hirschfelder, J; Van Hoek, W C; Hofer, H; Hoorani, H; Hou, S R; Hu, G; Iashvili, I; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Kasser, A; Khan, R A; Kamrad, D; Kapustinsky, J S; Karyotakis, Yu; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, D H; Kim, J K; Kim, S C; Kinnison, W W; Kirkby, A; Kirkby, D; Kirkby, Jasper; Kiss, D; Kittel, E W; Klimentov, A; König, A C; Kopp, A; Korolko, I; Koutsenko, V F; Krämer, R W; Krenz, W; Kunin, A; Lacentre, P E; Ladrón de Guevara, P; Laktineh, I; Landi, G; Lapoint, C; Lassila-Perini, K M; Laurikainen, P; Lavorato, A; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Lee, H J; Le Goff, J M; Leiste, R; Leonardi, E; Levchenko, P M; Li Chuan; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lu, W; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Luminari, L; Lustermann, W; Ma Wen Gan; Maity, M; Majumder, G; Malgeri, L; Malinin, A; Maña, C; Mangeol, D J J; Marchesini, P A; Marian, G; Marin, A; Martin, J P; Marzano, F; Massaro, G G G; Mazumdar, K; McNeil, R R; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Migani, D; Mihul, A; Van Mil, A J W; Milcent, H; Mirabelli, G; Mnich, J; Molnár, P; Monteleoni, B; Moore, R; Moulik, T; Mount, R; Muheim, F; Muijs, A J M; Nahn, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Niessen, T; Nippe, A; Nisati, A; Nowak, H; Oh, Yu D; Organtini, G; Ostonen, R; Palit, S; Palomares, C; Pandoulas, D; Paoletti, S; Paolucci, P; Park, H K; Park, I H; Pascale, G; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Peach, D; Pei, Y J; Pensotti, S; Perret-Gallix, D; Petersen, B; Petrak, S; Pevsner, A; Piccolo, D; Pieri, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Pothier, J; Produit, N; Prokofev, D; Prokofiev, D O; Quartieri, J; Rahal-Callot, G; Raja, N; Rancoita, P G; Rattaggi, M; Raven, G; Razis, P A; Ren, D; Rescigno, M; Reucroft, S; Van Rhee, T; Riemann, S; Riles, K; Robohm, A; Rodin, J; Roe, B P; Romero, L; Rosier-Lees, S; Roth, S; Rubio, Juan Antonio; Ruschmeier, D; Rykaczewski, H; Sakar, S; Salicio, J; Sánchez, E; Sanders, M P; Sarakinos, M E; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Scholz, N; Schopper, Herwig Franz; Schotanus, D J; Schwenke, J; Schwering, G; Sciacca, C; Sciarrino, D; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shukla, J; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Stone, A; Stone, H; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Susinno, G F; Suter, H; Swain, J D; Tang, X W; Tauscher, Ludwig; Taylor, L; Timmermans, C; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tung, K L; Uchida, Y; Ulbricht, J; Valente, E; Vesztergombi, G; Vetlitskii, I; Viertel, Gert M; Vivargent, M; Vlachos, S; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M; Wallraff, W; Wang, J C; Wang, X L; Wang, Z M; Weber, A; Wu, S X; Wynhoff, S; Xu, J; Xu, Z Z; Yang, B Z; Yang, C G; Yang, H J; Yang, M; Ye, J B; Yeh, S C; You, J M; Zalite, A; Zalite, Yu; Zemp, P; Zeng, Y; Zhang, Z P; Zhou, B; Zhu, G Y; Zhu, R Y; Zichichi, Antonino; Ziegler, F; Zilizi, G

    1998-01-01

    We report on a study of radiative Bhabha and quasi-real Compton scattering at centre-of-mass energies between 50~{\\GeV} and 170~{\\GeV} and 20~{\\GeV} and 140~{\\GeV}, respectively, using the L3 detector at LEP. The analysis is based on data corresponding to an integrated luminosity of $232.2 \\,\\pb$. A total of 2856 radiative Bhabha and 4641 Compton scattering events are collected. Total and differential cross sections for both reactions are presented and found to be in good agreement with QED expectations. Our measurement of Compton scattering at the highest energies obtained so far is used to derive exclusion limits on the coupling $\\lambda$ for the on-shell production of an excited electron $\\e^{\\star}$ decaying into a $\\gamma\\e$ pair in the mass range $20 \\gev < m_{\\e^{\\star}} < 170 \\gev$.

  16. GAMCOTE: a prototype for an advanced Compton Telescope

    Science.gov (United States)

    de Séréville, N.; Tatischeff, V.; Laurent, P.; Bertoli, W.; Brulin, G.; Dormard, J.-J.; Dosme, N.; Faul, T.; Genolini, B.; Gibelin, L.; Gostojić, A.; Grave, X.; Hamadache, C.; Karkour, N.; Kiener, J.; Lafay, X.; Legay, E.; Limousin, O.; Linget, D.; Maier, D.; Oger, R.; Peyré, J.; Rauly, E.; Rosier, P.; Santos, C.; Torrentó, A.-S.; Le Ven, V.; Wanlin, E.

    2016-07-01

    Astronomy in the MeV gamma-ray band (0.1 - 100 MeV) holds a rich promise for elucidating many fundamental questions concerning the most violent cosmic phenomena. The next generation of gamma-ray space instrument could be a Compton and pair-creation telescope made of two main parts: a silicon tracker optimized for Compton scattering of cosmic gamma rays and a calorimeter that absorbs the scattered photons. We present here the first results of GAMCOTE, a GAMma-ray COmpton TElescope prototype which includes thick double sided silicon strip detectors coupled to a LaBr3:Ce crystal read by a 64 multi-anode photomultiplier tube.

  17. Advanced CCD camera developments

    Energy Technology Data Exchange (ETDEWEB)

    Condor, A. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    Two charge coupled device (CCD) camera systems are introduced and discussed, describing briefly the hardware involved, and the data obtained in their various applications. The Advanced Development Group Defense Sciences Engineering Division has been actively designing, manufacturing, fielding state-of-the-art CCD camera systems for over a decade. These systems were originally developed for the nuclear test program to record data from underground nuclear tests. Today, new and interesting application for these systems have surfaced and development is continuing in the area of advanced CCD camera systems, with the new CCD camera that will allow experimenters to replace film for x-ray imaging at the JANUS, USP, and NOVA laser facilities.

  18. TARGETLESS CAMERA CALIBRATION

    Directory of Open Access Journals (Sweden)

    L. Barazzetti

    2012-09-01

    Full Text Available In photogrammetry a camera is considered calibrated if its interior orientation parameters are known. These encompass the principal distance, the principal point position and some Additional Parameters used to model possible systematic errors. The current state of the art for automated camera calibration relies on the use of coded targets to accurately determine the image correspondences. This paper presents a new methodology for the efficient and rigorous photogrammetric calibration of digital cameras which does not require any longer the use of targets. A set of images depicting a scene with a good texture are sufficient for the extraction of natural corresponding image points. These are automatically matched with feature-based approaches and robust estimation techniques. The successive photogrammetric bundle adjustment retrieves the unknown camera parameters and their theoretical accuracies. Examples, considerations and comparisons with real data and different case studies are illustrated to show the potentialities of the proposed methodology.

  19. TOUCHSCREEN USING WEB CAMERA

    Directory of Open Access Journals (Sweden)

    Kuntal B. Adak

    2015-10-01

    Full Text Available In this paper we present a web camera based touchscreen system which uses a simple technique to detect and locate finger. We have used a camera and regular screen to achieve our goal. By capturing the video and calculating position of finger on the screen, we can determine the touch position and do some function on that location. Our method is very easy and simple to implement. Even our system requirement is less expensive compare to other techniques.

  20. The Circular Camera Movement

    DEFF Research Database (Denmark)

    Hansen, Lennard Højbjerg

    2014-01-01

    It has been an accepted precept in film theory that specific stylistic features do not express specific content. Nevertheless, it is possible to find many examples in the history of film in which stylistic features do express specific content: for instance, the circular camera movement is used...... such as the circular camera movement. Keywords: embodied perception, embodied style, explicit narration, interpretation, style pattern, television style...

  1. Segment Based Camera Calibration

    Institute of Scientific and Technical Information of China (English)

    马颂德; 魏国庆; 等

    1993-01-01

    The basic idea of calibrating a camera system in previous approaches is to determine camera parmeters by using a set of known 3D points as calibration reference.In this paper,we present a method of camera calibration in whih camera parameters are determined by a set of 3D lines.A set of constraints is derived on camea parameters in terms of perspective line mapping.Form these constraints,the same perspective transformation matrix as that for point mapping can be computed linearly.The minimum number of calibration lines is 6.This result generalizes that of Liu,Huang and Faugeras[12] for camera location determination in which at least 8 line correspondences are required for linear computation of camera location.Since line segments in an image can be located easily and more accurately than points,the use of lines as calibration reference tends to ease the computation in inage preprocessing and to improve calibration accuracy.Experimental results on the calibration along with stereo reconstruction are reported.

  2. Nuclear compton scattering in the delta resonance region

    Energy Technology Data Exchange (ETDEWEB)

    Carrasco, R.C. (Departamento de Tecnologia Informatica y Computacion. Universidad de Alicante. Alicante (Spain))

    1994-01-01

    We develop a model in which the Compton amplitude at intermediate energies is split into a resonant and a background part. The resonant amplitude and the imaginary part of the background amplitude are calculated using microscopic many body methods. The background real part is obtained by subtracting the resonant one to total real amplitude-evaluated by means of a dispersion relation at forward angles. Uncertainties remain on how to extrapolate this forward real background amplitude to backward angles and we study the repercussion of these uncertainties in the Compton cross section. (Author) 30 refs.

  3. Theoretical Compton profile of diamond, boron nitride and carbon nitride

    Science.gov (United States)

    Aguiar, Julio C.; Quevedo, Carlos R.; Gomez, José M.; Di Rocco, Héctor O.

    2017-09-01

    In the present study, we used the generalized gradient approximation method to determine the electron wave functions and theoretical Compton profiles of the following super-hard materials: diamond, boron nitride (h-BN), and carbon nitride in its two known phases: βC3N4 and gC3N4 . In the case of diamond and h-BN, we compared our theoretical results with available experimental data. In addition, we used the Compton profile results to determine cohesive energies and found acceptable agreement with previous experiments.

  4. A simple configuration setup for compton suppression spectroscopy

    CERN Document Server

    Hai, N X; Dien, N N; Tan, V H; Hoa, N D

    2013-01-01

    The fast timing, standard timing and easy timing are popular timing configurations of compton suppression spectroscopy. Such spectroscopes always use a module of coincidence or time-to-amplitude converter (TAC). A compton suppression spectroscopy with semi-timing configuration is presented in this paper. The semi-timing configuration is relatively simple and easy system setup, especially this spectroscopy does not need to use module of coincidence or TAC. The performance of spectroscopy was tested and summarized. The count rate background, full peak efficiency and the ratios of area/background of peaks in suppressed and unsuppressed modes were comparative.

  5. Virtual versus Real Nuclear Compton Scattering in the $\\delta$(1232) region

    CERN Document Server

    Gil, A; Oset, E

    1996-01-01

    In this paper we calculate the cross section for Virtual Compton Scattering off nuclei in the delta resonance region. We also calculate the background for the process from Coherent Bremsstrahlung in nuclei and explore the regions where the Virtual Compton Scattering cross section dominates. The study also shows that it is possible to extract the cross section for Real Compton Scattering from the Virtual Compton one in a wide range of scattering angles.

  6. Virtual versus real nuclear Compton scattering in the {Delta}(1232) region

    Energy Technology Data Exchange (ETDEWEB)

    Gil, A. [Univ. de Valencia, Burjassot (Spain). Dept. de Fisica Teorica; Gomez Tejedor, J.A. [Univ. de Valencia, Burjassot (Spain). Dept. de Fisica Teorica; Oset, E. [Univ. de Valencia, Burjassot (Spain). Dept. de Fisica Teorica

    1997-03-10

    In this paper we calculate the cross section for virtual Compton scattering off nuclei in the delta resonance region. We also calculate the background for the process from coherent bremsstrahlung in nuclei and explore the regions where the virtual Compton scattering cross section dominates. The study also shows that it is possible to extract the cross section for real Compton scattering from the virtual Compton one in a wide range of scattering angles. (orig.).

  7. Uncooled radiometric camera performance

    Science.gov (United States)

    Meyer, Bill; Hoelter, T.

    1998-07-01

    Thermal imaging equipment utilizing microbolometer detectors operating at room temperature has found widespread acceptance in both military and commercial applications. Uncooled camera products are becoming effective solutions to applications currently using traditional, photonic infrared sensors. The reduced power consumption and decreased mechanical complexity offered by uncooled cameras have realized highly reliable, low-cost, hand-held instruments. Initially these instruments displayed only relative temperature differences which limited their usefulness in applications such as Thermography. Radiometrically calibrated microbolometer instruments are now available. The ExplorIR Thermography camera leverages the technology developed for Raytheon Systems Company's first production microbolometer imaging camera, the Sentinel. The ExplorIR camera has a demonstrated temperature measurement accuracy of 4 degrees Celsius or 4% of the measured value (whichever is greater) over scene temperatures ranges of minus 20 degrees Celsius to 300 degrees Celsius (minus 20 degrees Celsius to 900 degrees Celsius for extended range models) and camera environmental temperatures of minus 10 degrees Celsius to 40 degrees Celsius. Direct temperature measurement with high resolution video imaging creates some unique challenges when using uncooled detectors. A temperature controlled, field-of-view limiting aperture (cold shield) is not typically included in the small volume dewars used for uncooled detector packages. The lack of a field-of-view shield allows a significant amount of extraneous radiation from the dewar walls and lens body to affect the sensor operation. In addition, the transmission of the Germanium lens elements is a function of ambient temperature. The ExplorIR camera design compensates for these environmental effects while maintaining the accuracy and dynamic range required by today's predictive maintenance and condition monitoring markets.

  8. Neutron counting with cameras

    Energy Technology Data Exchange (ETDEWEB)

    Van Esch, Patrick; Crisanti, Marta; Mutti, Paolo [Institut Laue Langevin, Grenoble (France)

    2015-07-01

    A research project is presented in which we aim at counting individual neutrons with CCD-like cameras. We explore theoretically a technique that allows us to use imaging detectors as counting detectors at lower counting rates, and transits smoothly to continuous imaging at higher counting rates. As such, the hope is to combine the good background rejection properties of standard neutron counting detectors with the absence of dead time of integrating neutron imaging cameras as well as their very good spatial resolution. Compared to Xray detection, the essence of thermal neutron detection is the nuclear conversion reaction. The released energies involved are of the order of a few MeV, while X-ray detection releases energies of the order of the photon energy, which is in the 10 KeV range. Thanks to advances in camera technology which have resulted in increased quantum efficiency, lower noise, as well as increased frame rate up to 100 fps for CMOS-type cameras, this more than 100-fold higher available detection energy implies that the individual neutron detection light signal can be significantly above the noise level, as such allowing for discrimination and individual counting, which is hard to achieve with X-rays. The time scale of CMOS-type cameras doesn't allow one to consider time-of-flight measurements, but kinetic experiments in the 10 ms range are possible. The theory is next confronted to the first experimental results. (authors)

  9. The Dark Energy Camera

    CERN Document Server

    Flaugher, B; Honscheid, K; Abbott, T M C; Alvarez, O; Angstadt, R; Annis, J T; Antonik, M; Ballester, O; Beaufore, L; Bernstein, G M; Bernstein, R A; Bigelow, B; Bonati, M; Boprie, D; Brooks, D; Buckley-Geer, E J; Campa, J; Cardiel-Sas, L; Castander, F J; Castilla, J; Cease, H; Cela-Ruiz, J M; Chappa, S; Chi, E; Cooper, C; da Costa, L N; Dede, E; Derylo, G; DePoy, D L; de Vicente, J; Doel, P; Drlica-Wagner, A; Eiting, J; Elliott, A E; Emes, J; Estrada, J; Neto, A Fausti; Finley, D A; Flores, R; Frieman, J; Gerdes, D; Gladders, M D; Gregory, B; Gutierrez, G R; Hao, J; Holland, S E; Holm, S; Huffman, D; Jackson, C; James, D J; Jonas, M; Karcher, A; Karliner, I; Kent, S; Kessler, R; Kozlovsky, M; Kron, R G; Kubik, D; Kuehn, K; Kuhlmann, S; Kuk, K; Lahav, O; Lathrop, A; Lee, J; Levi, M E; Lewis, P; Li, T S; Mandrichenko, I; Marshall, J L; Martinez, G; Merritt, K W; Miquel, R; Munoz, F; Neilsen, E H; Nichol, R C; Nord, B; Ogando, R; Olsen, J; Palio, N; Patton, K; Peoples, J; Plazas, A A; Rauch, J; Reil, K; Rheault, J -P; Roe, N A; Rogers, H; Roodman, A; Sanchez, E; Scarpine, V; Schindler, R H; Schmidt, R; Schmitt, R; Schubnell, M; Schultz, K; Schurter, P; Scott, L; Serrano, S; Shaw, T M; Smith, R C; Soares-Santos, M; Stefanik, A; Stuermer, W; Suchyta, E; Sypniewski, A; Tarle, G; Thaler, J; Tighe, R; Tran, C; Tucker, D; Walker, A R; Wang, G; Watson, M; Weaverdyck, C; Wester, W; Woods, R; Yanny, B

    2015-01-01

    The Dark Energy Camera is a new imager with a 2.2-degree diameter field of view mounted at the prime focus of the Victor M. Blanco 4-meter telescope on Cerro Tololo near La Serena, Chile. The camera was designed and constructed by the Dark Energy Survey Collaboration, and meets or exceeds the stringent requirements designed for the wide-field and supernova surveys for which the collaboration uses it. The camera consists of a five element optical corrector, seven filters, a shutter with a 60 cm aperture, and a CCD focal plane of 250 micron thick fully-depleted CCDs cooled inside a vacuum Dewar. The 570 Mpixel focal plane comprises 62 2kx4k CCDs for imaging and 12 2kx2k CCDs for guiding and focus. The CCDs have 15 microns x15 microns pixels with a plate scale of 0.263 arc sec per pixel. A hexapod system provides state-of-the-art focus and alignment capability. The camera is read out in 20 seconds with 6-9 electrons readout noise. This paper provides a technical description of the camera's engineering, construct...

  10. CAOS-CMOS camera.

    Science.gov (United States)

    Riza, Nabeel A; La Torre, Juan Pablo; Amin, M Junaid

    2016-06-13

    Proposed and experimentally demonstrated is the CAOS-CMOS camera design that combines the coded access optical sensor (CAOS) imager platform with the CMOS multi-pixel optical sensor. The unique CAOS-CMOS camera engages the classic CMOS sensor light staring mode with the time-frequency-space agile pixel CAOS imager mode within one programmable optical unit to realize a high dynamic range imager for extreme light contrast conditions. The experimentally demonstrated CAOS-CMOS camera is built using a digital micromirror device, a silicon point-photo-detector with a variable gain amplifier, and a silicon CMOS sensor with a maximum rated 51.3 dB dynamic range. White light imaging of three different brightness simultaneously viewed targets, that is not possible by the CMOS sensor, is achieved by the CAOS-CMOS camera demonstrating an 82.06 dB dynamic range. Applications for the camera include industrial machine vision, welding, laser analysis, automotive, night vision, surveillance and multispectral military systems.

  11. The Dark Energy Camera

    Energy Technology Data Exchange (ETDEWEB)

    Flaugher, B. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States). et al.

    2015-04-11

    The Dark Energy Camera is a new imager with a 2.2-degree diameter field of view mounted at the prime focus of the Victor M. Blanco 4-meter telescope on Cerro Tololo near La Serena, Chile. The camera was designed and constructed by the Dark Energy Survey Collaboration, and meets or exceeds the stringent requirements designed for the wide-field and supernova surveys for which the collaboration uses it. The camera consists of a five element optical corrector, seven filters, a shutter with a 60 cm aperture, and a CCD focal plane of 250-μm thick fully depleted CCDs cooled inside a vacuum Dewar. The 570 Mpixel focal plane comprises 62 2k x 4k CCDs for imaging and 12 2k x 2k CCDs for guiding and focus. The CCDs have 15μm x 15μm pixels with a plate scale of 0.263" per pixel. A hexapod system provides state-of-the-art focus and alignment capability. The camera is read out in 20 seconds with 6-9 electrons readout noise. This paper provides a technical description of the camera's engineering, construction, installation, and current status.

  12. A test of local Lorentz invariance with Compton scattering asymmetry

    Science.gov (United States)

    Mohanmurthy, Prajwal; Narayan, Amrendra; Dutta, Dipangkar

    2016-11-01

    We report on a measurement of the constancy and anisotropy of the speed of light relative to the electrons in photon-electron scattering. We used the Compton scattering asymmetry measured by the new Compton polarimeter in Hall C at Jefferson Lab (JLab) to test for deviations from unity of the vacuum refractive index (n). For photon energies in the range of 9-46 MeV, we obtain a new limit of 1 - n speed of light. These constitute the first study of Lorentz invariance (LI) using Compton asymmetry. Within the minimal Standard Model extension (MSME) framework, our result yield limits on the photon and electron coefficients κ˜0+Y Z, cTX, κ˜0+ZX and cTY. Although these limits are several orders of magnitude larger than the current best limits, they demonstrate the feasibility of using Compton asymmetry for tests of LI. Future parity-violating electron-scattering experiments at JLab will use higher energy electrons enabling better constraints.

  13. Exploring the Dynamics of a Quantum-Mechanical Compton Generator

    Science.gov (United States)

    Kandes, Martin; Carretero, Ricardo

    2017-01-01

    In 1913, when American physicist Arthur Compton was an undergraduate, he invented a simple way to measure the rotation rate of the Earth with a tabletop-sized experiment. The experiment consisted of a large diameter circular ring of thin glass tubing filled with water and oil droplets. After placing the ring in a plane perpendicular to the surface of the Earth and allowing the fluid mixture of oil and water to come to rest, he then abruptly rotated the ring, flipping it 180 degrees about an axis passing through its own plane. The result of the experiment was that the water acquired a measurable drift velocity due to the Coriolis effect arising from the daily rotation of the Earth about its own axis. Compton measured this induced drift velocity by observing the motion of the oil droplets in the water with a microscope. This device, which is now named after him, is known as a Compton generator. The fundamental research objective of this project is to explore the dynamics of a quantum-mechanical analogue to the classical Compton generator experiment through the use of numerical simulations. We present our preliminary results on this system and the future direction of the project. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation Grant Number ACI-1053575.

  14. A test of local Lorentz invariance with Compton scattering asymmetry

    CERN Document Server

    Mohanmurthy, P; Dutta, D

    2016-01-01

    We report on a measurement of the constancy and anisotropy of the speed of light relative to the electrons in photon-electron scattering. We used the Compton scattering asymmetry measured by the new Compton polarimeter in Hall~C at Jefferson Lab to test for deviations from unity of the vacuum refractive index ($n$). For photon energies in the range of 9 - 46 MeV, we obtain a new limit of $1-n < 1.4 \\times 10^{-8}$. In addition, the absence of sidereal variation over the six month period of the measurement constrains any anisotropies in the speed of light. These constitute the first study of Lorentz invariance using Compton asymmetry. Within the minimal standard model extension framework, our result yield limits on the photon and electron coefficients $\\tilde{\\kappa}_{0^+}^{YZ}, c_{TX}, \\tilde{\\kappa}_{0^+}^{ZX}$, and $c_{TY}$. Although, these limits are several orders of magnitude larger than the current best limits, they demonstrate the feasibility of using Compton asymmetry for tests of Lorentz invarianc...

  15. Infrared phenomena in quantum electrodynamics : II. Bremsstrahlung and compton scattering

    NARCIS (Netherlands)

    Haeringen, W. van

    1960-01-01

    The infrared aspects of quantum electrodynamics are discussed by treating two examples of scattering processes, bremsstrahlung and Compton scattering. As in the previous paper one uses a non-covariant diagram technique which gives very clear insight in the cancelling of infrared divergences between

  16. Simple modification of Compton polarimeter to redirect synchrotron radiation

    Directory of Open Access Journals (Sweden)

    J. Benesch

    2015-11-01

    Full Text Available Synchrotron radiation produced as an electron beam passes through a bending magnet is a significant source of background in many experiments. Using modeling, we show that simple modifications of the magnet geometry can reduce this background by orders of magnitude in some circumstances. Specifically, we examine possible modifications of the four dipole magnets used in Jefferson Lab’s Hall A Compton polarimeter chicane. This Compton polarimeter has been a crucial part of experiments with polarized beams and the next generation of experiments will utilize increased beam energies, up to 11 GeV, requiring a corresponding increase in Compton dipole field to 1.5 T. In consequence, the synchrotron radiation (SR from the dipole chicane will be greatly increased. Three possible modifications of the chicane dipoles are studied; each design moves about 2% of the integrated bending field to provide a gentle bend in critical regions along the beam trajectory which, in turn, greatly reduces the synchrotron radiation within the acceptance of the Compton polarimeter photon detector. Each of the modifications studied also softens the SR energy spectrum at the detector sufficiently to allow shielding with 5 mm of lead. Simulations show that these designs are each capable of reducing the background signal due to SR by three orders of magnitude. The three designs considered vary in their need for vacuum vessel changes and in their effectiveness.

  17. All-optical Compton gamma-ray source

    CERN Document Server

    Phuoc, K Ta; Thaury, C; Malka, V; Tafzi, A; Goddet, J P; Shah, R C; Sebban, S; Rousse, A; 10.1038/nphoton.2012.82

    2013-01-01

    One of the major goals of research for laser-plasma accelerators is the realization of compact sources of femtosecond X-rays. In particular, using the modest electron energies obtained with existing laser systems, Compton scattering a photon beam off a relativistic electron bunch has been proposed as a source of high-energy and high-brightness photons. However, laser-plasma based approaches to Compton scattering have not, to date, produced X-rays above 1 keV. Here, we present a simple and compact scheme for a Compton source based on the combination of a laser-plasma accelerator and a plasma mirror. This approach is used to produce a broadband spectrum of X-rays extending up to hundreds of keV and with a 10,000-fold increase in brightness over Compton X-ray sources based on conventional accelerators. We anticipate that this technique will lead to compact, high-repetition-rate sources of ultrafast (femtosecond), tunable (X- through gamma-ray) and low-divergence (~1 degree) photons from source sizes on the order...

  18. Compton scattering as a probe for materials investigation

    Directory of Open Access Journals (Sweden)

    S Mohammadi

    2009-09-01

    Full Text Available This article investigates into the feasibility of using gamma radiation Compton backscatter spectra as a means of material characterization, with the view to developing a portable, hand held probe for investigative purposes such as searching for illicit substances hidden in wall or car door cavities.

  19. Study of Compton Broadening Due to Electron-Photon Scattering

    Directory of Open Access Journals (Sweden)

    Srinivasa Rao, M.

    2010-06-01

    Full Text Available We have investigated the effects of Compton broadening due to electron-photon scattering in hot stellar atmospheres. A purely electron-photon scattering media is assumed to have plane parallel geometry with an input radiation field localized on one side of the slab. The method is based on the discrete space theory of radiative transfer for the intensity of emitted radiation.The solution is developed to study the importance of scattering of radiation by free electrons in high temperature stellar atmospheres which produces a brodening and shift in spectral lines because of the Compton effect and the Doppler effect arising from mass and thermal motions of scattering electrons.It is noticed that the Comptonized spectrum depends on three parameters: the optical depth of the medium, the temperature of the thermal electrons and the viewing angle.We also showed that the Compton effect produces red shift and asymmetry in the line. These two effects increase as the optical depth increases. It is also noticed that the emergent specific intensities become completely asymmetric for higher optical depths.

  20. DEVELOPMENT OF A SPECIAL ANTI-COMPTON SPECTROMETER

    NARCIS (Netherlands)

    MICEK, SL; VERHOEF, BAW; DEVOIGT, MJA; BACELAR, JC; VERPLANCKE, J; SCHOTANUS, P

    1992-01-01

    This paper describes the investigation of the possibility to build a compact anti-Compton spectrometer consisting of a Ge detector and a cooled BGO suppressor. Monte Carlo calculations were carried out to obtain information about the performance of two different detector configurations. Light output

  1. Compton Scattering and Its Applications: The PLEIADES Femtosecond X-ray Source at LLNL

    Energy Technology Data Exchange (ETDEWEB)

    Hartemann, F V; Brown, W J; Anderson, S G; Barty, C P J; Betts, S M; Booth, R; Crane, J K; Cross, R R; Fittinghoff, D N; Gibson, D J; Kuba, J; Rupp, B; Tremaine, A M; Springer, P T

    2003-05-01

    Remarkable developments in critical technologies including terawatt-class lasers using chirped-pulse amplification, high brightness photoinjectors, high-gradient accelerators, and superconducting linacs make it possible to design and operate compact, tunable, subpicosecond Compton scattering x-ray sources with a wide variety of applications. In such novel radiation sources, the collision between a femtosecond laser pulse and a low emittance relativistic electron bunch in a small ({micro}m{sup 3}) interaction volume produces Doppler-upshifted scattered photons with unique characteristics: the energy is tunable in the 5-500 keV range, the angular divergence of the beam is small (mrad), and the pulses are ultrashort (10 fs - 10 ps). Two main paths are currently being followed in laboratories worldwide: high peak brightness, using ultrahigh intensity femtosecond lasers at modest repetition rates, and high average brightness, using superconducting linac and high average power laser technology at MHz repetition rates. Targeted applications range from x-ray protein crystallography and high contrast medical imaging to femtosecond pump-probe and diffraction experiments. More exotic uses of such sources include the {gamma}-{gamma} collider, NIF backlighting, nonlinear Compton scattering, and high-field QED. Theoretical considerations and experimental results will be discussed within this context.

  2. Compton Scattering and its Applications:. the Pleiades Femtosecond X-Ray Source at LLNL

    Science.gov (United States)

    Hartemann, F. V.; Brown, W. J.; Anderson, S. G.; Barty, C. P. J.; Betts, S. M.; Booth, R.; Crane, J. K.; Cross, R. R.; Fittinghoff, D. N.; Gibson, D. J.; Kuba, J.; Rupp, B.; Tremaine, A. M.; Springer, P. T.

    2004-10-01

    Remarkable developments in critical technologies including terawatt-class lasers using chirped-pulse amplification, high brightness photoinjectors, high-gradient accelerators, and superconducting linacs make it possible to design and operate compact, tunable, subpicosecond Compton scattering x-ray sources with a wide variety of applications. In such novel radiation sources, the collision between a femtosecond laser pulse and a low emittance relativistic electron bunch in a small (μm3) interaction volume produces Doppler-upshifted scattered photons with unique characteristics: the energy is tunable in the 5-500 keV range, the angular divergence of the beam is small (mrad), and the pulses are ultrashort (10 fs - 10 ps). Two main paths are currently being followed in laboratories worldwide: high peak brightness, using ultrahigh intensity femtosecond lasers at modest repetition rates, and high average brightness, using superconducting linac and high average power laser technology at MHz repetition rates. Targeted applications range from x-ray protein crystallography and high contrast medical imaging to femtosecond pump-probe and diffraction experiments. More exotic uses of such sources include the γ-γ collider, NIF backlighting, nonlinear Compton scattering, and high-field QED. Theoretical considerations and experimental results will be discussed within this context.

  3. HIGH SPEED CAMERA

    Science.gov (United States)

    Rogers, B.T. Jr.; Davis, W.C.

    1957-12-17

    This patent relates to high speed cameras having resolution times of less than one-tenth microseconds suitable for filming distinct sequences of a very fast event such as an explosion. This camera consists of a rotating mirror with reflecting surfaces on both sides, a narrow mirror acting as a slit in a focal plane shutter, various other mirror and lens systems as well as an innage recording surface. The combination of the rotating mirrors and the slit mirror causes discrete, narrow, separate pictures to fall upon the film plane, thereby forming a moving image increment of the photographed event. Placing a reflecting surface on each side of the rotating mirror cancels the image velocity that one side of the rotating mirror would impart, so as a camera having this short a resolution time is thereby possible.

  4. Automatic Camera Control

    DEFF Research Database (Denmark)

    Burelli, Paolo; Preuss, Mike

    2014-01-01

    Automatically generating computer animations is a challenging and complex problem with applications in games and film production. In this paper, we investigate howto translate a shot list for a virtual scene into a series of virtual camera configurations — i.e automatically controlling the virtual...... camera. We approach this problem by modelling it as a dynamic multi-objective optimisation problem and show how this metaphor allows a much richer expressiveness than a classical single objective approach. Finally, we showcase the application of a multi-objective evolutionary algorithm to generate a shot...

  5. Generating Stereoscopic Television Images With One Camera

    Science.gov (United States)

    Coan, Paul P.

    1996-01-01

    Straightforward technique for generating stereoscopic television images involves use of single television camera translated laterally between left- and right-eye positions. Camera acquires one of images (left- or right-eye image), and video signal from image delayed while camera translated to position where it acquires other image. Length of delay chosen so both images displayed simultaneously or as nearly simultaneously as necessary to obtain stereoscopic effect. Technique amenable to zooming in on small areas within broad scenes. Potential applications include three-dimensional viewing of geological features and meteorological events from spacecraft and aircraft, inspection of workpieces moving along conveyor belts, and aiding ground and water search-and-rescue operations. Also used to generate and display imagery for public education and general information, and possible for medical purposes.

  6. Communities, Cameras, and Conservation

    Science.gov (United States)

    Patterson, Barbara

    2012-01-01

    Communities, Cameras, and Conservation (CCC) is the most exciting and valuable program the author has seen in her 30 years of teaching field science courses. In this citizen science project, students and community volunteers collect data on mountain lions ("Puma concolor") at four natural areas and public parks along the Front Range of Colorado.…

  7. Make a Pinhole Camera

    Science.gov (United States)

    Fisher, Diane K.; Novati, Alexander

    2009-01-01

    On Earth, using ordinary visible light, one can create a single image of light recorded over time. Of course a movie or video is light recorded over time, but it is a series of instantaneous snapshots, rather than light and time both recorded on the same medium. A pinhole camera, which is simple to make out of ordinary materials and using ordinary…

  8. Underwater camera with depth measurement

    Science.gov (United States)

    Wang, Wei-Chih; Lin, Keng-Ren; Tsui, Chi L.; Schipf, David; Leang, Jonathan

    2016-04-01

    The objective of this study is to develop an RGB-D (video + depth) camera that provides three-dimensional image data for use in the haptic feedback of a robotic underwater ordnance recovery system. Two camera systems were developed and studied. The first depth camera relies on structured light (as used by the Microsoft Kinect), where the displacement of an object is determined by variations of the geometry of a projected pattern. The other camera system is based on a Time of Flight (ToF) depth camera. The results of the structural light camera system shows that the camera system requires a stronger light source with a similar operating wavelength and bandwidth to achieve a desirable working distance in water. This approach might not be robust enough for our proposed underwater RGB-D camera system, as it will require a complete re-design of the light source component. The ToF camera system instead, allows an arbitrary placement of light source and camera. The intensity output of the broadband LED light source in the ToF camera system can be increased by putting them into an array configuration and the LEDs can be modulated comfortably with any waveform and frequencies required by the ToF camera. In this paper, both camera were evaluated and experiments were conducted to demonstrate the versatility of the ToF camera.

  9. The PAU Camera

    Science.gov (United States)

    Casas, R.; Ballester, O.; Cardiel-Sas, L.; Carretero, J.; Castander, F. J.; Castilla, J.; Crocce, M.; de Vicente, J.; Delfino, M.; Fernández, E.; Fosalba, P.; García-Bellido, J.; Gaztañaga, E.; Grañena, F.; Jiménez, J.; Madrid, F.; Maiorino, M.; Martí, P.; Miquel, R.; Neissner, C.; Ponce, R.; Sánchez, E.; Serrano, S.; Sevilla, I.; Tonello, N.; Troyano, I.

    2011-11-01

    The PAU Camera (PAUCam) is a wide-field camera designed to be mounted at the William Herschel Telescope (WHT) prime focus, located at the Observatorio del Roque de los Muchachos in the island of La Palma (Canary Islands).Its primary function is to carry out a cosmological survey, the PAU Survey, covering an area of several hundred square degrees of sky. Its purpose is to determine positions and distances using photometric redshift techniques. To achieve accurate photo-z's, PAUCam will be equipped with 40 narrow-band filters covering the range from 450 to850 nm, and six broad-band filters, those of the SDSS system plus the Y band. To fully cover the focal plane delivered by the telescope optics, 18 CCDs 2k x 4k are needed. The pixels are square of 15 μ m size. The optical characteristics of the prime focus corrector deliver a field-of-view where eight of these CCDs will have an illumination of more than 95% covering a field of 40 arc minutes. The rest of the CCDs will occupy the vignetted region extending the field diameter to one degree. Two of the CCDs will be devoted to auto-guiding.This camera have some innovative features. Firstly, both the broad-band and the narrow-band filters will be placed in mobile trays, hosting 16 such filters at most. Those are located inside the cryostat at few millimeters in front of the CCDs when observing. Secondly, a pressurized liquid nitrogen tank outside the camera will feed a boiler inside the cryostat with a controlled massflow. The read-out electronics will use the Monsoon architecture, originally developed by NOAO, modified and manufactured by our team in the frame of the DECam project (the camera used in the DES Survey).PAUCam will also be available to the astronomical community of the WHT.

  10. 21 CFR 892.1620 - Cine or spot fluorographic x-ray camera.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cine or spot fluorographic x-ray camera. 892.1620... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1620 Cine or spot fluorographic x-ray camera. (a) Identification. A cine or spot fluorographic x-ray camera is a device intended to photograph...

