| 1. |
- Pausch, G., et al.
(författare)
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RoSiB - a 4 pi silicon ball for charged-particle detection in EUROBALL
- 2000
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 443:03-feb, s. 304-318
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Tidskriftsartikel (refereegranskat)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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| 2. |
- Akkoyun, S., et al.
(författare)
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AGATA - Advanced GAmma Tracking Array
- 2012
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Ingår i: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002 .- 0167-5087 .- 1872-9576. ; 668, s. 26-58
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Tidskriftsartikel (refereegranskat)abstract
- The Advanced GAmma Tracking Array (AGATA) is a European project to develop and operate the next generation γ-ray spectrometer. AGATA is based on the technique of γ-ray energy tracking in electrically segmented high-purity germanium crystals. This technique requires the accurate determination of the energy, time and position of every interaction as a γ ray deposits its energy within the detector volume. Reconstruction of the full interaction path results in a detector with very high efficiency and excellent spectral response. The realisation of γ-ray tracking and AGATA is a result of many technical advances. These include the development of encapsulated highly segmented germanium detectors assembled in a triple cluster detector cryostat, an electronics system with fast digital sampling and a data acquisition system to process the data at a high rate. The full characterisation of the crystals was measured and compared with detector- response simulations. This enabled pulse-shape analysis algorithms, to extract energy, time and position, to be employed. In addition, tracking algorithms for event reconstruction were developed. The first phase of AGATA is now complete and operational in its first physics campaign. In the future AGATA will be moved between laboratories in Europe and operated in a series of campaigns to take advantage of the different beams and facilities available to maximise its science output. The paper reviews all the achievements made in the AGATA project including all the necessary infrastructure to operate and support the spectrometer. © 2011 Elsevier B.V. All rights reserved.
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| 3. |
- Chishti, M.M.R., et al.
(författare)
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Response of the FAst TIMing Array (FATIMA) for DESPEC at FAIR Phase-0
- 2023
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier B.V.. - 0168-9002 .- 1872-9576. ; 1056
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Tidskriftsartikel (refereegranskat)abstract
- The Monte-Carlo simulated response for γ-ray detection of the FAst TIMing Array (FATIMA) for exploitation within the DEcay SPECtroscopy (DESPEC) experimental system at the FAIR Phase-0 facility at Darmstadt, Germany is presented. In this configuration, FATIMA consisted of 36 LaBr3(Ce) detectors surrounding the AIDA, position-sensitive charged-particle active stopper. The decay of the Iπ=8+ isomer-fed decay cascade in 96Pd, measured in the first DESPEC experiment at the FAIR-0 facility was used to validate the simulations. The experimental data yielded in-situ full-energy peak efficiency values for FATIMA of 11.2(11)%, 6.8(7)%, 3.8(4)% and 2.1(4)% at 106, 325, 684 and 1415 keV respectively, consistent with the values derived from the simulated response.
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| 4. |
- Doncel, Maria, et al.
(författare)
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Performance and imaging capabilities of the DEGAS high-resolution gamma-ray detector array for the DESPEC experiment at FAIR
- 2017
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : ELSEVIER SCIENCE BV. - 0168-9002 .- 1872-9576. ; 873, s. 36-38
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Tidskriftsartikel (refereegranskat)abstract
- Monte Carlo simulations of one of the possible configurations of the imaging phase for the DEGAS spectrometer situated at the DESPEC/NUSTAR experiment have been performed. The geometry consists of the coupling of the high-resolution gamma spectroscopy array, AGATA, with a high-resolution segmented planar detector utilized as an implantation detector in a compact configuration. The sensitivity and performance of the array in terms of efficiency and imaging capability is deduced.
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| 5. |
- Lalovic, Natasa, et al.
(författare)
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Performance of the AGATA gamma-ray spectrometer in the PreSPEC set-up at GSI
- 2016
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576 .- 0167-5087. ; 806, s. 258-266
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Tidskriftsartikel (refereegranskat)abstract
- In contemporary nuclear physics, the European Advanced GAmma Tracking Array (AGATA) represents a crucial detection system for cutting-edge nuclear structure studies. AGATA consists of highly segmented high-purity germanium crystals and uses the pulse-shape analysis technique to determine both the position and the energy of the y-ray interaction points in the crystals. It is the tracking algorithms that deploy this information and enable insight into the sequence of interactions, providing information on the full or partial absorption of the 7 ray. A series of dedicated performance measurements for an AGATA set-up comprising 21 crystals is described. This set-up was used within the recent PreSPEC-AGATA experimental campaign at the GSI Helmholtzzentrum fur Schwerionenforschung. Using the radioactive sources Co-56, Co-60 and Eu-152, absolute and normalized efficiencies and the peak-to-total of the array were measured. These quantities are discussed using different data analysis procedures. The quality of the pulse-shape analysis and the tracking algorithm are evaluated. The agreement between the experimental data and the Geant4 simulations is also investigated.
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| 6. |
- Lorente, A. Sanchez, et al.
