| 1. |
- Bäck, Torbjörn, et al.
(author)
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A TOF-PET system for educational purposes
- 2002
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In: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier. - 0168-9002 .- 1872-9576. ; 477, s. 82-82
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Journal article (peer-reviewed)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.
(author)
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An educational tool for demonstrating the TOF-PET technique
- 2001
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In: 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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Journal article (peer-reviewed)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. |
- Caceres, L., et al.
(author)
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Nuclear structure studies of F-24
- 2015
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In: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 92:1
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Journal article (peer-reviewed)abstract
- The structure of the F-24 nucleus has been studied at GANIL using the beta decay of O-24 and the in-beam.-ray spectroscopy from the fragmentation of Na-27,Na-28, Ne-25,Ne-26, and Mg-29,Mg-30 nuclei. Combining these complementary experimental techniques, the level scheme of F-24 has been constructed up to 3.6 MeV by means of particle-gamma and particle-gamma gamma coincidence relations. Experimental results are compared to shell-model calculations using the standard USDA and USDB interactions as well as ab initio valence-space Hamiltonians calculated from the in-medium similarity renormalization group based on chiral two- and three-nucleon forces. Both methods reproduce the measured level spacings well, and this close agreement allows unidentified spins and parities to be consistently assigned.
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| 4. |
- Claesson, T., et al.
(author)
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An X-ray computed tomography demonstrator using a CZT solid-state detector
- 2002
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In: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 487:02-jan, s. 202-208
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Journal article (peer-reviewed)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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| 5. |
- Dénes, E., et al.
(author)
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Radiation tolerance qualification tests of the final source interface unit for the ALICE experiment for the ALICE collaboration
- 2007
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In: Proceedings - 12th Workshop on Electronics for LHC and Future Experiments, LECC 2006. - : CERN. ; , s. 438-441
-
Conference paper (peer-reviewed)abstract
- The ALICE Detector Data Link (DDL) is a high-speed optical link designed to interface the readout electronics of ALICE sub-detectors to the DAQ computers. The Source Interface Unit (SIU) of the DDL will operate in radiation environment. Previous tests showed that a configuration loss of SRAM-based FPGA devices may happen and the frequency of undetected data errors in the FPGA user memory area is also not acceptable. Therefore, we redesigned the SIU card using another FPGA based on flash technology. In order to detect bit errors in the user memory we added parity check logic to the design. The new SIU has been extensively tested using neutron and proton irradiation to verify its radiation tolerance. In this paper we summarize the design changes, introduce the final design, and the results of the radiation tolerance measurements on the final card.
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| 6. |
- Dénes, E., et al.
(author)
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Radiation tolerant source interface unit for the ALICE experiment
- 2005
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In: Proceedings - 11th Workshop on Electronics for LHC and Future Experiments, LECC 2005. - : CERN. ; , s. 291-293
-
Conference paper (peer-reviewed)abstract
- The ALICE Detector Data Link (DDL) is a high-speed optical link designed to interface the readout electronics of ALICE sub-detectors to the DAQ computers. The Source Interface Unit (SIU) of the DDL will operate in radiation environment. Tests showed that configuration loss of the Altera APEX II FPGA device used earlier on the DDL SIU card is only marginally acceptable. We developed a new version of the SIU card using Actel ProASIC+ device based on flash memory technology. The new SIU card has been extensively tested using neutron and proton irradiation. In this paper we present the SIU card and describe the results of irradiation measurements.
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| 7. |
- Emri, M., et al.
(author)
-
Software development framework supporting multimodal tomographic imaging
- 2007
-
In: 2006 IEEE Nuclear Science Symposium Conference Record. - : IEEE. - 1424405610 - 9781424405619 ; , s. 1857-1859
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Conference paper (peer-reviewed)abstract
- Engineers specialized in multimodal tomography regularly face a wide scale of programming tasks requiring an integrated software system to ensure cost efficiency. Accordingly, a software development framework has been worked out comprising libraries for cluster-based data acquisition, image reconstruction, management of data files and complex multimodal volumetric visualization. This framework enabled us to develop complex software for our miniPET project [1]. This software contains a graphical application integrating data acquisition, cluster monitoring, event sorting, image reconstruction, interactive image processing tools for advanced multimodal visualization. It also contains utilities to solve these tasks without graphical user interface. The components of our acquisition program can run on embedded Linux systems making new ways to develop any other types of data acquisition software that uses embedded Linux systems. A versatile development framework is developed containing specific libraries and special file formats that support multimodal tomography. This framework was successfully used to elaborate our complex miniPET software.