  11. Polarisation-based coincidence event discrimination: an in silico study towards a feasible scheme for Compton-PET

    Science.gov (United States)

    Toghyani, M.; Gillam, J. E.; McNamara, A. L.; Kuncic, Z.

    2016-08-01

    Current positron emission tomography (PET) systems use temporally localised coincidence events discriminated by energy and time-of-flight information. The two annihilation photons are in an entangled polarisation state and, in principle, additional information from the polarisation correlation of photon pairs could be used to improve the accuracy of coincidence classification. In a previous study, we demonstrated that in principle, the polarisation correlation information could be transferred to an angular correlation in the distribution of scattered photon pairs in a planar Compton camera system. In the present study, we model a source-phantom-detector system using Geant4 and we develop a coincidence classification scheme that exploits the angular correlation of scattered annihilation quanta to improve the accuracy of coincidence detection. We find a 22% image quality improvement in terms of the peak signal-to-noise ratio when scattered coincidence events are discriminated solely by their angular correlation, thus demonstrating the feasibility of this novel classification scheme. By integrating scatter events (both single-single and single-only) with unscattered coincidence events discriminated using conventional methods, our results suggest that Compton-PET may be a promising candidate for optimal emission tomographic imaging.

  12. Image Sensors Enhance Camera Technologies

    Science.gov (United States)

    2010-01-01

    In the 1990s, a Jet Propulsion Laboratory team led by Eric Fossum researched ways of improving complementary metal-oxide semiconductor (CMOS) image sensors in order to miniaturize cameras on spacecraft while maintaining scientific image quality. Fossum s team founded a company to commercialize the resulting CMOS active pixel sensor. Now called the Aptina Imaging Corporation, based in San Jose, California, the company has shipped over 1 billion sensors for use in applications such as digital cameras, camera phones, Web cameras, and automotive cameras. Today, one of every three cell phone cameras on the planet feature Aptina s sensor technology.

  13. MISR radiometric camera-by-camera Cloud Mask V004

    Data.gov (United States)

    National Aeronautics and Space Administration — This file contains the Radiometric camera-by-camera Cloud Mask dataset. It is used to determine whether a scene is classified as clear or cloudy. A new parameter has...

  14. Feasibility of a novel design of high resolution parallax-free Compton enhanced PET scanner dedicated to brain research

    Energy Technology Data Exchange (ETDEWEB)

    Braem, A [CERN, PH Department, CH-1211 Geneva (Switzerland); Llatas, M Chamizo [Department of Corpuscular and Nuclear Physics, Geneva University, Geneva (Switzerland); Chesi, E [CERN, PH Department, CH-1211 Geneva (Switzerland); Correia, J G [Instituto Tecnologico e Nuclear, Sacavem (Portugal); Garibaldi, F [Instituto Superiore di Sanita, Roma (Italy); Joram, C [CERN, PH Department, CH-1211 Geneva (Switzerland); Mathot, S [CERN, PH Department, CH-1211 Geneva (Switzerland); Nappi, E [INFN, Sezione di Bari, Bari (Italy); Silva, M Ribeiro da [Centro de FIsica Nuclear da Universidade de Lisboa, Lisbon (Portugal); Schoenahl, F [Division of Nuclear Medicine, Geneva University Hospital, CH-1211 Geneva (Switzerland); Seguinot, J [CERN, PH Department, CH-1211 Geneva (Switzerland); Weilhammer, P [CERN, PH Department, CH-1211 Geneva (Switzerland); Zaidi, H [Division of Nuclear Medicine, Geneva University Hospital, CH-1211 Geneva (Switzerland)

    2004-06-21

    A novel concept for a positron emission tomography (PET) camera module is proposed, which provides full 3D reconstruction with high resolution over the total detector volume, free of parallax errors. The key components are a matrix of long scintillator crystals and hybrid photon detectors (HPDs) with matched segmentation and integrated readout electronics. The HPDs read out the two ends of the scintillator package. Both excellent spatial (x, y, z) and energy resolution are obtained. The concept allows enhancing the detection efficiency by reconstructing a significant fraction of events which underwent Compton scattering in the crystals. The proof of concept will first be demonstrated with yttrium orthoaluminate perovskite (YAP):Ce crystals, but the final design will rely on other scintillators more adequate for PET applications (e.g. LSO:Ce or LaBr{sub 3}:Ce). A promising application of the proposed camera module, which is currently under development, is a high resolution 3D brain PET camera with an axial field-of-view of {approx}15 cm dedicated to brain research. The design philosophy and performance predictions based on analytical calculations and Monte Carlo simulations are presented. Image correction and reconstruction tools required to operate this transmissionless device in a research environment are also discussed. Better or similar performance parameters were obtained compared to other known designs at lower fabrication cost. The axial geometrical concept also seems to be promising for applications such as positron emission mammography.

  15. Feasibility of a novel design of high resolution parallax-free Compton enhanced PET scanner dedicated to brain research

    Science.gov (United States)

    Braem, A.; Chamizo Llatas, M.; Chesi, E.; Correia, J. G.; Garibaldi, F.; Joram, C.; Mathot, S.; Nappi, E.; Ribeiro da Silva, M.; Schoenahl, F.; Séguinot, J.; Weilhammer, P.; Zaidi, H.

    2004-06-01

    A novel concept for a positron emission tomography (PET) camera module is proposed, which provides full 3D reconstruction with high resolution over the total detector volume, free of parallax errors. The key components are a matrix of long scintillator crystals and hybrid photon detectors (HPDs) with matched segmentation and integrated readout electronics. The HPDs read out the two ends of the scintillator package. Both excellent spatial (x, y, z) and energy resolution are obtained. The concept allows enhancing the detection efficiency by reconstructing a significant fraction of events which underwent Compton scattering in the crystals. The proof of concept will first be demonstrated with yttrium orthoaluminate perovskite (YAP):Ce crystals, but the final design will rely on other scintillators more adequate for PET applications (e.g. LSO:Ce or LaBr3:Ce). A promising application of the proposed camera module, which is currently under development, is a high resolution 3D brain PET camera with an axial field-of-view of ~15 cm dedicated to brain research. The design philosophy and performance predictions based on analytical calculations and Monte Carlo simulations are presented. Image correction and reconstruction tools required to operate this transmissionless device in a research environment are also discussed. Better or similar performance parameters were obtained compared to other known designs at lower fabrication cost. The axial geometrical concept also seems to be promising for applications such as positron emission mammography. All the authors are members of the CIMA Collaboration.

  16. Feasibility of a novel design of high resolution parallax-free Compton enhanced PET scanner dedicated to brain research

    CERN Document Server

    Braem, André; Chesi, Enrico Guido; Correia, J G; Garibaldi, F; Joram, C; Mathot, S; Nappi, E; Ribeiro da Silva, M; Schoenahl, F; Séguinot, Jacques; Weilhammer, P; Zaidi, H

    2004-01-01

    A novel concept for a positron emission tomography (PET) camera module is proposed, which provides full 3D reconstruction with high resolution over the total detector volume, free of parallax errors. The key components are a matrix of long scintillator crystals and hybrid photon detectors (HPDs) with matched segmentation and integrated readout electronics. The HPDs read out the two ends of the scintillator package. Both excellent spatial (x, y, z) and energy resolution are obtained. The concept allows enhancing the detection efficiency by reconstructing a significant fraction of events which underwent Compton scattering in the crystals. The proof of concept will first be demonstrated with yttrium orthoaluminate perovskite (YAP):Ce crystals, but the final design will rely on other scintillators more adequate for PET applications (e.g. LSO:Ce or LaBr /sub 3/:Ce). A promising application of the proposed camera module, which is currently under development, is a high resolution 3D brain PET camera with an axial fi...

  17. Comparison between electron and neutron Compton scattering studies

    Directory of Open Access Journals (Sweden)

    Moreh Raymond

    2015-01-01

    Full Text Available We compare two techniques: Electron Compton Scattering (ECS and neutron Compton scattering (NCS and show that using certain incident energies, both can measure the atomic kinetic energy of atoms in molecules and solids. The information obtained is related to the Doppler broadening of nuclear levels and is very useful for deducing the widths of excited levels in many nuclei in self absorption measurements. A comparison between the atomic kinetic energies measured by the two methods on the same samples is made. Some results are also compared with calculated atomic kinetic energies obtained using the harmonic approximation where the vibrational frequencies were taken from IR/Raman optical measurements. The advantages of the ECS method are emphasized.

  18. Compton scattering off proton in the third resonance region

    Science.gov (United States)

    Cao, Xu; Lenske, H.

    2017-09-01

    Compton scattering off the proton in the third resonance region is analyzed for the first time, owing to the full combined analysis of pion- and photo-induced reactions in a coupled-channel effective Lagrangian model with K-matrix approximation. Two isospin I = 3 / 2 resonances D33 (1700) and F35 (1930) are found to be essential in the range of 1.6-1.8 GeV. The recent beam asymmetry data of Compton scattering from the GRAAL facility are used to determine the helicity couplings of these resonances, and strong constraints are coming also from πN and KΣ photoproduction data. The possible spin and parity of new narrow resonances is discussed.

  19. Backward Compton Scattering in Strong Uniform Magnetic Field

    CERN Document Server

    Huang, W; Yan, M L; Huang, Wei; Xu, Wang; Yan, Mu-Lin

    2006-01-01

    In strong uniform magnetic field, the vacuum Non-Commutative Plane (NCP) caused by the lowest Landau level(LLL) effect and the QED with NCP (QED-NCP) are studied. Being similar to the theory of Quantum Hall effect, an effective filling factor $f(B)$ is introduced to character the possibility that the electrons stays on LLL. The backward Compton scattering amplitudes of QED-NCP are derived, and the differential cross sections for the process with polarized initial electrons and photons are calculated. The existing Spring-8's data has been analyzed primitively and some hints for QED-NCP effects are shown. We propose to precisely measure the differential cross sections of the backward Compton scattering in perpendicular magnetic field experimentally, which may lead to reveal the effects of QED-NCP. PACS number: 12.20.Ds; 11.10.Nx; 71.70.Di; 73.43.Fj.

  20. Nucleon Polarizabilities: from Compton Scattering to Hydrogen Atom

    CERN Document Server

    Hagelstein, Franziska; Pascalutsa, Vladimir

    2015-01-01

    We review the current state of knowledge of the nucleon polarizabilities and of their role in nucleon Compton scattering and in hydrogen spectrum. We discuss the basic concepts, the recent lattice QCD calculations and advances in chiral effective-field theory. On the experimental side, we review the ongoing programs aimed to measure the nucleon (scalar and spin) polarizabilities via the Compton scattering processes, with real and virtual photons. A great part of the review is devoted to the general constraints based on unitarity, causality, discrete and continuous symmetries, which result in model-independent relations involving nucleon polarizabilities. We (re-)derive a variety of such relations and discuss their empirical value. The proton polarizability effects are presently the major sources of uncertainty in the assessment of the muonic hydrogen Lamb shift and hyperfine structure. Recent calculations of these effects are reviewed here in the context of the "proton-radius puzzle". We conclude with summary...

  1. The role of Compton heating in cluster cooling flows

    CERN Document Server

    Ciotti, L; Pellegrini, S

    2003-01-01

    Recent observations by Chandra and XMM-Newton demonstrate that the central gas in "cooling flow" galaxy clusters has a mass cooling rate that decreases rapidly with decreasing temperature. This contrasts the predictions of a steady state cooling flow model. On the basis of these observational results, the gas can be in a steady state only if a steady temperature dependent heating mechanism is present; alternatively the gas could be in an unsteady state, i.e., heated intermittently. Intermittent heating can be produced by accretion on the supermassive black hole residing in the central cluster galaxy, via Compton heating. This mechanism can be effective provided that the radiation temperature of the emitted spectrum is higher than the gas temperature. Here we explore whether this heating mechanism can be at the origin of the enigmatic behavior of the hot gas in the central regions of ``cooling flow'' clusters. Although several characteristics of Compton heating appear attractive in this respect, we find that t...

  2. Timelike Compton Scattering from JLAB to RHIC and LHC energies

    CERN Document Server

    Pire, B; Wagner, J

    2012-01-01

    Timelike Compton scattering (TCS) i.e. the exclusive photoproduction of a lepton pair with large invariant mass nicely complements the already successful experimental study of deeply virtual Compton scattering (DVCS). The same Generalized Parton Distributions enter both amplitudes, which offer a promissing way to access the quark and gluon nucleon structure. We review recent progress in this domain, emphasizing the fact that analyticity and factorization properties dictate the relation of the NLO corrections to TCS to those of DVCS. We also stress that data on TCS at high energy should be available soon thanks to the proposed experimental program at JLab at 12 GeV, and that, before the future high energy electron ion colliders become reality, the study of ultraperipheral collisions at the RHIC and LHC may open a window on quark and gluon GPDs at very small skewness. .

  3. Modeling the Compton Hump Reverberation Observed in Active Galactic Nuclei

    Science.gov (United States)

    Hoormann, Janie; Beheshtipour, Banafsheh; Krawczynski, Henric

    2016-04-01

    In recent years, observations of the Iron K alpha reverberation in supermassive black holes have provided a new way to probe the inner accretion flow. Furthermore, a time lag between the direct coronal emission and the reprocessed emission forming the Compton Hump in AGN has been observed. In order to model this Compton Hump reverberation we performed general relativistic ray tracing studies of the accretion disk surrounding supermassive black holes, taking into account both the radial and angular dependence of the ionization parameter. We are able to model emission not only from a lamp-post corona but also implementing 3D corona geometries. Using these results we are able to model the observed data to gain additional insight into the geometry of the corona and the structure of the inner accretion disk.

  4. Dual cameras acquisition and display system of retina-like sensor camera and rectangular sensor camera

    Science.gov (United States)

    Cao, Nan; Cao, Fengmei; Lin, Yabin; Bai, Tingzhu; Song, Shengyu

    2015-04-01

    For a new kind of retina-like senor camera and a traditional rectangular sensor camera, dual cameras acquisition and display system need to be built. We introduce the principle and the development of retina-like senor. Image coordinates transformation and interpolation based on sub-pixel interpolation need to be realized for our retina-like sensor's special pixels distribution. The hardware platform is composed of retina-like senor camera, rectangular sensor camera, image grabber and PC. Combined the MIL and OpenCV library, the software program is composed in VC++ on VS 2010. Experience results show that the system can realizes two cameras' acquisition and display.

  5. The electromagnetic calorimeter in JLab Real Compton Scattering Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Albert Shahinyan; Eugene Chudakov; A. Danagoulian; P. Degtyarenko; K. Egiyan; V. Gorbenko; J. Hines; E. Hovhannisyan; Ch. Hyde; C.W. de Jager; A. Ketikyan; V. Mamyan; R. Michaels; A.M. Nathan; V. Nelyubin; I. Rachek; M. Roedelbrom; A. Petrosyan; R. Pomatsalyuk; V. Popov; J. Segal; Yu. Shestakov; J. Templon; H. Voskanyan; B. Wojtsekhowski

    2007-04-16

    A hodoscope calorimeter comprising of 704 lead-glass blocks is described. The calorimeter was constructed for use in the JLab Real Compton Scattering experiment. The detector provides a measurement of the coordinates and the energy of scattered photons in the GeV energy range with resolutions of 5 mm and 6\\%/$\\sqrt{E_\\gamma \\, [GeV]}$, respectively. Design features and performance parameters during the experiment are presented.

  6. Dual color x-rays from Thomson or Compton sources

    Science.gov (United States)

    Petrillo, V.; Bacci, A.; Curatolo, C.; Ferrario, M.; Maroli, C.; Rau, J. V.; Ronsivalle, C.; Serafini, L.; Vaccarezza, C.; Venturelli, M.

    2015-05-01

    We analyze the possibility of producing two color X or γ radiation by Thomson/Compton back-scattering between a high intensity laser pulse and a two-energy level electron beam, constituted by a couple of beamlets separated in time and/or energy obtained by a photoinjector with comb laser techniques and linac velocity bunching. The parameters of the Thomson source at SPARC_LAB have been simulated, proposing a set of values for a realistic experiments.

  7. Dual color x rays from Thomson or Compton sources

    Science.gov (United States)

    Petrillo, V.; Bacci, A.; Curatolo, C.; Ferrario, M.; Gatti, G.; Maroli, C.; Rau, J. V.; Ronsivalle, C.; Serafini, L.; Vaccarezza, C.; Venturelli, M.

    2014-02-01

    We analyze the possibility of producing two-color x or γ radiation by Thomson/Compton backscattering between a high intensity laser pulse and a two-energy level electron beam, constituted by a couple of beamlets separated in time and/or energy obtained by a photoinjector with comb laser techniques and linac velocity bunching. The parameters of the Thomson source at SPARC_LAB have been simulated, proposing a set of realistic experiments.

  8. Timelike Compton scattering off the neutron and generalized parton distributions

    Energy Technology Data Exchange (ETDEWEB)

    Boer, M.; Guidal, M. [CNRS-IN2P3, Universite Paris-Sud, Institut de Physique Nucleaire d' Orsay, Orsay (France); Vanderhaeghen, M. [Johannes Gutenberg Universitaet, Institut fuer Kernphysik and PRISMA Cluster of Excellence, Mainz (Germany)

    2016-02-15

    We study the exclusive photoproduction of an electron-positron pair on a neutron target in the Jefferson Lab energy domain. The reaction consists of two processes: the Bethe-Heitler and the Timelike Compton Scattering. The latter process provides potentially access to the Generalized Parton Distributions (GPDs) of the nucleon. We calculate all the unpolarized, single- and double-spin observables of the reaction and study their sensitivities to GPDs. (orig.)

  9. Timelike Compton scattering off the proton and generalized parton distributions

    Energy Technology Data Exchange (ETDEWEB)

    Boer, M.; Guidal, M. [Universite Paris-Sud, Institut de Physique Nucleaire d' Orsay, CNRS-IN2P3, Orsay (France); Vanderhaeghen, M. [Johannes Gutenberg Universitaet, Institut fuer Kernphysik and PRISMA Cluster of Excellence, Mainz (Germany)

    2015-08-15

    We study the exclusive photoproduction of a lepton pair off the proton with the aim of studying the proton quark structure via the Generalized Parton Distributions (GPD) formalism. After deriving the amplitudes of the processes contributing to the γP → P' e{sup +}e{sup -}, the timelike Compton scattering and the Bethe-Heitler process, we calculate all unpolarized, single- and double- spin beam-target observables in the valence region in terms of GPDs. (orig.)

  10. Photon Polarization in Photonic Crystal Fibers under Compton Scattering

    Institute of Scientific and Technical Information of China (English)

    HAO Dong-shan; ZHANG Xiao-fu

    2007-01-01

    Using the quantum invariant theory and unitary transformation means, we study the influences of multi-photon nonlinear Compton scattering on the photon polarization in photonic crystal fibers(PCF). The results show that the photon polarization of the incident photon changes a lot due to scattered optical, and its general geometric phase factor, Hamiton number and evolution operator are definited both by the incident and scattered optical.

  11. The Compton-Schwarzschild correspondence from extended de Broglie relations

    Energy Technology Data Exchange (ETDEWEB)

    Lake, Matthew J. [The Institute for Fundamental Study, “The Tah Poe Academia Institute' ,Naresuan University, Phitsanulok 65000 (Thailand); Thailand Center of Excellence in Physics, Ministry of Education,Bangkok 10400 (Thailand); Carr, Bernard [School of Physics and Astronomy, Queen Mary University of London,Mile End Road, London E1 4NS (United Kingdom)

    2015-11-17

    The Compton wavelength gives the minimum radius within which the mass of a particle may be localized due to quantum effects, while the Schwarzschild radius gives the maximum radius within which the mass of a black hole may be localized due to classial gravity. In a mass-radius diagram, the two lines intersect near the Planck point (l{sub P},m{sub P}), where quantum gravity effects become significant. Since canonical (non-gravitational) quantum mechanics is based on the concept of wave-particle duality, encapsulated in the de Broglie relations, these relations should break down near (l{sub P},m{sub P}). It is unclear what physical interpretation can be given to quantum particles with energy E≫m{sub P}c{sup 2}, since they correspond to wavelengths λ≪l{sub P} or time periods τ≪t{sub P} in the standard theory. We therefore propose a correction to the standard de Broglie relations, which gives rise to a modified Schrödinger equation and a modified expression for the Compton wavelength, which may be extended into the region E≫m{sub P}c{sup 2}. For the proposed modification, we recover the expression for the Schwarzschild radius for E≫m{sub P}c{sup 2} and the usual Compton formula for E≪m{sub P}c{sup 2}. The sign of the inequality obtained from the uncertainty principle reverses at m≈m{sub P}, so that the Compton wavelength and event horizon size may be interpreted as minimum and maximum radii, respectively. We interpret the additional terms in the modified de Broglie relations as representing the self-gravitation of the wave packet.

  12. Combustion pinhole camera system

    Science.gov (United States)

    Witte, Arvel B.

    1984-02-21

    A pinhole camera system utilizing a sealed optical-purge assembly which provides optical access into a coal combustor or other energy conversion reactors. The camera system basically consists of a focused-purge pinhole optical port assembly, a conventional TV vidicon receiver, an external, variable density light filter which is coupled electronically to the vidicon automatic gain control (agc). The key component of this system is the focused-purge pinhole optical port assembly which utilizes a purging inert gas to keep debris from entering the port and a lens arrangement which transfers the pinhole to the outside of the port assembly. One additional feature of the port assembly is that it is not flush with the interior of the combustor.

  13. Triple-head gamma camera PET: system overview and performance characteristics.

    Science.gov (United States)

    Grosev, D; Loncarić, S; Vandenberghe, S; Dodig, D

    2002-08-01

    Positron emission tomography (PET) is currently performed using either a dedicated PET scanner or scintillation gamma camera equipped with electronic circuitry for coincidence detection of 511 keV annihilation quanta (gamma camera PET system). Although the resolution limits of these two instruments are comparable, the sensitivity and count rate performance of the gamma camera PET system are several times lower than that of the PET scanner. Most gamma camera PET systems are manufactured as dual-detector systems capable of performing dual-head coincidence imaging. One possible step towards the improvement of the sensitivity of the gamma camera PET system is to add another detector head. This work investigates the characteristics of one such triple-head gamma camera PET system capable of performing triple-head coincidence imaging. The following performance characteristics of the system were assessed: spatial resolution, sensitivity, count rate performance. The spatial resolution, expressed as the full width at half-maximum (FWHM), at 1 cm radius is 5.9 mm; at 10 cm radius, the transverse radial resolution is 5.3 mm, whilst the transverse tangential and axial resolutions are 8.9 mm and 13.3 mm, respectively. The sensitivity for a standard cylindrical phantom is 255 counts.s(-1).MBq*(-1)), using a 30% width photopeak energy window. An increase of 35% in the PET sensitivity is achievable by opening an additional 30% width energy window in the Compton region. The count rate in coincidence mode, at the upper limit of the systems optimal performance, is 45 kc.s(-1) (kc=kilocounts) using the photopeak energy window only, and increases to 60 kc.s(-1) using the photopeak + Compton windows. Sensitivity results are compared with published data for a similar dual-head detector system.

  14. Rosseland and Flux Mean Opacities for Compton Scattering

    Science.gov (United States)

    Poutanen, Juri

    2017-02-01

    Rosseland mean opacity plays an important role in theories of stellar evolution and X-ray burst models. In the high-temperature regime, when most of the gas is completely ionized, the opacity is dominated by Compton scattering. Our aim here is to critically evaluate previous works on this subject and to compute the exact Rosseland mean opacity for Compton scattering over a broad range of temperature and electron degeneracy parameter. We use relativistic kinetic equations for Compton scattering and compute the photon mean free path as a function of photon energy by solving the corresponding integral equation in the diffusion limit. As a byproduct we also demonstrate the way to compute photon redistribution functions in the case of degenerate electrons. We then compute the Rosseland mean opacity as a function of temperature and electron degeneracy and present useful approximate expressions. We compare our results to previous calculations and find a significant difference in the low-temperature regime and strong degeneracy. We then proceed to compute the flux mean opacity in both free-streaming and diffusion approximations, and show that the latter is nearly identical to the Rosseland mean opacity. We also provide a simple way to account for the true absorption in evaluating the Rosseland and flux mean opacities.

  15. ILC beam energy measurement by means of laser Compton backscattering

    Energy Technology Data Exchange (ETDEWEB)

    Muchnoi, N. [Budker Inst. for Nuclear Physics, Novosibirsk (Russian Federation); Schreiber, H.J.; Viti, M. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2008-10-15

    A novel, non-invasive method of measuring the beam energy at the International Linear Collider is proposed. Laser light collides head-on with beam particles and either the energy of the Compton scattered electrons near the kinematic end-point is measured or the positions of the Compton backscattered {gamma}-rays, the edge electrons and the unscattered beam particles are recorded. A compact layout for the Compton spectrometer is suggested. It consists of a bending magnet and position sensitive detectors operating in a large radiation environment. Several options for high spatial resolution detectors are discussed. Simulation studies support the use of an infrared or green laser and quartz fiber detectors to monitor the backscattered photons and edge electrons. Employing a cavity monitor, the beam particle position downstream of the magnet can be recorded with submicrometer precision. Such a scheme provides a feasible and promising method to access the incident beam energy with precisions of 10{sup -4} or better on a bunch-to-bunch basis while the electron and positron beams are in collision. (orig.)

  16. Comptonization and QPO Origins in Accreting Neutron Star Systems

    CERN Document Server

    Lee, H C; Lee, Hyong C.; Miller, Guy S.

    1997-01-01

    We develop a simple, time-dependent Comptonization model to probe the origins of spectral variability in accreting neutron star systems. In the model, soft ``seed photons'' are injected into a corona of hot electrons, where they are Compton upscattered before escaping as hard X-rays. The model describes how the hard X-ray spectrum varies when the properties of either the soft photon source or the Comptonizing medium undergo small oscillations. Observations of the resulting spectral modulations can determine whether the variability is due to (i) oscillations in the injection of seed photons, (ii) oscillations in the coronal electron density, or (iii) oscillations in the coronal energy dissipation rate. Identifying the origin of spectral variability should help clarify how the corona operates and its relation to the accretion disk. It will also help in finding the mechanisms underlying the various quasi-periodic oscillations (QPO) observed in the X-ray outputs of many accreting neutron star and black hole syste...

  17. The Compton-Schwarzschild relations in higher dimensions

    CERN Document Server

    Lake, Matthew J

    2016-01-01

    In three spatial dimensions, the Compton wavelength $(R_C \\propto M$) and Schwarzschild radius $(R_S \\propto M^{-1}$) are dual under the transformation $M \\rightarrow M_{P}^2/M$, where $M_{P}$ is the Planck mass. This suggests that there is a fundamental link -- termed the Black Hole Uncertainty Principle or Compton-Schwarzschild correspondence -- between elementary particles in the $M M_{P}$ regime. In the presence of $n$ extra dimensions, compactified on some scale $R_E$, one expects $R_S \\propto M^{1/(1+n)}$ for $R < R_E$, which breaks this duality. However, it may be restored in some circumstances because the effective Compton wavelength depends on the form of the $(3+n)$-dimensional wavefunction. If this is spherically symmetric, then one still has $R_C \\propto M^{-1}$, as in the $3$-dimensional case. The effective Planck length is then increased and the Planck mass reduced, allowing the possibility of TeV quantum gravity and black hole production at the LHC. However, if the wave function is pancaked...

  18. Electronic structure of the palladium hydride studied by compton scattering

    CERN Document Server

    Mizusaki, S; Yamaguchi, M; Hiraoka, N; Itou, M; Sakurai, Y

    2003-01-01

    The hydrogen-induced changes in the electronic structure of Pd have been investigated by Compton scattering experiments associated with theoretical calculations. Compton profiles (CPs) of single crystal of Pd and beta phase hydride PdH sub x (x=0.62-0.74) have been measured along the [100], [110] and [111] directions with a momentum resolution of 0.14-0.17 atomic units using 115 keV x-rays. The theoretical Compton profiles have been calculated from the wavefunctions obtained utilizing the full potential linearized augmented plane wave method within the local density approximation for Pd and stoichiometric PdH. The experimental and the theoretical results agreed well with respect to the difference in the CPs between PdH sub x and Pd, and the anisotropy in the CPs of Pd or PdH sub x. This study provides lines of evidence that upon hydride formation the lowest valance band of Pd is largely modified due to hybridization with H 1s-orbitals and the Fermi energy is raised into the sp-band. (author)

  19. The Star Formation Camera

    CERN Document Server

    Scowen, Paul A; Beasley, Matthew; Calzetti, Daniela; Desch, Steven; Fullerton, Alex; Gallagher, John; Lisman, Doug; Macenka, Steve; Malhotra, Sangeeta; McCaughrean, Mark; Nikzad, Shouleh; O'Connell, Robert; Oey, Sally; Padgett, Deborah; Rhoads, James; Roberge, Aki; Siegmund, Oswald; Shaklan, Stuart; Smith, Nathan; Stern, Daniel; Tumlinson, Jason; Windhorst, Rogier; Woodruff, Robert

    2009-01-01

    The Star Formation Camera (SFC) is a wide-field (~15'x19, >280 arcmin^2), high-resolution (18x18 mas pixels) UV/optical dichroic camera designed for the Theia 4-m space-borne space telescope concept. SFC will deliver diffraction-limited images at lambda > 300 nm in both a blue (190-517nm) and a red (517-1075nm) channel simultaneously. Our aim is to conduct a comprehensive and systematic study of the astrophysical processes and environments relevant for the births and life cycles of stars and their planetary systems, and to investigate and understand the range of environments, feedback mechanisms, and other factors that most affect the outcome of the star and planet formation process. This program addresses the origins and evolution of stars, galaxies, and cosmic structure and has direct relevance for the formation and survival of planetary systems like our Solar System and planets like Earth. We present the design and performance specifications resulting from the implementation study of the camera, conducted ...

  20. Gamma ray camera

    Science.gov (United States)

    Perez-Mendez, V.

    1997-01-21

    A gamma ray camera is disclosed for detecting rays emanating from a radiation source such as an isotope. The gamma ray camera includes a sensor array formed of a visible light crystal for converting incident gamma rays to a plurality of corresponding visible light photons, and a photosensor array responsive to the visible light photons in order to form an electronic image of the radiation therefrom. The photosensor array is adapted to record an integrated amount of charge proportional to the incident gamma rays closest to it, and includes a transparent metallic layer, photodiode consisting of a p-i-n structure formed on one side of the transparent metallic layer, and comprising an upper p-type layer, an intermediate layer and a lower n-type layer. In the preferred mode, the scintillator crystal is composed essentially of a cesium iodide (CsI) crystal preferably doped with a predetermined amount impurity, and the p-type upper intermediate layers and said n-type layer are essentially composed of hydrogenated amorphous silicon (a-Si:H). The gamma ray camera further includes a collimator interposed between the radiation source and the sensor array, and a readout circuit formed on one side of the photosensor array. 6 figs.

  1. Hemispherical Laue camera

    Science.gov (United States)

    Li, James C. M.; Chu, Sungnee G.

    1980-01-01

    A hemispherical Laue camera comprises a crystal sample mount for positioning a sample to be analyzed at the center of sphere of a hemispherical, X-radiation sensitive film cassette, a collimator, a stationary or rotating sample mount and a set of standard spherical projection spheres. X-radiation generated from an external source is directed through the collimator to impinge onto the single crystal sample on the stationary mount. The diffracted beam is recorded on the hemispherical X-radiation sensitive film mounted inside the hemispherical film cassette in either transmission or back-reflection geometry. The distances travelled by X-radiation diffracted from the crystal to the hemispherical film are the same for all crystal planes which satisfy Bragg's Law. The recorded diffraction spots or Laue spots on the film thereby preserve both the symmetry information of the crystal structure and the relative intensities which are directly related to the relative structure factors of the crystal orientations. The diffraction pattern on the exposed film is compared with the known diffraction pattern on one of the standard spherical projection spheres for a specific crystal structure to determine the orientation of the crystal sample. By replacing the stationary sample support with a rotating sample mount, the hemispherical Laue camera can be used for crystal structure determination in a manner previously provided in conventional Debye-Scherrer cameras.

  2. Gamma ray camera

    Science.gov (United States)

    Perez-Mendez, Victor

    1997-01-01

    A gamma ray camera for detecting rays emanating from a radiation source such as an isotope. The gamma ray camera includes a sensor array formed of a visible light crystal for converting incident gamma rays to a plurality of corresponding visible light photons, and a photosensor array responsive to the visible light photons in order to form an electronic image of the radiation therefrom. The photosensor array is adapted to record an integrated amount of charge proportional to the incident gamma rays closest to it, and includes a transparent metallic layer, photodiode consisting of a p-i-n structure formed on one side of the transparent metallic layer, and comprising an upper p-type layer, an intermediate layer and a lower n-type layer. In the preferred mode, the scintillator crystal is composed essentially of a cesium iodide (CsI) crystal preferably doped with a predetermined amount impurity, and the p-type upper intermediate layers and said n-type layer are essentially composed of hydrogenated amorphous silicon (a-Si:H). The gamma ray camera further includes a collimator interposed between the radiation source and the sensor array, and a readout circuit formed on one side of the photosensor array.

  3. First Compton telescope prototype based on continuous LaBr{sub 3}-SiPM detectors

    Energy Technology Data Exchange (ETDEWEB)

    Llosá, G., E-mail: gabriela.llosa@ific.uv.es [Instituto de Física Corpuscular (IFIC-CSIC/UVEG), Valencia (Spain); Cabello, J. [Instituto de Física Corpuscular (IFIC-CSIC/UVEG), Valencia (Spain); Callier, S. [Laboratoire de L' Accélérateur Linéaire, Orsay (France); Gillam, J.E.; Lacasta, C. [Instituto de Física Corpuscular (IFIC-CSIC/UVEG), Valencia (Spain); Rafecas, M. [Instituto de Física Corpuscular (IFIC-CSIC/UVEG), Valencia (Spain); Departamento de Física Atómica, Molecular y Nuclear, Universitat de Valencia, Valencia (Spain); Raux, L. [Laboratoire de L' Accélérateur Linéaire, Orsay (France); Solaz, C.; Stankova, V.; La Taille, C. de; Trovato, M.; Barrio, J. [Instituto de Física Corpuscular (IFIC-CSIC/UVEG), Valencia (Spain)

    2013-08-01

    A first prototype of a Compton camera based on continuous scintillator crystals coupled to silicon photomultiplier (SiPM) arrays has been successfully developed and operated. The prototype is made of two detector planes. The first detector is made of a continuous 16×18×5 mm{sup 3} LaBr{sub 3} crystal coupled to a 16-elements SiPM array. The elements have a size of 3×3 mm {sup 3} in a 4.5×4.05 mm{sup 2} pitch. The second detector, selected by availability, consists of a continuous 16×18×5 mm{sup 3} LYSO crystal coupled to a similar SiPM array. The SPIROC1 ASIC is employed in the readout electronics. Data have been taken with a {sup 22}Na source placed at different positions and images have been reconstructed with the simulated one-pass list-mode (SOPL) algorithm. Detector development for the construction of a second prototype with three detector planes is underway. LaBr{sub 3} crystals of 32×36 mm{sup 2} size and 5/10 mm thickness have been acquired and tested with a PMT. The resolution obtained is 3.5% FWHM at 511 keV. Each crystal will be coupled to four MPPC arrays. Different options are being tested for the prototype readout.

  4. Final state interaction and temperature effects in Compton scattering from lithium

    CERN Document Server

    Sternemann, C

    2000-01-01

    of the valence electron Compton profile with increasing temperature. The Compton profile measured at 95 K is above the room temperature profile around the Fermi momentum and below at the Compton peak. No temperature dependence of the core electron contribution to the Compton profile is detected. The temperature effect is confronted with a temperature dependent jellium calculation and with computations utilizing an empirical local pseudopotential, where in the pseudopotential calculation the influence of temperature is considered via the Debye-Waller factor. With respect to the calculations the temperature effect is attributed to the lattice expansion and to the diminishing of the high momentum component contribution to the Compton profile with increasing temperature. This thesis presents measurements of lithium Compton profiles with an incident energy around 9 keV and a momentum space resolution of 0.02 a.u. to investigate the effect of final state interaction and thus to test the validity of the impulse appr...

  5. A magnetic Compton scattering study of NpNiGa{sub 5}

    Energy Technology Data Exchange (ETDEWEB)

    Tsutsui, S. [Japan Synchrotron Radiation Research Institute, SPring-8, Mikazuki, Hyogo 679-5198 (Japan)]. E-mail: satoshi@spring8.or.jp; Sakurai, Y. [Japan Synchrotron Radiation Research Institute, SPring-8, Mikazuki, Hyogo 679-5198 (Japan); Itou, M. [Japan Synchrotron Radiation Research Institute, SPring-8, Mikazuki, Hyogo 679-5198 (Japan); Aoki, D. [Institute for Materials Science, Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Yamamoto, E. [Advanced Science Research Center, Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195 (Japan); Homma, Y. [Institute for Materials Science, Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Haga, Y. [Advanced Science Research Center, Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195 (Japan); Nakamura, A. [Advanced Science Research Center, Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195 (Japan); Shiokawa, Y. [Institute for Materials Science, Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Onuki, Y. [Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan)

    2006-05-01

    We have performed the first magnetic Compton scattering study of a transuranium compound, NpNiGa{sub 5}. We have measured magnetic Compton profiles in two magnetic ordered phases of this compound. The magnetic Compton profiles in both ordered phases indicate that ferromagnetic components exist in the ordered phases. The signs of the magnetic effects suggest that the contribution of the 5f electrons of Np atoms is dominant to the total spin moments in the ordered phases.

