| 1. |
- Bäck, Torbjörn, et al.
(författare)
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A TOF-PET system for educational purposes
- 2002
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; 477, s. 82-82
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Tidskriftsartikel (refereegranskat)abstract
- A TOF-PET system has been designed and constructed for educational purposes. The aim of this system is to demonstrate the possibilities of positron emission tomography in general and the time-of-flight method in particular to the students of various courses at the Royal Institute of Technology, Stockholm, Sweden. The set-up consists of 48 small BaF2 crystals coupled to fast photomultipliers placed in a ring geometry. The signals of the photomultipliers are fed into fast constant fraction discriminators (CFD). The outputs of these are directed to a specially designed logic VME unit. which combines the CFD signals of 6 neighbouring channels to one signal by adding a different delay to each channel. The logic circuitry produces a prompt pulse for each event that serves as the start pulse for the 8-channel fast TDC. The delayed pulses act as the stop pulses for the TDC. In a computer. the measured times are converted into information about which the photomultipliers fired with the difference in the time of flight. The set-up is described and the results are presented.
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| 2. |
- Bäck, Torbjörn, et al.
(författare)
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An educational tool for demonstrating the TOF-PET technique
- 2001
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : AMERICAN PHYSICAL SOC. - 0168-9002 .- 1872-9576. ; 471:1-2, s. 200-204
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Tidskriftsartikel (refereegranskat)abstract
- A detector system for positron emission tomography with time-of-flight capability has been built to serve as an educational tool for undergraduate students. The set-up consists of 48 BaF2 scintillator crystals, each coupled to a fast photo-multiplier tube, mounted in a circular geometry. The analogue detector pulses are handled by fast constant fraction discriminators. A dedicated unit reduces the 48 channels to eight channels via delay-fine encoding, and the signals are then fed to an eight channel fast time-to-digital converter. A VME processor sorts the events and sends them to a workstation where the coincident events are extracted. The time resolution of the detectors together with fast VME based electronics allows for time-of-flight measurements to improve on the signal-to-noise ratio in the, reconstructed images. The system can be used for different types of exercises for the students, varying from the fundamentals of scintillator detectors to advanced image reconstruction. The set-up is described and some results are presented. (C) 2001 Elsevier Science B.V. All rights reserved.
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| 3. |
- Hegyesi, G., et al.
(författare)
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Development of an FPGA-based data acquisition module for small animal PET
- 2004
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Ingår i: 2004 IEEE Nuclear Science Symposium Conference Record. - 0780387007 ; , s. 2957-2961
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Konferensbidrag (refereegranskat)abstract
- We report on the design of a DAQ module for a small animal PET camera developed at our institutes. During the design an important guideline was to develop a system which is built up from strictly identical DAQ modules, and which has no built-in hardware limitation on the maximum number of modules. The developed DAQ module comprises of an LSO scintillator crystal block, a position sensitive PMT, analog signal conditioning circuits, a digitizer, an FPGA for digital signal processing and a communication module through which the collected data is sent to a cluster of computers for post processing and storage. Instead of implementing hardware coincidence detection between the modules we attach a precise time-stamp to each event in our design, and the coincidence is determined by the data collecting computers during the post processing. The digital CFD algorithm implemented in the FPGA gives a time resolution of 2 to 3 ns FWHM for real detector signals.
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| 4. |
- Podolyak, Z., et al.
(författare)
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gamma-ray spectroscopy with a He-8 beam
- 2003
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 511:3, s. 354-359
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Tidskriftsartikel (refereegranskat)abstract
- The He-8 + Pb-208 reaction was studied in the first experiment with the EXOGAM germanium detector array using beam delivered by the SPIRAL facility. gamma-rays from direct and fusion-evaporation reactions were observed with high resolution. gamma-gamma coincidence data were obtained at a beam intensity level of 105 8He particles per second. Specially designed absorbers and beam detectors could further reduce the background radiation by orders of magnitude.
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| 5. |
- Podolyak, Zs., P.M.Walker, H.Mach, G.de France, G.Sletten, F.Azaiez, J.M.Casandjian, B.Cederwall, D.M.Cullen, Zs.Dombradi, G.D.Dracoulis, L.M.Fraile, S.Franchoo, H.Fynbo, M.Gorska, Y.Kopatch, G.J.Lane, S.Mandal, L.Milechina, J.Molnar, C.O'Leary, W.Plocien
(författare)
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g-ray spectroscopy with a 8He beam
- 2003
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Ingår i: Nucl.Instrum.Methods Phys.Res. A. ; 511, s. 354-
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Tidskriftsartikel (refereegranskat)
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| 6. |
- Claesson, T., et al.
(författare)
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An X-ray computed tomography demonstrator using a CZT solid-state detector
- 2002
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 487:02-jan, s. 202-208
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Tidskriftsartikel (refereegranskat)abstract
- A demonstrator of Computed Tomography (CT) has been designed and built for educational purposes. The system is based on a solid-state CdZnTe detector and a standard PC. The mechanics of the system is controlled and data is acquired by programs written in LabVIEW. CT images are reconstructed using MATLAB programs.
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| 7. |
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| 8. |
- Sanchez-Crespo, A., et al.
(författare)
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Proton therapy beam dosimetry with silicon CMOS image sensors
- 2004
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 525:02-jan, s. 289-293
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Tidskriftsartikel (refereegranskat)abstract
- A 16 mm(2) CMOS Image Sensor with more than 100 000 pixels and with a standard video output was irradiated with 48, 95 and 180 MeV protons. Proton-induced nuclear reactions in silicon were detected as bright spots or tracks in the images. The angular and energy-dependent response of the detector were studied. The application to proton dosimetry is discussed.
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| 9. |
- Sipos, A., et al.
(författare)
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Visualization of neutron and proton induced particle production in a CMOS image sensor
- 2003
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 509:03-jan, s. 328-332
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Tidskriftsartikel (refereegranskat)abstract
- A commercially available off the shelf CMOS Image Sensor was irradiated with neutron and proton beams. The Image Sensor is equipped with standard video output. The data were collected on VHS videotapes and analyzed off-line after digitization. The camera chip with 110 000 pixels each having 12 x 12 mum(2) size, shows the nuclear reactions occurring in the sensitive layer as bright spots or tracks. Several applications are suggested based on the inexpensive CMOS Image Sensor.
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| 10. |
- Vegh, J., et al.
(författare)
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Visualization of heavy ion-induced charge production in a CMOS image sensor
- 2004
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 525:02-jan, s. 229-235
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Tidskriftsartikel (refereegranskat)abstract
- A commercial CMOS image sensor was irradiated with heavy ion beams in the several MeV energy range. The image sensor is equipped with a standard video output. The data were collected on-line through frame grabbing and analysed off-line after digitisation. It was shown that the response of the image sensor to the heavy ion bombardment varied with the type and energy of the projectiles. The sensor will be used for the CMS Barrel Muon Alignment system.
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