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| 8. |
- Franchoo, S., et al.
(author)
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RECENT RESULTS FROM GANIL
- 2009
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In: Acta Physica Polonica B. - 0587-4254 .- 1509-5770. ; 40:3, s. 419-425
-
Journal article (peer-reviewed)abstract
- The shell structure of the nucleus implies the existence of magic numbers. Since several years many indications have been accumulated, theoretically as well as through experiments at various laboratories around the world, that if one moves away from stability, the location of the magic numbers shifts as an inescapable consequence of the evolving nature of the nuclear force itself. In this respect, it is the balance between the tensor and spin-orbit components that seems particularly instrumental. Illustrative examples from recent experiments at Ganil, at the neutron-rich and proton-rich side of the nuclear chart for N or Z equal 20 or 28, will be presented here.
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| 9. |
- Hegyesi, G., et al.
(author)
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Development of an FPGA-based data acquisition module for small animal PET
- 2004
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In: 2004 IEEE Nuclear Science Symposium Conference Record. - 0780387007 ; , s. 2957-2961
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Conference paper (peer-reviewed)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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| 10. |
- Hegyesi, G., et al.
(author)
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Ethernet based distributed data acquisition system for a small animal PET
- 2006
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In: IEEE Transactions on Nuclear Science. - 0018-9499 .- 1558-1578. ; 53:4, s. 2112-2117
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Journal article (peer-reviewed)abstract
- We report on the design of a small animal PET scanner being developed at our institutes. The existing setup is the first version of the miniPET machine consisting of four detector modules. Each detector module consists of an 8 x 8 LSO scintillator crystal block, a position sensitive photomultiplier, a digitizer including a digital signal processing board and an Ethernet interface board. There is no hardware coincidence detection implemented in the system and coincidence is determined based on a time stamp attached to every event by a digital CFD algorithm. The algorithm is implemented in the digital signal processing board and generates a time stamp with a coincidence resolution of less than 2 us. The data acquisition system is based on Ethernet network and is highly scalable in size and performance.
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| 11. |
- Hegysei, G., et al.
(author)
-
Ethernet based distributed data acquistion system for small animal PET
- 2006
-
In: IEEE Transactions on Nuclear Science. - 0018-9499 .- 1558-1578. ; 53:4
-
Journal article (peer-reviewed)abstract
- We report on the design of a small animal PET scanner being developed at our institutes. The existing setup is the first version of the miniPET machine consisting of four detector modules. Each detector module consists of an 8times8 LSO scintillator crystal block, a position sensitive photomultiplier, a digitizer and digital signal processing board and an Ethernet interface board. There is no hardware coincidence detection implemented in the system, coincidence is determined based on a time stamp attached to every event by a digital CFD algorithm. The algorithm is implemented in the digital signal processing board and it generates a time stamp with a coincidence resolution of 2 to 3 ns. The data acquisition System is based on Ethernet network and is highly scalable in size and performance
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| 12. |
- Imrek, J., et al.
(author)
-
Development of an improved detector module for miniPET-II
- 2007
-
In: 2006 IEEE Nuclear Science Symposium Conference Record. - : IEEE. - 1424405610 - 9781424405619 ; , s. 3037-3040
-
Conference paper (peer-reviewed)abstract
- We present a new detector module developed for miniPET-II, the second generation of the miniPET small animal PET scanners. The improved module features new hardware components for better performance: LySO crystal material, increased number of crystal segments, Hamamatsu H9500 PSPMT, Xilinx Virtex-4 FPGA and Gigabit Ethernet. However, the principle of operation is the same: no hardware coincidence detection is implemented, data is acquired in list mode and transfered over an Ethernet network. The resulting new module is more suitable for full ring configurations.
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| 13. |
- Imrek, J., et al.
(author)
-
Internals and evaluation of the miniPET-II detector module
- 2007
-
In: 2007 IEEE Nuclear Science Symposium Conference Record. - 1424409233 - 9781424409235 ; , s. 2930-2932
-
Conference paper (peer-reviewed)abstract
- We report on the architecture of the System-on-Module (SoM) developed by our group for miniPET-II, the second version of our small animal PET scanner. The paper describes the hardware and software implementation details of the SoM we realized inside the miniPET-II detector module, the embedded Linux operation system, and the the initial results of bandwidth test measurements on the assembled SoM. Detailed description is given on the interfacing of the updated miniPET IP Core to the SoM, on the efficient data transfer method that implements device-to-device DMA transfer, and on the usage of User Datagram Protocol (UDP/IP) for high speed data transfer.