  6. Design and Modeling of a Compton-Suppressed Phoswich Detector for Radioxenon Monitoring

    Science.gov (United States)

    2010-09-01

    modeled using MCNPX Version 2.5.0. The Compton suppression mechanism is integrated into the phoswich design to effectively reduce the Compton continuum...background radiation was modeled using MCNPX Version 2.5.0. The Compton suppression mechanism is integrated into the phoswich design to effectively reduce...be calculated through regions of interest corresponding to the four xenon radioisotopes in the 2D spectrum. An alternative solution to measure

  7. Adaptive compressive sensing camera

    Science.gov (United States)

    Hsu, Charles; Hsu, Ming K.; Cha, Jae; Iwamura, Tomo; Landa, Joseph; Nguyen, Charles; Szu, Harold

    2013-05-01

    We have embedded Adaptive Compressive Sensing (ACS) algorithm on Charge-Coupled-Device (CCD) camera based on the simplest concept that each pixel is a charge bucket, and the charges comes from Einstein photoelectric conversion effect. Applying the manufactory design principle, we only allow altering each working component at a minimum one step. We then simulated what would be such a camera can do for real world persistent surveillance taking into account of diurnal, all weather, and seasonal variations. The data storage has saved immensely, and the order of magnitude of saving is inversely proportional to target angular speed. We did design two new components of CCD camera. Due to the matured CMOS (Complementary metal-oxide-semiconductor) technology, the on-chip Sample and Hold (SAH) circuitry can be designed for a dual Photon Detector (PD) analog circuitry for changedetection that predicts skipping or going forward at a sufficient sampling frame rate. For an admitted frame, there is a purely random sparse matrix [Φ] which is implemented at each bucket pixel level the charge transport bias voltage toward its neighborhood buckets or not, and if not, it goes to the ground drainage. Since the snapshot image is not a video, we could not apply the usual MPEG video compression and Hoffman entropy codec as well as powerful WaveNet Wrapper on sensor level. We shall compare (i) Pre-Processing FFT and a threshold of significant Fourier mode components and inverse FFT to check PSNR; (ii) Post-Processing image recovery will be selectively done by CDT&D adaptive version of linear programming at L1 minimization and L2 similarity. For (ii) we need to determine in new frames selection by SAH circuitry (i) the degree of information (d.o.i) K(t) dictates the purely random linear sparse combination of measurement data a la [Φ]M,N M(t) = K(t) Log N(t).

  8. Optical follow-up observations of Locburst GRB locations with OMC test camera

    Science.gov (United States)

    Rezek, Tomás

    1999-01-01

    The test camera of the Optical Monitoring Camera (OMC) experiment for INTEGRAL spacecraft achieving the angular pixel size of 18 arcsec and the field of view 7.5 degx5.1 deg has been succesfully developed and tested at the Astronomical Institute Ondrejov. The test camera is able to provide imaging down to 15 mag over the whole field of view within one exposure of 300 seconds. Although developed primarily to test the OMC performance and help with software development, this device is ideally suitable for the use as ground-based camera for the sites where Compton Gamma-Ray Observatory BATSE Locburst triggers are followed-up in optical waveband and also for widefield sky monitoring in general. The low cost of this camera makes it possible to duplicate the system to a number of observing sites. A chart and a corresponding CCD-image for the BACODINE Locburst Position 6368 taken with OMC test camera at Ondrejov observatory are also presented. The image taken 18 hours after the trigger was computer-blinked with the frame taken 30 days later. No optical activity has been found down to 13.5 mag.

  9. Digital camera in ophthalmology

    Directory of Open Access Journals (Sweden)

    Ashish Mitra

    2015-01-01

    Full Text Available Ophthalmology is an expensive field and imaging is an indispensable modality in ophthalmology; and in developing countries including India, it is not possible for every ophthalmologist to afford slit-lamp photography unit. We here present our experience of slit-lamp photography using digital camera. Good quality pictures of anterior and posterior segment disorders were captured using readily available devices. It can be a used as a good teaching tool for residents learning ophthalmology and can also be a method to document lesions which at many times is necessary for medicolegal purposes. It's a technique which is simple, inexpensive, and has a short learning curve.

  10. Observed inter-camera variability of clinically relevant performance characteristics for Siemens Symbia gamma cameras.

    Science.gov (United States)

    Kappadath, S Cheenu; Erwin, William D; Wendt, Richard E

    2006-11-28

    We conducted an evaluation of the intercamera (i.e., between cameras) variability in clinically relevant performance characteristics for Symbia gamma cameras (Siemens Medical Solutions, Malvern, PA) based on measurements made using nine separate systems. The significance of the observed intercamera variability was determined by comparing it to the intracamera (i.e., within a single camera) variability. Measurements of performance characteristics were based on the standards of the National Electrical Manufacturers Association and reports 6, 9, 22, and 52 from the American Association of Physicists in Medicine. All measurements were performed using 99mTc (except 57Co used for extrinsic resolution) and low-energy, high-resolution collimation. Of the nine cameras, four have crystals 3/8 in. thick and five have crystals 5/8 in. thick. We evaluated intrinsic energy resolution, intrinsic and extrinsic spatial resolution, intrinsic integral and differential flood uniformity over the useful field-of-view, count rate at 20% count loss, planar sensitivity, single-photon emission computed tomography (SPECT) resolution, and SPECT integral uniformity. The intracamera variability was estimated by repeated measurements of the performance characteristics on a single system. The significance of the observed intercamera variability was evaluated using the two-tailed F distribution. The planar sensitivity of the gamma cameras tested was found be variable at the 99.8% confidence level for both the 3/8-in. and 5/8-in. crystal systems. The integral uniformity and energy resolution were found to be variable only for the 5/8-in. crystal systems at the 98% and 90% confidence level, respectively. All other performance characteristics tested exhibited no significant variability between camera systems. The measured variability reported here could perhaps be used to define nominal performance values of Symbia gamma cameras for planar and SPECT imaging.

  11. Mars Science Laboratory Engineering Cameras

    Science.gov (United States)

    Maki, Justin N.; Thiessen, David L.; Pourangi, Ali M.; Kobzeff, Peter A.; Lee, Steven W.; Dingizian, Arsham; Schwochert, Mark A.

    2012-01-01

    NASA's Mars Science Laboratory (MSL) Rover, which launched to Mars in 2011, is equipped with a set of 12 engineering cameras. These cameras are build-to-print copies of the Mars Exploration Rover (MER) cameras, which were sent to Mars in 2003. The engineering cameras weigh less than 300 grams each and use less than 3 W of power. Images returned from the engineering cameras are used to navigate the rover on the Martian surface, deploy the rover robotic arm, and ingest samples into the rover sample processing system. The navigation cameras (Navcams) are mounted to a pan/tilt mast and have a 45-degree square field of view (FOV) with a pixel scale of 0.82 mrad/pixel. The hazard avoidance cameras (Haz - cams) are body-mounted to the rover chassis in the front and rear of the vehicle and have a 124-degree square FOV with a pixel scale of 2.1 mrad/pixel. All of the cameras utilize a frame-transfer CCD (charge-coupled device) with a 1024x1024 imaging region and red/near IR bandpass filters centered at 650 nm. The MSL engineering cameras are grouped into two sets of six: one set of cameras is connected to rover computer A and the other set is connected to rover computer B. The MSL rover carries 8 Hazcams and 4 Navcams.

  12. HONEY -- The Honeywell Camera

    Science.gov (United States)

    Clayton, C. A.; Wilkins, T. N.

    The Honeywell model 3000 colour graphic recorder system (hereafter referred to simply as Honeywell) has been bought by Starlink for producing publishable quality photographic hardcopy from the IKON image displays. Full colour and black & white images can be recorded on positive or negative 35mm film. The Honeywell consists of a built-in high resolution flat-faced monochrome video monitor, a red/green/blue colour filter mechanism and a 35mm camera. The device works on the direct video signals from the IKON. This means that changing the brightness or contrast on the IKON monitor will not affect any photographs that you take. The video signals from the IKON consist of separate red, green and blue signals. When you take a picture, the Honeywell takes the red, green and blue signals in turn and displays three pictures consecutively on its internal monitor. It takes an exposure through each of three filters (red, green and blue) onto the film in the camera. This builds up the complete colour picture on the film. Honeywell systems are installed at nine Starlink sites, namely Belfast (locally funded), Birmingham, Cambridge, Durham, Leicester, Manchester, Rutherford, ROE and UCL.

  13. Stereoscopic camera design

    Science.gov (United States)

    Montgomery, David J.; Jones, Christopher K.; Stewart, James N.; Smith, Alan

    2002-05-01

    It is clear from the literature that the majority of work in stereoscopic imaging is directed towards the development of modern stereoscopic displays. As costs come down, wider public interest in this technology is expected to increase. This new technology would require new methods of image formation. Advances in stereo computer graphics will of course lead to the creation of new stereo computer games, graphics in films etc. However, the consumer would also like to see real-world stereoscopic images, pictures of family, holiday snaps etc. Such scenery would have wide ranges of depth to accommodate and would need also to cope with moving objects, such as cars, and in particular other people. Thus, the consumer acceptance of auto/stereoscopic displays and 3D in general would be greatly enhanced by the existence of a quality stereoscopic camera. This paper will cover an analysis of existing stereoscopic camera designs and show that they can be categorized into four different types, with inherent advantages and disadvantages. A recommendation is then made with regard to 3D consumer still and video photography. The paper will go on to discuss this recommendation and describe its advantages and how it can be realized in practice.

  14. PAU camera: detectors characterization

    Science.gov (United States)

    Casas, Ricard; Ballester, Otger; Cardiel-Sas, Laia; Castilla, Javier; Jiménez, Jorge; Maiorino, Marino; Pío, Cristóbal; Sevilla, Ignacio; de Vicente, Juan

    2012-07-01

    The PAU Camera (PAUCam) [1,2] is a wide field camera that will be mounted at the corrected prime focus of the William Herschel Telescope (Observatorio del Roque de los Muchachos, Canary Islands, Spain) in the next months. The focal plane of PAUCam is composed by a mosaic of 18 CCD detectors of 2,048 x 4,176 pixels each one with a pixel size of 15 microns, manufactured by Hamamatsu Photonics K. K. This mosaic covers a field of view (FoV) of 60 arcmin (minutes of arc), 40 of them are unvignetted. The behaviour of these 18 devices, plus four spares, and their electronic response should be characterized and optimized for the use in PAUCam. This job is being carried out in the laboratories of the ICE/IFAE and the CIEMAT. The electronic optimization of the CCD detectors is being carried out by means of an OG (Output Gate) scan and maximizing it CTE (Charge Transfer Efficiency) while the read-out noise is minimized. The device characterization itself is obtained with different tests. The photon transfer curve (PTC) that allows to obtain the electronic gain, the linearity vs. light stimulus, the full-well capacity and the cosmetic defects. The read-out noise, the dark current, the stability vs. temperature and the light remanence.

  15. Testing of the BGO Compton-suppression detectors for gammasphere

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, M.P.; Ahmad, I.; Annan, G.A. [and others

    1995-08-01

    Gammasphere, the national {gamma}-ray facility, when completed will consist of 110 Compton-suppressed Ge detectors. The bismuth germanate (BGO) Compton-suppression detector system for each Ge detector consists of one tapered hexagonal BGO side shield and one slotted BGO back plug. Due to the geometry of the array, three types of annular shields are required. These types are referred to as B, C and D, and the array consists of 60, 30 and 20 of these units, respectively. Shield types B, C and D have a hexagonal geometry. They are divided into six optically separate sections, each with its own pair of photomultiplier tubes. Argonne assumed responsibility for the procurement and testing of the BGO Compton-suppression units. We received all detectors from the two vendors. In the past year, twenty-four of the B-type detectors were delivered to Stony Brook for evaluation tests. Since the number of crystals to test is quite large (six per detector), we involved undergraduate students working at ANL under the Department of Educational Programs (DEP) in this effort. The quality of students was excellent, and they played a major role in the performance testing of these detectors. Ninety-nine of the hexagonal side shields and 112 backplug detectors were shipped to LBL for use in Gammasphere. The remaining detectors did not meet the performance criteria when they were first delivered and tested and are either at the vendor being repaired or were returned to us for retesting. We anticipate that the remaining detectors will be ready for use in Gammasphere within the next few months.

  16. External inverse-Compton emission from jetted tidal disruption events

    Science.gov (United States)

    Lu, Wenbin; Kumar, Pawan

    2016-05-01

    The recent discoveries of Sw J1644+57 and Sw J2058+05 show that tidal disruption events (TDEs) can launch relativistic jets. Super-Eddington accretion produces a strong radiation field of order Eddington luminosity. In a jetted TDE, electrons in the jet will inverse-Compton scatter the photons from the accretion disc and wind (external radiation field). Motivated by observations of thermal optical-UV spectra in Sw J2058+05 and several other TDEs, we assume the spectrum of the external radiation field intercepted by the relativistic jet to be blackbody. Hot electrons in the jet scatter this thermal radiation and produce luminosities 1045-1048 erg s- 1 in the X/γ-ray band. This model of thermal plus inverse-Compton radiation is applied to Sw J2058+05. First, we show that the blackbody component in the optical-UV spectrum most likely has its origin in the super-Eddington wind from the disc. Then, using the observed blackbody component as the external radiation field, we show that the X-ray luminosity and spectrum are consistent with the inverse-Compton emission, under the following conditions: (1) the jet Lorentz factor is Γ ≃ 5-10; (2) electrons in the jet have a power-law distribution dN_e/dγ _e ∝ γ _e^{-p} with γmin ˜ 1 and p = 2.4; (3) the wind is mildly relativistic (Lorentz factor ≳ 1.5) and has isotropic-equivalent mass-loss rate ˜ 5 M⊙ yr- 1. We describe the implications for jet composition and the radius where jet energy is converted to radiation.

  17. Polarization of final electrons in the Compton effect

    Energy Technology Data Exchange (ETDEWEB)

    Kotkin, G.L.; Polityko, S.I.; Serbo, V.G. [Novosibirskij Gosudarstvennyj Univ. (Russian Federation)

    1998-03-01

    A final electron polarization is calculated for scattering of a polarized photon by a polarized electron. The electron polarization is obtained in terms of the electron helicity and the transverse polarization vector in an arbitrary frame of reference. As an example, we consider the Compton scattering of high energy electrons off a laser beam in the set-up which is important for future {gamma}{gamma} and {gamma}e colliders. In this case we find that the polarization effects are significant and should be taken into account in calculating multiple electron scattering by a laser beam. (orig.). 10 refs.

  18. Time Projection Compton Spectrometer (TPCS). User`s guide

    Energy Technology Data Exchange (ETDEWEB)

    Landron, C.O. [Sandia National Labs., Albuquerque, NM (United States); Baldwin, G.T. [International Atomic Energy Agency, Vienna (Austria)

    1994-04-01

    The Time Projection Compton Spectrometer (TPCS) is a radiation diagnostic designed to determine the time-integrated energy spectrum between 100 keV -- 2 MeV of flash x-ray sources. This guide is intended as a reference for the routine operator of the TPCS. Contents include a brief overview of the principle of operation, detailed component descriptions, detailed assembly and disassembly procedures, guide to routine operations, and troubleshooting flowcharts. Detailed principle of operation, signal analysis and spectrum unfold algorithms are beyond the scope of this guide; however, the guide makes reference to sources containing this information.

  19. Electronic structure of hafnium: A Compton profile study

    Indian Academy of Sciences (India)

    S Khera; S Mathur; B L Ahuja

    2007-01-01

    In this paper, we report the first-ever isotropic Compton profile of hafnium measured at an intermediate resolution, with 661.65 keV -radiation. To compare our experimental data, the theoretical computations have also been carried out within the framework of pseudopotential using CRYSTAL03 code and the renormalized-free-atom (RFA) model. It is found that the present experimental profile is in better agreement with the RFA calculations if the outer electronic configuration is chosen as 5d3.26s0.8. The cohesive energy of Hf is also deduced from the experimental data and is compared with the available data.

  20. Limits on Lorentz violation from synchrotron and inverse Compton sources.

    Science.gov (United States)

    Altschul, B

    2006-05-26

    We derive new bounds on Lorentz violations in the electron sector from existing data on high-energy astrophysical sources. Synchrotron and inverse Compton data give precisely complementary constraints. The best bound on a specific combination of electron Lorentz-violating coefficients is at the 6 x 10(-20) level, and independent bounds are available for all the Lorentz-violating c coefficients at the 2 x 10(-14)level or better. This represents an improvement in some bounds by 14 orders of magnitude.

  1. Measurement of Deeply Virtual Compton Scattering at HERA

    CERN Document Server

    Adloff, C.; Andrieu, B.; Anthonis, T.; Arkadov, V.; Astvatsatourov, A.; Babaev, A.; Bahr, J.; Baranov, P.; Barrelet, E.; Bartel, W.; Bate, P.; Beglarian, A.; Behnke, O.; Beier, C.; Belousov, A.; Benisch, T.; Berger, Christoph; Berndt, T.; Bizot, J.C.; Boudry, V.; Braunschweig, W.; Brisson, V.; Broker, H.B.; Brown, D.P.; Bruckner, W.; Bruncko, D.; Burger, J.; Busser, F.W.; Bunyatyan, A.; Burrage, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A.J.; Cao, Jun; Caron, S.; Clarke, D.; Clerbaux, B.; Collard, C.; Contreras, J.G.; Coppens, Y.R.; Coughlan, J.A.; Cousinou, M.C.; Cox, B.E.; Cozzika, G.; Cvach, J.; Dainton, J.B.; Dau, W.D.; Daum, K.; Davidsson, M.; Delcourt, B.; Delerue, N.; Demirchyan, R.; De Roeck, A.; De Wolf, E.A.; Diaconu, C.; Dingfelder, J.; Dixon, P.; Dodonov, V.; Dowell, J.D.; Droutskoi, A.; Dubak, A.; Duprel, C.; Eckerlin, Guenter; Eckstein, D.; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Eisenhandler, E.; Ellerbrock, M.; Elsen, E.; Erdmann, M.; Erdmann, W.; Faulkner, P.J.W.; Favart, L.; Fedotov, A.; Felst, R.; Ferencei, J.; Ferron, S.; Fleischer, M.; Fleming, Y.H.; Flugge, G.; Fomenko, A.; Foresti, I.; Formanek, J.; Foster, J.M.; Franke, G.; Gabathuler, E.; Gabathuler, K.; Garvey, J.; Gassner, J.; Gayler, Joerg; Gerhards, R.; Gerlich, C.; Ghazaryan, Samvel; Goerlich, L.; Gogitidze, N.; Goldberg, M.; Goodwin, C.; Grab, C.; Grassler, H.; Greenshaw, T.; Grindhammer, Guenter; Hadig, T.; Haidt, D.; Hajduk, L.; Haynes, W.J.; Heinemann, B.; Heinzelmann, G.; Henderson, R.C.W.; Hengstmann, S.; Henschel, H.; Heremans, R.; Herrera, G.; Herynek, I.; Hildebrandt, M.; Hilgers, M.; Hiller, K.H.; Hladky, J.; Hoting, P.; Hoffmann, D.; Horisberger, R.; Hurling, S.; Ibbotson, M.; Issever, C .; Jacquet, M.; Jaffre, M.; Janauschek, L.; Janssen, X.; Jemanov, V.; Jonsson, L.; Johnson, D.P.; Jones, M.A.S.; Jung, H.; Kastli, H.K.; Kant, D.; Kapichine, M.; Karlsson, M.; Karschnick, O.; Keil, F.; Keller, N.; Kennedy, J.; Kenyon, I.R.; Kermiche, S.; Kiesling, Christian M.; Kjellberg, P.; Klein, M.; Kleinwort, C.; Kluge, T.; Knies, G.; Koblitz, B.; Kolya, S.D.; Korbel, V.; Kostka, P.; Kotelnikov, S.K.; Koutouev, R.; Koutov, A.; Krehbiel, H.; Kroseberg, J.; Kruger, K.; Kupper, A.; Kuhr, T.; Kurca, T.; Lahmann, R.; Lamb, D.; Landon, M.P.J.; Lange, W.; Lastovicka, T.; Laycock, P.; Lebailly, E.; Lebedev, A.; Leissner, B.; Lemrani, R.; Lendermann, V.; Levonian, S.; Lindstroem, M.; List, B.; Lobodzinska, E.; Lobodzinski, B.; Loginov, A.; Loktionova, N.; Lubimov, V.; Luders, S.; Luke, D.; Lytkin, L.; Mahlke-Kruger, H.; Malden, N.; Malinovski, E.; Malinovski, I.; Maracek, R.; Marage, P.; Marks, J.; Marshall, R.; Martyn, H.U.; Martyniak, J.; Maxfield, S.J.; Meer, D.; Mehta, A.; Meier, K.; Meyer, A.B.; Meyer, H.; Meyer, J.; Meyer, P.O.; Mikocki, S.; Milstead, D.; Mkrtchyan, T.; Mohr, R.; Mohrdieck, S.; Mondragon, M.N.; Moreau, F.; Morozov, A.; Morris, J.V.; Muller, K.; Murin, P.; Nagovizin, V.; Naroska, B.; Naumann, J.; Naumann, T.; Nellen, G.; Newman, Paul R.; Nicholls, T.C.; Niebergall, F.; Niebuhr, C.; Nix, O.; Nowak, G.; Olsson, J.E.; Ozerov, D.; Panassik, V.; Pascaud, C.; Patel, G.D.; Peez, M.; Perez, E.; Phillips, J.P.; Pitzl, D.; Poschl, R.; Potachnikova, I.; Povh, B.; Rabbertz, K.; Radel, G.; Rauschenberger, J.; Reimer, P.; Reisert, B.; Reyna, D.; Risler, C.; Rizvi, E.; Robmann, P.; Roosen, R.; Rostovtsev, A.; Rusakov, S.; Rybicki, K.; Sankey, D.P.C.; Scheins, J.; Schilling, F.P.; Schleper, P.; Schmidt, D.; Schmidt, S.; Schmitt, S.; Schneider, M.; Schoeffel, L.; Schoning, A.; Schorner, T.; Schroder, V.; Schultz-Coulon, H.C.; Schwanenberger, C.; Sedlak, K.; Sefkow, F.; Chekelian, V.; Sheviakov, I.; Shtarkov, L.N.; Sirois, Y.; Sloan, T.; Smirnov, P.; Solovev, Y.; South, D.; Spaskov, V.; Specka, Arnd E.; Spitzer, H.; Stamen, R.; Stella, B.; Stiewe, J.; Straumann, U.; Swart, M.; Tasevsky, M.; Chernyshov, V.; Chetchelnitski, S.; Thompson, Graham; Thompson, P.D.; Tobien, N.; Traynor, D.; Truoel, Peter; Tsipolitis, G.; Tsurin, I.; Turnau, J.; Turney, J.E.; Tzamariudaki, E.; Udluft, S.; Urban, Marcel; Usik, A.; Valkar, S.; Valkarova, A.; Vallee, C.; Van Mechelen, P.; Vassilev, S.; Vazdik, Y.; Vichnevski, A.; Wacker, K.; Wallny, R.; Waugh, B.; Weber, G.; Weber, M.; Wegener, D.; Werner, C.; Werner, M.; Werner, N.; White, G.; Wiesand, S.; Wilksen, T.; Winde, M.; Winter, G.G.; Wissing, C.; Wobisch, M.; Wunsch, E.; Wyatt, A.C.; Zacek, J.; Zalesak, J.; Zhang, Z.; Zhokin, A.; Zomer, F.; Zsembery, J.; zur Nedden, M.

    2001-01-01

    A measurement is presented of elastic Deeply Virtual Compton Scattering e^+ + p -> e^+ + photon + p at HERA using data taken with the H1 detector. The cross section is measured as a function of the photon virtuality, Q^2, and the invariant mass, W, of the gamma p system, in the kinematic range 2 < Q^2 < 20 GeV^2, 30 < W < 120 GeV and |t| < 1 GeV^2, where t is the squared momentum transfer to the proton. The measurement is compared to QCD based calculations.

  2. Quantum radiation reaction effects in multiphoton Compton scattering.

    Science.gov (United States)

    Di Piazza, A; Hatsagortsyan, K Z; Keitel, C H

    2010-11-26

    Radiation reaction effects in the interaction of an electron and a strong laser field are investigated in the realm of quantum electrodynamics. We identify the quantum radiation reaction with the multiple photon recoils experienced by the laser-driven electron due to consecutive incoherent photon emissions. After determining a quantum radiation dominated regime, we demonstrate how in this regime quantum signatures of the radiation reaction strongly affect multiphoton Compton scattering spectra and that they could be measurable in principle with presently available laser technology.

  3. Two-photon Compton process in pulsed intense laser fields

    CERN Document Server

    Seipt, D

    2012-01-01

    Based on strong-field QED in the Furry picture we use the Dirac-Volkov propagator to derive a compact expression for the differential emission probability of the two-photon Compton process in a pulsed intense laser field. The relation of real and virtual intermediate states is discussed, and the natural regularization of the on-shell contributions due to the finite laser pulse is highlighted. The inclusive two-photon spectrum is two orders of magnitude stronger than expected from a perturbative estimate.

  4. Induced Compton Scattering by Relativistic Electrons in Magnetized Astrophysical Plasmas.

    Science.gov (United States)

    Sincell, Mark William

    1994-01-01

    The effects of stimulated scattering on high brightness temperature radiation are studied in two important contexts. In the first case, we assume that the radiation is confined to a collimated beam traversing a relativistically streaming magnetized plasma. When the plasma is cold in the bulk frame, stimulated scattering is only significant if the angle between the photon motion and the plasma velocity is less than gamma^{-1} , where gamma is the bulk Lorentz factor. Under the assumption that the center of the photon beam is parallel to the bulk motion, we calculate the scattering rate as a function of the angular spread of the beam and gamma. Magnetization changes the photon recoil, without which stimulated scattering has no effect. It also introduces a strong dependence on frequency and polarization: if the photon frequency matches the electron cyclotron frequency, the scattering rate of photons polarized perpendicular to the magnetic field can be substantially enhanced relative to Thomson, and if the photon frequency is much less than the cyclotron frequency the scattering is suppressed. Applying these calculations to pulsars, we find that stimulated scattering of the radio beam in the magnetized wind believed to exist outside the light cylinder can substantially alter the spectrum and polarization state of the radio signal. We suggest that the scattering rate is so high in some pulsars that the ability of the radio signal to penetrate the pulsar magnetosphere requires modification of either the conventional model of the magnetosphere or assumptions about the effects of stimulated scattering upon a beam. In the second case, we present a model of the radio emission from synchrotron self-absorbed sources, including the effects of induced Compton scattering by the relativistic electrons in the source. Order of magnitude estimates show that stimulated scattering becomes the dominant absorption process when (kTB/m ec^2)tau_{T }_sp{~}> 0.1. Numerical simulations

  5. Photoneutron production with the Laser-Compton backscattered photons

    Energy Technology Data Exchange (ETDEWEB)

    Toyokawa, Hiroyuki; Ohgaki, Hideaki; Sugiyama, Suguru; Mikado, Tomohisa; Yamada, Kawakatsu; Suzuki, Ryoichi; Ohdaira, Toshiyuki; Sei, Norihiro; Chiwaki, Mitsukuni [Electrotechnical Laboratory, Tsukuba, Ibaraki (Japan)

    1999-03-01

    A method to produce quasi-monoenergetic photoneutrons for detector calibration was examined. The photoneutrons were produced with a photo-induced neutron emission of a {sup 9}Be using the Laser-Compton backscattered photons. Because the photon energy is continuously tunable, neutrons with various energies are obtained. Yield of the neutrons was measured with a liquid scintillation detector at the photon energies from 1651 keV to 3019 keV. Neutron yield at around the threshold energy for the {sup 9}Be ({gamma}, n) reaction was measured by changing the photon energy in a 10 keV step. (author)

  6. A hard X-ray polarimeter utilizing Compton scattering

    Science.gov (United States)

    Sakurai, H.; Noma, M.; Niizeki, H.

    1991-01-01

    The paper describes a 50-cm-diam prototype of a novel Compton-scattering-type polarimeter for hard X-rays in the energy range 30-100 keV. The characteristics of the prototype polarimeter were investigated for various conditions. It was found that, with polarized X-rays from a simple polarizer, the detection efficiency and the modulation factor of the polarimeter with a 40-mm thick scatterer were 3.2 percent and 0.57 percent, respectively, at about 60 keV.

  7. Compton scattering from chiral dynamics with unitarity and causality

    Energy Technology Data Exchange (ETDEWEB)

    Gasparyan, A.M. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Planckstrasse 1, 64291 Darmstadt (Germany); SSC RF ITEP, Bolshaya Cheremushkinskaya 25, 117218 Moscow (Russian Federation); Lutz, M.F.M., E-mail: m.lutz@gsi.de [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Planckstrasse 1, 64291 Darmstadt (Germany); Pasquini, B. [Dipartimento di Fisica Nucleare e Teorica, Universita degli Studi di Pavia and INFN, Sezione di Pavia, Pavia (Italy)

    2011-09-15

    Proton Compton scattering is analyzed with the chiral Lagrangian. Partial-wave amplitudes are obtained by an analytic extrapolation of subthreshold reaction amplitudes computed in chiral perturbation theory, where the constraints set by electromagnetic-gauge invariance, causality and unitarity are used to stabilize the extrapolation. We present and discuss predictions for various spin observables and polarizabilities of the proton. While for the transition polarizabilities {gamma}{sub E1M2}, {gamma}{sub M1E2} we recover the results of strict chiral perturbation theory, for the diagonal {gamma}{sub E1E1}, {gamma}{sub M1M1} elements we find significant effects from rescattering.

  8. Magnetic Bunch Compression for a Compact Compton Source

    Energy Technology Data Exchange (ETDEWEB)

    Gamage, B. [ODU; Satogata, Todd J. [JLAB

    2013-12-01

    A compact electron accelerator suitable for Compton source applications is in design at the Center for Accelerator Science at Old Dominion University and Jefferson Lab. Here we discuss two options for transverse magnetic bunch compression and final focus, each involving a 4-dipole chicane with M_{56} tunable over a range of 1.5-2.0m with independent tuning of final focus to interaction point $\\beta$*=5mm. One design has no net bending, while the other has net bending of 90 degrees and is suitable for compact corner placement.

  9. Optical inverse Compton emission from clusters of galaxies

    CERN Document Server

    Yamazaki, Ryo

    2015-01-01

    Shocks around clusters of galaxies accelerate electrons which upscatter the Cosmic Microwave Background photons to higher-energies. We use an analytical model to calculate this inverse Compton (IC) emission, taking into account the effects of additional energy losses via synchrotron and Coulomb scattering. We find that the surface brightness of the optical IC emission increases with redshift and halo mass. The IC emission surface brightness, 32--34~mag~arcsec$^{-2}$, for massive clusters is potentially detectable by the newly developed Dragonfly Telephoto Array.

  10. Polarization Transfer in Proton Compton Scattering at High Momentum Transfer

    CERN Document Server

    Hamilton, D J; Aniol, K A; Annand, J R M; Bertin, P Y; Bimbot, L; Bosted, P; Calarco, J R; Camsonne, A; Chang, G C; Chang, T H; Chen, J P; Seonho Choi; Chudakov, E; Danagulyan, A S; Degtyarenko, P; De Jager, C W; Deur, A; Dutta, D; Egiyan, K; Gao, H; Garibaldi, F; Gayou, O; Gilman, R; Glamazdin, A; Glashausser, C; Gómez, J; Hansen, J O; Hayes, D; Higinbotham, D W; Hinton, W; Horn, T; Howell, C; Hunyady, T; Hyde-Wright, C E; Jiang, X; Jones, M K; Khandaker, M; Ketikyan, A; Koubarovski, V; Krämer, K; Kumbartzki, G; Laveissière, G; Le Rose, J J; Lindgren, R A; Margaziotis, D J; Markowitz, P; McCormick, K; Meziani, Z E; Michaels, R; Moussiegt, P; Nanda, S; Nathan, A M; Nikolenko, D M; Nelyubin, V V; Norum, B E; Paschke, K; Pentchev, L; Perdrisat, C F; Piasetzky, E; Pomatsalyuk, R I; Punjabi, V A; Rachek, Igor A; Radyushkin, A V; Reitz, B; Roché, R; Roedelbronn, M; Ron, G; Sabatie, F; Saha, A; Savvinov, N; Shahinyan, A; Shestakov, Yu V; Sirca, S; Slifer, K J; Solvignon, P; Stoler, P; Tajima, S; Sulkosky, V; Todor, L; Vlahovic, B; Weinstein, L B; Wang, K; Wojtsekhowski, B; Voskanyan, H; Xiang, H; Zheng, X; Zhu, L

    2004-01-01

    Compton scattering from the proton was investigated at s=6.9 (GeV/c)**2 and \\t=-4.0 (GeV/c)**2 via polarization transfer from circularly polarized incident photons. The longitudinal and transverse components of the recoil proton polarization were measured. The results are in excellent agreement with a prediction based on a reaction mechanism in which the photon interacts with a single quark carrying the spin of the proton and in disagreement with a prediction of pQCD based on a two-gluon exchange mechanism.

  11. Transmission electron microscope CCD camera

    Science.gov (United States)

    Downing, Kenneth H.

    1999-01-01

    In order to improve the performance of a CCD camera on a high voltage electron microscope, an electron decelerator is inserted between the microscope column and the CCD. This arrangement optimizes the interaction of the electron beam with the scintillator of the CCD camera while retaining optimization of the microscope optics and of the interaction of the beam with the specimen. Changing the electron beam energy between the specimen and camera allows both to be optimized.

  12. Determination of Rest Mass Energy of the Electron by a Compton Scattering Experiment

    Science.gov (United States)

    Prasannakumar, S.; Krishnaveni, S.; Umesh, T. K.

    2012-01-01

    We report here a simple Compton scattering experiment which may be carried out in graduate and undergraduate laboratories to determine the rest mass energy of the electron. In the present experiment, we have measured the energies of the Compton scattered gamma rays with a NaI(Tl) gamma ray spectrometer coupled to a 1 K multichannel analyzer at…

  13. Critical remarks on the electron (positron) beam polarization by Compton scattering on circular polarized laser photons

    CERN Document Server

    Kotkin, G L; Telnov, V I

    2003-01-01

    In a number of papers an attractive method of laser polarization of electrons (positrons) at storage rings or linear colliders have been proposed. We show that these suggestions are incorrect and based on errors in simulation of multiple Compton scattering and in calculation of the Compton spin-flip cross sections. We argue that the equilibrium polarization in this method is zero.

  14. Determination of Rest Mass Energy of the Electron by a Compton Scattering Experiment

    Science.gov (United States)

    Prasannakumar, S.; Krishnaveni, S.; Umesh, T. K.

    2012-01-01

    We report here a simple Compton scattering experiment which may be carried out in graduate and undergraduate laboratories to determine the rest mass energy of the electron. In the present experiment, we have measured the energies of the Compton scattered gamma rays with a NaI(Tl) gamma ray spectrometer coupled to a 1 K multichannel analyzer at…

  15. Inverse Compton X-ray signature of AGN feedback

    Science.gov (United States)

    Bourne, Martin A.; Nayakshin, Sergei

    2013-12-01

    Bright AGN frequently show ultrafast outflows (UFOs) with outflow velocities vout ˜ 0.1c. These outflows may be the source of AGN feedback on their host galaxies sought by galaxy formation modellers. The exact effect of the outflows on the ambient galaxy gas strongly depends on whether the shocked UFOs cool rapidly or not. This in turn depends on whether the shocked electrons share the same temperature as ions (one-temperature regime, 1T) or decouple (2T), as has been recently suggested. Here we calculate the inverse Compton spectrum emitted by such shocks, finding a broad feature potentially detectable either in mid-to-high energy X-rays (1T case) or only in the soft X-rays (2T). We argue that current observations of AGN do not seem to show evidence for the 1T component. The limits on the 2T emission are far weaker, and in fact it is possible that the observed soft X-ray excess of AGN is partially or fully due to the 2T shock emission. This suggests that UFOs are in the energy-driven regime outside the central few pc, and must pump considerable amounts of not only momentum but also energy into the ambient gas. We encourage X-ray observers to look for the inverse Compton components calculated here in order to constrain AGN feedback models further.

  16. Compton reflection in AGN with Simbol-X

    CERN Document Server

    Beckmann, V; Gehrels, N; Lubinski, P; Malzac, J; Petrucci, P O; Shrader, C R; Soldi, S

    2009-01-01

    AGN exhibit complex hard X-ray spectra. Our current understanding is that the emission is dominated by inverse Compton processes which take place in the corona above the accretion disk, and that absorption and reflection in a distant absorber play a major role. These processes can be directly observed through the shape of the continuum, the Compton reflection hump around 30 keV, and the iron fluorescence line at 6.4 keV. We demonstrate the capabilities of Simbol-X to constrain complex models for cases like MCG-05-23-016, NGC 4151, NGC 2110, and NGC 4051 in short (10 ksec) observations. We compare the simulations with recent observations on these sources by INTEGRAL, Swift and Suzaku. Constraining reflection models for AGN with Simbol-X will help us to get a clear view of the processes and geometry near to the central engine in AGN, and will give insight to which sources are responsible for the Cosmic X-ray background at energies above 20 keV.