(författare)
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Performance of HPGe detectors in high magnetic fields
- 2007
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 573:3, s. 410-417
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Tidskriftsartikel (refereegranskat)abstract
- A new generation of high-resolution hypernuclear gamma-spectroscopy experiments with high-purity germanium detectors (HPGe) are presently designed at the FINUDA spectrometer at DA Phi NE, the Frascati phi-factory, and at (P) over bar ANDA, the (p) over barp hadron spectrometer at the future FAIR facility. Both, the FINUDA and (P) over bar ANDA spectrometers are built around the target region covering a large solid angle. To maximise the detection efficiency the HPGe detectors have to be located near the target, and therefore they have to be operated in strong magnetic fields (B approximate to I T). The performance of HPGe detectors in such an environment has not been well investigated so far. In the present work VEGA and EUROBALL Cluster HPGe detectors were tested in the field provided by the ALADiN magnet at GSI. No significant degradation of the energy resolution was found, and a change in the rise time distribution of the pulses from preamplifiers was observed. A correlation between rise time and pulse height was observed and is used to correct the measured energy, recovering the energy resolution almost completely. Moreover, no problems in the electronics due to the magnetic field were observed.
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| 7. |
- Recchia, F, et al.
(författare)
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Position resolution of the prototype AGATA triple-cluster detector from an in-beam experiment
- 2009
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 604:3, s. 555-562
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Tidskriftsartikel (refereegranskat)abstract
- AGATA belongs to a new generation of gamma-ray detector arrays for nuclear spectroscopy at present in its final stage of development. The detectors of these new arrays will be based on 36-fold electronically segmented coaxial germanium diodes operated in position sensitive mode. An in-beam test of the AGATA prototype triple cluster detector was carried out with the purpose of demonstrating the feasibility of such detectors and in order to measure the most sensitive parameters for their overall performance. An inverse kinematics reaction was performed, using a Ti-48 beam at an energy of 100MeV, impinging on a deuterated titanium tat-get. The results from the analysis of the experimental data, compared with the predictions of Monte Carlo Simulations, give an estimation of the position sensitivity of these detectors of about 5 mm FWHM, consistent with the specifications required. (C) 2009 Elsevier B.V. All rights reserved.
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| 8. |
- Szymanska, K., et al.
(författare)
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Resolution, efficiency and stability of HPGe detector operating in a magnetic field at various gamma-ray energies
- 2008
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 592:3, s. 486-492
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Tidskriftsartikel (refereegranskat)abstract
- The use of High Purity Germanium detectors (HPGe) has been planned in some future experiments of hadronic physics. The crystals will be located close to large spectrometers where the magnetic fringing field will not be negligible and their performances might change. Moreover high precision is required in these experiments. The contribution of magnetic field presence and long term measurements is unique. In this paper the results of systematic measurements of the resolution, stability and efficiency of a crystal operating inside a magnetic field of 0.8 T, using radioactive sources in the energy range from 0.08 to 1.33 MeV, are reported. The measurements have been repeated during several months in order to test if any permanent damage occurred. The resolution at 1.117 and 1.332 MeV gamma-rays from a Co-60 source has been measured at different magnetic fields in the range of 0-0.8 T and the results are compared with the previous data.
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| 9. |
- Tashenov, Stanislav, et al.
(författare)
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TANGO-New tracking AlGOrithm for gamma-rays
- 2010
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 622:3, s. 592-601
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Tidskriftsartikel (refereegranskat)abstract
- For spectroscopy, polarimetry and imaging purposes a new gamma-ray tracking algorithm has been developed featuring identification of Compton escape events. The rejection of these events results in a significant increase of the Peak/Total ratio. The initial photon energy is restored for these events. Although the energy resolution in the spectrum reconstructed from the escape events is lower than the one from the full-energy events, the Monte-Carlo simulations show that the combined spectrum has an increased detector full-energy efficiency of up to 130% compared to its intrinsic full-energy efficiency. The assumed geometrical origin of the photons is verified event-by-event. This enables separation of photons emitted from a target and from background sources. A linear polarization analysis of the gamma-lines can be performed. The efficiency of the algorithm and the Peak/Total ratio depending on the detector properties is discussed along with the proposed optimization schemes. The influence of the intrinsic properties of the scattering process like Compton profile and electron recoiling is discussed as well. The described algorithm deals with single photon events with energies of approximate to 100 keV up to a few MeV.
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| 10. |
- Andersson, L-L, et al.
(författare)
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TASISpec - A Highly Efficient Multi-coincidence Spectrometer for Nuclear Structure Investigations of the Heaviest Nuclei
- 2010
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 622:1, s. 164-170
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Tidskriftsartikel (refereegranskat)abstract
- TASISpec (TASCA in Small Image mode Spectroscopy) combines composite Ge- and Si-detectors for a new detector setup aimed towards multi-coincidence gamma -ray, X-ray, conversion electron, fission fragment, and a-particle spectroscopy of the heaviest nuclei. It exploits the TASCA separator's unique small image focal mode, i.e. the fact that evaporation residues produced in fusion-evaporation reactions can be focused into an area of less than 3 cm in diameter. This provides the possibility to pack detectors in very close geometry, resulting in an unprecedented detection efficiency of radioactive decays in prompt and delayed coincidence with implanted nuclei. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.
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