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| 14. |
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| 15. |
- Kis, S. A., et al.
(author)
-
Comparison of Monte Carlo simulated and measured performance parameters of miniPET scanner
- 2007
-
In: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 571:02-jan, s. 449-452
-
Journal article (peer-reviewed)abstract
- In vivo imaging of small laboratory animals is a valuable tool in the development of new drugs. For this purpose, miniPET, an easy to scale modular small animal PET camera has been developed at our institutes. The system has four modules, which makes it possible to rotate the whole detector system around the axis of the field of view. Data collection and image reconstruction are performed using a data acquisition (DAQ) module with Ethernet communication facility and a computer cluster of commercial PCs. Performance tests were carried out to deter-mine system parameters, such as energy resolution, sensitivity and noise equivalent count rate. A modified GEANT4-based GATE Monte Carlo software package was used to simulate PET data analogous to those of the performance measurements. GATE was run on a Linux cluster of 10 processors (64 bit, Xeon with 3.0 GHz) and controlled by a SUN grid engine. The application of this special computer cluster reduced the time necessary for the simulations by an order of magnitude. The simulated energy spectra, maximum rate of true coincidences and sensitivity of the camera were in good agreement with the measured parameters.
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| 16. |
- Kis, S. A., et al.
(author)
-
Performance Characteristics of a miniPET Scanner Dedicated to Small Animal Imaging
- 2005
-
In: 2005 IEEE Nuclear Science Symposium Conference Record. - 0780392213 - 9780780392212 ; , s. 1645-1648
-
Conference paper (peer-reviewed)abstract
- An easy to scale up modular PET scanner was developed for imaging small animals. Energy resolution, spatial resolution and count rate performance were determined as system parameters. The configuration provided an average energy resolution of 19.6 % and the image resolution ranges was 1.5 to 2.3 mm in radial direction. The sensitivity of the miniPET was 1.08 cps/kBq as determined using a point source. In addition, results of rat brain scan performed with FDG are given to characterize imaging capability of the system. The displayed data document that the miniPET scanner supports good quality brain imaging of small animals.
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| 17. |
- Klamra, Wlodzimierz, et al.
(author)
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Response of BaF2 and YAP : Ce to heavy ions
- 2000
-
In: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 444:3, s. 626-630
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Journal article (peer-reviewed)abstract
- The light output and energy resolution for BaF2 and YAP:Ce have been measured with O-16, Cl-35 and Br-79 in the energy region 8.5-34 MeV. Both crystals show a nonproportional light yield response, mostly pronounced for the lighter ions.
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| 18. |
- Klamra, Wlodzimierz, et al.
(author)
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Studies of scintillation light nonproportionality of ZnSe(Te), CsI(Tl) and YAP(Ce) crystals using heavy ions
- 2002
-
In: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 484:03-jan, s. 327-332
-
Journal article (peer-reviewed)abstract
- The scintillation light yield for ZnSe(Te), CsI(T1) and YAP(Ce) crystals have been studied with alpha particles, C-12 and Br-81 in the energy region 2.8-42.2 MeV. A nonproportional behavior was observed, mostly pronounced for alpha particles on YAP(Ce). The results are understood in terms of delta-rays effect.
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| 19. |
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| 20. |
- Novák, D., et al.
(author)
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Component tests for the PRISMA spacecraft
- 2007
-
In: RADECS 2007. - : IEEE. - 9781424417049 ; , s. 595-598
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Conference paper (peer-reviewed)abstract
- TID and proton tests are reported on some COTS components for the PRISMA satellite project. TID test level was more than 20 krad and 170 MeV protons were used for the single event tests.
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| 21. |
- Novák, D., et al.
(author)
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In flight SEU tests on the European SMART-1 spacecraft
- 2005
-
In: Proceedings of the European Conference on Radiation and its Effects on Components and Systems, RADECS. - 0780395018 - 9780780395015 ; , s. PH11-PH13
-
Conference paper (peer-reviewed)abstract
- The SMART-I satellite launched by the European Space Agency has traveled to an orbit around the Moon driven by its own ion engine. Because of the characteristics of the ion engine mission required many revolutions to reach the Moon and the time to pass through the radiation belts around the Earth was significant. The spacecraft is exposed to solar protons throughout its mission. In advance the flight in-beam test data was collected to asses the radiation hardness properties of an SRAM, one of the components of the system unit of the satellite. Single Event Upset data is available for this component and Solar Proton Flux was measured by the GOES satellite in Geosynchronous orbit. The aim of this work is to compare the predictions of the in-beam tests and the effects of the in space irradiation of SRAM circuits on board.