  17. Status of the inverse Compton backscattering source at Daresbury Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Priebe, G. [Science and Technology Facilities Council, Daresbury Laboratory, Cheshire (United Kingdom)], E-mail: Gerd.priebe@stfc.ac.uk; Filippetto, D. [Instituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati, Rome (Italy); Williams, O. [University of California at Los Angeles, Department of Physics and Astronomy, CA (United States); Saveliev, Y.M.; Jones, L.B. [Science and Technology Facilities Council, Daresbury Laboratory, Cheshire (United Kingdom); Accelerator Science and Technology Centre, Daresbury Laboratory, Cheshire (United Kingdom); Laundy, D.; MacDonald, M.A.; Diakun, G.P. [Science and Technology Facilities Council, Daresbury Laboratory, Cheshire (United Kingdom); Phillips, P.J. [Electronic and Physics Department, Dundee University, Nethergate (United Kingdom); Jamison, S.P. [Accelerator Science and Technology Centre, Daresbury Laboratory, Cheshire (United Kingdom); Spohr, K.M. [School of Engineering and Science, University of the West of Scotland, Paisley (United Kingdom); Ter-Avetisyan, S. [School of Mathematics and Physics, Queen' s University Belfast, Belfast (United Kingdom); Hirst, G.J. [STFC Rutherford Appleton Laboratory, Chilton, Didcot (United Kingdom); Collier, J. [STFC Rutherford Appleton Laboratory, Chilton, Didcot (United Kingdom); University of Wales Swansea, Singleton Park, Swansea (United Kingdom); Seddon, E.A. [University of Manchester, Manchester (United Kingdom); Smith, S.L. [Science and Technology Facilities Council, Daresbury Laboratory, Cheshire (United Kingdom); Accelerator Science and Technology Centre, Daresbury Laboratory, Cheshire (United Kingdom)

    2009-09-01

    Inverse Compton scattering is a promising method to implement a high-brightness, ultra-short, energy tuneable X-ray source at accelerator facilities and at laser facilities using laser wake-field acceleration. We have developed an inverse Compton X-ray source driven by the multi-10-TW laser installed at Daresbury Laboratory. Polarized X-ray pulses will be generated through the interaction of laser pulses with electron bunches delivered by the energy recovery linac commissioned at the ALICE facility with spectral peaks ranging from 0.4 to 12 A, depending on the electron bunch energy and the scattering geometry. X-ray pulses containing up to 10{sup 7} photons per pulse will be created from head-on collisions, with a pulse duration comparable to the incoming electron bunch length. For transverse collisions the laser pulse transit time defines the X-ray pulse duration. The peak spectral brightness is predicted to be up to 10{sup 21} photon/(s mm{sup 2} mrad{sup 2} 0.1% {delta}{lambda}/{lambda}). Called COBALD, this source will be initially used as a short-pulse diagnostic for the ALICE electron beam and will explore the extreme challenges of photon/electron beam synchronization, which is a fundamental requirement for all conventional accelerator and laser wake-field-acceleration-based sources.

  18. Detection of inverse Compton scattering in plasma wakefield experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bohlen, Simon

    2016-12-15

    Inverse Compton scattering (ICS) is the process of scattering of photons and electrons, where the photons gain a part of the electrons energy. In combination with plasma wakefield acceleration (PWA), ICS offers a compact MeV γ-ray source. A numerical study of ICS radiation produced in PWA experiments at FLASHForward was performed, using an ICS simulation code and the results from particle-in-cell modelling. The possibility of determining electron beam properties from measurements of the γ-ray source was explored for a wide range of experimental conditions. It was found that information about the electron divergence, the electron spectrum and longitudinal information can be obtained from measurements of the ICS beams for some cases. For the measurement of the ICS profile at FLASHForward, a CsI(Tl) scintillator array was chosen, similar to scintillators used in other ICS experiments. To find a suitable detector for spectrum measurements, an experimental test of a Compton spectrometer at the RAL was conducted. This test showed that a similar spectrometer could also be used at FLASHForward. However, changes to the spectrometer could be needed in order to use the pair production effect. In addition, further studies using Geant4 could lead to a better reconstruction of the obtained data. The studies presented here show that ICS is a promising method to analyse electron parameters from PWA experiments in further detail.

  19. Recent Deuteron Compton Scattering Results and Extracted Neutron Polarizabilities

    Directory of Open Access Journals (Sweden)

    Myers L.S.

    2016-01-01

    Full Text Available The COMPTON@MAX-lab collaboration has recently published a new measurement of elastic photon scattering from deuterium using tagged photons at the MAX IV Laboratory [1]. The experiment utilized the Tagged Photon Facility at MAX IV and three of the largest NaI(Tl detectors in the world. Correction terms to the cross section were determined via Monte Carlo simulations [2, 3] and were confirmed by comparisons to the well-known 12C(γ,γ12C reaction [4]. These results represent the most extensive data on deuteron Compton scattering ever measured and effectively double the world data set. In addition, the energy range overlaps previous experiments and extends nearly 20 MeV higher where the sensitivity to the polarizabilities is enhanced. As a result, we have obtained the neutron polarizabilities as αn=[11.55 ± 1.25(stat ± 0.2(BSR ± 0.8(th] × 10−4 fm3 and βn=[3.65 ∓ 1.25(stat ± 0.2(BSR ± 0.8(th] × 10−4 fm3, which represents a 30% reduction in the statistical uncertainty.

  20. A Compton thick AGN in the barred spiral NGC 4785

    CERN Document Server

    Gandhi, P; Ricci, C; Asmus, D; Mushotzky, R F; Ueda, Y; Terashima, Y; La Parola, V

    2014-01-01

    We present X-ray observations of the active galactic nucleus (AGN) in NGC 4785. The source is a local Seyfert 2 which has not been studied so far in much detail. It was recently detected with high significance in the 15-60 keV band in the 66 month Swift/BAT all sky survey, but there have been no prior pointed X-ray observations of this object. With Suzaku, we clearly detect the source below 10 keV, and find it to have a flat continuum and prominent neutral iron fluorescence line with equivalent width >~1 keV. Fitting the broadband spectra with physical reflection models shows the source to be a bona fide Compton thick AGN with Nh of at least 2x10^{24} cm^{-2} and absorption-corrected 2-10 keV X-ray power L(2-10) ~ few times 10^{42} erg s^{-1}. Realistic uncertainties on L(2-10) computed from the joint confidence interval on the intrinsic power law continuum photon index and normalization are at least a factor of 10. The local bona fide Compton thick AGN population is highly heterogeneous in terms of WISE mid-...

  1. Compton profile study and electronic properties of tantalum diboride.

    Science.gov (United States)

    Raykar, Veera; Bhamu, K C; Ahuja, B L

    2013-07-01

    We have reported the first-ever experimental Compton profile (CP) of TaB2 using 20 Ci(137)Cs Compton spectrometer. To compare the experimental data, we have also computed the theoretical CPs using density functional theory (DFT) and hybridization of DFT and Hartree-Fock (HF) within linear combination of the atomic orbitals (LCAO) method. In addition, we have reported energy bands and density of states of TaB2 using LCAO and full potential-linearized augmented plane wave (FP-LAPW) methods. A real space analysis of CP of TaB2 confirms its metallic character which is in tune with the cross-overs of Fermi level by energy bands and Fermi surface topology. A comparison of equal-valence-electron-density (EVED) experimental profiles of isoelectronic TaB2 and NbB2 show more covalent (or less ionic) character of TaB2 than that of NbB2 which is in agreement with available ionicity data.

  2. Timelike Virtual Compton Scattering from Electron-Positron Radiative Annihilation

    Energy Technology Data Exchange (ETDEWEB)

    Afanasev, Andrei; /Hampton U. /Jefferson Lab; Brodsky, Stanley J.; /SLAC; Carlson, Carl E.; /William-Mary Coll.; Mukherjee, Asmita; /Indian Inst. Tech., Mumbai

    2009-03-31

    We propose measurements of the deeply virtual Compton amplitude (DVCS) {gamma}* {yields} H{bar H}{gamma} in the timelike t = (p{sub H} + p{sub {bar H}}){sup 2} > 0 kinematic domain which is accessible at electron-positron colliders via the radiative annihilation process e{sup +}e{sup -} {yields} H{bar H}{gamma}. These processes allow the measurement of timelike deeply virtual Compton scattering for a variety of H{bar H} hadron pairs such as {pi}{sup +}{pi}{sup -}, K{sup +}K{sup -}, and D{bar D} as well as p{bar p}. As in the conventional spacelike DVCS, there are interfering coherent amplitudes contributing to the timelike processes involving C = - form factors. The interference between the amplitudes measures the phase of the C = + timelike DVCS amplitude relative to the phase of the timelike form factors and can be isolated by considering the forward-backward e{sup +} {leftrightarrow} e{sup -} asymmetry. The J = 0 fixed pole contribution which arises from the local coupling of the two photons to the quark current plays a special role. As an example we present a simple model.

  3. Timelike Virtual Compton Scattering from Electron-Positron Radiative Annihilation

    Energy Technology Data Exchange (ETDEWEB)

    Andrei Afanaciev,Andrei Afanasev, Stanley J. Brodsky, Carl E. Carlson, Asmita Mukherjee

    2010-02-01

    We propose measurements of the deeply virtual Compton amplitude (DVCS), gamma* to H H-bar gamma, in the timelike t = (p_{H} + p_{H-bar})^2 > 0 kinematic domain which is accessible at electron-positron colliders via the radiative annihilation process e+ e- to H H-bar gamma. These processes allow the measurement of timelike deeply virtual Compton scattering for a variety of H H-bar hadron pairs such as pi+ pi-, K+ K-, and D D-bar as well as p p-bar. As in the conventional spacelike DVCS, there are interfering coherent amplitudes contributing to the timelike processes involving C= - form factors. The interference between the amplitudes measures the phase of the C=+ timelike DVCS amplitude relative to the phase of the timelike form factors and can be isolated by considering the forward-backward e+ \\leftrightarrow e- asymmetry. The J=0 fixed pole contribution which arises from the local coupling of the two photons to the quark current plays a special role. As an example we present a simple model.

  4. The polarization effect of a laser in multiphoton Compton scattering

    Science.gov (United States)

    Liang, Guo-Hua; Lü, Qing-Zheng; Teng, Ai-Ping; Li, Ying-Jun

    2014-05-01

    The multiphoton Compton scattering in a high-intensity laser beam is studied by using the laser-dressed quantum electrodynamics (QED) method, which is a non-perturbative theory for the interaction between a plane electromagnetic field and a charged particle. In order to analyze in the real experimental condition, a Lorentz transformation for the cross section of this process is derived between the laboratory frame and the initial rest frame of electrons. The energy of the scattered photon is analyzed, as well as the cross sections for different laser intensities and polarizations and different electron velocities. The angular distribution of the emitted photon is investigated in a special velocity of the electron, in which for a fixed number of absorbed photons, the electron energy will not change after the scattering in the lab frame. We obtain the conclusion that higher laser intensities suppress few-laser-photon absorption and enhance more-laser-photon absorption. A comparison between different polarizations is also made, and we find that the linearly polarized laser is more suitable to generate nonlinear Compton scattering.

  5. External inverse-Compton emission from jetted tidal disruption events

    CERN Document Server

    Lu, Wenbin

    2016-01-01

    The recent discoveries of Swift J1644+57 and J2058+05 show that tidal disruption events (TDEs) can launch relativistic jets. Super-Eddington accretion produces a strong radiation field of order Eddington luminosity. In a jetted TDE, electrons in the jet will inverse-Compton scatter the external radiation field from the accretion disk and wind. Motivated by observations of thermal optical-UV spectra in Swift J2058+05 and several other TDEs, we assume the spectrum of the external radiation field intercepted by the relativistic jet to be blackbody. Hot electrons in the jet scatter this thermal radiation and produce luminosities 10^45-10^48 erg/s in the X/gamma-ray band. This model of thermal plus inverse-Compton radiation is applied to Swift J2058+05. First, we show that the blackbody component in the optical-UV spectrum most likely has its origin in the super-Eddington wind from the disk. Then, using the observed blackbody component as the external radiation field, we show that the X-ray luminosity and spectrum...

  6. Higher-dimensional catastrophes in nonlinear Compton scattering

    Science.gov (United States)

    Kharin, Vasily; Seipt, Daniel; Rykovanov, Sergey

    2016-10-01

    The Compton scattering of the light on the accelerated electron beam is a valuable tool for generating tunable wide range X- and γ-radiation.However, the cross-section of the scattering is relatively low. That is, in order to obtain bright X-rays one naturally may consider increasing the intensity of the incident light. Passing to relativistic values of laser intensity significantly changes scattering mechanism. Precise QED analysis of the scattered spectra leads to the study of the corresponding elements of S-matrix. Evaluation is usually performed numerically (except cases of specific pulse shapes and scattering angles). We argue that the problem of extracting the scattered spectra in nonlinear Compton scattering of the pulse can be reformulated in terms of studying properties of projection map of specific surfaces associated to the pulse. They are stable with respect to initial conditions, and the brightest regions of the spectrum appear to be in correspondence with the singularities of the projection map, also known as caustics in pure mathematics, diffraction optics and cosmology. Work was supported by the Helmholtz Association (Helmholtz Young Investigators group VH-NG-1037).

  7. Compton Scattering of Quasi-Real Virtual Photons at LEP

    CERN Document Server

    Achard, P; Aguilar-Benítez, M; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Anderhub, H; Andreev, V P; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Bajo, A; Baksay, G; Baksay, L; Baldew, S V; Banerjee, S; Barczyk, A; Barillère, R; Bartalini, P; Basile, M; Batalova, N; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Bellucci, L; Berbeco, R; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Biasini, M; Biglietti, M; Biland, A; Blaising, J J; Blyth, S C; Bobbink, G J; Böhm, A; Boldizsar, L; Borgia, B; Bottai, S; Bourilkov, D; Bourquin, Maurice; Braccini, S; Branson, J G; Brochu, F; Burger, J D; Burger, W J; Cai, X D; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A; Casaus, J; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada, M; Chamizo-Llatas, M; Chang, Y H; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chiefari, G; Cifarelli, Luisa; Cindolo, F; Clare, I; Clare, R; Coignet, G; Colino, N; Costantini, S; de la Cruz, B; Cucciarelli, S; van Dalen, J A; De Asmundis, R; Déglon, P L; Debreczeni, J; Degré, A; Dehmelt, K; Deiters, K; Della Volpe, D; Delmeire, E; Denes, P; De Notaristefani, F; De Salvo, A; Diemoz, M; Dierckxsens, M; Dionisi, C; Dittmar, M; Doria, A; Dova, M T; Duchesneau, D; Duda, M; Echenard, B; Eline, A; El-Hage, A; El-Mamouni, H; Engler, A; Eppling, F J; Extermann, P; Falagán, M A; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, M; Ferguson, T; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, F; Fisher, P H; Fisher, W; Fisk, I; Forconi, G; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gataullin, M; Gentile, S; Giagu, S; Gong, Z F; Grenier, G; Grimm, O; Grünewald, M W; Guida, M; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hirschfelder, J; Hofer, H; Hohlmann, M; Holzner, G; Hou, S R; Hu, Y; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Kaur, M; Kienzle-Focacci, M N; Kim, J K; Kirkby, Jasper; Kittel, E W; Klimentov, A; König, A C; Kopal, M; Koutsenko, V F; Kraber, M; Krämer, R W; Krüger, A; Kunin, A; Ladrón de Guevara, P; Laktineh, I; Landi, G; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Le Goff, J M; Leiste, R; Levtchenko, M; Levchenko, P M; Li, C; Likhoded, S; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lü, Y S; Luci, C; Luminari, L; Lustermann, W; Ma Wen Gan; Malgeri, L; Malinin, A; Maña, C; Mans, J; Martin, J P; Marzano, F; Mazumdar, K; McNeil, R R; Mele, S; Merola, L; Meschini, M; Metzger, W J; Mihul, A; Milcent, H; Mirabelli, G; Mnich, J; Mohanty, G B; Muanza, G S; Muijs, A J M; Musicar, B; Musy, M; Nagy, S; Natale, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Nisati, A; Novák, T; Nowak, H; Ofierzynski, R A; Organtini, G; Pal, I; Palomares, C; Paolucci, P; Paramatti, R; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Pedace, M; Pensotti, S; Perret-Gallix, D; Petersen, B; Piccolo, D; Pierella, F; Pioppi, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Pothier, J; Prokofev, D; Prokofiev, D O; Quartieri, J; Rahal-Callot, G; Rahaman, M A; Raics, P; Raja, N; Ramelli, R; Rancoita, P G; Ranieri, R; Raspereza, A V; Razis, P; Ren, D; Rescigno, M; Reucroft, S; Riemann, S; Riles, K; Roe, B P; Romero, L; Rosca, A; Rosemann, C; Rosenbleck, C; Rosier-Lees, S; Roth, S; Rubio, J A; Ruggiero, G; Rykaczewski, H; Sakharov, A; Saremi, S; Sarkar, S; Salicio, J; Sánchez, E; Schäfer, C; Shchegelskii, V; Schopper, Herwig Franz; Schotanus, D J; Sciacca, C; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shumilov, E; Shvorob, A; Son, D; Souga, C; Spillantini, P; Steuer, M; Stickland, D P; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Sushkov, S; Suter, H; Swain, J D; Szillási, Z; Tang, X W; Tarjan, P; Tauscher, L; Taylor, L; Tellili, B; Teyssier, D; Timmermans, C; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tung, K L; Ulbricht, J; Valente, E; Van de Walle, R T; Vásquez, R; Veszpremi, V; Vesztergombi, G; Vetlitskii, I; Vicinanza, D; Viertel, Gert M; Villa, S; Vivargent, M; Vlachos, S; Vodopyanov, I; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Wadhwa, M; Wang, Q; Wang, X L; Wang, Z M; Weber, M; Wilkens, H; Wynhoff, S; Xia, L; Xu, Z Z; Yamamoto, J; Yang, B Z; Yang, C G; Yang, H J; Yang, M; Yeh, S C; Zalite, A; Zalite, Yu; Zhang, Z P; Zhao, J; Zhu, G Y; Zhu, R Y; Zhuang, H L; Zichichi, A; Zimmermann, B; Zöller, M

    2005-01-01

    Compton scattering of quasi-real virtual photons, gamma e+- -> gamma e+-, is studied with 0.6fb-1 of data collected by the L3 detector at the LEP e+e- collider at centre-of-mass energies root(s')=189-209GeV. About 4500 events produced by the interaction of virtual photons emitted by e+- of one beam with e-+ of the opposite beam are collected for effective centre-of-mass energies of the photon-electron and photon-positron systems in the range from root(s')= 35GeV up to root(s')=175GeV, the highest energy at which Compton scattering was ever probed. The cross sections of the gamma e+- -> gamma e+- process as a function of root(s') and of the rest-frame scattering angle are measured, combined with previous L3 measurements down to root(s')~20GeV, and found to agree with the QED expectations.

  8. Observation of redshifting and harmonic radiation in inverse Compton scattering

    Science.gov (United States)

    Sakai, Y.; Pogorelsky, I.; Williams, O.; O'Shea, F.; Barber, S.; Gadjev, I.; Duris, J.; Musumeci, P.; Fedurin, M.; Korostyshevsky, A.; Malone, B.; Swinson, C.; Stenby, G.; Kusche, K.; Babzien, M.; Montemagno, M.; Jacob, P.; Zhong, Z.; Polyanskiy, M.; Yakimenko, V.; Rosenzweig, J.

    2015-06-01

    Inverse Compton scattering of laser photons by ultrarelativistic electron beam provides polarized x- to γ -ray pulses due to the Doppler blueshifting. Nonlinear electrodynamics in the relativistically intense linearly polarized laser field changes the radiation kinetics established during the Compton interaction. These are due to the induced figure-8 motion, which introduces an overall redshift in the radiation spectrum, with the concomitant emission of higher order harmonics. To experimentally analyze the strong field physics associated with the nonlinear electron-laser interaction, clear modifications to the angular and wavelength distributions of x rays are observed. The relativistic photon wave field is provided by the ps CO2 laser of peak normalized vector potential of 0.5 laser [M. Babzien et al., Phys. Rev. Lett. 96, 054802 (2006)]. The angular spectral characteristics are revealed using K -, L -edge, and high energy attenuation filters. The observation indicates existence of the electrons' longitudinal motion through frequency redshifting understood as the mass shift effect. Thus, the 3rd harmonic radiation has been observed containing on-axis x-ray component that is directly associated with the induced figure-8 motion. These are further supported by an initial evidence of off-axis 2nd harmonic radiation produced in a circularly polarized laser wave field. Total x-ray photon number per pulse, scattered by 65 MeV electron beam of 0.3 nC, at the interaction point is measured to be approximately 109 .

  9. Densitometry and temperature measurement of combustion gas by X-ray Compton scattering

    Energy Technology Data Exchange (ETDEWEB)

    Sakurai, Hiroshi, E-mail: sakuraih@gunma-u.ac.jp [Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 (Japan); Kawahara, Nobuyuki [Okayama University, Tsushima-Naka 3, Okayama 700-8530 (Japan); Itou, Masayoshi [Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Tomita, Eiji [Okayama University, Tsushima-Naka 3, Okayama 700-8530 (Japan); Suzuki, Kosuke [Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 (Japan); Sakurai, Yoshiharu [Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan)

    2016-02-17

    Measurement of combustion gas by high-energy X-ray Compton scattering is reported. Measurement of combustion gas by high-energy X-ray Compton scattering is reported. The intensity of Compton-scattered X-rays has shown a position dependence across the flame of the combustion gas, allowing us to estimate the temperature distribution of the combustion flame. The energy spectra of Compton-scattered X-rays have revealed a significant difference across the combustion reaction zone, which enables us to detect the combustion reaction. These results demonstrate that high-energy X-ray Compton scattering can be employed as an in situ technique to probe inside a combustion reaction.

  10. Analysis of the factors that affect photon counts in Compton scattering.

    Science.gov (United States)

    Luo, Guang; Xiao, Guangyu

    2014-10-30

    Compton scattering has been applied in a variety of fields. The factors that affect Compton scattering have been studied extensively in the literature. However, the factors that affect the measured photon counts in Compton scattering are rarely considered. In this paper, we make a detailed discussion on those factors. First, Compton scattering experiments of some alloy series and powder mixture series are explored. Second, the electron density is researched in terms of atom and lattice constants. Third, the factor of attenuation coefficient is discussed. And then, the active degree of electrons is discussed based on the DFT theory. Lastly, the conclusions are made, that the factors affecting Compton scattering photon counts include mainly electron number density, attenuation coefficient and active degree of electrons.

  11. Camera artifacts in IUE spectra

    Science.gov (United States)

    Bruegman, O. W.; Crenshaw, D. M.

    1994-01-01

    This study of emission line mimicking features in the IUE cameras has produced an atlas of artifiacts in high-dispersion images with an accompanying table of prominent artifacts and a table of prominent artifacts in the raw images along with a medium image of the sky background for each IUE camera.

  12. Radiation camera motion correction system

    Science.gov (United States)

    Hoffer, P.B.

    1973-12-18

    The device determines the ratio of the intensity of radiation received by a radiation camera from two separate portions of the object. A correction signal is developed to maintain this ratio at a substantially constant value and this correction signal is combined with the camera signal to correct for object motion. (Official Gazette)

  13. Coherent infrared imaging camera (CIRIC)

    Energy Technology Data Exchange (ETDEWEB)

    Hutchinson, D.P.; Simpson, M.L.; Bennett, C.A.; Richards, R.K.; Emery, M.S.; Crutcher, R.I.; Sitter, D.N. Jr.; Wachter, E.A.; Huston, M.A.

    1995-07-01

    New developments in 2-D, wide-bandwidth HgCdTe (MCT) and GaAs quantum-well infrared photodetectors (QWIP) coupled with Monolithic Microwave Integrated Circuit (MMIC) technology are now making focal plane array coherent infrared (IR) cameras viable. Unlike conventional IR cameras which provide only thermal data about a scene or target, a coherent camera based on optical heterodyne interferometry will also provide spectral and range information. Each pixel of the camera, consisting of a single photo-sensitive heterodyne mixer followed by an intermediate frequency amplifier and illuminated by a separate local oscillator beam, constitutes a complete optical heterodyne receiver. Applications of coherent IR cameras are numerous and include target surveillance, range detection, chemical plume evolution, monitoring stack plume emissions, and wind shear detection.

  14. Camera Movement in Narrative Cinema

    DEFF Research Database (Denmark)

    Nielsen, Jakob Isak

    2007-01-01

    known as ‘the poetics of cinema.’ The dissertation embraces two branches of research within this perspective: stylistics and historical poetics (stylistic history). The dissertation takes on three questions in relation to camera movement and is accordingly divided into three major sections. The first...... section unearths what characterizes the literature on camera movement. The second section of the dissertation delineates the history of camera movement itself within narrative cinema. Several organizational principles subtending the on-screen effect of camera movement are revealed in section two...... to illustrate how the functions may mesh in individual camera movements six concrete examples are analyzed. The analyses illustrate how the taxonomy presented can substantiate analysis and interpretation of film style. More generally, the dissertation - and particularly these in-depth analyses - illustrates how...

  15. Searches for optical counterparts of BATSE gamma-ray bursts with the Explosive Transient Camera.

    Science.gov (United States)

    Krimm, H. A.; Vanderspek, R. K.; Ricker, G. R.

    1996-12-01

    The Explosive Transient Camera (ETC) is a wide-field CCD camera system capable of detecting short (1-10s) celestial optical flashes as faint as m~10 over a field-of-view of 0.75-steradians between -15° and +62° declination. The ETC has been operating automatically under computer control since January 1991. Since the launch of the Compton Gamma Ray Observatory, the ETC has been capable of observing an optical flash coincident with a gamma-ray burst (GRB) detected by the Burst and Transient Spectroscopy Experiment (BATSE). Between April 1991 and August 1995, there were seven cases of at least partial spatial overlap between a BATSE 68% confidence positional error box and the ETC field-of-view during an ETC observation. In each case upper limits are placed on the optical-to-gamma-ray flux ratio.

  16. Design considerations for a high-spatial-resolution positron camera with dense-drift-space MWPC's

    Science.gov (United States)

    Delguerra, A.; Perez-Mendez, V.; Schwartz, G.; Nelson, W. R.

    1982-10-01

    A multiplane Positron Camera is proposed, made of six MWPC modules arranged to form the lateral surface of a hexagonal prism. Each module (50 x 50 sq cm) has a 2 cm thick lead-glass tube converter on both sides of a MWPC pressurized to 2 atm. Experimental measurements are presented to show how to reduce the parallax error by determining in which of the two converter layers the photon has interacted. The results of a detailed Monte Carlo calculation for the efficiency of this type of converter are shown to be in excellent agreement with the experimental measurements. The expected performance of the Positron Camera is presented: a true coincidence rate of 56,000 counts/s (with an equal accidental coincidence rate and a 30% Compton scatter contamination) and a spatial resolution better than 5.0 mm (FWHM) for a 400 micron Ci pointlike source embedded in a 10 cm radius water phantom.

  17. Space and camera path reconstruction for omni-directional vision

    CERN Document Server

    Knill, Oliver

    2007-01-01

    In this paper, we address the inverse problem of reconstructing a scene as well as the camera motion from the image sequence taken by an omni-directional camera. Our structure from motion results give sharp conditions under which the reconstruction is unique. For example, if there are three points in general position and three omni-directional cameras in general position, a unique reconstruction is possible up to a similarity. We then look at the reconstruction problem with m cameras and n points, where n and m can be large and the over-determined system is solved by least square methods. The reconstruction is robust and generalizes to the case of a dynamic environment where landmarks can move during the movie capture. Possible applications of the result are computer assisted scene reconstruction, 3D scanning, autonomous robot navigation, medical tomography and city reconstructions.

  18. Printed circuit board for a CCD camera head

    Science.gov (United States)

    Conder, Alan D.

    2002-01-01

    A charge-coupled device (CCD) camera head which can replace film for digital imaging of visible light, ultraviolet radiation, and soft to penetrating x-rays, such as within a target chamber where laser produced plasmas are studied. The camera head is small, capable of operating both in and out of a vacuum environment, and is versatile. The CCD camera head uses PC boards with an internal heat sink connected to the chassis for heat dissipation, which allows for close (0.04" for example) stacking of the PC boards. Integration of this CCD camera head into existing instrumentation provides a substantial enhancement of diagnostic capabilities for studying high energy density plasmas, for a variety of military industrial, and medical imaging applications.

  19. Camera sensitivity study

    Science.gov (United States)

    Schlueter, Jonathan; Murphey, Yi L.; Miller, John W. V.; Shridhar, Malayappan; Luo, Yun; Khairallah, Farid

    2004-12-01

    As the cost/performance Ratio of vision systems improves with time, new classes of applications become feasible. One such area, automotive applications, is currently being investigated. Applications include occupant detection, collision avoidance and lane tracking. Interest in occupant detection has been spurred by federal automotive safety rules in response to injuries and fatalities caused by deployment of occupant-side air bags. In principle, a vision system could control airbag deployment to prevent this type of mishap. Employing vision technology here, however, presents a variety of challenges, which include controlling costs, inability to control illumination, developing and training a reliable classification system and loss of performance due to production variations due to manufacturing tolerances and customer options. This paper describes the measures that have been developed to evaluate the sensitivity of an occupant detection system to these types of variations. Two procedures are described for evaluating how sensitive the classifier is to camera variations. The first procedure is based on classification accuracy while the second evaluates feature differences.

  20. Proportional counter radiation camera

    Science.gov (United States)

    Borkowski, C.J.; Kopp, M.K.

    1974-01-15

    A gas-filled proportional counter camera that images photon emitting sources is described. A two-dimensional, positionsensitive proportional multiwire counter is provided as the detector. The counter consists of a high- voltage anode screen sandwiched between orthogonally disposed planar arrays of multiple parallel strung, resistively coupled cathode wires. Two terminals from each of the cathode arrays are connected to separate timing circuitry to obtain separate X and Y coordinate signal values from pulse shape measurements to define the position of an event within the counter arrays which may be recorded by various means for data display. The counter is further provided with a linear drift field which effectively enlarges the active gas volume of the counter and constrains the recoil electrons produced from ionizing radiation entering the counter to drift perpendicularly toward the planar detection arrays. A collimator is interposed between a subject to be imaged and the counter to transmit only the radiation from the subject which has a perpendicular trajectory with respect to the planar cathode arrays of the detector. (Official Gazette)

  1. The Advanced Scintillator Compton Telescope (ASCOT) balloon project

    Science.gov (United States)

    Bloser, Peter F.; Sharma, Tejaswita; Legere, Jason S.; Bancroft, Christopher M.; McConnell, Mark L.; Ryan, James M.; Wright, Alex M.

    2016-07-01

    We describe a project to develop new medium-energy gamma-ray instrumentation by constructing and flying a balloon-borne Compton telescope using advanced scintillator materials combined with silicon photomultiplier readouts. There is a need in high-energy astronomy for a medium-energy gamma-ray mission covering the energy range from approximately 0.4 - 20 MeV to follow the success of the COMPTEL instrument on CGRO. We believe that directly building on the legacy of COMPTEL, using relatively robust, low-cost, off-the-shelf technologies, is the most promising path for such a mission. Fortunately, high-performance scintillators, such as Lanthanum Bromide (LaBr3), Cerium Bromide (CeBr3), and p-terphenyl, and compact readout devices, such as silicon photomultipliers (SiPMs), are already commercially available and capable of meeting this need. We have conducted two balloon flights of prototype instruments to test these technologies. The first, in 2011, demonstrated that a Compton telescope consisting of an liquid organic scintillator scattering layer and a LaBr3 calorimeter effectively rejects background under balloon-flight conditions, using time-of-flight (ToF) discrimination. The second, in 2014, showed that a telescope using an organic stilbene crystal scattering element and a LaBr3 calorimeter with SiPM readouts can achieve similar ToF performance. We are now constructing a much larger balloon instrument, an Advanced Scintillator Compton Telescope (ASCOT) with SiPM readout, with the goal of imaging the Crab Nebula at MeV energies in a one-day flight. We expect a 4σ detection up to 1 MeV in a single transit. We present calibration results of the first detector modules, and updated simulations of the balloon instrument sensitivity. If successful, this project will demonstrate that the energy, timing, and position resolution of this technology are sufficient to achieve an order of magnitude improvement in sensitivity in the mediumenergy gamma-ray band, were it to be

  2. Laser pulse-shape dependence of Compton scattering

    CERN Document Server

    Titov, Alexander I; Shibata, Takuya; Hosaka, Atsushi; Takabe, Hideaki

    2014-01-01

    Compton scattering of short and ultra short (sub-cycle) laser pulses off mildly relativistic electrons is considered within a QED framework. The temporal shape of the pulse is essential for the differential cross section as a function of the energy of the scattered photon at fixed observation angle. The partly integrated cross section is sensitive to the non-linear dynamics resulting in a large enhancement of the cross section for short and, in particular, for ultra-short flat-top pulse envelopes which can reach several orders of magnitude, as compared with the case of a long pulse. Such effects can be studied experimentally and must be taken into account in Monte-Carlo/transport simulations of %$e^+e^-$ pair production in the interaction of electrons and photons in a strong laser field.

  3. Calculation of Nuclear Deeply Virtual Compton Scattering in HERMES Experiment

    Institute of Scientific and Technical Information of China (English)

    YE Hong-Xue; MAO Ya-Jun; WANG Si-Guang; SUN Bo

    2009-01-01

    We investigate the possibility to acquire information of nuclear generalized parton distribution (GPD) H by studying the deeply virtual Compton scattering (DVCS) off several nuclear targets at the HERMES group (Hadron-Electron Ring Accelerator Measurement of Spin). Two different models are used and developed to demonstrate the leading asymmetry amplitude AsinφLU for coherent-enriched and incoherent-enriched parts with both statistical and systematic uncertainties estimated. It is found that a clear enhancement of ratio of nuclear asymmetry AA,sinφLU to free proton asymmetry AH,sinφLU in the coherent-enriched region is expected by both models, and a decrease of the ratio in incoherent-enriched region; both give the information about nuclear modifications. It is also possible to distinguish between those two models even under the limited statistics.

  4. Fast cooling of bunches in compton storage rings*

    CERN Document Server

    Bulyak, E; Zimmermann, F

    2011-01-01

    We propose an enhancement of laser radiative cooling by utilizing laser pulses of small spatial and temporal dimensions, which interact only with a fraction of an electron bunch circulating in a storage ring. We studied the dynamics of such electron bunch when laser photons scatter off the electrons at a collision point placed in a section with nonzero dispersion. In this case of ‘asymmetric cooling’, the stationary energy spread is much smaller than under conditions of regular scattering where the laser spot size is larger than the electron beam; and the synchrotron oscillations are damped faster. Coherent oscillations of large amplitude may be damped within one synchrotron period, so that this method can support the rapid successive injection of many bunches in longitudinal phase space for stacking purposes. Results of extensive simulations are presented for the performance optimization of Compton gamma-ray sources and damping rings.

  5. Results from the Daresbury Compton backscattering X-ray source

    Energy Technology Data Exchange (ETDEWEB)

    Laundy, D. [STFC Daresbury Laboratory, Daresbury, Warrington, Cheshire, WA4 4AD (United Kingdom); Priebe, G. [Max Born Institute, Max-Born-Strasse 2A, 12489 Berlin, DE (Germany); Jamison, S.P. [STFC Daresbury Laboratory, Daresbury, Warrington, Cheshire, WA4 4AD (United Kingdom); Graham, D.M. [The Photon Science Institute, The University of Manchester, Manchester M13 9PL (United Kingdom); Phillips, P.J. [STFC Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX (United Kingdom); Smith, S.L.; Saveliev, Y. [STFC Daresbury Laboratory, Daresbury, Warrington, Cheshire, WA4 4AD (United Kingdom); Vassilev, S. [The University of Nottingham, Nottingham, NG7 2RD (United Kingdom); Seddon, E.A., E-mail: elaine.seddon@stfc.ac.uk [The Photon Science Institute, The University of Manchester, Manchester M13 9PL (United Kingdom)

    2012-10-11

    The Daresbury Compton Backscattering X-ray Source uses a high power Ti Sapphire laser interacting in head on geometry with electron bunches in the ALICE energy recovery linear accelerator. X-ray photons with peak energy of 21 keV were generated with the accelerator operating at an energy of 29.6 MeV. The spatial profile of the X-rays emitted near the electron beam axis was measured. The characteristics of the X-ray yield measured as a function of relative timing between the laser pulse and the interacting electron bunch was found to be consistent with the modelled intensity behaviour using measured electron and laser beam parameters.

  6. Photon Acceleration of Laser-plasma Based on Compton Scattering

    Institute of Scientific and Technical Information of China (English)

    HAO Dong-shan; XIE Hong-jun

    2006-01-01

    The one-dimensional electron density disturbance is studied by using the inelastic collision model of the relativity electron and photon group, the relativity theory, the momentum equation and the continuity equation, which is generated by a driving laser pulse and scattered laser pulse propagating through a tenuous plasma, and the electron density disturbance is closely associated with the incident laser and scattering laser. The electron plasma wave(EPW)is formed by the propagation of the electron density disturbance. Owing to the action of EPW, the increasing of the frequency of the photons in the incident laser pulses that there is a distance with the driving laser pulses is studied by using optical metric. The results show that it is possible that the photon will gain higher energy from the EPW when photon number is decreased and one-photon Compton scattering enters, the photon will be accelerated.

  7. Spectral characteristics of Compton backscattering sources. Linear and nonlinear modes

    Energy Technology Data Exchange (ETDEWEB)

    Potylitsyn, A.P., E-mail: potylitsyn@tpu.ru [National Research Tomsk Polytechnic University, 634050 Tomsk (Russian Federation); National Research Nuclear University MEPhI, 115409 Moscow (Russian Federation); Kolchuzhkin, A.M. [Moscow State University of Technology “STANKIN”, 127994 Moscow (Russian Federation)

    2015-07-15

    Compton backscattering (CBS) of laser photons by relativistic electrons is widely used to design X-ray and gamma sources with a bandwidth better than 1% using a tight collimation. In order to obtain a reasonable intensity of the resulting beam one has to increase power of a laser pulse simultaneously with narrowing of the waist in the interaction point. It can lead to nonlinearity of CBS process which is affected on spectral characteristics of the collimated gamma beam (so-called “red-shift” of the spectral line, emission of “soft” photons with energy much less than the spectral line energy). In this paper we have analyzed such an influence using Monte-Carlo technique and have shown that even weak nonlinearity should be taken into account if the gamma beam is formed by a narrow aperture.

  8. MPGDs in Compton imaging with liquid-xenon

    CERN Document Server

    Samuel, Duval; Herve, Carduner; Jean-Pierre, Cussonneau; Jacob, Lamblin; Patrick, Le Ray; Eric, Morteau; Tugdual, Oger; Jean-Sebastien, Stutzmann; Dominique, Thers

    2009-01-01

    The interaction of radiation with liquid xenon, inducing both scintillation and ionization signals, is of particular interest for Compton-sequences reconstruction. We report on the development and recent results of a liquid-xenon time-projection chamber, dedicated to a novel nuclear imaging technique named "3 gamma imaging". In a first prototype, the scintillation is detected by a vacuum photomultiplier tube and the charges are collected with a MICROMEGAS structure; both are fully immersed in liquid xenon. In view of the final large-area detector, and with the aim of minimizing dead-zones, we are investigating a gaseous photomultiplier for recording the UV scintillation photons. The prototype concept is presented as well as preliminary results in liquid xenon. We also present soft x-rays test results of a gaseous photomultiplier prototype made of a double Thick Gaseous Electron Multiplier (THGEM) at normal temperature and pressure conditions.

  9. Nonlinear double Compton scattering in the full quantum regime

    CERN Document Server

    Mackenroth, F

    2012-01-01

    A detailed analysis of the process of two photon emission by an electron scattered from a high-intensity laser pulse is presented. The calculations are performed in the framework of strong-field QED and include exactly the presence of the laser field, described as a plane wave. We investigate the full quantum regime of interaction, where photon recoil plays an essential role in the emission process, and substantially alters the emitted photon spectra as compared to those in previously-studied regimes. We provide a semiclassical explanation for such differences, based on the possibility of assigning a trajectory to the electron in the laser field before and after each quantum photon emission. Our numerical results indicate the feasibility of investigating experimentally the full quantum regime of nonlinear double Compton scattering with already available plasma-based electron accelerator and laser technology.

  10. Compton scattering from nuclei and photo-absorption sum rules

    Science.gov (United States)

    Gorchtein, Mikhail; Hobbs, Timothy; Londergan, J. Timothy; Szczepaniak, Adam P.

    2011-12-01

    We revisit the photo-absorption sum rule for real Compton scattering from the proton and from nuclear targets. In analogy with the Thomas-Reiche-Kuhn sum rule appropriate at low energies, we propose a new “constituent quark model” sum rule that relates the integrated strength of hadronic resonances to the scattering amplitude on constituent quarks. We study the constituent quark model sum rule for several nuclear targets. In addition, we extract the α=0 pole contribution for both proton and nuclei. Using the modern high-energy proton data, we find that the α=0 pole contribution differs significantly from the Thomson term, in contrast with the original findings by Damashek and Gilman.

  11. Compton Scattering and Photo-absorption Sum Rules on Nuclei

    Science.gov (United States)

    Gorshteyn, Mikhail; Hobbs, Timothy; Londergan, J. Timothy; Szczepaniak, Adam P.

    2012-03-01

    We revisit the photo-absorption sum rule for real Compton scattering from the proton and from nuclear targets. In analogy with the Thomas-Reiche-Kuhn sum rule appropriate at low energies, we propose a new ``constituent quark model'' sum rule that relates the integrated strength of hadronic resonances to the scattering amplitude on constituent quarks. We study the constituent quark model sum rule for several nuclear targets. In addition we extract the J=0 pole contribution for both proton and nuclei. Using the modern high energy proton data we find that the J=0 pole contribution differs significantly from the Thomson term, in contrast with the original findings by Damashek and Gilman. We discuss phenomenological implications of this new result.

  12. Deeply Virtual Compton Scattering Beam-Spin Asymmetries

    CERN Document Server

    Girod, F X; Ball, J; Bedlinskiy, I; Burkert, V D; De Masi, R; Elouadrhiri, L; Garçon, M; Guidal, M; Jo, H S; Joo, K; Kubarovski, V; Kuleshov, S V; MacCormick, M; Niccolai, S; Pogorelko, O; Sabati, F; Stepanyan, S; Stoler, P; Ungaro, M; Zhao, B; Amaryan, M J; Ambrozewicz, P; Anghinolfi, M; Asryan, G; Bagdasaryan, H; Baillie, N; Ball, J P; Baltzell, N A; Batourine, V; Battaglieri, M; Bellis, M; Benmouna, N; Berman, B L; Biselli, A S; Blaszczyk, L; Bouchigny, S; Boiarinov, S; Bradford, R; Branford, D; Briscoe, W J; Brooks, W K; Bültmann, S; Butuceanu, C; Calarco, J R; Careccia, S L; Carman, D S; Casey, L; Chen, S; Cheng, L; Cole, P L; Collins, P; Coltharp, P; Crabb, D; Credé, V; Dashyan, N; De Sanctis, E; De Vita, R; Degtyarenko, P V; Deur, A; Dharmawardane, K V; Dickson, R; Djalali, C; Dodge, G E; Donnelly, J; Doughty, D; Dugger, M; Dzyubak, O P; Egiyan, H; Egiyan, K S; El Fassi, L; Eugenio, P; Fedotov, G; Feldman, G; Funsten, H; Gavalian, G; Gilfoyle, G P; Giovanetti, K L; Goetz, J T; Gonenc, A; Gothe, R W; Griffioen, K A; Guler, N; Guo, L; Gyurjyan, V; Hafidi, K; Hakobyan, H; Hanretty, C; Hersman, F W; Hicks, K; Hleiqawi, I; Holtrop, M; Hyde, C E; Ilieva, Y; Ireland, D G; Ishkhanov, B S; Isupov, E L; Ito, M M; Jenkins, D; Johnstone, J R; Jüngst, H G; Kalantarians, N; Kellie, J D; Khandaker, M; Kim, W; Klein, A; Klein, F J; Klimenko, A V; Kossov, M; Krahn, Z; Kramer, L H; Kühn, J; Kuhn, S E; Lachniet, J; Laget, J M; Langheinrich, J; Lawrence, D; Lee, T; Livingston, K; Lu, H Y; Markov, N; Mattione, P; Mazouz, M; McKinnon, B; Mecking, B A; Mestayer, M D; Meyer, C A; Mibe, T; Michel, B; Mikhailov, K; Mirazita, M; Miskimen, R; Mokeev, V; Moriya, K; Morrow, S A; Moteabbed, M; Munevar, E; Mutchler, G S; Nadel-Turonski, P; Nasseripour, R; Niculescu, G; Niculescu, I; Niczyporuk, B B; Niroula, M R; Nozar, M; Osipenko, M; Ostrovidov, A I; Park, K; Pasyuk, E; Paterson, C; Anefalos Pereira, S; Pierce, J; Pivnyuk, N; Pocanic, D; Pozdniakov, S; Price, J W; Procureur, S; Prok, Y; Protopopescu, D; Raue, B A; Ricco, G; Ripani, M; Ritchie, B G; Rosner, G; Rossi, P; Salamanca, J; Salgado, C; Santoro, J P; Sapunenko, V; Schumacher, R A; Serov, V S; Sharabyan, Yu G; Sharov, D; Shvedunov, N V; Smith, E S; Smith, L C; Sober, D I; Sokhan, D; Stavinsky, A; Stepanyan, S S; Stokes, B E; Strakovsky, I I; Strauch, S; Taiuti, M; Tedeschi, D J; Tkabladze, A; Tkachenko, S; Tur, C; Vineyard, M F; Vlassov, A V; Voutier, E; Watts, D P; Weinstein, L B; Weygand, D P; Williams, M; Wolin, E; Wood, M H; Yegneswaran, A; Zana, L; Zhang, J; Zhao, Z W

    2007-01-01

    The beam spin asymmetries in the hard exclusive electroproduction of photons on the proton (ep -> epg) were measured over a wide kinematic range and with high statistical accuracy. These asymmetries result from the interference of the Bethe-Heitler process and of deeply virtual Compton scattering. Over the whole kinematic range (x_B from 0.11 to 0.58, Q^2 from 1 to 4.8 GeV^2, -t from 0.09 to 1.8 GeV^2), the azimuthal dependence of the asymmetries is compatible with expectations from leading-twist dominance, A = a*sin(phi)/[1+c*cos(phi)]. This extensive set of data can thus be used to constrain significantly the generalized parton distributions of the nucleon in the valence quark sector.

  13. Measurement of deeply virtual Compton scattering at HERA

    CERN Document Server

    Chekanov, S; Krakauer, D A; Loizides, J H; Magill, S; Musgrave, B; Repond, J; Yoshida, R; Mattingly, M C K; Antonioli, P; Bari, G; Basile, M; Bellagamba, L; Boscherini, D; Bruni, A; Bruni, G; Cara Romeo, G; Cifarelli, Luisa; Cindolo, F; Contin, A; Corradi, M; De Pasquale, S; Giusti, P; Iacobucci, G; Margotti, A; Nania, R; Palmonari, F; Pesci, A; Sartorelli, G; Zichichi, A; Aghuzumtsyan, G; Bartsch, D; Brock, I; Goers, S; Hartmann, H; Hilger, E; Irrgang, P; Jakob, H P; Kappes, A; Katz, U F; Kind, O; Meyer, U; Paul, E; Rautenberg, J; Renner, R; Stifutkin, A; Tandler, J; Voss, K C; Wang, M; Weber, A; Bailey, D S; Brook, N H; Cole, J E; Foster, B; Heath, G P; Heath, H F; Robins, S; Rodrigues, E; Scott, J; Tapper, R J; Wing, M; Capua, M; Mastroberardino, A; Schioppa, M; Susinno, G; Kim, J Y; Kim, Y K; Lee, J H; Lim, I T; Pac, M Y; Caldwell, A; Helbich, M; Liu, X; Mellado, B; Ning, Y; Paganis, S; Ren, Z; Schmidke, W B; Sciulli, F; Chwastowski, J; Eskreys, Andrzej; Figiel, J; Olkiewicz, K; Stopa, P; Zawiejski, L; Adamczyk, L; Bold, T; Grabowska-Bold, I; Kisielewska, D; Kowal, A M; Kowal, M; Kowalski, T; Przybycien, M B; Suszycki, L; Szuba, D; Szuba, J; Kotanski, A; Slominski, W; Adler, D; Bauerdick, L A T; Behrens, U; Bloch, I; Borras, K; Chiochia, V; Dannheim, D; Drews, G; Fourletova, J; Fricke, U; Geiser, A; Göttlicher, P; Gutsche, O; Haas, T; Hain, W; Hartner, G F; Hillert, S; Kahle, B; Kowalski, H; Kramberger, G; Labes, H; Lelas, D; Löhr, B; Mankel, R; Melzer-Pellmann, I A; Moritz, M; Nguyen, C N; Notz, D; Petrucci, M C; Polini, A; Raval, A; Schneekloth, U; Selonke, F; Stoesslein, U; Wessoleck, H; Wolf, G; Youngman, C; Zeuner, W; Schlenstedt, S; Barbagli, G; Gallo, E; Genta, C; Pelfer, P G; Bamberger, A; Benen, A; Coppola, N; Bell, M; Bussey, P J; Doyle, A T; Glasman, C; Hamilton, J; Hanlon, S; Lee, S W; Lupi, A; Saxon, D H; Skillicorn, I O; Gialas, I; Bodmann, B; Carli, T; Holm, U; Klimek, K; Krumnack, N; Lohrmann, E; Milite, M; Salehi, H; Stonjek, S; Wick, K; Ziegler, A; Collins-Tooth, C; Foudas, C; Goncalo, R; Long, K R; Tapper, A D; Cloth, P; Filges, D; Nagano, K; Tokushuku, K; Yamada, S; Yamazaki, Y; Barakbaev, A N; Boos, E G; Pokrovskiy, N S; Zhautykov, B O; Lim, H; Son, D; Barreiro, F; González, O; Labarga, L; Del Peso, J; Tassi, E; Terron, J; Vázquez, M; Barbi, M; Corriveau, F; Gliga, S; Lainesse, J; Padhi, S; Stairs, D G; Tsurugai, T; Antonov, A; Danilov, P; Dolgoshein, B A; Gladkov, D; Sosnovtsev, V V; Suchkov, S; Dementiev, R K; Ermolov, P F; Golubkov, Yu A; Katkov, I I; Khein, L A; Korzhav--, I A; Kuzmin, V A; Levchenko, B B; Lukina, O Yu; Proskuryakov, A S; Shcheglova, L M; Vlasov, N N; Zotkin, S A; Grijpink, S; Koffeman, E; Kooijman, P; Maddox, E; Pellegrino, A; Schagen, S; Tiecke, H G; Velthuis, J J; Wiggers, L; De Wolf, E; Br mmer, N; Bylsma, B; Durkin, L S; Ling, T Y; Cooper-Sarkar, A M; Cottrell, A; Devenish, R C E; Ferrando, J; Grzelak, G; Patel, S; Sutton, M R; Walczak, R; Bertolin, A; Brugnera, R; Carlin, R; Dal Corso, F; Dusini, S; Garfagnini, A; Limentani, S; Longhin, A; Parenti, A; Posocco, M; Stanco, L; Turcato, M; Heaphy, E A; Metlica, F; Oh, B Y; Saull, P R B; Toothacker, W S; Whitmore, J J; Iga, Y; D'Agostini, Giulio; Marini, G; Nigro, A; Cormack, C; Hart, J C; McCubbin, N A; Heusch, C A; Park, I H; Pavel, N; Abramowicz, H; Gabareen, A; Kananov, S; Kreisel, A; Levy, A; Kuze, M; Abe, T; Fusayasu, T; Kagawa, S; Kohno, T; Tawara, T; Yamashita, T; Hamatsu, R; Hirose, T; Inuzuka, M; Kitamura, S; Matsuzawa, K; Nishimura, T; Arneodo, M; Ferrero, M I; Monaco, V; Ruspa, M; Sacchi, R; Solano, A; Koop, T; Levman, G M; Martin, J F; Mirea, A; Butterworth, J M; Gwenlan, C; Hall-Wilton, R; Jones, T W; Lightwood, M S; West, B J; Ciborowski, J; Ciesielski, R; Nowak, R J; Pawlak, J M; Sztuk, J; Tymieniecka, T; Ukleja, A; Ukleja, J; Eisenberg, Y; Gladilin, L K; Hochman, D; Riveline, U; Karshon, M; Kcira, D; Lammers, S; Li, L; Reeder, D D; Savin, A A; Smith, W H; Deshpande, A A; Dhawan, S; Straub, P B; Bhadra, S; Catterall, C D; Fourletov, S; Hartner, G; Menary, S R; Soares, M; Standage, J

    2003-01-01

    The cross section for deeply virtual Compton scattering in the reaction ep -> e gamma p has been measured with the ZEUS detector at HERA using integrated luminosities of 95.0 pb-1 of e+p and 16.7 pb-1 of e-p collisions. Differential cross sections are presented as a function of the exchanged-photon virtuality, Q2, and the centre-of-mass energy, W, of the gamma*p system in the region 5

  14. Measurement of Deeply Virtual Compton Scattering at HERA

    CERN Document Server

    Andreev, V; Aplin, S; Asmone, A; Babaev, A; Backovic, S; Bähr, J; Baghdasaryan, A; Baranov, P; Barrelet, E; Bartel, Wulfrin; Baudrand, S; Baumgartner, S; Becker, J; Beckingham, M; Behnke, O; Behrendt, O; Belousov, A; Berger, C; Berger, N; Bizot, J C; Boenig, M O; Boudry, V; Bracinik, J; Brandt, G; Brisson, V; Brown, D P; Bruncko, Dusan; Büsser, F W; Bunyatyan, A; Buschhorn, G; Bystritskaya, L; Campbell, A J; Caron, S; Cassol-Brunner, F; Cerny, K; Chekelian, V; Contreras, J G; Coughlan, J A; Cox, B E; Cozzika, G; Cvach, J; Dainton, J B; Dau, W D; Daum, K; Delcourt, B; Demirchyan, R; de Roeck, A; Desch, Klaus; De Wolf, E A; Diaconu, C; Dodonov, V; Dubak, A; Eckerlin, G; Efremenko, V; Egli, S; Eichler, R; Eisele, F; Ellerbrock, M; Elsen, E; Erdmann, W; Essenov, S; Faulkner, P J W; Favart, L; Fedotov, A; Felst, R; Ferencei, J; Finke, L; Fleischer, M; Fleischmann, P; Fleming, Y H; Flucke, G; Fomenko, A; Foresti, I; Formánek, J; Franke, G; Frising, G; Frisson, T; Gabathuler, Erwin; Garutti, E; Gayler, J; Gerhards, R; Gerlich, C; Ghazaryan, S; Ginzburgskaya, S; Glazov, A; Glushkov, I; Görlich, L; Göttlich, M; Gogitidze, N; Gorbounov, S; Goyon, C; Grab, C; Greenshaw, T; Gregori, M; Grindhammer, G; Gwilliam, C; Haidt, D; Hajduk, L; Haller, J; Hansson, M; Heinzelmann, G; Henderson, R C W; Henschel, H; Henshaw, O; Herrera-Corral, G; Herynek, I; Heuer, R D; Hildebrandt, M; Hiller, K H; Hoffmann, D; Horisberger, R P; Hovhannisyan, A; Ibbotson, M; Ismail, M; Jacquet, M; Janauschek, L; Janssen, X; Jemanov, V; Jönsson, L B; Johnson, D P; Jung, H; Kapichine, M; Karlsson, M; Katzy, J; Keller, N; Kenyon, I R; Kiesling, C; Klein, M; Kleinwort, C; Klimkovich, T; Kluge, T; Knies, G; Knutsson, A; Korbel, V; Kostka, P; Koutouev, R; Krastev, K; Kretzschmar, J; Kropivnitskaya, A; Krüger, K; Kuckens, J; Landon, M P J; Lange, W; Lastoviicka, T; Laycock, P; Lebedev, A; Leiner, B; Lendermann, V; Levonian, S; Lindfeld, L; Lipka, K; List, B; Lobodzinska, E; Loktionova, N; López-Fernandez, R; Lubimov, V; Lucaci-Timoce, A I; Lüders, H; Lüke, D; Lux, T; Lytkin, L; Makankine, A; Malden, N; Malinovskii, E I; Mangano, S; Marage, P; Marshall, R; Martisikova, M; Martyn, H U; Maxfield, S J; Meer, D; Mehta, A; Meier, K; Meyer, A B; Meyer, H; Meyer, J; Mikocki, S; Milcewicz-Mika, I; Milstead, D; Mohamed, A; Moreau, F; Morozov, A; Morris, J V; Mozer, M U; Müller, K; Murn, P; Nankov, K; Naroska, Beate; Naumann, J; Naumann, T; Newman, P R; Niebuhr, C B; Nikiforov, A; Nikitin, D K; Nowak, G; Nozicka, M; Oganezov, R; Olivier, B; Olsson, J E; Osman, S; Ozerov, D; Pascaud, C; Patel, G D; Peez, M; Pérez, E; Perez-Astudillo, D; Perieanu, A; Petrukhin, A; Pitzl, D; Placakyte, R; Pöschl, R; Portheault, B; Povh, B; Prideaux, P; Raicevic, N; Reimer, P; Rimmer, A; Risler, C; Rizvi, E; Robmann, P; Roland, B; Roosen, R; Rostovtsev, A; Rurikova, Z; Rusakov, S V; Salvaire, F; Sankey, D P C; Sauvan, E; Schatzel, S; Scheins, J; Schilling, F P; Schmidt, S; Schmitt, S; Schmitz, C; Schoeffel, L; Schöning, A; Schröder, V; Schultz-Coulon, H C; Schwanenberger, C; Sedlak, K; Sefkow, F; Shevyakov, I; Shtarkov, L N; Sirois, Y; Sloan, T; Smirnov, P; Soloviev, Yu; South, D; Spaskov, V; Specka, A; Stella, B; Stiewe, J; Strauch, I; Straumann, U; Tchoulakov, V; Thompson, G; Thompson, P D; Tomasz, F; Traynor, D; Truöl, P; Tsakov, I; Tsipolitis, G; Tsurin, I; Turnau, J; Tzamariudaki, E; Urban, M; Usik, A; Utkin, D; Valkár, S; Valkárová, A; Vallée, C; Van Mechelen, P; Van Remortel, N; Vargas-Trevino, A; Vazdik, Ya A; Veelken, C; Vest, A; Vinokurova, S; Volchinski, V; Vujicic, B; Wacker, K; Wagner, J; Weber, G; Weber, R; Wegener, D; Werner, C; Werner, N; Wessels, M; Wessling, B; Wigmore, C; Winter, G G; Wissing, C; Wolf, R; Wünsch, E; Xella, S M; Yan, W; Yeganov, V; Zaicek, J; Zaleisak, J; Zhang, Z; Zhelezov, A; Zhokin, A; Zimmermann, J; Zohrabyan, H G; Zomer, F

    2005-01-01

    A measurement is presented of elastic deeply virtual Compton scattering \\gamma* p \\to \\gamma p made using e^+ p collision data corresponding to a luminosity of 46.5 pb^{-1}, taken with the H1 detector at HERA. The cross section is measured as a function of the photon virtuality, Q^2, the invariant mass of the \\gamma* p system, W, and for the first time, differentially in the squared momentum transfer at the proton vertex, t, in the kinematic range 2 < Q^2 < 80 GeV^2, 30 < W < 140 GeV and |t| < 1 GeV^2. QCD based calculations at next-to-leading order using generalized parton distributions can describe the data, as can colour dipole model predictions.

  15. Hybrid coded aperture and Compton imaging using an active mask

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, L.J. [Los Alamos National Laboratory, Los Alamos, NM (United States)], E-mail: schultz@lanl.gov; Wallace, M.S.; Galassi, M.C.; Hoover, A.S.; Mocko, M.; Palmer, D.M.; Tornga, S.R.; Kippen, R.M. [Los Alamos National Laboratory, Los Alamos, NM (United States); Hynes, M.V.; Toolin, M.J.; Harris, B.; McElroy, J.E. [Raytheon Integrated Defense Systems, Tewksbury, MA (United States); Wakeford, D. [Bubble Technology Industries, Chalk River, Ontario (Canada); Lanza, R.C.; Horn, B.K.P. [Massachusetts Institute of Technology, Cambridge, MA (United States); Wehe, D.K. [University of Michigan, Ann Arbor, MI (United States)

    2009-09-11

    The trimodal imager (TMI) images gamma-ray sources from a mobile platform using both coded aperture (CA) and Compton imaging (CI) modalities. In this paper we will discuss development and performance of image reconstruction algorithms for the TMI. In order to develop algorithms in parallel with detector hardware we are using a GEANT4 [J. Allison, K. Amako, J. Apostolakis, H. Araujo, P.A. Dubois, M. Asai, G. Barrand, R. Capra, S. Chauvie, R. Chytracek, G. Cirrone, G. Cooperman, G. Cosmo, G. Cuttone, G. Daquino, et al., IEEE Trans. Nucl. Sci. NS-53 (1) (2006) 270] based simulation package to produce realistic data sets for code development. The simulation code incorporates detailed detector modeling, contributions from natural background radiation, and validation of simulation results against measured data. Maximum likelihood algorithms for both imaging methods are discussed, as well as a hybrid imaging algorithm wherein CA and CI information is fused to generate a higher fidelity reconstruction.

  16. Effect of Transverse Coupling on Asymmetric Cooling in Compton Rings

    CERN Document Server

    Bulyak, E; Zimmermann, F

    2013-01-01

    Fast cooling of bunches circulating in a Compton ring is achieved by placing the collision point between electron bunches and laser pulses in a dispersive section and by, in addition, introducing a transverse offset between the laser pulse and the electron-beam closed orbit. Growth of the emittance in the dispersive transversal direction due to the additional excitation of betatron oscillations limits this type of cooling. Here we present the results of further studies on the fast cooling process, looking at the effect of the coupling of the transverse (betatron) oscillations. We first show theoretically that the transverse betatron coupling shortens the cooling time and hence reduces the steady-state energy spread of the electron beam, as well as the quantum losses. The theoretical estimates are then validated by simulations. Finally, a proof-of-principle experiment at the KEK ATF Damping Ring is proposed.

  17. A Compton polarimeter for Parametric X-radiation

    CERN Document Server

    They, J; Kotthaus, R; Pugachev, D

    2001-01-01

    A compact 90 deg.-Compton scatter polarimeter has been developed to be used for energy resolved linear polarization analysis of Parametric X-radiation (PXR) in the energy range below 10 keV. The polarimeter employs thermoelectrically cooled silicon drift detectors. The polarization sensitivity and instrumental asymmetries of the polarimeter have been studied with synchrotron radiation at energies from 6 to 11 keV. The analyzing power is close to unity in agreement with expectations and Monte Carlo simulation results. Instrumental asymmetries of a few percent have been measured and corrected with residual statistical uncertainties of O (10 sup - sup 3). The orientation of the polarization plane is determined to be within 4 m.

  18. Gamma-ray Explosion in Multiple Compton Scattering Regime

    CERN Document Server

    Gong, Z; Shou, Y R; Qiao, B; Bulanov, S V; Esirkepov, T Zh; Bulanov, S S; Chen, C E; He, X T; Yan, X Q

    2016-01-01

    Gamma-ray explosion from near critical density (NCD) target irradiated by four symmetrical imploding laser pulses is numerically investigated. With peak intensities about $10^{23}$ W/cm$^2$, the laser pulses boost electron energy through direct laser acceleration, while pushing them inward with the ponderomotive force. After backscattering with counter-propagating laser, the accelerated electron will be trapped in the optical lattice or the electromagnetic standing waves (SW) created by the coherent overlapping of the laser pulses, and meanwhile emit gamma-ray photon in Multiple Compton Scattering regime, where electron acts as a medium to transfer energy from laser to gamma-ray. The energy conversion rate from laser pulses to gamma-ray can be as high as around 50\\%. It may become one of the most efficient gamma-ray sources in laboratory.

  19. High duty cycle inverse Compton scattering X-ray source

    Science.gov (United States)

    Ovodenko, A.; Agustsson, R.; Babzien, M.; Campese, T.; Fedurin, M.; Murokh, A.; Pogorelsky, I.; Polyanskiy, M.; Rosenzweig, J.; Sakai, Y.; Shaftan, T.; Swinson, C.

    2016-12-01

    Inverse Compton Scattering (ICS) is an emerging compact X-ray source technology, where the small source size and high spectral brightness are of interest for multitude of applications. However, to satisfy the practical flux requirements, a high-repetition-rate ICS system needs to be developed. To this end, this paper reports the experimental demonstration of a high peak brightness ICS source operating in a burst mode at 40 MHz. A pulse train interaction has been achieved by recirculating a picosecond CO2 laser pulse inside an active optical cavity synchronized to the electron beam. The pulse train ICS performance has been characterized at 5- and 15- pulses per train and compared to a single pulse operation under the same operating conditions. With the observed near-linear X-ray photon yield gain due to recirculation, as well as noticeably higher operational reliability, the burst-mode ICS offers a great potential for practical scalability towards high duty cycles.

  20. Virtual compton scattering on the proton below pion threshold

    Energy Technology Data Exchange (ETDEWEB)

    Bertin, P.Y.; VCS Collaboration

    1995-12-31

    This paper presents the preliminary results of an electron-proton interaction experiment carried out with the accelerator of MAMI at Mainz (Germany) for the recording of virtual compton scattering events. More than 2 10{sup 4} events were recorded in a two days run with a liquid hydrogen target. The main limitation for the counting rate comes from the limitation of the acquisition rate (100 Hz) and the single rates (10{sup 5}) in the drift chambers. The aim of this experiment is the understanding of both the low energy expansion and the generalized polarizabilities in order to compare, confirm or exclude the models of Quantum Chromodynamics used for the understanding of the nucleon. (J.S.). 3 refs., 5 figs.

  1. Determining the covering factor of Compton-thick active galactic nuclei with NuSTAR

    CERN Document Server

    Brightman, M; Stern, D; Arevalo, P; Ballantyne, D R; Bauer, F E; Boggs, S E; Craig, W W; Christensen, F E; Comastri, A; Fuerst, F; Gandhi, P; Hailey, C J; Harrison, F A; Hickox, R C; Koss, M; LaMassa, S; Puccetti, S; Rivers, E; Vasudevan, R; Walton, D J; Zhang, W W

    2015-01-01

    The covering factor of Compton-thick obscuring material associated with the torus in active galactic nuclei (AGN) is at present best understood through the fraction of sources exhibiting Compton-thick absorption along the line of sight ($N_{H}>1.5\\times10^{24}$ cm$^{-2}$) in the X-ray band, which reveals the average covering factor. Determining this Compton-thick fraction is difficult however, due to the extreme obscuration. With its spectral coverage at hard X-rays ($>$10 keV), NuSTAR is sensitive to the AGN covering factor since Compton scattering of X-rays off optically thick material dominates at these energies. We present a spectral analysis of 10 AGN observed with NuSTAR where the obscuring medium is optically thick to Compton scattering, so called Compton-thick (CT) AGN. We use the torus models of Brightman & Nandra which predict the X-ray spectrum from reprocessing in a torus and include the torus opening angle as a free parameter and aim to determine the covering factor of the Compton-thick gas i...

  2. Compton suppressed LaBr{sub 3} detection system for use in nondestructive spent fuel assay

    Energy Technology Data Exchange (ETDEWEB)

    Bender, S., E-mail: BenderESarah@gmail.com; Heidrich, B.; Ünlü, K.

    2015-06-01

    Current methods for safeguarding and accounting for spent nuclear fuel in reprocessing facilities are extremely resource and time intensive. The incorporation of autonomous passive gamma-ray detectors into the procedure could make the process significantly less burdensome. In measured gamma-ray spectra from spent nuclear fuel, the Compton continuum from dominant fission product photopeaks obscure the lower energy lines from other isotopes. The application of Compton suppression to gamma-ray measurements of spent fuel may reduce this effect and allow other less intense, lower energy peaks to be detected, potentially improving the accuracy of multivariate analysis algorithms. Compton suppressed spectroscopic measurements of spent nuclear fuel using HPGe, LaBr{sub 3}, and NaI(Tl) primary detectors were performed. Irradiated fuel was measured in two configurations: as intact fuel elements viewed through a collimator and as feed solutions in a laboratory to simulate the measurement of a dissolved process stream. These two configurations allowed the direct assessment and quantification of the differences in measured gamma-ray spectra from the application of Compton suppression. In the first configuration, several irradiated fuel elements of varying cooling times from the Penn State Breazeale Reactor spent fuel inventory were measured using the three collimated Compton suppression systems. In the second geometry, Compton suppressed measurements of two samples of Approved Test Material commercial fuel elements were recorded inside the guard detector annulus to simulate the siphoning of small quantities from the main process stream for long dwell measurement periods. Compton suppression was found to improve measured gamma-ray spectra of spent fuel for multivariate analysis by notably lowering the Compton continuum from dominant photopeaks such as {sup 137}Cs and {sup 140}La, due to scattered interactions in the detector, which allowed more spectral features to be resolved

  3. [Segmental wall movement of the left ventricle in healthy persons and myocardial infarct patients studied by a catheter-less nuclear medical method (camera-cinematography of the heart)].

    Science.gov (United States)

    Geffers, H; Sigel, H; Bitter, F; Kampmann, H; Stauch, M; Adam, W E

    1976-08-01

    Camera-Kinematography is a nearly noninvasive method to investigate regional motion of the myocard, and allows evaluation of the function of the heart. About 20 min after injection of 15-20 mCi of 99mTC-Human-Serum-Albumin, when the tracer is distributed homogenously within the bloodpool, data acquisition starts. Myocardial wall motion is represented in an appropriate quasi three-dimensional form. In this representation scars can be revealed as "silent" (akinetic) regions, aneurysms by asynchronic motion. Time activity curves for arbitrarily chosen regions can be calculated and give an equivalent for regional volume changes. 16 patients with an old infarction have been investigated. In fourteen cases the location and extent of regions with abnormal motion could be evaluated. Only two cases of a small posterior wall infarction did not show deviations from normal contraction pattern.

  4. Cryogenic system for X-ray Compton scattering measurements of superfluid helium below 2 K

    Science.gov (United States)

    Tanaka, Hiroyuki; Yamaguchi, Akira; Koizumi, Akihisa; Kawasaki, Ikuto; Sumiyama, Akihiko; Itou, Masayoshi; Sakurai, Yoshiharu

    2017-07-01

    A cryostat was constructed for high-resolution X-ray Compton scattering measurements at temperature down to 1.7 K, in order to investigate superfluid helium-4. Compton profiles of helium were measured using synchrotron X-rays for gas and liquid phases, respectively. In the measurement of the liquid phase, we succeeded in measuring the Compton profile of the superfluid helium at 1.7 K. Comparison of the results with theoretical calculation reveals importance of many-body effects beyond the mean-field treatment of electron systems.

  5. High flux, narrow bandwidth compton light sources via extended laser-electron interactions

    Science.gov (United States)

    Barty, V P

    2015-01-13

    New configurations of lasers and electron beams efficiently and robustly produce high flux beams of bright, tunable, polarized quasi-monoenergetic x-rays and gamma-rays via laser-Compton scattering. Specifically, the use of long-duration, pulsed lasers and closely-spaced, low-charge and low emittance bunches of electron beams increase the spectral flux of the Compton-scattered x-rays and gamma rays, increase efficiency of the laser-electron interaction and significantly reduce the overall complexity of Compton based light sources.

  6. On the bremsstrahlung background correction to the high-energy Compton spectroscopy

    Indian Academy of Sciences (India)

    S Mathur; B L Ahuja

    2005-07-01

    A methodology for bremsstrahlung (BS) background correction to extract a true Compton profile in high-energy Compton scattering experiments is presented. The BS background profiles for Hg, computed within the Born approximation, are estimated for different values of incident energy. It is seen for the first time that the BS background contribution in high-energy Compton profile experiments like those employing third generation synchrotron radiation sources comes out to be significant and non-linear. Further, it is found that the incorporation of BS correction in data reduction of such an experiment performed on Hg at 662 keV energy helps in reconciliation of theory and experiment.

  7. Relationship between Scattered Photon Counts and Concentrations of Some Saline Solutions in Compton Scattering

    Institute of Scientific and Technical Information of China (English)

    LUO Guang; ZHOU Shang-Qi; HAN Zhong; CHEN Shuang-Kou

    2007-01-01

    Compton scattering saline solution was researched.Firstly according to the Compton scattering theory the linear relationship between the concentration and the scattered photon counts was obtained.And then it was proved by Compton scattering experiments for some solutions.According to those experiments, it was found that the slope was decreased when the atomic number of the cation was increased for alkali metal chloride solutions and alkaline-earth metal chloride solutions.Based on those relationships,a new method was promoted with which to measure the concentration of saline solution untouched the measured solution.

  8. Status of the FACT camera

    Energy Technology Data Exchange (ETDEWEB)

    Weitzel, Quirin [ETH Zurich, Institute for Particle Physics, 8093 Zurich (Switzerland); Collaboration: FACT-Collaboration

    2011-07-01

    The First G-APD Cherenkov Telescope (FACT) project develops a novel camera type for very high energy gamma-ray astronomy. A total of 1440 Geiger-mode avalanche photodiodes (G-APD) are used for light detection, each accompanied by a solid light concentrator. All electronics for analog signal processing, digitization and triggering are fully integrated into the camera body. The event data are sent via Ethernet to the counting house. In order to compensate for gain variations of the G-APDs an online feedback system analyzing calibration light pulses is employed. Once the construction and commissioning of the camera is finished it will be transported to La Palma, Canary Islands, and mounted on the refurbished HEGRA CT3 telescope structure. In this talk the architecture and status of the FACT camera is presented.

  9. An Inexpensive Digital Infrared Camera

    Science.gov (United States)

    Mills, Allan

    2012-01-01

    Details are given for the conversion of an inexpensive webcam to a camera specifically sensitive to the near infrared (700-1000 nm). Some experiments and practical applications are suggested and illustrated. (Contains 9 figures.)

  10. The future of consumer cameras

    Science.gov (United States)

    Battiato, Sebastiano; Moltisanti, Marco

    2015-03-01

    In the last two decades multimedia, and in particular imaging devices (camcorders, tablets, mobile phones, etc.) have been dramatically diffused. Moreover the increasing of their computational performances, combined with an higher storage capability, allows them to process large amount of data. In this paper an overview of the current trends of consumer cameras market and technology will be given, providing also some details about the recent past (from Digital Still Camera up today) and forthcoming key issues.

  11. X-ray generation by inverse Compton scattering at the superconducting RF test facility

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Hirotaka, E-mail: hirotaka@post.kek.jp [KEK, 1-1 Oho, Tsukuba 305-0801, Ibaraki (Japan); Akemoto, Mitsuo; Arai, Yasuo; Araki, Sakae; Aryshev, Alexander; Fukuda, Masafumi; Fukuda, Shigeki; Haba, Junji; Hara, Kazufumi; Hayano, Hitoshi; Higashi, Yasuo; Honda, Yosuke; Honma, Teruya; Kako, Eiji; Kojima, Yuji; Kondo, Yoshinari; Lekomtsev, Konstantin; Matsumoto, Toshihiro; Michizono, Shinichiro; Miyoshi, Toshinobu [KEK, 1-1 Oho, Tsukuba 305-0801, Ibaraki (Japan); and others

    2015-02-01

    Quasi-monochromatic X-rays with high brightness have a broad range of applications in fields such as life sciences, bio-, medical applications, and microlithography. One method for generating such X-rays is via inverse Compton scattering (ICS). X-ray generation experiments using ICS were carried out at the superconducting RF test facility (STF) accelerator at KEK. A new beam line, newly developed four-mirror optical cavity system, and new X-ray detector system were prepared for experiments downstream section of the STF electron accelerator. Amplified pulsed photons were accumulated into a four-mirror optical cavity and collided with an incoming 40 MeV electron beam. The generated X-rays were detected using a microchannel plate (MCP) detector for X-ray yield measurements and a new silicon-on-insulator (SOI) detector system for energy measurements. The detected X-ray yield by the MCP detector was 1756.8±272.2 photons/(244 electron bunches). To extrapolate this result to 1 ms train length under 5 Hz operations, 4.60×10{sup 5} photons/1%-bandwidth were obtained. The peak X-ray energy, which was confirmed by the SOI detector, was 29 keV, and this is consistent with ICS X-rays.