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| 22. |
- Pausch, G., et al.
(author)
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RoSiB - a 4 pi silicon ball for charged-particle detection in EUROBALL
- 2000
-
In: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 443:03-feb, s. 304-318
-
Journal article (peer-reviewed)abstract
- A 4 pi silicon bail for detection and identification of light charged particles in large multidetector gamma-arrays as EUROBALL is presented. The design is based on a N = 42 ball with 12 pentagons and 30 hexagons as used in the GASP array. The absorptive material for gamma-rays is minimized to the detector thickness of 300 or 500 mu m and a 0.63 mm ceramic backing. The geometrical coverage is designed for about 90% of 4 pi. A pulse shape discrimination method with totally depleted detectors working in the reverse mount allows identifying protons and alpha-particles above an energy threshold of about 2 MeV. The performances of the ball were rested at the tandem - booster accelerator combination of the MPI Heidelberg in two experiments using the high-recoil reaction of 228 MeV Ni-58 + Ti-46 and the low-recoil reaction of 95 MeV O-16 + Ni-58. The two-dimensional spectra of zero-crossing (ZC) versus energy confirmed an excellent discrimination of protons and alpha-particles in all the detectors at different angles. The energy spectra of protons and alpha-particles measured in the experiments are presented. too. The gamma-spectra measured in coincidence with various combinations of emitted particles showed a high selectivity of the ball. The reduced total efficiency for protons of 59% and 55% and alpha-particles of 44% and 32% measured in a nuclear spectroscopy application is analyzed in a Monte-Carlo simulation (GEANT). It is due to a combined influence of a thick target needed to stop the recoiling residual nuclei and thick absorbers needed to protect the Si-detectors from scattered beam. The results along with the GEANT extrapolation to optimum experimental conditions confirm that RoSiB is a highly efficient and selective device for identification of rare reaction channels with heavy ions.
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| 23. |
- Ruchowska, E., et al.
(author)
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Nuclear structure of Th-229
- 2006
-
In: Physical Review C. Nuclear Physics. - : American Physical Society. - 0556-2813 .- 1089-490X. ; 73:4
-
Journal article (peer-reviewed)abstract
- Lifetimes of excited states in Th-229, populated in the beta decay of Ac-229, have been measured using the advanced time-delayed beta gamma gamma(t) method. Half-lives of 14 states have been determined including 11 of them for the first time. Twenty-seven new gamma lines have been introduced into the beta-decay scheme of Ac-229 based on results of gamma gamma coincidence measurements. Reduced transition probabilities have been determined for more than 70 gamma transitions in Th-229. Average parallel to D-0 parallel to values of 0.029(1), 0.077(3), and 0.024(5) e fm have been deduced for the lowest K-pi=1/2(+/-),3/2(+/-), and 5/2(+/-) parity partner bands, respectively. Excited states in Th-229 and experimental transition rates have been interpreted within the quasiparticle-plus-phonon model. The half-life of the 3.5-eV, 3/2(+) isomeric state is predicted to be about 10 h. Potential energy surfaces on the (beta(2),beta(3)) plane for the lowest single quasiparticle configurations in Th-229 have been calculated using the Strutinsky method.
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| 24. |
- Sanchez-Crespo, A., et al.
(author)
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Proton therapy beam dosimetry with silicon CMOS image sensors
- 2004
-
In: 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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Journal article (peer-reviewed)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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| 25. |
- Simon, A., et al.
(author)
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High spatial resolution measurement of depth-of-interaction of a PET LSO crystal
- 2005
-
In: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 546:1-2, s. 33-36
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Journal article (peer-reviewed)abstract
- A new type of experimental technique to investigate the depth- of-interaction (DOI) dependence in small scintillator elements designed for high-resolution animal PET is tested. An Oxford-type nuclear microprobe was used to irradiate a lutetium oxyorthosilicate (LSO) crystal (2 x 2 x 10 mm) with a highly focused, (few micrometers diam.), 2 MeV He+ beam. Pulse height spectra from a PMT attached to one end of the LSO crystal were collected in list mode. By scanning the beam over the crystal high-resolution 2D-images are generated and thus the DOI effect in the scintillator could be investigated. The obtained results of the overall DOI dependence confirm previous findings using gamma-rays. Since the present experimental setup allows obtaining data with several orders of magnitude better spatial resolution than with collimated gamma-beam, the method can be applied for variety of problems where high spatial resolution is required.
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