  12. Upgrade of X-band thermionic cathode RF gun for Compton scattering X-ray source

    Science.gov (United States)

    Taniguchi, Yoshihiro; Sakamoto, Fumito; Natsui, Takuya; Yamamoto, Tomohiko; Hashimoto, Eiko; Lee, KiWoo; Uesaka, Mitsuru; Yoshida, Mitsuhiro; Higo, Toshiyasu; Fukuda, Shigeki; Akemoto, Mitsuo

    2009-09-01

    A Compton scattering X-ray source consisting of an X-band (11.424 GHz) electron linear accelerator (linac) and Q-switched Nd: YAG laser is currently under development at the University of Tokyo. Monochromatic X-rays are required for a variety of medical and biological applications. The X-ray source produces monochromatic X-rays via collision between a 35-MeV multi-bunch (104 bunches in a 1 μs RF pulse) electron beam and 1.4 J/10 ns (532 nm) Nd: YAG laser pulse. The linac uses an X-band 3.5-cell thermionic cathode RF gun and an alpha magnet as an injector. Until now, electron beam generation (2 MeV, 1 pC/bunch at the exit of the injector), beam acceleration, and X-ray generation have been verified. In order to increase X-ray energy and intensity, we have completed the design and construction of a new RF gun with relevant modifications in some structures. In this paper, we describe the details of the concepts of designing a new RF gun and discuss future works.

  13. Technical Development of Profile Measurement for the Soft X-Ray Via Compton Backward Scattering

    CERN Document Server

    Saito, Taku; Hayano, Hitoshi; Hidume, Kentaro; Kashiwagi, Shigeru; Kuroda, Ryunosuke; Minamiguchi, Shuichi; Oshima, Akihiro; Ueyama, Daisuke; Urakawa, Junji; Washio, Masakazu

    2005-01-01

    A compact X-ray source is called for such various fields as material development, biological science, and medical treatment. At Waseda University, we have already succeeded to generate the soft X-ray of the wavelength within so-called water window region (250-500eV) via Compton backward scattering between 1047nm Nd:YLF laser and 4.2MeV high quality electron beam. Although this method equips some useful characters, e.g. high intensity, short pulse, energy variableness, etc, the X-ray generating system is compact enough to fit in tabletop size. In the next step, there rises two principal tasks, that is, to make the soft X-ray intensity higher, and to progress X-ray profile measurement techniques as preliminary experiments for biomicroscopy. Specifically, we utilize two-pass amp for the former, and irradiate X-ray to a resist film which is previously exposed by UV lamp or get images with X-ray CCD for the latter. In this conference, we will show the experimental results and some future plans.

  14. Constraint on Parameters of Inverse Compton Scattering Model for PSR B2319+60

    Indian Academy of Sciences (India)

    H. G. Wang; M. Lv

    2011-03-01

    Using the multifrequency radio profiles of pulsar PSR B2319+60, two parameters of inverse Compton scattering model, the initial Lorentz factor and the factor of energy loss of relativistic particles are constrained.

  15. Properties of Differential Scattering Section Based on Multi-photon Nonlinear Compton Effect

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Properties of damping electrons in collision with photons based on multi-photon nonlinear Compton effect are investigated. The expressions of the differential scattering section are derived. Several useful conclusions are drawn.

  16. Importance of Compton scattering to radiation spectra of isolated neutron stars

    CERN Document Server

    Suleimanov, V

    2006-01-01

    Model atmospheres of isolated neutron stars with low magnetic field are calculated with Compton scattering taking into account. Models with effective temperatures 1, 3 and 5 MK, with two values of surface gravity log(g)g = 13.9 and 14.3), and different chemical compositions are calculated. Radiation spectra computed with Compton scattering are softer than the computed with Thomson scattering at high energies (E > 5 keV) for hot (T_eff > 1 MK) atmospheres with hydrogen-helium composition. Compton scattering is more significant to hydrogen models with low surface gravity. The emergent spectra of the hottest (T_eff > 3 MK) model atmospheres can be described by diluted blackbody spectra with hardness factors ~ 1.6 - 1.9. Compton scattering is less important for models with solar abundance of heavy elements.

  17. Nucleon spin-averaged forward virtual Compton tensor at large $Q^2$

    CERN Document Server

    Hill, Richard J

    2016-01-01

    The nucleon spin-averaged forward virtual Compton tensor determines important physical quantities such as electromagnetically-induced mass differences of nucleons, and two-photon exchange contributions in hydrogen spectroscopy. It depends on two kinematic variables: $\

  18. Development of TOF-PET using Compton scattering by plastic scintillators

    Science.gov (United States)

    Kuramoto, M.; Nakamori, T.; Kimura, S.; Gunji, S.; Takakura, M.; Kataoka, J.

    2017-02-01

    We propose a time-of-flight (TOF) technique using plastic scintillators which have fast decay time of a few ns for positron emission tomography (PET). While the photoelectric absorption probability of the plastic for 511 keV gamma rays are extremely low due to its small density and effective atomic number, the cross section of Compton scattering is comparable to that of absorption by conventional inorganic scintillators. We thus propose TOF-PET using Compton scattering with plastic scintillators (Compton-PET), and performed fundamental experiments towards exploration of the Compton-PET capability. We demonstrated that the plastic scintillators achieved the better time resolution in comparison to LYSO(Ce) and GAGG(Ce) scintillators. In addition we evaluated the depth-of-interaction resolving capability with the plastic scintillators.

  19. Double Compton and Cyclo-Synchrotron in Super-Eddington Disks, Magnetized Coronae, and Jets

    CERN Document Server

    McKinney, Jonathan C; Wielgus, Maciek; Narayan, Ramesh; Sadowski, Aleksander

    2016-01-01

    We present an extension to the general relativistic radiation magnetohydrodynamic code HARMRAD to account for emission and absorption by thermal cyclo-synchrotron, double Compton, bremsstrahlung, low-temperature OPAL opacities as well as Thomson and Compton scattering. We approximate the radiation field as a Bose-Einstein distribution and evolve it using the radiation number-energy-momentum conservation equations in order to track photon hardening. We perform various simulations to study how these extensions affect the radiative properties of magnetically-arrested disks accreting at Eddington to super-Eddington rates. We find that double Compton dominates bremsstrahlung in the disk within a radius of $r\\sim 15r_g$ (gravitational radii) at a hundred times the Eddington accretion rate, and within smaller radii at lower accretion rates. Double Compton and cyclo-synchrotron regulate radiation and gas temperatures in the corona, while cyclo-synchrotron regulates temperatures in the jet. Interestingly, as the accre...

  20. Narrowband inverse Compton scattering x-ray sources at high laser intensities

    CERN Document Server

    Seipt, D; Surzhykov, A; Fritzsche, S

    2014-01-01

    Narrowband x- and gamma-ray sources based on the inverse Compton scattering of laser pulses suffer from a limitation of the allowed laser intensity due to the onset of nonlinear effects that increase their bandwidth. It has been suggested that laser pulses with a suitable frequency modulation could compensate this ponderomotive broadening and reduce the bandwidth of the spectral lines, which would allow to operate narrowband Compton sources in the high-intensity regime. In this paper we, therefore, present the theory of nonlinear Compton scattering in a frequency modulated intense laser pulse. We systematically derive the optimal frequency modulation of the laser pulse from the scattering matrix element of nonlinear Compton scattering, taking into account the electron spin and recoil. We show that, for some particular scattering angle, an optimized frequency modulation completely cancels the ponderomotive broadening for all harmonics of the backscattered light. We also explore how sensitive this compensation ...

  1. The synchrotron-self-Compton spectrum of relativistic blast waves at large Y

    CERN Document Server

    Lemoine, M

    2015-01-01

    Recent analyses of multiwavelength light curves of gamma-ray bursts afterglows point to values of the magnetic turbulence well below the canonical $\\sim1\\,$\\% of equipartition, in agreement with theoretical expectations of a micro-turbulence generated in the shock precursor, which then decays downstream of the shock front through collisionless damping. As a direct consequence, the Compton parameter $Y$ can take large values in the blast. In the presence of decaying micro-turbulence and/or as a result of the Klein-Nishina suppression of inverse Compton cooling, the $Y$ parameter carries a non-trivial dependence on the electron Lorentz factor, which modifies the spectral shape of the synchrotron and inverse Compton components. This paper provides detailed calculations of this synchrotron-self-Compton spectrum in this large $Y$ regime, accounting for the possibility of decaying micro-turbulence. It calculates the expected temporal and spectral indices $\\alpha$ and $\\beta$ customarily defined by $F_\

  2. Electron Trajectory Reconstruction for Advanced Compton Imaging of Gamma Rays

    Science.gov (United States)

    Plimley, Brian Christopher

    Gamma-ray imaging is useful for detecting, characterizing, and localizing sources in a variety of fields, including nuclear physics, security, nuclear accident response, nuclear medicine, and astronomy. Compton imaging in particular provides sensitivity to weak sources and good angular resolution in a large field of view. However, the photon origin in a single event sequence is normally only limited to the surface of a cone. If the initial direction of the Compton-scattered electron can be measured, the cone can be reduced to a cone segment with width depending on the uncertainty in the direction measurement, providing a corresponding increase in imaging sensitivity. Measurement of the electron's initial direction in an efficient detection material requires very fine position resolution due to the electron's short range and tortuous path. A thick (650 mum), fully-depleted charge-coupled device (CCD) developed for infrared astronomy has 10.5-mum position resolution in two dimensions, enabling the initial trajectory measurement of electrons of energy as low as 100 keV. This is the first time the initial trajectories of electrons of such low energies have been measured in a solid material. In this work, the CCD's efficacy as a gamma-ray detector is demonstrated experimentally, using a reconstruction algorithm to measure the initial electron direction from the CCD track image. In addition, models of fast electron interaction physics, charge transport and readout were used to generate modeled tracks with known initial direction. These modeled tracks allowed the development and refinement of the reconstruction algorithm. The angular sensitivity of the reconstruction algorithm is evaluated extensively with models for tracks below 480 keV, showing a FWHM as low as 20° in the pixel plane, and 30° RMS sensitivity to the magnitude of the out-of-plane angle. The measurement of the trajectories of electrons with energies as low as 100 keV have the potential to make electron

  3. The low Q$^2$ chicane and Compton polarimeter at the JLab EIC

    Energy Technology Data Exchange (ETDEWEB)

    Camsonne, Alexandre [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-03-01

    The JLAB EIC (JLEIC) design includes a chicane after the interaction point to detect electron associated with production of quasi-real photon at the interaction. This chicane layout can also be used for Compton polarimetry to measure the electron beam polarization. This proceeding will present the layout of the low Q^2 chicane and the implementation and current R&D; of a Compton polarimeter which would be located in the middle of this chicane.

  4. Calculating electron momentum densities and Compton profiles using the linear tetrahedron method.

    Science.gov (United States)

    Ernsting, D; Billington, D; Haynes, T D; Millichamp, T E; Taylor, J W; Duffy, J A; Giblin, S R; Dewhurst, J K; Dugdale, S B

    2014-12-10

    A method for computing electron momentum densities and Compton profiles from ab initio calculations is presented. Reciprocal space is divided into optimally-shaped tetrahedra for interpolation, and the linear tetrahedron method is used to obtain the momentum density and its projections such as Compton profiles. Results are presented and evaluated against experimental data for Be, Cu, Ni, Fe3Pt, and YBa2Cu4O8, demonstrating the accuracy of our method in a wide variety of crystal structures.

  5. Simulation of laser-Compton cooling of electron beams for future linear colliders

    Directory of Open Access Journals (Sweden)

    T. Ohgaki

    2001-11-01

    Full Text Available We study a method of laser-Compton cooling of electron beams for future linear colliders. Using a Monte Carlo code, we evaluate the effects of the laser-electron interaction for transverse cooling. The optics with and without chromatic correction for the cooling are examined. The laser-Compton cooling for Japan Linear Collider/Next Linear Collider at E_{0}=2 GeV is considered.

  6. An FPGA-based trigger processor for a measurement of deeply virtual Compton scattering at the COMPASS-II experiment

    Energy Technology Data Exchange (ETDEWEB)

    Schopferer, Sebastian

    2013-12-16

    The COMPASS-II experiment at CERN is focusing on a measurement of the deeply virtual Compton scattering. Several upgrades of the experimental setup have been performed in 2012, namely the construction of a long liquid hydrogen target and a surrounding recoil proton detector called CAMERA. Based on a time-of-flight measurement between two barrels of scintillators, the CAMERA detector allows to detect protons with a kinetic energy down to 35 MeV, which leave the target under large polar angles. At the same time, protons can be distinguished from other particles resulting from background processes by means of an energy loss measurement in the scintillating material. In order to extend the existing COMPASS trigger scheme, a digital trigger system has been developed, which is detailed in the thesis at hand. The trigger system is able to select events with a recoil proton in the final state while suppressing background events, using the particle identification capabilities of the CAMERA detector. Challenging selection criteria based on both the time-of-flight and the energy loss measurement call for a powerful programmable logic board. At the same time, the integration into the existing COMPASS trigger system poses strict constraints on the latency of the trigger decision. For the implementation of the proton trigger system, a new FPGA-based trigger and DAQ hardware called TIGER has been built. The module is operated in two firmware configurations, serving two distinct purposes. Firstly, the trigger processor is responsible for the generation of a trigger signal based on recoil particles, which is included in the global first-level trigger decision. Secondly, a readout concentrator allows to multiplex the data streams of up to 18 readout modules into one link to the DAQ. The CAMERA detector and the corresponding readout and trigger electronics was commissioned during a test run in autumn 2012. This thesis contains details about the trigger concept, the development of the

  7. SUB-CAMERA CALIBRATION OF A PENTA-CAMERA

    Directory of Open Access Journals (Sweden)

    K. Jacobsen

    2016-03-01

    Full Text Available Penta cameras consisting of a nadir and four inclined cameras are becoming more and more popular, having the advantage of imaging also facades in built up areas from four directions. Such system cameras require a boresight calibration of the geometric relation of the cameras to each other, but also a calibration of the sub-cameras. Based on data sets of the ISPRS/EuroSDR benchmark for multi platform photogrammetry the inner orientation of the used IGI Penta DigiCAM has been analyzed. The required image coordinates of the blocks Dortmund and Zeche Zollern have been determined by Pix4Dmapper and have been independently adjusted and analyzed by program system BLUH. With 4.1 million image points in 314 images respectively 3.9 million image points in 248 images a dense matching was provided by Pix4Dmapper. With up to 19 respectively 29 images per object point the images are well connected, nevertheless the high number of images per object point are concentrated to the block centres while the inclined images outside the block centre are satisfying but not very strongly connected. This leads to very high values for the Student test (T-test of the finally used additional parameters or in other words, additional parameters are highly significant. The estimated radial symmetric distortion of the nadir sub-camera corresponds to the laboratory calibration of IGI, but there are still radial symmetric distortions also for the inclined cameras with a size exceeding 5μm even if mentioned as negligible based on the laboratory calibration. Radial and tangential effects of the image corners are limited but still available. Remarkable angular affine systematic image errors can be seen especially in the block Zeche Zollern. Such deformations are unusual for digital matrix cameras, but it can be caused by the correlation between inner and exterior orientation if only parallel flight lines are used. With exception of the angular affinity the systematic image errors

  8. Iterative reconstruction of detector response of an Anger gamma camera

    Science.gov (United States)

    Morozov, A.; Solovov, V.; Alves, F.; Domingos, V.; Martins, R.; Neves, F.; Chepel, V.

    2015-05-01

    Statistical event reconstruction techniques can give better results for gamma cameras than the traditional centroid method. However, implementation of such techniques requires detailed knowledge of the photomultiplier tube light-response functions. Here we describe an iterative method which allows one to obtain the response functions from flood irradiation data without imposing strict requirements on the spatial uniformity of the event distribution. A successful application of the method for medical gamma cameras is demonstrated using both simulated and experimental data. An implementation of the iterative reconstruction technique capable of operating in real time is presented. We show that this technique can also be used for monitoring photomultiplier gain variations.

  9. Double Compton and Cyclo-Synchrotron in Super-Eddington Discs, Magnetized Coronae, and Jets

    Science.gov (United States)

    McKinney, Jonathan C.; Chluba, Jens; Wielgus, Maciek; Narayan, Ramesh; Sadowski, Aleksander

    2017-01-01

    Black hole accretion discs accreting near the Eddington rate are dominated by bremsstrahlung cooling, but above the Eddington rate the double Compton process can dominate in radiation-dominated regions while the cyclo-synchrotron can dominate in strongly-magnetized regions like in a corona or jet. We present an extension to the general relativistic radiation magnetohydrodynamic code HARMRAD to account for emission and absorption by thermal cyclo-synchrotron, double Compton, bremsstrahlung, low-temperature OPAL opacities as well as Thomson and Compton scattering. We approximate the radiation field as a Bose-Einstein distribution and evolve it using the radiation number-energy-momentum conservation equations in order to track photon hardening. We perform various simulations to study how these extensions affect the radiative properties of magnetically-arrested discs accreting at Eddington to super-Eddington rates. We find that double Compton dominates bremsstrahlung in the disc within a radius of r ˜ 15rg (gravitational radii) at a hundred times the Eddington accretion rate, and within smaller radii at lower accretion rates. Double Compton and cyclo-synchrotron regulate radiation and gas temperatures in the corona, while cyclo-synchrotron regulates temperatures in the jet. Interestingly, as the accretion rate drops to Eddington, an optically thin corona develops whose gas temperature of T ˜ 109K is ˜100 times higher than the disc's black body temperature. Our results show the importance of double Compton and synchrotron in super-Eddington discs, magnetized coronae, and jets.

  10. The contribution of bulk Comptonization to the soft X-ray excess in AGN

    Science.gov (United States)

    Kaufman, J.; Blaes, O. M.; Hirose, S.

    2017-01-01

    Bulk velocities exceed thermal velocities for sufficiently radiation pressure dominated accretion flows. We model the contribution of bulk Comptonization to the soft X-ray excess in AGN. Bulk Comptonization is due to both turbulence and the background shear. We calculate spectra both taking into account and not taking into account bulk velocities using scaled data from radiation magnetohydrodynamic (MHD) shearing box simulations. We characterize our results with temperatures and optical depths to make contact with other warm Comptonization models of the soft excess. We chose our fiducial mass, M = 2 × 106M⊙, and accretion rate, L/LEdd = 2.5, to correspond to those fit to the super-Eddington narrow line Seyfert 1 (NLS1) RE1034+396. The temperatures, optical depths, and Compton y parameters we find broadly agree with those fit to RE1034+396. The effect of bulk Comptonization is to shift the Wien tail to higher energy and lower the gas temperature, broadening the spectrum. Observations of the soft excess in NLS1s can constrain the properties of disc turbulence if the bulk Comptonization contribution can be separated out from contributions from other physical effects, such as reflection and absorption.

  11. Recent Results From a Si/CdTe Semiconductor Compton Telescope

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, T.; Watanabe, S.; Takeda, S.; Oonuki, K.; Mitani, T.; Nakazawa, K.; Takashima, T.; Takahashi, T.; Tajima, H.; Sawamoto, N.; Fukazawa, Y.; Nomachi, M.; /JAXA,

    2007-01-23

    We are developing a Compton telescope based on high resolution Si and CdTe detectors for astrophysical observations in sub-MeV/MeV gamma-ray region. Recently, we constructed a prototype Compton telescope which consists of six layers of double-sided Si strip detectors and CdTe pixel detectors to demonstrate the basic performance of this new technology. By irradiating the detector with gamma-rays from radio isotope sources, we have succeeded in Compton reconstruction of images and spectra. The obtained angular resolution is 3.9{sup o} (FWHM) at 511 keV, and the energy resolution is 14 keV (FWHM) at the same energy. In addition to the conventional Compton reconstruction, i.e., drawing cones in the sky, we also demonstrated a full reconstruction by tracking Compton recoil electrons using the signals detected in successive Si layers. By irradiating {sup 137}Cs source, we successfully obtained an image and a spectrum of 662 keV line emission with this method. As a next step, development of larger double-sided Si strip detectors with a size of 4 cm x 4 cm is underway to improve the effective area of the Compton telescope. We are also developing a new low-noise analog ASIC to handle the increasing number of channels. Initial results from these two new technologies are presented in this paper as well.

  12. Can We Trust the Use of Smartphone Cameras in Clinical Practice? Laypeople Assessment of Their Image Quality.

    Science.gov (United States)

    Boissin, Constance; Fleming, Julian; Wallis, Lee; Hasselberg, Marie; Laflamme, Lucie

    2015-11-01

    Smartphone cameras are rapidly being introduced in medical practice, among other devices for image-based teleconsultation. Little is known, however, about the actual quality of the images taken, which is the object of this study. A series of nonclinical objects (from three broad categories) were photographed by a professional photographer using three smartphones (iPhone(®) 4 [Apple, Cupertino, CA], Samsung [Suwon, Korea] Galaxy S2, and BlackBerry(®) 9800 [BlackBerry Ltd., Waterloo, ON, Canada]) and a digital camera (Canon [Tokyo, Japan] Mark II). In a Web survey a convenience sample of 60 laypeople "blind" to the types of camera assessed the quality of the photographs, individually and best overall. We then measured how each camera scored by object category and as a whole and whether a camera ranked best using a Mann-Whitney U test for 2×2 comparisons. There were wide variations between and within categories in the quality assessments for all four cameras. The iPhone had the highest proportion of images individually evaluated as good, and it also ranked best for more objects compared with other cameras, including the digital one. The ratings of the Samsung or the BlackBerry smartphone did not significantly differ from those of the digital camera. Whereas one smartphone camera ranked best more often, all three smartphones obtained results at least as good as those of the digital camera. Smartphone cameras can be a substitute for digital cameras for the purposes of medical teleconsulation.

  13. Traditional gamma cameras are preferred.

    Science.gov (United States)

    DePuey, E Gordon

    2016-08-01

    Although the new solid-state dedicated cardiac cameras provide excellent spatial and energy resolution and allow for markedly reduced SPECT acquisition times and/or injected radiopharmaceutical activity, they have some distinct disadvantages compared to traditional sodium iodide SPECT cameras. They are expensive. Attenuation correction is not available. Cardio-focused collimation, advantageous to increase depth-dependent resolution and myocardial count density, accentuates diaphragmatic attenuation and scatter from subdiaphragmatic structures. Although supplemental prone imaging is therefore routinely advised, many patients cannot tolerate it. Moreover, very large patients cannot be accommodated in the solid-state camera gantries. Since data are acquired simultaneously with an arc of solid-state detectors around the chest, no temporally dependent "rotating" projection images are obtained. Therefore, patient motion can be neither detected nor corrected. In contrast, traditional sodium iodide SPECT cameras provide rotating projection images to allow technologists and physicians to detect and correct patient motion and to accurately detect the position of soft tissue attenuators and to anticipate associated artifacts. Very large patients are easily accommodated. Low-dose x-ray attenuation correction is widely available. Also, relatively inexpensive low-count density software is provided by many vendors, allowing shorter SPECT acquisition times and reduced injected activity approaching that achievable with solid-state cameras.

  14. Développement expérimental d'un télescope Compton au xenon liquide pour l'imagerie médicale fonctionnelle

    OpenAIRE

    Oger, Tugdual

    2012-01-01

    3γ imaging is a new nuclear medical imaging technique which has been suggested by Subatech laboratory. This technique involves locating three-dimensional position of the decay of an innovative radioisotope (β+, γ) emitter the 44Sc. The principle consist in the detection of two photons of 511 keV gamma rays from the decay of the positron, provided by a PET ring detector, associated to the detection of the third photon by a Liquid xenon Compton telescope. The energy deposited in the interaction...

  15. Development of large area gamma-ray camera with GSO(Ce) scintillator arrays and PSPMTs

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, H. [Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa-oiwake, Sakyo, Kyoto 606-8502 (Japan)]. E-mail: nisimura@cr.scphys.kyoto-u.ac.jp; Hattori, K. [Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa-oiwake, Sakyo, Kyoto 606-8502 (Japan); Kabuki, S. [Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa-oiwake, Sakyo, Kyoto 606-8502 (Japan); Kubo, H. [Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa-oiwake, Sakyo, Kyoto 606-8502 (Japan); Miuchi, K. [Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa-oiwake, Sakyo, Kyoto 606-8502 (Japan); Nagayoshi, T. [Advanced Research Institute for Science and Engineering, Waseda University, 17 Kikui-cho, Shinjyuku, Tokyo 162-0044 (Japan); Okada, Y. [Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa-oiwake, Sakyo, Kyoto 606-8502 (Japan); Orito, R. [Department of Physics, Graduate School of Science and Technology, Kobe University, 1-1 Rokkoudai, Nada, Kobe 657-8501 (Japan); Sekiya, H. [Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa-oiwake, Sakyo, Kyoto 606-8502 (Japan); Takada, A. [Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa-oiwake, Sakyo, Kyoto 606-8502 (Japan); Takeda, A. [Kamioka Observatory, ICRR, University of Tokyo, 456 Higasi-mozumi, Hida-shi, Gifu 506-1205 (Japan); Tanimori, T. [Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa-oiwake, Sakyo, Kyoto 606-8502 (Japan); Ueno, K. [Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa-oiwake, Sakyo, Kyoto 606-8502 (Japan)

    2007-04-01

    We have developed a position-sensitive scintillation camera with a large area as an absorber of an advanced Compton gamma-ray camera. At first we tested GSO(Ce) crystals. We compared light output from the GSO(Ce) crystals under various conditions: the method of surface polishing, the concentration of Ce, and co-doping Zr. As a result, we chose the GSO(Ce) crystals doped only 0.5mol% Ce, surface of which was polished by chemical etching for the scintillator of our camera. We also made a 16x16cm{sup 2} scintillation camera which consisted of nine position-sensitive PMTs (PSPMTs Hamamatsu flat-panel H8500 ), the each of which had 8x8 anodes with a pitch of 6mm and coupled to 8x8 arrays of pixelated 6x6x13mm{sup 3} GSO(Ce) scintillators. For the readout system of 576 anodes of the PMTs, we used chained resistors to reduce the number of readout channels down to 48 for saving power consumption. The camera has the position resolution of less than 6mm and a typical energy resolution of 10.5% (FWHM) at 662keV at each pixel in a large area of 16x16cm{sup 2}. Furthermore, we constructed a 16x16 array of 3x3x13mm{sup 3} pixelated GSO(Ce) scintillators, and glued it to a PMT H8500. This camera had the position resolution of less than 3mm in area of 5x5cm{sup 2}, except for some of edge pixels; the energy resolution was typically 13% (FWHM) at 662keV.

  16. Realistic simulation of the Space-borne Compton Polarimeter POLAR

    Science.gov (United States)

    Xiao, Hualin

    2016-07-01

    POLAR is a compact wide field space-borne detector dedicated for precise measurements of the linear polarization of hard x-rays emitted by transient sources. Its energy range sensitivity is optimized for the detection of the prompt emission of Gamma-ray bursts (GRBs). POLAR is developed by an international collaboration of China, Switzerland and Poland. It is planned to be launched into space in 2016 onboard the Chinese space laboratory TG2. The energy range of POLAR spans between 50 keV and 500 keV. POLAR detects gamma rays with an array of 1600 plastic scintillator bars read out by 25 muti-anode PMTs (MAPMTs). Polarization measurements use Compton scattering process and are based on detection of energy depositions in the scintillator bars. Reconstruction of the polarization degree and polarization angle of GRBs requires comparison of experimental modulation curves with realistic simulations of the full instrument response. In this paper we present a method to model and parameterize the detector response including efficiency of the light collection, contributions from crosstalk and non-uniformity of MAPMTs as well as dependency on low energy detection thresholds and noise from readout electronics. The performance of POLAR for determination of polarization is predicted with such realistic simulations and carefully cross-checked with dedicated laboratory tests.

  17. Wide Angle Compton Scattering within the SCET factorization Framework

    Directory of Open Access Journals (Sweden)

    Kivel Nikolay

    2016-01-01

    Full Text Available Existing data for the electromagnetic proton form factors and for the cross section of the wide angle Compton scattering (WACS show that the hard two-gluon exchange mechanism (collinear factorization is still not applicable in the kinematical region where Mandelstam variables s ~ −t ~ −u are about few GeV2. On the other hand these observables can be described in phenomenological models where spectator quarks are soft which assumes a large contribution due to the soft-overlap mechanism. It turns out that the simple QCD factorization picture is not complete and must also include the soft-overlap contribution which can be described as a certain matrix element in the soft collinear effective theory (SCET. Then the leading power contribution to WACS amplitude is described as a sum of the hard- and soft-spectator contributions. The existing experimental data allows one to check certain conclusions based on the assumption about dominant role of the soft-spectator mechanism.

  18. Photon flux and spectrum of {gamma}-rays Compton sources

    Energy Technology Data Exchange (ETDEWEB)

    Petrillo, V., E-mail: Petrillo@mi.infn.it [INFN Milano, Via Celoria, 16 20133 Milano (Italy); Universita degli Studi di Milano, Via Celoria, 16 20133 Milano (Italy); Bacci, A. [INFN Milano, Via Celoria, 16 20133 Milano (Italy); Ben Ali Zinati, R. [Universita degli Studi di Milano, Via Celoria, 16 20133 Milano (Italy); Chaikovska, I. [LAL Universite Paris-Sud IN2P3/CNRS, Orsay-Ville (France); Curatolo, C. [INFN Milano, Via Celoria, 16 20133 Milano (Italy); Universita degli Studi di Milano, Via Celoria, 16 20133 Milano (Italy); Ferrario, M. [LNF, INFN Via E.Fermi, 40 Frascati, Roma (Italy); Maroli, C. [Universita degli Studi di Milano, Via Celoria, 16 20133 Milano (Italy); Ronsivalle, C. [ENEA Via E.Fermi, 45 Frascati, Roma (Italy); Rossi, A.R.; Serafini, L. [INFN Milano, Via Celoria, 16 20133 Milano (Italy); Tomassini, P. [Universita degli Studi di Milano, Via Celoria, 16 20133 Milano (Italy); Vaccarezza, C. [LNF, INFN Via E.Fermi, 40 Frascati, Roma (Italy); Variola, A. [LAL Universite Paris-Sud IN2P3/CNRS, Orsay-Ville (France)

    2012-11-21

    We analyze the characteristics of the {gamma} radiation produced by Compton back-scattering of a high brightness electron beam produced by a photoinjector and accelerated in a linac up to energies of 360-720 MeV and a laser operated at about 500 nm, by comparing classical and quantum models and codes. The interaction produces {gamma} rays in the range 4.9-18.8 MeV. In view of the application to nuclear resonance fluorescence a relative bandwidth of few 10{sup -3} is needed. The bandwidth is reduced by taking advantage of the frequency-angular correlation typical of the phenomenon and selecting the radiation in an angle of tens of {mu}rads. The foreseen spectral density is 20-6 photons per eV in a single shot, a number that can be increased by developing multi-bunch techniques and laser recirculation. In this way a final value of 10{sup 4} photon per eV per second can be achieved.

  19. Photon flux and spectrum of γ-rays Compton sources

    Science.gov (United States)

    Petrillo, V.; Bacci, A.; Ben Alì Zinati, R.; Chaikovska, I.; Curatolo, C.; Ferrario, M.; Maroli, C.; Ronsivalle, C.; Rossi, A. R.; Serafini, L.; Tomassini, P.; Vaccarezza, C.; Variola, A.

    2012-11-01

    We analyze the characteristics of the γ radiation produced by Compton back-scattering of a high brightness electron beam produced by a photoinjector and accelerated in a linac up to energies of 360-720 MeV and a laser operated at about 500 nm, by comparing classical and quantum models and codes. The interaction produces γ rays in the range 4.9-18.8 MeV. In view of the application to nuclear resonance fluorescence a relative bandwidth of few 10-3 is needed. The bandwidth is reduced by taking advantage of the frequency-angular correlation typical of the phenomenon and selecting the radiation in an angle of tens of μrads. The foreseen spectral density is 20-6 photons per eV in a single shot, a number that can be increased by developing multi-bunch techniques and laser recirculation. In this way a final value of 104 photon per eV per second can be achieved.

  20. A new technique to efficiently select Compton-thick AGN

    CERN Document Server

    Severgnini, P; Della Ceca, R

    2012-01-01

    We present a new efficient diagnostic method, based on mid-infrared and X-ray data, to select local (z-0.2. We build up a sample of 43 CT AGN candidates using data from IRAS-PSC and 2XMM catalogue. In order to test the efficiency of the proposed method in selecting CT AGN we use the results of the X-ray spectral analysis performed on all the sources of our sample. After taking into account the different selection effects, we have estimated the number of CT in the local Universe and their density down to the IRAS flux limit of F25=0.5Jy. We find that the diagnostic plot proposed here is an efficient method to select Compton-thick AGN in the nearby Universe since ~84% of the sources populating the proposed CT region are actually CT AGN. Twenty percent are newly-discovered CT AGN. We then estimate the surface density of CT AGN down to the IRAS PSC catalogue flux limit (F25=0.5Jy) that turns out to be ~3e-3 src deg-2. After estimating an equivalent IR-hard X-ray limiting flux, we compare our result with those fou...

  1. Higher twist effects in deeply virtual Compton scattering

    Energy Technology Data Exchange (ETDEWEB)

    Pirnay, Bjoern Michael

    2016-08-01

    In this work we explore the effects of higher twist power corrections on the deeply virtual Compton scattering process. The calculation of the helicity amplitudes for all possible polarization combinations is performed within the framework of QCD operator product expansion. As a result the known accuracy of the amplitudes is improved to include the (kinematic) twist-4 contributions. For the most part the analysis focuses on spin-1/2 targets, the answers for scalar targets conveniently emerge as a byproduct. We investigate the analytical structure of these corrections and prove consistency with QCD factorization. We give an estimation of the numerical impact of the sub-leading twist contributions for proton targets with the help of a phenomenological model for the nonperturbative proton generalized parton distributions. We compare different twist approximations and relate predictions for physical observables to experiments performed by the Hall A, CLAS, HERMES, H1 and ZEUS collaborations. The estimate also includes a numerical study for planned COMPASS-II runs. Throughout the analysis special emphasis is put on the convention dependence induced by finite twist truncation of scattering amplitudes.

  2. Polarized Compton Scattering Experiments at the Mainz Microtron

    Science.gov (United States)

    Martel, Philippe

    2017-01-01

    Interactions between an electromagnetic wave and a proton are described at the basic level by the mass, charge, and anomalous magnetic moment of the proton. Such a description, however, assumes a point-like particle, something the proton is certainly not. The internal structure of the proton leads to higher order terms, such as the scalar and vector polarizabilities, in the interaction. To study these polarizabilities, a multi-experiment program has been undertaken at the Mainz Microtron to measure observables in Compton scattering that exhibit dependence on these parameters. This program has made use of the A2 tagged photon beam, with either a linear or circular polarization, proton targets of either unpolarized LH2 or frozen-spin butanol with transverse or longitudinal polarization, as well as the nearly 4 π detection capability of the Crystal Ball and TAPS detectors. The first of these measurements, the double-polarization asymmetry Σ2 x, also the first of its kind, has already been published. Measurements of the beam asymmetry Σ3 and another double-polarization asymmetry Σ2 z have also been performed and are in various stages of analysis and publication. This talk will discuss the status of these measurements, as well as various fitting studies that are being performed with the data in hand, and plans for future measurements. on behalf of the A2 collaboration at MAMI.

  3. Compton imaging with thick Si and CZT detectors

    Energy Technology Data Exchange (ETDEWEB)

    Subramanian, Mythili, E-mail: mythili.subramanian@gmail.com [George Mason University, 4400 University Dr., Fairfax, VA 22030 (United States); Wulf, Eric A.; Phlips, Bernard [U S Naval Research Lab, 4555 Overlook Ave SW, Washington DC 20375 (United States); Krawczynski, Henric; Martin, Jerrad; Dowknott, Paul [Washington University at St. Louis, St. Louis. MO (United States)

    2012-08-01

    A Compton imaging telescope has been constructed using a 0.2 cm thick Silicon (Si) detector of active area 9.0 Multiplication-Sign 9.0 cm{sup 2} and a pixelated Cadmium Zinc Telluride (CZT) detector of dimensions 2.0 Multiplication-Sign 2.0 Multiplication-Sign 0.5 cm{sup 3}. The Si detector is double sided with 64 strips per side in two orthogonal directions. The CZT detector has 64 pixels of pitch 0.25 cm. We used several ASICs (32 channel) to read out both detectors. A {sup 137}Cs source was used in the study. The energy deposited in the Si and CZT detectors and the points of interaction of the {gamma}-ray in both detectors were read out. We varied the position of the source as well as the vertical separation between the Si and CZT detectors and measured the angular resolution of the source image for the different configurations. The best angular resolution (1{sigma}) was 2.4 Degree-Sign . Monte Carlo simulations were run for similar detector configurations and agree with the experimental results.

  4. GRB Spectra in the complex of synchrotron and Compton processes

    CERN Document Server

    Jiang, Yunguo; Chen, Xu; Li, Kai; Guo, Di-Fu; Li, Yu-Tong; Li, Huai-Zhen; Lin, Hai-Nan; Chang, Zhe

    2015-01-01

    Under the steady state condition, the spectrum of electrons is investigated by solving the continuity equation under the complex radiation of both the synchrotron and Compton processes. The resulted GRB spectrum is a broken power law in both the fast and slow cooling phases. On the basis of this electron spectrum, the spectral indices of the Band function in four different phases are presented. In the complex radiation frame, the detail investigation on physical parameters reveals that both the reverse shock photosphere model and the forward shock with strong coupling model can answer the $\\alpha \\sim -1$ problem. A possible marginal to fast cooling phase transition in GRB 080916C is discussed. The time resolved spectra in different pulses of GRB 100724B, GRB 100826A and GRB 130606B are investigated. We found that the flux is proportional to the peak energy in almost all pulses. The phases for different pulses are determined according to the spectral index revolution. We found the strong correlations between ...

  5. Development of a Compton imager based on bars of scintillator

    CERN Document Server

    MacLeod, A M L; Hanna, D S; Saull, P R B; Sinclair, L E; Seywerd, H C J

    2015-01-01

    We have developed a compact Compton gamma-ray imager with a large field of view and a low channel-count that is capable of quickly localizing gamma-ray sources in the few hundred keV - several MeV range. The two detector planes (scatter and absorber) employ bars of NaI(Tl) read out by photomultiplier tubes (PMTs) located at each end. The long-range imaging performance has been tested from 392 keV to 1274 keV. An angular resolution measure of 2.72 +/- 0.06 degrees and an efficiency of (1.79 +/- 0.04) x 10^(-3) at 662 keV is obtained. A Cs-137 (662 keV) source equivalent to a 10 mCi source 40 m away can be located in 60 seconds with an uncertainty of about a degree. No significant degradation in imaging performance is observed for source angles up to 40 degrees off axis.

  6. Inverse Compton X-ray signature of AGN feedback

    CERN Document Server

    Bourne, Martin A

    2013-01-01

    Bright AGN frequently show ultra-fast outflows (UFOs) with outflow velocities vout ! 0.1c. These outflows may be the source of AGN feedback on their host galaxies sought by galaxy formation modellers. The exact effect of the outflows on the ambient galaxy gas strongly depends on whether the shocked UFOs cool rapidly or not. This in turn depends on whether the shocked electrons share the same temperature as ions (one temperature regime; 1T) or decouple (2T), as has been recently suggested. Here we calculate the Inverse Compton spectrum emitted by such shocks, finding a broad feature potentially detectable either in mid-to-high energy X-rays (1T case) or only in the soft X-rays (2T). We argue that current observations of AGN do not seem to show evidence for the 1T component, while the limits on the 2T emission are far weaker. This suggests that UFOs are in the energy-driven regime outside the central few pc, and must pump considerable amounts of not only momentum but also energy into the ambient gas. We encoura...

  7. Compton-thick Accretion in the local Universe

    CERN Document Server

    Ricci, C; Koss, M J; Trakhtenbrot, B; Bauer, F E; Gandhi, P

    2016-01-01

    Heavily obscured accretion is believed to represent an important stage in the growth of supermassive black holes, and to play an important role in shaping the observed spectrum of the Cosmic X-ray Background (CXB). Hard X-ray (E$>$10 keV) selected samples are less affected by absorption than samples selected at lower energies, and are therefore one of the best ways to detect and identify Compton-thick (CT, $\\log N_{\\rm\\,H}\\geq 24$) Active Galactic Nuclei (AGN). In this letter we present the first results of the largest broad-band (0.3-150 keV) X-ray spectral study of hard X-ray selected AGN to date, focusing on the properties of heavily obscured sources. Our sample includes the 834 AGN (728 non-blazar, average redshift $z\\simeq 0.055$) reported in the 70-months catalog of the all-sky hard X-ray Swift/BAT survey. We find 55 CT AGN, which represent $7.6^{+1.1}_{-2.1}\\%$ of our non-blazar sample. Of these, 26 are reported as candidate CT AGN for the first time. We correct for selection bias and derive the intrin...

  8. FRONT-END ASIC FOR A SILICON COMPTON TELESCOPE.

    Energy Technology Data Exchange (ETDEWEB)

    DE GERONIMO,G.; FRIED, J.; FROST, E.; PHLIPS, B.; VERNON, E.; WULF, E.A.

    2007-10-27

    We describe a front-end application specific integrated circuit (ASIC) developed for a silicon Compton telescope. Composed of 32 channels, it reads out signals in both polarities from each side of a Silicon strip sensor, 2 mm thick 27 cm long, characterized by a strip capacitance of 30 pF. Each front-end channel provides low-noise charge amplification, shaping with a stabilized baseline, discrimination, and peak detection with an analog memory. The channels can process events simultaneously, and the read out is sparsified. The charge amplifier makes uses a dual-cascode configuration and dual-polarity adaptive reset, The low-hysteresis discriminator and the multi-phase peak detector process signals with a dynamic range in excess of four hundred. An equivalent noise charge (ENC) below 200 electrons was measured at 30 pF, with a slope of about 4.5 electrons/pF at a peaking time of 4 {micro}s. With a total dissipated power of 5 mW the channel covers an energy range up to 3.2 MeV.

  9. The intergalactic medium temperature and Compton y parameter

    CERN Document Server

    Zhang, P; Trac, H; Zhang, Pengjie; Pen, Ue-Li; Trac, Hy

    2004-01-01

    (Abridged) The precision modeling of the thermal Sunyaev Zeldovich (SZ) effect and future high accuracy measurements will provide a powerful way to constrain the thermal history of the universe. In this paper, we combine high resolution adiabatic hydro simulations and analytical models to provide a precision modeling of the gas density weighted temperature $\\bar{T}_g$ and the mean SZ Compton $y$ parameter. Simulation artifacts are quantified and corrected and our analytical model passes tests of various simulations and is able to predict $\\bar{T}_g$ and $\\bar{y}$ to several percent accuracy. For low matter density $\\Lambda$CDM cosmology, the present $\\bar{T}_g$ is $0.32 (\\sigma_8/0.84)^{3.05-0.15\\Omega_m}(\\Omega_m/0.268)^{1.28-0.2\\sigma_8} {\\rm keV}$. The mean $y$ parameter is $2.6\\times 10^{-6} (\\sigma_8/0.84)^{4.1-2\\Omega_m}(\\Omega_m/0.268)^{1.28-0.2\\sigma_8}$. The current upper limit of $y<1.5\\times 10^{-5}$ measured by FIRAS has already ruled out combinations of high $\\sigma_8\\ga 1.1$ and high $\\Omega_...

  10. Beam Diagnostics for Laser Undulator Based on Compton Backward Scattering

    CERN Document Server

    Kuroda, R

    2005-01-01

    A compact soft X-ray source is required in various research fields such as material and biological science. The laser undulator based on Compton backward scattering has been developed as a compact soft X-ray source for the biological observation at Waseda University. It is performed in a water window region (250eV - 500 eV) using the interaction between 1047 nm Nd:YLF laser (10ps FWHM) and about 5 MeV high quality electron beam (10ps FWHM) generated from rf gun system. The range of X-ray energy in the water window region has K-shell absorption edges of Oxygen, Carbon and Nitrogen, which mainly constitute of living body. Since the absorption coefficient of water is much smaller than the protein's coefficient in this range, a dehydration of the specimens is not necessary. To generate the soft X-ray pulse stably, the electron beam diagnostics have been developed such as the emittance measurement using double slit scan technique, the bunch length measurement using two frequency analysis technique. In this confere...

  11. Calculation of Theoretical Isotropic Compton Profile for Many Particle Systems

    Science.gov (United States)

    Alzubadi, Ali A.; Albayati, Khalil H.

    Theoretical isotropic (spherically symmetric) Compton profiles (ICP) have been calculated for many particle systems' He, Li, Be and B atoms in their ground states. Our calculations were performed using Roothan-Hartree-Fock (RHF) wave function, HF wave function of Thakkar and re-optimized HF wave function of Clementi-Roetti, taking into account the impulse approximation. The theoretical analysis included a decomposition of the various intra and inter shells and their contributions in the total ICP. A high momentum region of up to 4 a.u. was investigated and a non-negligible tail was observed in all ICP curves. The existence of a high momentum tail was mainly due to the electron-electron interaction. The ICP for the He atom has been compared with the available experimental data and it is found that the ICP values agree very well with them. A few low order radial momentum expectation values and the total energy for these atomic systems have also been calculated and compared with their counterparts' wave functions.

  12. Compton Thick AGN in the XMM-COSMOS survey

    CERN Document Server

    Lanzuisi, G; Georgantopoulos, I; Georgakakis, A; Delvecchio, I; Akylas, T; Berta, S; Bongiorno, A; Brusa, M; Cappelluti, N; Civano, F; Comastri, A; Gilli, R; Gruppioni, C; Hasinger, G; Iwasawa, K; Koekemoer, A; Lusso, E; Marchesi, S; Mainieri, V; Merloni, A; Mignoli, M; Piconcelli, E; Pozzi, F; Rosario, D J; Salvato, M; Silverman, J; Trakhtenbrot, B; Vignali, C; Zamorani, G

    2014-01-01

    Heavily obscured, Compton Thick (CT, NH>10^24 cm-2) AGN may represent an important phase in AGN/galaxy co-evolution and are expected to provide a significant contribution to the cosmic X-ray background (CXB) at its peak. Through direct X-ray spectra analysis, we selected 39 heavily obscured AGN (NH>3x10^23 cm-2) in the 2 deg^2 XMM-COSMOS survey. Thanks to deeper Chandra data available in the field, we can define 10 of these sources as bona-fide CT, spanning a large range of redshift and luminosity, and estimate the efficiency of our selection to be of the order of 80%. We collected the multi-wavelength information available for these sources, to study the distribution of BH mass (MBH), Eddington ratio (lambda_Edd), stellar mass (M*), specific star formation rate (sSFR) in comparison with a sample of unobscured AGN. We find that highly obscured sources tend to have significantly smaller MBH and higher lambda_Edd with respect to unobscured sources. The sSFR of highly obscured sources is consistent with the one ...

  13. Optimization of compton source performance through electron beam shaping

    Science.gov (United States)

    Malyzhenkov, Alexander; Yampolsky, Nikolai

    2017-03-01

    We investigate a novel scheme for significantly increasing the brightness of x-ray light sources based on inverse Compton scattering (ICS) - scattering laser pulses off relativistic electron beams. The brightness of ICS sources is limited by the electron beam quality, since electrons traveling at different angles, and/or having different energies, produce photons with different energies. Therefore, the spectral brightness of the source is defined by the 6D electron phase space shape and size, as well as laser beam parameters. The peak brightness of the ICS source can be maximized, then, if the electron phase space is transformed in a way such that all electrons scatter off the x-ray photons of same frequency in the same direction, arriving to the observer at the same time. We describe the x-ray photon beam quality through the Wigner function (6D photon phase space distribution), and derive it for the ICS source when the electron and laser rms matrices are arbitrary.

  14. Deeply virtual Compton scattering off unpolarised deuterium at HERMES

    Energy Technology Data Exchange (ETDEWEB)

    Hill, Gordon D.

    2008-10-15

    The HERMES experiment was a forward angle spectrometer on the HERA storage ring at DESY, Hamburg, Germany. HERMES successfully increased understanding of the ''spin puzzle'', the spin structure of the nucleon, by providing high precision measurements of {delta}{sigma} in the Quark Parton Model, the fraction of the spin carried by the current quarks. Following the link of another piece of the puzzle, the orbital angular momentum of quarks and gluons, to the Generalised Parton Distribution (GPD) theoretical framework, HERMES focused on measurements of the Deeply Virtual Compton Scattering (DVCS) process. These measurements are sensitive to GPDs, allowing further experimental constraints to be made on the components of nucleon spin. In the Winter shutdown period 2005-2006 HERMES was upgraded with a Recoil Detector in the target region. This allowed the experiment to make exclusive measurements of the DVCS process for the rst time, reducing background and increasing the resolution of various kinematic variables. The method for reconstructing particle tracks in the inhomogeneous magnetic eld is investigated here. DVCS o a deuterium target is measured with all available data prior to the installation of the Recoil Detector. A comparison is made to currently available models of spin-(1)/(2) GPDs. This analysis has been approved for publication by the HERMES collaboration. The data is further employed in an investigation of a model dependent constraint of the total angular momentum of up and down quarks in the nucleon. (orig.)

  15. Optimization of Compton Source Performance through Electron Beam Shaping

    Energy Technology Data Exchange (ETDEWEB)

    Malyzhenkov, Alexander [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Yampolsky, Nikolai [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-26

    We investigate a novel scheme for significantly increasing the brightness of x-ray light sources based on inverse Compton scattering (ICS) - scattering laser pulses off relativistic electron beams. The brightness of ICS sources is limited by the electron beam quality since electrons traveling at different angles, and/or having different energies, produce photons with different energies. Therefore, the spectral brightness of the source is defined by the 6d electron phase space shape and size, as well as laser beam parameters. The peak brightness of the ICS source can be maximized then if the electron phase space is transformed in a way so that all electrons scatter off the x-ray photons of same frequency in the same direction, arriving to the observer at the same time. We describe the x-ray photon beam quality through the Wigner function (6d photon phase space distribution) and derive it for the ICS source when the electron and laser rms matrices are arbitrary.

  16. Two Compton-Thick Active Nuclei in Arp 220?

    CERN Document Server

    Paggi, Alessandro; Risaliti, Guido; Wang, Junfeng; Elvis, Martin

    2013-01-01

    Narrow-band spectral imaging with sub-pixel resolution of the Chandra-ACIS archival observation of the ULIRG merger Arp 220 strongly suggests two Compton thick nuclei, spatially coincident with the infrared and radio emitting nuclear clusters, and separated by 1" (~ 365 pc at a distance of 76 Mpc). These previously undetected highly obscured AGNs - West (W) and East (E) - are imaged, and separated from neighboring sources, in the 6-7 keV band, where the Fe-K lines dominate the emission. The western nucleus is also detected at energies above 7 keV. We estimate Fe-K equivalent width ~ 1 keV or possibly greater for both sources, and observed 2-10 keV luminosities L_X < 3.2 x 10^40 erg/s (W) and <1.3 x 10^40 erg/s (E). From the observed Fe-K lines luminosities{, and assuming on the basis of the XMM-Newton spectrum that 40% of this may be from the 6.4 keV component, we evaluate 2-10 keV intrinsic luminosities L_X ~ 1 x 10^42 erg/s (W) and L_X ~ 0.4 x 10^42 erg/s (E). The inferred X-ray luminosity is at least...

  17. Initial State Helicity Correlation in Wide Angle Compton Scattering

    Science.gov (United States)

    Zhang, Jixie; Day, Donal; Keller, Dustin; Rondon, Oscar

    2014-09-01

    The applicability of pQCD to exclusive reactions at medium energies is a subject of considerable interest. Real Compton scattering (RCS) has the potential to provide insight to this unsettled issue. In pQCD, three active quarks and two hard gluons are involved when describing RCS. But the cross sections do not agree with the pQCD predictions. In contrast, a handbag dominance model, involving only one single quark coupling to the spectator through generalized parton distributions (GPDs) does a good job of matching the cross section data. A measurement of the longitudinal polarization transfer parameter KLL was found inconsistent with predictions of pQCD yet consistent with calculations within the hand-bag mechanism. Further Miller's handbag approach, which including quark and hadron helicity flip, contradicts pQCD and others which demands that KLL =ALL , the initial state helicity correlation asymmetry, by finding that KLL ≠ALL . The first ever measurement of ALL has been proposed to run in Jefferson Lab's Hall C. This experiment will utilize an untagged bremsstrahlung photon beam and the longitudinally polarized UVA/JLAB proton target. After a brief introduction to the physics, the experiment will be described and the expected results presented.

  18. Dark Energy Camera for Blanco

    Energy Technology Data Exchange (ETDEWEB)

    Binder, Gary A.; /Caltech /SLAC

    2010-08-25

    In order to make accurate measurements of dark energy, a system is needed to monitor the focus and alignment of the Dark Energy Camera (DECam) to be located on the Blanco 4m Telescope for the upcoming Dark Energy Survey. One new approach under development is to fit out-of-focus star images to a point spread function from which information about the focus and tilt of the camera can be obtained. As a first test of a new algorithm using this idea, simulated star images produced from a model of DECam in the optics software Zemax were fitted. Then, real images from the Mosaic II imager currently installed on the Blanco telescope were used to investigate the algorithm's capabilities. A number of problems with the algorithm were found, and more work is needed to understand its limitations and improve its capabilities so it can reliably predict camera alignment and focus.

  19. Perceptual Color Characterization of Cameras

    Directory of Open Access Journals (Sweden)

    Javier Vazquez-Corral

    2014-12-01

    Full Text Available Color camera characterization, mapping outputs from the camera sensors to an independent color space, such as \\(XYZ\\, is an important step in the camera processing pipeline. Until now, this procedure has been primarily solved by using a \\(3 \\times 3\\ matrix obtained via a least-squares optimization. In this paper, we propose to use the spherical sampling method, recently published by Finlayson al., to perform a perceptual color characterization. In particular, we search for the \\(3 \\times 3\\ matrix that minimizes three different perceptual errors, one pixel based and two spatially based. For the pixel-based case, we minimize the CIE \\(\\Delta E\\ error, while for the spatial-based case, we minimize both the S-CIELAB error and the CID error measure. Our results demonstrate an improvement of approximately 3for the \\(\\Delta E\\ error, 7& for the S-CIELAB error and 13% for the CID error measures.

  20. The GISMO-2 Bolometer Camera

    Science.gov (United States)

    Staguhn, Johannes G.; Benford, Dominic J.; Fixsen, Dale J.; Hilton, Gene; Irwin, Kent D.; Jhabvala, Christine A.; Kovacs, Attila; Leclercq, Samuel; Maher, Stephen F.; Miller, Timothy M.; Moseley, Samuel H.; Sharp, Elemer H.; Wollack, Edward J.

    2012-01-01

    We present the concept for the GISMO-2 bolometer camera) which we build for background-limited operation at the IRAM 30 m telescope on Pico Veleta, Spain. GISM0-2 will operate Simultaneously in the 1 mm and 2 mm atmospherical windows. The 1 mm channel uses a 32 x 40 TES-based Backshort Under Grid (BUG) bolometer array, the 2 mm channel operates with a 16 x 16 BUG array. The camera utilizes almost the entire full field of view provided by the telescope. The optical design of GISM0-2 was strongly influenced by our experience with the GISMO 2 mm bolometer camera which is successfully operating at the 30m telescope. GISMO is accessible to the astronomical community through the regular IRAM call for proposals.

  1. Towards the Implementation of an Autonomous Camera Algorithm on the da Vinci Platform.

    Science.gov (United States)

    Eslamian, Shahab; Reisner, Luke A; King, Brady W; Pandya, Abhilash K

    2016-01-01

    Camera positioning is critical for all telerobotic surgical systems. Inadequate visualization of the remote site can lead to serious errors that can jeopardize the patient. An autonomous camera algorithm has been developed on a medical robot (da Vinci) simulator. It is found to be robust in key scenarios of operation. This system behaves with predictable and expected actions for the camera arm with respect to the tool positions. The implementation of this system is described herein. The simulation closely models the methodology needed to implement autonomous camera control in a real hardware system. The camera control algorithm follows three rules: (1) keep the view centered on the tools, (2) keep the zoom level optimized such that the tools never leave the field of view, and (3) avoid unnecessary movement of the camera that may distract/disorient the surgeon. Our future work will apply this algorithm to the real da Vinci hardware.

  2. EDICAM (Event Detection Intelligent Camera)

    Energy Technology Data Exchange (ETDEWEB)

    Zoletnik, S. [Wigner RCP RMI, EURATOM Association, Budapest (Hungary); Szabolics, T., E-mail: szabolics.tamas@wigner.mta.hu [Wigner RCP RMI, EURATOM Association, Budapest (Hungary); Kocsis, G.; Szepesi, T.; Dunai, D. [Wigner RCP RMI, EURATOM Association, Budapest (Hungary)

    2013-10-15

    Highlights: ► We present EDICAM's hardware modules. ► We present EDICAM's main design concepts. ► This paper will describe EDICAM firmware architecture. ► Operation principles description. ► Further developments. -- Abstract: A new type of fast framing camera has been developed for fusion applications by the Wigner Research Centre for Physics during the last few years. A new concept was designed for intelligent event driven imaging which is capable of focusing image readout to Regions of Interests (ROIs) where and when predefined events occur. At present these events mean intensity changes and external triggers but in the future more sophisticated methods might also be defined. The camera provides 444 Hz frame rate at full resolution of 1280 × 1024 pixels, but monitoring of smaller ROIs can be done in the 1–116 kHz range even during exposure of the full image. Keeping space limitations and the harsh environment in mind the camera is divided into a small Sensor Module and a processing card interconnected by a fast 10 Gbit optical link. This camera hardware has been used for passive monitoring of the plasma in different devices for example at ASDEX Upgrade and COMPASS with the first version of its firmware. The new firmware and software package is now available and ready for testing the new event processing features. This paper will present the operation principle and features of the Event Detection Intelligent Camera (EDICAM). The device is intended to be the central element in the 10-camera monitoring system of the Wendelstein 7-X stellarator.

  3. Multi-spectral camera development

    CSIR Research Space (South Africa)

    Holloway, M

    2012-10-01

    Full Text Available stream_source_info Holloway_2012.pdf.txt stream_content_type text/plain stream_size 6209 Content-Encoding ISO-8859-1 stream_name Holloway_2012.pdf.txt Content-Type text/plain; charset=ISO-8859-1 Multi-Spectral Camera... Development 4th Biennial Conference Presented by Mark Holloway 10 October 2012 Fused image ? Red, Green and Blue Applications of the Multi-Spectral Camera ? CSIR 2012 Slide 2 Green and Blue, Near Infrared (IR) RED Applications of the Multi...

  4. Production of X-rays by inverse Compton effect; Produccion de rayos X por efecto Compton inverso

    Energy Technology Data Exchange (ETDEWEB)

    Mainardi, R.T. [Facultad de Matematica, Astronomia y Fisica, Universidad Nacional de Cordoba, 5000 Cordoba (Argentina)

    2005-07-01

    X-rays and gamma rays of high energy values can be produced by the scattering of low energy photons with high energy electrons, being this a process controlled by the Compton scattering. If a laser beam is used, the x-ray beam inherits the properties of intensity, monochromaticity and collimation from the laser. In this work we analyze the generation of intense x-ray beams of energies between 10 and 100 KeV to be used in a wide range of applications where a high intensity and high degrees of monochromaticity and polarization are important properties to improve image reduce doses and improve radiation treatments. To this purpose we evaluated, using relativistic kinematics the scattered beam properties in terms of the scattering angle. This arrangement is being considered in several worldwide laboratories as an alternative to synchrotron radiation and is referred to as 'table top synchrotron radiation', since it cost of installation is orders of magnitude smaller than a 'synchrotron radiation source'. The radiation beam might exhibit non-linear properties in its interaction with matter, in a similar way as a laser beam and we will investigate how to calibrate and evaluate TLD dosemeters properties, both in low and high intensity fields either mono or polyenergetic in wide spectral energy ranges. (Author)

  5. Contribution of inner shell Compton ionization to the X-ray fluorescence line intensity

    Science.gov (United States)

    Fernández, Jorge E.; Scot, Viviana; Di Giulio, Eugenio

    2016-10-01

    The Compton effect is a potential ionization mechanism of atoms. It produces vacancies in inner shells that are filled with the same mechanism of atomic relaxation as the one following photo-absorption. This contribution to X-ray fluorescence emission is frequently neglected because the total Compton cross-section is apparently much lower than the photoelectric one at useful X-ray energies. However, a more careful analysis suggests that is necessary to consider single shell cross sections (instead of total cross sections) as a function of energy. In this article these Compton cross sections are computed for the shells K, L1-L3 and M1-M5 in the framework of the impulse approximation. By comparing the Compton and the photoelectric cross-section for each shell it is then possible to determine the extent of the Compton correction to the intensity of the corresponding characteristic lines. It is shown that for the K shell the correction becomes relevant for excitation energies which are too high to be influent in X-ray spectrometry. In contrast, for L and M shells the Compton contribution is relevant for medium-Z elements and medium energies. To illustrate the different grades of relevance of the correction, for each ionized shell, the energies for which the Compton contribution reaches the extent levels of 1, 5, 10, 20, 50 and 100% of the photoelectric one are determined for all the elements with Z = 11-92. For practical applications it is provided a simple formula and fitting coefficients to compute average correction levels for the shells considered.

  6. The Camera Comes to Court.

    Science.gov (United States)

    Floren, Leola

    After the Lindbergh kidnapping trial in 1935, the American Bar Association sought to eliminate electronic equipment from courtroom proceedings. Eventually, all but two states adopted regulations applying that ban to some extent, and a 1965 Supreme Court decision encouraged the banning of television cameras at trials as well. Currently, some states…

  7. OSIRIS camera barrel optomechanical design

    Science.gov (United States)

    Farah, Alejandro; Tejada, Carlos; Gonzalez, Jesus; Cobos, Francisco J.; Sanchez, Beatriz; Fuentes, Javier; Ruiz, Elfego

    2004-09-01

    A Camera Barrel, located in the OSIRIS imager/spectrograph for the Gran Telescopio Canarias (GTC), is described in this article. The barrel design has been developed by the Institute for Astronomy of the University of Mexico (IA-UNAM), in collaboration with the Institute for Astrophysics of Canarias (IAC), Spain. The barrel is being manufactured by the Engineering Center for Industrial Development (CIDESI) at Queretaro, Mexico. The Camera Barrel includes a set of eight lenses (three doublets and two singlets), with their respective supports and cells, as well as two subsystems: the Focusing Unit, which is a mechanism that modifies the first doublet relative position; and the Passive Displacement Unit (PDU), which uses the third doublet as thermal compensator to maintain the camera focal length and image quality when the ambient temperature changes. This article includes a brief description of the scientific instrument; describes the design criteria related with performance justification; and summarizes the specifications related with misalignment errors and generated stresses. The Camera Barrel components are described and analytical calculations, FEA simulations and error budgets are also included.

  8. Deeply virtual Compton scattering off longitudinally polarised protons at HERMES

    Energy Technology Data Exchange (ETDEWEB)

    Mahon, David Francis

    2010-06-15

    This thesis details the simultaneous extraction of three polarisation-dependent asymmetries in the distribution of real photons from the ep{yields}ep{gamma} interaction and its indistinguishable deeply virtual Compton scattering and Bethe-Heitler processes at the HERMES fixed-target experiment at Desy. The data analysed were taken using a longitudinally polarised 27.57 GeV positron beam incident on a longitudinally polarised hydrogen gas target. The extracted asymmetries include two single-spin asymmetries A{sub UL} and A{sub LU} which depend on the polarisation of the target and beam respectively, averaged over all other polarisation states. The double-spin asymmetry A{sub LL} dependent on the product of the beam and target polarisations is extracted for the first time. The asymmetry amplitudes extracted relate to combinations of Generalised Parton Distributions (GPDs), predominantly H and H. The extracted amplitudes are presented across the HERMES kinematic range alongside theoretical predictions from a GPD model based on double distributions. Large sin {phi} and cos(0{phi}) amplitudes are observed for A{sub UL} and A{sub LL} respectively, with an unexpectedly large sin(2{phi}) amplitude for A{sub UL}. The results for the A{sub UL} and A{sub LL} asymmetries are broadly compatible with theory predictions, and the extracted A{sub LU} amplitudes are compatible with HERMES results extracted from a significantly larger data set. It is foreseen that these results will form input to future global data-based GPD models which aim to provide a better understanding of GPDs. (orig.)

  9. A new Compton densitometer for measuring pulmonary edema

    Energy Technology Data Exchange (ETDEWEB)

    Loo, B.W.; Goulding, F.S.; Simon, S.

    1986-02-01

    Pulmonary edema (PE) is the pathological increase of extravascular lung water found most often in patients with congestive heart failure and other critically ill patients who suffer from intravenous fluid overload. The chest x-ray, the standard method for validating the presence of PE, is neither quantitative nor sensitive. A non-invasive lung density monitor that is accurate, easily portable, safe and inexpensive is needed for clinical use. To deal with the problem of attenuation along the beam paths, previous gamma-ray techniques require simultaneous measurement of transmitted and scattered beams. Since multiple scattering is a strong function of the density of the scattering medium and the mass distribution within the detection geometry, there will be inherent uncertainties in the system calibration unless it is performed on a body structure closely matched to that of each individual patient. Other researchers who have employed Compton scattering techniques generally used systems of extended size and detectors with poor energy resolution. This has resulted in significant systematic biases from multiply-scattered photons and larger errors in counting statistics at a given radiation dose to the patient. We are proposing a patented approach in which only backscattered photons are measured with a high-resolution HPGe detector in a compact system geometry. By proper design and a unique data extraction scheme, effects of the variable chest wall on lung density measurements are minimized. Preliminary test results indicate that with a radioactive source of under 30 GBq, it should be possible to make an accurate lung density, measurement in one minute, with a risk of radiation exposure to the patient a thousand times smaller than that from a typical chest x-ray.

  10. Study of Compton suppression for use in spent nuclear fuel assay

    Science.gov (United States)

    Bender, Sarah

    The focus of this study has been to assess Compton suppressed gamma-ray detection systems for the multivariate analysis of spent nuclear fuel. This objective has been achieved using direct measurement of samples of irradiated fuel elements in two geometrical configurations with Compton suppression systems. In order to address the objective to quantify the number of additionally resolvable photopeaks, direct Compton suppressed spectroscopic measurements of spent nuclear fuel in two configurations were performed: as intact fuel elements and as dissolved feed solutions. These measurements directly assessed and quantified the differences in measured gamma-ray spectrum from the application of Compton suppression. Several irradiated fuel elements of varying cooling time from the Penn State Breazeale Reactor spent fuel inventory were measured using three Compton suppression systems that utilized different primary detectors: HPGe, LaBr3, and NaI(Tl). The application of Compton suppression using a LaBr3 primary detector to the measurement of the current core fuel element, which presented the highest count rate, allowed four additional spectral features to be resolved. In comparison, the HPGe-CSS was able to resolve eight additional photopeaks as compared to the standalone HPGe measurement. Measurements with the NaI(Tl) primary detector were unable to resolve any additional peaks, due to its relatively low resolution. Samples of Approved Test Material (ATM) commercial fuel elements were obtained from Pacific Northwest National Laboratory. The samples had been processed using the beginning stages of the PUREX method and represented the unseparated feed solution from a reprocessing facility. Compton suppressed measurements of the ATM fuel samples were recorded inside the guard detector annulus, to simulate the siphoning of small quantities from the main process stream for long dwell measurement periods. Photopeak losses were observed in the measurements of the dissolved ATM

  11. Dynamic Camera Positioning and Reconfiguration for Multi-Camera Networks

    OpenAIRE

    Konda, Krishna Reddy

    2015-01-01

    The large availability of different types of cameras and lenses, together with the reduction in price of video sensors, has contributed to a widespread use of video surveillance systems, which have become a widely adopted tool to enforce security and safety, in detecting and preventing crimes and dangerous events. The possibility for personalization of such systems is generally very high, letting the user customize the sensing infrastructure, and deploying ad-hoc solutions based on the curren...

  12. Collective Evidence for Inverse Compton Emission from External Photons in High-Power Blazars

    Science.gov (United States)

    Meyer, Eileen T.; Fossati, Giovanni; Georganopoulos, Markos; Lister, Matthew L.

    2012-01-01

    We present the first collective evidence that Fermi-detected jets of high kinetic power (L(sub kin)) are dominated by inverse Compton emission from upscattered external photons. Using a sample with a broad range in orientation angle, including radio galaxies and blazars, we find that very high power sources (L(sub kin) > 10(exp 45.5) erg/s) show a significant increase in the ratio of inverse Compton to synchrotron power (Compton dominance) with decreasing orientation angle, as measured by the radio core dominance and confirmed by the distribution of superluminal speeds. This increase is consistent with beaming expectations for external Compton (EC) emission, but not for synchrotron self Compton (SSC) emission. For the lowest power jets (L(sub kin) photon fields. Coupled with the evidence that jet power is linked to the jet speed, this finding suggests that external photon fields become the dominant source of seed photons in the jet comoving frame only for the faster and therefore more powerful jets.

  13. Direct Comparison of Møller and Compton Polarimeters in Hall C at Jefferson Lab

    Science.gov (United States)

    Gaskell, Dave

    2017-01-01

    Knowledge of the electron beam polarization is one of the most important systematic uncertainties in precision, parity-violating electron scattering experiments with next generation experiments aiming to measure the electron beam polarization to better than 0.5%. At high energies, the most typical polarimetry techniques are Møller (polarized electron-electron) and Compton (polarized electron-photon) scattering. The use of two techniques with different systematic uncertainties provides confidence in the extracted beam polarization. Direct comparisons of the two polarimetry techniques are challenging in that Compton polarimeters typically desire maximum beam flux (high beam currents) while Møller polarimeters need to limit the beam current to avoid depolarization effects in the target. We have performed a direct comparison of the Møller and Compton polarimeters in experimental Hall C at Jefferson Lab. This test is unique in that the data were taken sequentially under identical beam conditions at 4.5 μA. We found excellent agreement between the Hall C Møller and Compton polarimeters. Combined with high-current Compton data, we were also able to limit the beam current dependence of the beam polarization to 1% or less up to a beam current of 180 μA. Supported in part by the U.S. Deparment of Energy, contract number AC05-06OR23177, under which Jefferson Science Associates, LLC operates Thomas Jefferson National Accelerator Facility.

  14. Effect of Compton Scattering on the Electron Beam Dynamics at the ATF Damping Ring

    CERN Document Server

    Chaikovska, I; Delerue, N; Variola, A; Zomer, F; Kubo, K; Naito, T; Omori, T; Terunuma, N; Urakawa, J

    2011-01-01

    Compton scattering provides one of the most promising scheme to obtain polarized positrons for the next generation of $e^-$ -- $e^+$ colliders. Moreover it is an attractive method to produce monochromatic high energy polarized gammas for nuclear applications and X-rays for compact light sources. In this framework a four-mirror Fabry-P\\'erot cavity has been installed at the Accelerator Test Facility (ATF - KEK, Tsukuba, Japan) and is used to produce an intense flux of polarized gamma rays by Compton scattering \\cite{ipac-mightylaser}. For electrons at the ATF energy (1.28 GeV) Compton scattering may result in a shorter lifetime due to the limited bucket acceptance. We have implemented the effect of Compton scattering on a 2D tracking code with a Monte-Carlo method. This code has been used to study the longitudinal dynamics of the electron beam at the ATF damping ring, in particular the evolution of the energy spread and the bunch length under Compton scattering. The results obtained are presented and discussed...

  15. On the possibility of using X-ray Compton scattering to study magnetoelectrical properties of crystals

    Energy Technology Data Exchange (ETDEWEB)

    Collins, S. P., E-mail: steve.collins@diamond.ac.uk; Laundy, D.; Connolley, T.; Laan, G. van der; Fabrizi, F. [Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, OX11 0DE (United Kingdom); Janssen, O. [Department of Physics, New York University, New York, NY 10003 (United States); Cooper, M. J. [Department of Physics, University of Warwick, CV4 7AL (United Kingdom); Ebert, H.; Mankovsky, S. [Universität München, Department Chemie, Haus E2.033, Butenandtstrasse 5-13, D-81377 München (Germany)

    2016-02-16

    The possibility of using X-ray Compton scattering to reveal antisymmetric components of the electron momentum density, as a fingerprint of magnetoelectric sample properties, is investigated experimentally and theoretically by studying the polar ferromagnet GaFeO{sub 3}. This paper discusses the possibility of using Compton scattering – an inelastic X-ray scattering process that yields a projection of the electron momentum density – to probe magnetoelectrical properties. It is shown that an antisymmetric component of the momentum density is a unique fingerprint of such time- and parity-odd physics. It is argued that polar ferromagnets are ideal candidates to demonstrate this phenomenon and the first experimental results are shown, on a single-domain crystal of GaFeO{sub 3}. The measured antisymmetric Compton profile is very small (≃ 10{sup −5} of the symmetric part) and of the same order of magnitude as the statistical errors. Relativistic first-principles simulations of the antisymmetric Compton profile are presented and it is shown that, while the effect is indeed predicted by theory, and scales with the size of the valence spin–orbit interaction, its magnitude is significantly overestimated. The paper outlines some important constraints on the properties of the antisymmetric Compton profile arising from the underlying crystallographic symmetry of the sample.

  16. Technical Note: Influence of Compton currents on profile measurements in small-volume ion chambers

    Energy Technology Data Exchange (ETDEWEB)

    Tanny, Sean; Sperling, Nicholas; Parsai, E. Ishmael, E-mail: e.parsai@utoledo.edu [Department of Radiation Oncology, University of Toledo Medical Center, 1325 Conference Drive, Toledo, Ohio 43614 (United States); Holmes, Shannon [Standard Imaging, 3120 Deming Way, Middleton, Wisconsin 53562 (United States)

    2015-10-15

    Purpose: This work is to evaluate the effects of Compton current generation in three small-volume ionization chambers on measured beam characteristics for electron fields. Methods: Beam scans were performed using Exradin A16, A26, and PTW 31014 microchambers. Scans with varying chamber components shielded were performed. Static point measurements, output factors, and cable only irradiations were performed to determine the contribution of Compton currents to various components of the chamber. Monte Carlo simulations were performed to evaluate why one microchamber showed a significant reduction in Compton current generation. Results: Beam profiles demonstrated significant distortion for two of the three chambers when scanned parallel to the chamber axis, produced by electron deposition within the wire. Measurements of ionization produced within the cable identified Compton current generation as the cause of these distortions. The size of the central collecting wire was found to have the greatest influence on the magnitude of Compton current generation. Conclusions: Microchambers can demonstrate significant (>5%) deviations from properties as measured with larger volume chambers (0.125 cm{sup 3} and above). These deviations can be substantially reduced by averaging measurements conducted at opposite polarities.

  17. Architectural Design Document for Camera Models

    DEFF Research Database (Denmark)

    Thuesen, Gøsta

    1998-01-01

    Architecture of camera simulator models and data interface for the Maneuvering of Inspection/Servicing Vehicle (MIV) study.......Architecture of camera simulator models and data interface for the Maneuvering of Inspection/Servicing Vehicle (MIV) study....

  18. Architectural Design Document for Camera Models

    DEFF Research Database (Denmark)

    Thuesen, Gøsta

    1998-01-01

    Architecture of camera simulator models and data interface for the Maneuvering of Inspection/Servicing Vehicle (MIV) study.......Architecture of camera simulator models and data interface for the Maneuvering of Inspection/Servicing Vehicle (MIV) study....

  19. An optical metasurface planar camera

    CERN Document Server

    Arbabi, Amir; Kamali, Seyedeh Mahsa; Horie, Yu; Han, Seunghoon; Faraon, Andrei

    2016-01-01

    Optical metasurfaces are 2D arrays of nano-scatterers that modify optical wavefronts at subwavelength spatial resolution. They are poised to revolutionize optical design by enabling complex low cost systems where multiple metasurfaces are lithographically stacked on top of each other and are integrated with electronics. For imaging applications, metasurface stacks can perform sophisticated image corrections and can be directly integrated with image sensors. Here, we demonstrate this concept with a miniature flat camera integrating a monolithic metasurface lens doublet corrected for monochromatic aberrations, and an image sensor. The doublet lens, which acts as a fisheye photographic objective, has an f-number of 0.9, an angle-of-view larger than 60$^\\circ$$\\times$60$^\\circ$, and operates at 850 nm wavelength with large transmission. The camera exhibits high image quality, which indicates the potential of this technology to produce a paradigm shift in future designs of imaging systems for microscopy, photograp...

  20. Combustion pinhole-camera system

    Science.gov (United States)

    Witte, A.B.

    1982-05-19

    A pinhole camera system is described utilizing a sealed optical-purge assembly which provides optical access into a coal combustor or other energy conversion reactors. The camera system basically consists of a focused-purge pinhole optical port assembly, a conventional TV vidicon receiver, an external, variable density light filter which is coupled electronically to the vidicon automatic gain control (agc). The key component of this system is the focused-purge pinhole optical port assembly which utilizes a purging inert gas to keep debris from entering the port and a lens arrangement which transfers the pinhole to the outside of the port assembly. One additional feature of the port assembly is that it is not flush with the interior of the combustor.

  1. Mirrored Light Field Video Camera Adapter

    OpenAIRE

    Tsai, Dorian; Dansereau, Donald G.; Martin, Steve; Corke, Peter

    2016-01-01

    This paper proposes the design of a custom mirror-based light field camera adapter that is cheap, simple in construction, and accessible. Mirrors of different shape and orientation reflect the scene into an upwards-facing camera to create an array of virtual cameras with overlapping field of view at specified depths, and deliver video frame rate light fields. We describe the design, construction, decoding and calibration processes of our mirror-based light field camera adapter in preparation ...

  2. Automated Placement of Multiple Stereo Cameras

    OpenAIRE

    Malik, Rahul; Bajcsy, Peter

    2008-01-01

    International audience; This paper presents a simulation framework for multiple stereo camera placement. Multiple stereo camera systems are becoming increasingly popular these days. Applications of multiple stereo camera systems such as tele-immersive systems enable cloning of dynamic scenes in real-time and delivering 3D information from multiple geographic locations to everyone for viewing it in virtual (immersive) 3D spaces. In order to make such multi stereo camera systems ubiquitous, sol...

  3. Graphic design of pinhole cameras

    Science.gov (United States)

    Edwards, H. B.; Chu, W. P.

    1979-01-01

    The paper describes a graphic technique for the analysis and optimization of pinhole size and focal length. The technique is based on the use of the transfer function of optical elements described by Scott (1959) to construct the transfer function of a circular pinhole camera. This transfer function is the response of a component or system to a pattern of lines having a sinusoidally varying radiance at varying spatial frequencies. Some specific examples of graphic design are presented.

  4. Compton sources for the observation of elastic photon-photon scattering events

    Science.gov (United States)

    Micieli, D.; Drebot, I.; Bacci, A.; Milotti, E.; Petrillo, V.; Conti, M. Rossetti; Rossi, A. R.; Tassi, E.; Serafini, L.

    2016-09-01

    We present the design of a photon-photon collider based on conventional Compton gamma sources for the observation of elastic γ γ scattering. Two symmetric electron beams, generated by photocathodes and accelerated in linacs, produce two primary gamma rays through Compton backscattering with two high energy lasers. The elastic photon-photon scattering is analyzed by start-to-end simulations from the photocathodes to the detector. A new Monte Carlo code has been developed ad hoc for the counting of the QED events. Realistic numbers of the secondary gamma yield, obtained by using the parameters of existing or approved Compton devices, a discussion of the feasibility of the experiment and of the nature of the background are presented.

  5. Influence of Heat-radiating on Multi-photon Compton Scattering High-energy Electron

    Institute of Scientific and Technical Information of China (English)

    HAO Dong-shan; WANG Xin-min

    2007-01-01

    Using the model of the inverse Compton scattering between high-energy electrons and heat-radiation photons, the influence of heat-radiating photons on multi-photon Compton scattering high-energy electrons is studied . The results show that the energy loss, power loss, light resistance and light pressure of the high-energy electron formed by heat radiating are all proportional to the temperature T4 of the vacuum cavity of the electron,the Lorentz factor γ2 of the high-energy electrons, the scattering section of the electron and the number of photons acting at the same time with high-energy electrons. A good method for lessening the energy loss of the high-energy electron by using the one-photon Compton scattering between high-energy electrons and heat radiation photons is proposed.

  6. Comptonization efficiencies of the variability classes of GRS 1915+105

    CERN Document Server

    Pal, Partha Sarathi; Nandi, Anuj

    2013-01-01

    The Galactic microquasar GRS 1915+105 exhibits at least seventeen types of variability classes. Intra and inter class transitions are reported to be observed within seconds to hours. Since the observation was not continuous, these classes appeared to be exhibited in a random order. Our goal is to predict a sequence of these classes. In this paper, we compute the ratio of the photon counts obtained from the power-law component and the blackbody component of each class and call this ratio as the `Comptonizing efficiency' (CE) of that class. We sequence the classes in the ascending order of CE and find that this sequence matches with a few class transitions observed by RXTE satellite and IXAE instruments on board IRS-P3. A change in CE corresponds to a change in the optical depth of the Compton cloud. Our result implies that the optical depth of the Compton cloud gradually rises as the variability class becomes harder.

  7. Generation of attosecond x-ray and gamma-ray via Compton backscattering.

    Science.gov (United States)

    Chung, Sang-Young; Yoon, Moohyun; Kim, Dong Eon

    2009-05-11

    The generation of an isolated attosecond gamma-ray pulse utilizing Compton backscattering of a relativistic electron bunch has been investigated. The energy of the electron bunch is modulated while the electron bunch interacts with a co-propagating few-cycle CEP (carrier envelope phase)-locked laser in a single-period wiggler. The energy-modulated electron bunch interacts with a counter-propagating driver laser, producing Compton back-scattered radiation. The energy modulation of the electron bunch is duplicated to the temporal modulation of the photon energy of Compton back-scattered radiation. The spectral filtering using a crystal spectrometer allows one to obtain an isolated attosecond gamma-ray.

  8. High-Power Laser Pulse Recirculation for Inverse Compton Scattering-Produced Gamma-Rays

    Energy Technology Data Exchange (ETDEWEB)

    Jovanovic, I; Shverdin, M; Gibson, D; Brown, C

    2007-04-17

    Inverse Compton scattering of high-power laser pulses on relativistic electron bunches represents an attractive method for high-brightness, quasi-monoenergetic {gamma}-ray production. The efficiency of {gamma}-ray generation via inverse Compton scattering is severely constrained by the small Thomson scattering cross section. Furthermore, repetition rates of high-energy short-pulse lasers are poorly matched with those available from electron accelerators, resulting in low repetition rates for generated {gamma}-rays. Laser recirculation has been proposed as a method to address those limitations, but has been limited to only small pulse energies and peak powers. Here we propose and experimentally demonstrate an alternative method for laser pulse recirculation that is uniquely capable of recirculating short pulses with energies exceeding 1 J. Inverse Compton scattering of recirculated Joule-level laser pulses has a potential to produce unprecedented peak and average {gamma}-ray brightness in the next generation of sources.

  9. A simple algorithm for estimation of source-to-detector distance in Compton imaging.

    Science.gov (United States)

    Rawool-Sullivan, Mohini W; Sullivan, John P; Tornga, Shawn R; Brumby, Steven P

    2008-12-01

    Compton imaging is used to predict the location of gamma-emitting radiation sources. The X and Y coordinates of the source can be obtained using a back-projected image and a two-dimensional peak-finding algorithm. The emphasis of this work is to estimate the source-to-detector distance (Z). The algorithm presented uses the solid angle subtended by the reconstructed image at various source-to-detector distances. This algorithm was validated using both measured data from the prototype Compton imager (PCI) constructed at the Los Alamos National Laboratory and simulated data of the same imager. Results show this method can be applied successfully to estimate Z, and it provides a way of determining Z without prior knowledge of the source location. This method is faster than the methods that employ maximum likelihood method because it is based on simple back projections of Compton scatter data.

  10. HEROIC: 3D General Relativistic Radiative Postprocessor with Comptonization for Black Hole Accretion Discs

    CERN Document Server

    Narayan, Ramesh; Psaltis, Dimitrios; Sadowski, Aleksander

    2015-01-01

    We describe HEROIC, an upgraded version of the relativistic radiative post-processor code HERO described in a previous paper, but which now Includes Comptonization. HEROIC models Comptonization via the Kompaneets equation, using a quadratic approximation for the source function in the short characteristics radiation solver. It employs a simple form of accelerated lambda iteration to handle regions of high scattering opacity. In addition to solving for the radiation field, HEROIC also solves for the gas temperature by applying the condition of radiative equilibrium. We present benchmarks and tests of the Comptonization module in HEROIC with simple 1D and 3D scattering problems. We also test the ability of the code to handle various relativistic effects using model atmospheres and accretion flows in a black hole space-time. We present two applications of HEROIC to general relativistic MHD simulations of accretion discs. One application is to a thin accretion disc around a black hole. We find that the gas below ...

  11. Electronic properties of Laves phase ZrFe{sub 2} using Compton spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Bhatt, Samir, E-mail: sameerbhatto11@gmail.com; Kumar, Kishor; Ahuja, B. L. [Department of Physics, University College of Science, ML Sukhadia University, Udaipur-313001 (India); Dashora, Alpa [UM-DAE Centre for Excellence in Basic Sciences, Vidyanagari, Santacruz(E), Mumbai-400098 (India)

    2016-05-06

    First-ever experimental Compton profile of Laves phase ZrFe{sub 2}, using indigenous 20 Ci {sup 137}Cs Compton spectrometer, is presented. To analyze the experimental electron momentum density, we have deduced the theoretical Compton profiles using density functional theory (DFT) and hybridization of DFT and Hartree-Fock scheme within linear combination of atomic orbitals (LCAO) method. The energy bands and density of states are also calculated using LCAO prescription. The theoretical profile based on local density approximation gives a better agreement with the experimental profile than other reported schemes. The present investigations validate the inclusion of correlation potential of Perdew-Zunger in predicting the electronic properties of ZrFe{sub 2}.

  12. High energy Compton spectroscopy and electronic structure of Laves phase ZrFe2

    Science.gov (United States)

    Bhatt, Samir; Kumar, Kishor; Arora, Gunjan; Bapna, Komal; Ahuja, B. L.

    2016-08-01

    We present the first-ever experimental Compton profile of Laves phase ZrFe2 using indigenous 20 Ci 137Cs Compton spectrometer. To annotate the experimental electron momentum density, we have calculated the theoretical Compton profiles using density functional theory (DFT) and hybridization of Hartree-Fock and DFT within linear combination of atomic orbitals (LCAO) method. The spin-polarized energy bands and density of states are computed using LCAO and full potential-linearized augmented plane wave methods. The revised Perdew-Burke-Ernzerhof functional (for solids) based theoretical profile gives a marginally better agreement with the experimental profile as compared to other approximations considered in the present work. The Fermi surface topology of ZrFe2 is explained in terms of majority- and minority-spin energy bands.

  13. Electronic properties of Laves phase ZrFe2 using Compton spectroscopy

    Science.gov (United States)

    Bhatt, Samir; Kumar, Kishor; Dashora, Alpa; Ahuja, B. L.

    2016-05-01

    First-ever experimental Compton profile of Laves phase ZrFe2, using indigenous 20 Ci 137Cs Compton spectrometer, is presented. To analyze the experimental electron momentum density, we have deduced the theoretical Compton profiles using density functional theory (DFT) and hybridization of DFT and Hartree-Fock scheme within linear combination of atomic orbitals (LCAO) method. The energy bands and density of states are also calculated using LCAO prescription. The theoretical profile based on local density approximation gives a better agreement with the experimental profile than other reported schemes. The present investigations validate the inclusion of correlation potential of Perdew-Zunger in predicting the electronic properties of ZrFe2.

  14. Laser-plasma electron accelerator for all-optical inverse Compton X-ray source

    Energy Technology Data Exchange (ETDEWEB)

    Koyama, K. [University of Tokyo, 2-22 Shirakata shirane, Tokai-mura, Naka-gun, Ibaraki 319-1188 (Japan)], E-mail: koyama@nuclear.jp; Yamazaki, A.; Maekawa, A.; Uesaka, M. [University of Tokyo, 2-22 Shirakata shirane, Tokai-mura, Naka-gun, Ibaraki 319-1188 (Japan); Hosokai, T. [Tokyo Institute of Technology, 4259 Nagatsuda-cho, Midori-ku, Yokohama 226-8503 (Japan); Miyashita, M. [Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan); Masuda, S.; Miura, E. [AIST, Tsukuba-central-2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan)

    2009-09-01

    Inverse Compton scattering has been gaining attention as a process for the generation of X/{gamma}-ray, since it produces tunable X/{gamma}-ray pulses with a small cone angle of radiation. A table-top tunable Compton X/{gamma}-ray source would be realized by replacing a radio frequency (rf) linac with a laser wakefield accelerator (LWFA), which is one of the advanced accelerators. An empirical scaling law for the LWFA in the self-injection mode showed that the energy gain was inversely proportional to the plasma density. In order to effectively employ the LWFA as a Compton X/{gamma}-ray source, its stability must be improved. For this purpose, we are developing techniques for the injection of initial electrons by a localized wavebreaking at the density ramp of a plasma. The pointing stability and acceleration efficiency of the electron beam were significantly improved by applying an axial magnetic field to the plasma channel.

  15. A Quartz Cherenkov Detector for Compton-Polarimetry at Future e+e- Colliders

    CERN Document Server

    List, Jenny; Vormwald, Benedikt

    2015-01-01

    Precision polarimetry is essential for future e+ e- colliders and requires Compton polarimeters designed for negligible statistical uncertainties. In this paper, we discuss the design and construction of a quartz Cherenkov detector for such Compton polarimeters. The detector concept has been developed with regard to the main systematic uncertainties of the polarisation measurements, namely the linearity of the detector response and detector alignment. Simulation studies presented here imply that the light yield reachable by using quartz as Cherenkov medium allows to resolve in the Cherenkov photon spectra individual peaks corresponding to different numbers of Compton electrons. The benefits of the application of a detector with such single-peak resolution to the polarisation measurement are shown for the example of the upstream polarimeters foreseen at the International Linear Collider. Results of a first testbeam campaign with a four-channel prototype confirming simulation predictions for single electrons ar...

  16. A calibration system for Compton polarimetry at e{sup +}e{sup -} linear colliders

    Energy Technology Data Exchange (ETDEWEB)

    Vormwald, Benedikt; Vauth, Annika [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Hamburg Univ. (Germany). Inst. fuer Experimentalphysik; List, Jenny [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2015-09-15

    Polarimetry with permille-level precision is essential for future electron-positron linear colliders. Compton polarimeters can reach negligible statistical uncertainties within seconds of measurement time. The dominating systematic uncertainties originate from the response and alignment of the detector which records the Compton scattered electrons. The robust baseline technology for the Compton polarimeters foreseen at future linear colliders is based on an array of gas Cherenkov detectors read out by photomultipliers. In this paper, we will present a calibration method which promises to monitor nonlinearities in the response of such a detector at the level of a few permille. This method has been implemented in an LED-based calibration system which matches the existing prototype detector. The performance of this calibration system is sufficient to control the corresponding contribution to the total uncertainty on the extracted polarisation to better than 0.1%.

  17. A Calibration System for Compton Polarimetry at $e^+e^-$ Linear Colliders

    CERN Document Server

    Vormwald, Benedikt; Vauth, Annika

    2015-01-01

    Polarimetry with permille-level precision is essential for future electron-positron linear colliders. Compton polarimeters can reach negligible statistical uncertainties within seconds of measurement time. The dominating systematic uncertainties originate from the response and alignment of the detector which records the Compton scattered electrons. The robust baseline technology for the Compton polarimeters foreseen at future linear colliders is based on an array of gas Cherenkov detectors read out by photomultipliers. In this paper, we will present a calibration method which promises to monitor nonlinearities in the response of such a detector at the level of a few permille. This method has been implemented in an LED-based calibration system which matches the existing prototype detector. The performance of this calibration system is sufficient to control the corresponding contribution to the total uncertainty on the extracted polarisation to better than $0.1\\%$.

  18. A method for determination mass absorption coefficient of gamma rays by Compton scattering.

    Science.gov (United States)

    El Abd, A

    2014-12-01

    A method was proposed for determination mass absorption coefficient of gamma rays for compounds, alloys and mixtures. It is based on simulating interaction processes of gamma rays with target elements having atomic numbers from Z=1 to Z=92 using the MCSHAPE software. Intensities of Compton scattered gamma rays at saturation thicknesses and at a scattering angle of 90° were calculated for incident gamma rays of different energies. The obtained results showed that the intensity of Compton scattered gamma rays at saturations and mass absorption coefficients can be described by mathematical formulas. These were used to determine mass absorption coefficients for compound, alloys and mixtures with the knowledge of their Compton scattered intensities. The method was tested by calculating mass absorption coefficients for some compounds, alloys and mixtures. There is a good agreement between obtained results and calculated ones using WinXom software. The advantages and limitations of the method were discussed.

  19. Automatic tracking sensor camera system

    Science.gov (United States)

    Tsuda, Takao; Kato, Daiichiro; Ishikawa, Akio; Inoue, Seiki

    2001-04-01

    We are developing a sensor camera system for automatically tracking and determining the positions of subjects moving in three-dimensions. The system is intended to operate even within areas as large as soccer fields. The system measures the 3D coordinates of the object while driving the pan and tilt movements of camera heads, and the degree of zoom of the lenses. Its principal feature is that it automatically zooms in as the object moves farther away and out as the object moves closer. This maintains the area of the object as a fixed position of the image. This feature makes stable detection by the image processing possible. We are planning to use the system to detect the position of a soccer ball during a soccer game. In this paper, we describe the configuration of the developing automatic tracking sensor camera system. We then give an analysis of the movements of the ball within images of games, the results of experiments on method of image processing used to detect the ball, and the results of other experiments to verify the accuracy of an experimental system. These results show that the system is sufficiently accurate in terms of obtaining positions in three-dimensions.

  20. Unassisted 3D camera calibration

    Science.gov (United States)

    Atanassov, Kalin; Ramachandra, Vikas; Nash, James; Goma, Sergio R.

    2012-03-01

    With the rapid growth of 3D technology, 3D image capture has become a critical part of the 3D feature set on mobile phones. 3D image quality is affected by the scene geometry as well as on-the-device processing. An automatic 3D system usually assumes known camera poses accomplished by factory calibration using a special chart. In real life settings, pose parameters estimated by factory calibration can be negatively impacted by movements of the lens barrel due to shaking, focusing, or camera drop. If any of these factors displaces the optical axes of either or both cameras, vertical disparity might exceed the maximum tolerable margin and the 3D user may experience eye strain or headaches. To make 3D capture more practical, one needs to consider unassisted (on arbitrary scenes) calibration. In this paper, we propose an algorithm that relies on detection and matching of keypoints between left and right images. Frames containing erroneous matches, along with frames with insufficiently rich keypoint constellations, are detected and discarded. Roll, pitch yaw , and scale differences between left and right frames are then estimated. The algorithm performance is evaluated in terms of the remaining vertical disparity as compared to the maximum tolerable vertical disparity.

  1. Coaxial fundus camera for opthalmology

    Science.gov (United States)

    de Matos, Luciana; Castro, Guilherme; Castro Neto, Jarbas C.

    2015-09-01

    A Fundus Camera for ophthalmology is a high definition device which needs to meet low light illumination of the human retina, high resolution in the retina and reflection free image1. Those constraints make its optical design very sophisticated, but the most difficult to comply with is the reflection free illumination and the final alignment due to the high number of non coaxial optical components in the system. Reflection of the illumination, both in the objective and at the cornea, mask image quality, and a poor alignment make the sophisticated optical design useless. In this work we developed a totally axial optical system for a non-midriatic Fundus Camera. The illumination is performed by a LED ring, coaxial with the optical system and composed of IR of visible LEDs. The illumination ring is projected by the objective lens in the cornea. The Objective, LED illuminator, CCD lens are coaxial making the final alignment easily to perform. The CCD + capture lens module is a CCTV camera with autofocus and Zoom built in, added to a 175 mm focal length doublet corrected for infinity, making the system easily operated and very compact.

  2. Hadronic weak charges and parity-violating forward Compton scattering

    Science.gov (United States)

    Gorchtein, Mikhail; Spiesberger, Hubert

    2016-11-01

    Background: Parity-violating elastic electron-nucleon scattering at low momentum transfer allows one to access the nucleon's weak charge, the vector coupling of the Z -boson to the nucleon. In the Standard Model and at tree level, the weak charge of the proton is related to the weak mixing angle and accidentally suppressed, QWp ,tree=1 -4 sin2θW≈0.07 . Modern experiments aim at extracting QWp at ˜1 % accuracy. Similarly, parity nonconservation in atoms allows to access the weak charge of atomic nuclei. Purpose: We consider a novel class of radiative corrections due to the exchange of two photons, with parity violation in the hadronic/nuclear system. These corrections are prone to long-range interactions and may affect the extraction of sin2θW from the experimental data at the relevant level of precision. Methods: The two-photon exchange contribution to the parity-violating electron-proton scattering amplitude is studied in the framework of forward dispersion relations. We address the general properties of the parity-violating forward Compton scattering amplitude and use relativistic chiral perturbation theory to provide the first field-theoretical proof that it obeys a superconvergence relation. Results: We show that the significance of this new correction increases with the beam energy in parity-violating electron scattering, but the superconvergence relation protects the formal definition of the weak charge as a limit at zero-momentum transfer and zero energy. We evaluate the new correction in a hadronic model with pion loops and the Δ (1232 ) resonance, supplemented with a high-energy contribution. For the kinematic conditions of existing and upcoming experiments we show that two-photon exchange corrections with hadronic or nuclear parity violation do not pose a problem for the interpretation of the data in terms of the weak mixing angle at the present level of accuracy. Conclusions: Two-photon exchange in presence of hadronic or nuclear parity violation

  3. Polarized gamma-rays with laser-Compton backscattering

    Energy Technology Data Exchange (ETDEWEB)

    Ohgaki, H.; Noguchi, T.; Sugiyama, S. [Electrotechnical Lab., Ibaraki (Japan)] [and others

    1995-12-31

    Polarized gamma-rays were generated through laser-Compton backscattering (LCS) of a conventional Nd:YAG laser with electrons circulating in the electron storage ring TERAS at Electrotechnical Laboratory. We measured the energy, the energy spread, and the yield of the gamma-rays to characterize our gamma-ray source. The gamma-ray energy can be varied by changing the energy of the electrons circulating the storage ring. In our case, the energy of electrons in the storage ring were varied its energy from 200 to 750 MeV. Consequently, we observed gamma-ray energies of 1 to 10 MeV with 1064 run laser photons. Furthermore, the gamma-ray energy was extended to 20 MeV by using the 2nd harmonic of the Nd:YAG laser. This shows a good agreement with theoretical calculation. The gamma-ray energy spread was also measured to be 1% FWHM for -1 MeV gamma-rays and to be 4% FWHM for 10 MeV gamma-rays with a narrow collimator that defined the scattering cone. The gamma-ray yield was 47.2 photons/mA/W/s. This value is consistent with a rough estimation of 59.5 photons/mA/W/s derived from theory. Furthermore, we tried to use these gamma-rays for a nuclear fluorescence experiment. If we use a polarized laser beam, we can easily obtain polarized gamma-rays. Elastically scattered photons from {sup 208} Pb were clearly measured with the linearly polarized gamma-rays, and we could assign the parity of J=1 states in the nucleus. We should emphasize that the polarized gamma-ray from LCS is quit useful in this field, because we can use highly, almost completely, polarized gamma-rays. We also use the LCS gamma-rays to measure the photon absorption coefficients. In near future, we will try to generate a circular polarized gamma-ray. We also have a plan to use an FEL, because it can produce intense laser photons in the same geometric configuration as the LCS facility.

  4. Image Based Camera Localization: an Overview

    OpenAIRE

    Wu, Yihong

    2016-01-01

    Recently, virtual reality, augmented reality, robotics, self-driving cars et al attractive much attention of industrial community, in which image based camera localization is a key task. It is urgent to give an overview of image based camera localization. In this paper, an overview of image based camera localization is presented. It will be useful to not only researchers but also engineers.

  5. 21 CFR 886.1120 - Opthalmic camera.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Opthalmic camera. 886.1120 Section 886.1120 Food... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1120 Opthalmic camera. (a) Identification. An ophthalmic camera is an AC-powered device intended to take photographs of the eye and the surrounding...

  6. 21 CFR 892.1110 - Positron camera.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Positron camera. 892.1110 Section 892.1110 Food... DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1110 Positron camera. (a) Identification. A positron camera is a device intended to image the distribution of positron-emitting radionuclides in the...

  7. 16 CFR 501.1 - Camera film.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Camera film. 501.1 Section 501.1 Commercial Practices FEDERAL TRADE COMMISSION RULES, REGULATIONS, STATEMENT OF GENERAL POLICY OR INTERPRETATION AND... 500 § 501.1 Camera film. Camera film packaged and labeled for retail sale is exempt from the...

  8. Modulated method for efficient, narrow-bandwidth, laser Compton X-ray and gamma-ray sources

    Energy Technology Data Exchange (ETDEWEB)

    Barty, Christopher P. J.

    2017-07-11

    A method of x-ray and gamma-ray generation via laser Compton scattering uses the interaction of a specially-formatted, highly modulated, long duration, laser pulse with a high-frequency train of high-brightness electron bunches to both create narrow bandwidth x-ray and gamma-ray sources and significantly increase the laser to Compton photon conversion efficiency.

  9. Conceptual design report of a compton polarimeter for CEBAF hall A

    Energy Technology Data Exchange (ETDEWEB)

    Bardin, G.; Cavata, C.; Neyret, D.; Frois, B.; Jorda, J.P.; Legoff, J.M.; Platchkov, S.; Steinmetz, L.; Juillard, M.; Authier, M.; Mangeot, P.; Rebourgeard, P.; Colombel, N.; Girardot, P.; Martinot, J.; Sellier, J.C.; Veyssiere, C. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee; Berthot, J.; Bertin, P.Y.; Breton, V.; Fonvieille, H.; Roblin, Y. [Institut National de Physique Nucleaire et de Physique des Particules (IN2P3), 75 - Paris (France); Chen, J.P. [Continuous Electron Beam Accelerator Facility, Newport News, VA (United States)

    1996-12-31

    This report describes the design of the Compton polarimeter for the Cebaf electron beam in End Station A. The method of Compton polarimeter is first introduced. It is shown that at CEBAF beam intensities, the use of standard visible LASER light gives too low counting rates. An amplification scheme of the LASER beam based on a high finesse optical cavity is proposed. Expected luminosities with and without such a cavity are given. The polarimeter setup, including a 4 dipole magnet chicane, a photon and an electron detector, is detailed. The various sources of systematic error on the electron beam polarization measurement are discussed. (author). 82 refs.

  10. Performance of 20 Ci 137Cs -ray Compton spectrometer for the study of momentum densities

    Indian Academy of Sciences (India)

    B L Ahuja; M Sharma

    2005-07-01

    In this paper, we present the design and construction of a 20 Ci -ray Compton spectrometer that employs a 137Cs source with a strong line at 661.65 keV. The total resolution of the spectrometer in momentum scale is 0.40 a.u., which is much better than the conventional 241Am Compton spectrometers. The in-house 137Cs spectrometer is very useful for the measurement of momentum densities of heavy materials. The performance of the machine is assessed using aluminum, terbium and mercury samples and the experimental data from comparable apparatus.

  11. High intensity compact Compton X-ray sources: Challenges and potential of applications

    Energy Technology Data Exchange (ETDEWEB)

    Jacquet, M., E-mail: mjacquet@lal.in2p3.fr

    2014-07-15

    Thanks to the exceptional development of high power femtosecond lasers in the last 15 years, Compton based X-ray sources are in full development over the world in the recent years. Compact Compton sources are able to combine the compactness of the instrument with a beam of high intensity, high quality, tunable in energy. In various fields of applications such as biomedical science, cultural heritage preservation and material science researches, these sources should provide an easy working environment and the methods currently used at synchrotrons could be largely developed in a lab-size environment as hospitals, labs, or museums.

  12. Search for light-speed anisotropies using Compton scattering of high-energy electrons

    CERN Document Server

    Rebreyend, Dominique

    2010-01-01

    Based on the high sensitivity of Compton scattering off ultra relativistic electrons, the possibility of anisotropies in the speed of light is investigated. The result discussed in this contribution is based on the gamma-ray beam of the ESRF's GRAAL facility (Grenoble, France) and the search for sidereal variations in the energy of the Compton-edge photons. The absence of oscillations yields the two-sided limit of 1.6 x 10^{-14} at 95 % confidence level on a combination of photon and electron coefficients of the minimal Standard Model Extension (mSME). This new constraint provides an improvement over previous bounds by one order of magnitude.

  13. Determination of the scalar polarizabilities of the proton using beam asymmetry $\\Sigma_{3}$ in Compton scattering

    CERN Document Server

    Sokhoyan, V; Mornacchi, E; McGovern, J A; Krupina, N; Afzal, F; Ahrens, J; Akondi, C S; Annand, J R M; Arends, H J; Beck, R; Braghieri, A; Briscoe, W J; Cividini, F; Collicott, C; Costanza, S; Denig, A; Dieterle, M; Ferretti, M; Gardner, S; Garni, S; Glazier, D I; Glowa, D; Gradl, W; Gurevich, G; Hamilton, D; Hornidge, D; Huber, G M; Käser, A; Kashevarov, V L; Keshelashvili, I; Kondratiev, R; Korolija, M; Krusche, B; Lensky, V; Linturi, J; Lisin, V; Livingston, K; MacGregor, I J D; Macrae, R; Manley, D M; Martel, P P; Middleton, D G; Miskimen, R; Mushkarenkov, A; Neiser, A; Oberle, M; Spina, H Ortega; Ostrick, M; Ott, P; Otte, P B; Oussena, B; Paudyal, D; Pedroni, P; Polonski, A; Polyansky, V; Prakhov, S; Rajabi, A; Rostomyan, T; Sarty, A; Schumann, S; Steffen, O; Strakovsky, I I; Strandberg, B; Strub, T; Supek, I; Thiel, M; Thomas, A; Unverzagt, M; Wagner, S; Watts, D P; Wettig, J; Witthauer, L; Werthmüller, D; Wolfes, M; Zana, L

    2016-01-01

    The scalar dipole polarizabilities, $\\alpha_{E1}$ and $\\beta_{M1}$, are fundamental properties related to the internal dynamics of the nucleon. The currently accepted values of the proton polarizabilities were determined by fitting to unpolarized proton Compton scattering cross section data. The measurement of the beam asymmetry $\\Sigma_{3}$ in a certain kinematical range provides an alternative approach to the extraction of the scalar polarizabilities. At the Mainz Microtron (MAMI) the beam asymmetry was measured for Compton scattering below pion photoproduction threshold for the first time. The results are compared with model calculations and the influence of the experimental data on the extraction of the scalar polarizabilities is determined.

  14. Gravitation and Special Relativity from Compton Wave Interactions at the Planck Scale: An Algorithmic Approach

    Science.gov (United States)

    Blackwell, William C., Jr.

    2004-01-01

    In this paper space is modeled as a lattice of Compton wave oscillators (CWOs) of near- Planck size. It is shown that gravitation and special relativity emerge from the interaction between particles Compton waves. To develop this CWO model an algorithmic approach was taken, incorporating simple rules of interaction at the Planck-scale developed using well known physical laws. This technique naturally leads to Newton s law of gravitation and a new form of doubly special relativity. The model is in apparent agreement with the holographic principle, and it predicts a cutoff energy for ultrahigh-energy cosmic rays that is consistent with observational data.

  15. A software package for stellar and solar inverse-Compton emission: Stellarics

    CERN Document Server

    Orlando, Elena

    2013-01-01

    We present our software to compute gamma-ray emission from inverse-Compton scattering by cosmic-ray leptons in the heliosphere, as well as in the photospheres of stars. It includes a formulation of modulation in the heliosphere, but it can be used for any user-defined modulation model. Profiles and spectra are output to FITS files in a variety of forms for convenient use. Also included are general-purpose inverse-Compton routines with other features like energy loss rates and emissivity for any user-defined target photon and lepton spectra. The software is publicly available and it is under continuing development.

  16. A software package for Stellar and solar Inverse Compton emission: StellarICs

    Science.gov (United States)

    Orlando, Elena; Strong, Andrew

    2013-06-01

    We present our software to compute gamma-ray emission from inverse-Compton scattering by cosmic-ray leptons in the heliosphere, as well as in the photospheres of stars. It includes a formulation of modulation in the heliosphere, but can be used for any user-defined modulation model. Profiles and spectra are output to FITS files in a variety of forms for convenient use. Also included are general-purpose inverse-Compton routines with other features like energy loss rates and emissivity for any user-defined target photon and lepton spectra. The software is publicly available and it is under continuing development.

  17. Analysis of Rayleigh and Compton scattering for breast cancer diagnosis;Analise do espalhamento Rayleigh e Compton para o diagnostico de neoplasias mamarias

    Energy Technology Data Exchange (ETDEWEB)

    Antoniassi, Marcelo; Conceicao, Andre Luiz Coelho; Poletti, Martin Eduardo [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Dept. de Fisica e Matematica

    2009-07-01

    In this work we have been measured the intensity of Rayleigh and Compton scattering from normal (adipose and fibrous) and neoplastic (benign and malignant) breast tissues using a monoenergetic beam of 17,44keV and a Si(Li) detector positioned at 90 degrees of the direction of incidence. From the scattering peaks were obtained parameters like area, full width at half maximum (FWHM) and combined like the Rayleigh to Compton area ratio (R/C). The results showed that the FWHM and the R/C ratio are different for each tissue type. In this way, the obtained results suggest that it is possible to use this information to characterize and to differentiate the breast tissues, pointing the possibility of its use as complementary tool to the breast cancer diagnosis. (author)

  18. Mini gamma camera, camera system and method of use

    Science.gov (United States)

    Majewski, Stanislaw; Weisenberger, Andrew G.; Wojcik, Randolph F.

    2001-01-01

    A gamma camera comprising essentially and in order from the front outer or gamma ray impinging surface: 1) a collimator, 2) a scintillator layer, 3) a light guide, 4) an array of position sensitive, high resolution photomultiplier tubes, and 5) printed circuitry for receipt of the output of the photomultipliers. There is also described, a system wherein the output supplied by the high resolution, position sensitive photomultipiler tubes is communicated to: a) a digitizer and b) a computer where it is processed using advanced image processing techniques and a specific algorithm to calculate the center of gravity of any abnormality observed during imaging, and c) optional image display and telecommunications ports.

  19. Spectrometry with consumer-quality CMOS cameras.

    Science.gov (United States)

    Scheeline, Alexander

    2015-01-01

    Many modern spectrometric instruments use diode arrays, charge-coupled arrays, or CMOS cameras for detection and measurement. As portable or point-of-use instruments are desirable, one would expect that instruments using the cameras in cellular telephones and tablet computers would be the basis of numerous instruments. However, no mass market for such devices has yet developed. The difficulties in using megapixel CMOS cameras for scientific measurements are discussed, and promising avenues for instrument development reviewed. Inexpensive alternatives to use of the built-in camera are also mentioned, as the long-term question is whether it is better to overcome the constraints of CMOS cameras or to bypass them.

  20. Single Camera Calibration in 3D Vision

    Directory of Open Access Journals (Sweden)

    Caius SULIMAN

    2009-12-01

    Full Text Available Camera calibration is a necessary step in 3D vision in order to extract metric information from 2D images. A camera is considered to be calibrated when the parameters of the camera are known (i.e. principal distance, lens distorsion, focal length etc.. In this paper we deal with a single camera calibration method and with the help of this method we try to find the intrinsic and extrinsic camera parameters. The method was implemented with succes in the programming and simulation environment Matlab.