In this paper, five detectors (EJ-270 — single plastic scintillator, EJ-309B5 — single liquid scintillator, and 3 phoswich detectors: EJ-276+GS20, GS20+EJ-276, EJ-309+GS20) were studied in terms of ...simultaneous detection of gamma-rays and slow and fast neutrons. The measurements were carried out in a mixed field of neutron and gamma radiation from an intense (∼106 neutrons/s/4π) PuBe source. The PuBe neutron source was placed in an 18 cm diameter paraffin ball in order to increase the number of slow neutron detections. This paper covers the measurements of the neutron/gamma discrimination, photoelectron yield and analysis of the light pulse shapes originating from events related to gamma-rays, slow neutrons and fast neutrons. Sensitivity to slow neutrons is also briefly discussed. A comparison of n/γ discrimination for all of the tested detectors shows excellent performance of all phoswich detectors. Phoswich configurations tested within the scope of this study allow unambiguously resolve all three types of radiation and show superior performance in comparison with single loaded plastic or liquid scintillators.
The market of Silicon Photomultipliers (SiPMs) consists of many manufacturers that produce their detectors in different technology. Hamamatsu (Japan) and SensL (Ireland) seems to be the most popular ...companies that produce large SiPM arrays. The aim of this work is characterization and comparison of 4×4 channel SiPM arrays produced by these two producers. Both of the tested SiPMs are made in through-silicon via (TSV) technology, consist of 16, 3×3mm avalanche photodiode (APD) cells and have fill factor slightly above 60%. The largest difference is a single APD cell size and hence total number of APD cells (55,424 for Hamamatsu, 76,640 for SensL). In the case of SensL SiPM, its spectral response characteristics is shifted slightly toward shorter wavelengths with maximum at 420nm (450nm for Hamamatsu). The presented measurements cover selection of the SiPM optimum operating voltage (in respect to energy resolution), verification of the excess noise factor and check of the linearity characteristics. Moreover, the gamma spectrometry with LSO, BGO and CsI:Tl scintillators together with pulse characteristics for these crystals (rise time and fall time) is reported, as well as temperature dependence. The presented measurements show better performance of the SensL array comparing to the Hamamatsu detector.
MCORD - MPD Cosmic Ray Detector a new features Bielewicz, M.; Milewicz-Zalewska, M.; Grodzicka-Kobylka, M. ...
EPJ Web of Conferences,
2019, Letnik:
204
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
The main detector system at the Nuclotron-based Ion Collider fAcility (NICA) located in Dubna, Russia is the Multi-Purpose Detector (MPD). For better calibration reason, the MPD needs an additional ...trigger system for an off-beam calibration of MPD sub-detectors and for rejection (veto) of cosmic muons. The system should also be useful for practical astrophysics observations of cosmic showers. The consortium NICA-PL group defines goals and basic assumptions for the MPD Cosmic Ray Detector (MCORD). This article describes the conceptual design and simulation plans of the MCORD detector based on plastic scintillators with SiPM photodetectors and electronic digital system based on the MicroTCA crate.
Silicon photomultipliers in gamma spectroscopy with scintillators Grodzicka-Kobylka, M.; Moszyński, M.; Szczęśniak, T.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2019, Letnik:
926
Journal Article
Recenzirano
In the first part of this paper the various characteristics of SiPMs that affect the use of SiPMs in gamma spectroscopy using scintillators, are reviewed. It covers SiPM gain, photon detection ...efficiency (PDE), after-pulses and cross-talk (which are responsible for the excess noise factor), dark noise, and linearity of response. In this respect the influence of the SiPMs’ effective dead time on the linearity of the response is discussed. In the second part, the optimization of SiPM operation for the best energy resolution and linearity of response is presented. Finally, a number of tests on combinations of SiPM arrays of different sizes that are coupled to different scintillators used in gamma spectroscopy are reported (such as NaI(Tl), BGO, LaBr3, and LYSO are reviewed, including 3x3 inch NaI(Tl) and BGO tests. Besides the characterization of the different SiPMs used in scintillation detection and spectroscopy, a discussion is carried out concerning their present and future application in various fields of use — covering instrumentation for homeland security, environmental study, plasma physics and others.
•The main performance parameters of SiPMs.•SiPMs in gamma spectroscopy using scintillators.•Present and future applications of SiPM arrays in gamma spectroscopy using scintillators.
The paper presents a study of n∕γ discrimination with 4x4 ch and 8x8 ch Multi Pixel Photon Counter (MPPC) arrays in neutron detectors based on Stilbene and EJ299-33 plastic scintillators. The n∕γ ...discrimination showed an excellent capability of the MPPC arrays, comparable to that observed earlier with the classical PMTs. Particularly, an application of a zero-crossing method of n−γ discrimination prevented deterioration of the discrimination by the slow response of the Silicon Photomultiplier (SiPM, or MPPC interchangeably) array related to its large capacitance. It was confirmed by a good agreement of the Figure of Merit normalized to the number of photoelectrons determined for the MPPC arrays and XP5500 PMT.
Majority of papers concerning scintillation detectors with light readout by means of silicon photomultipliers refer to nuclear medicine or radiation monitoring devices where energy of detected gamma ...rays do not exceed 2 MeV. Detection of gamma radiation with higher energies is of interest to e.g. high energy physics and plasma diagnostics. The aim of this paper is to study applicability (usefulness) of SiPM light readout in detection of gamma rays up to 6.1 MeV in combination with various scintillators. The reported measurements were made with 3 samples of one type of Hamamatsu TSV (Through-Silicon Via technology) MPPC arrays. These 4x4 channel arrays have a 50×50μm2 cell size and 12×12 mm2 effective active area. The following scintillators were used: CeBr3, NaI:Tl, CsI:Tl. During all the tests detectors were located in a climatic chamber. The studies are focused on optimization of the MPPC performance for practical use in detection of high energy gamma rays. The optimization includes selection of the optimum operating voltage in respect to the required energy resolution, dynamic range, linearity and pulse amplitude. The presented temperature tests show breakdown voltage dependence on the temperature change and define requirements for a power supply and gain stabilization method. The energy spectra for energies between 511 keV and 6.1 MeV are also presented and compared with data acquired with a classic photomultiplier XP5212B readout. Such a comparison allowed study of nonlinearity of the tested MPPCs, correction of the energy spectra and proper analysis of the energy resolution.
The main objective of this work was to characterize the new multi-pixel photon counter (MPPC) arrays with a 12×12mm2 and a 24×24mm2 active area, made using through-silicon via (TSV) technology and ...with trenches introduced between the cells, in gamma-ray spectrometry with five different scintillators: CsI:Tl, NaI:Tl, LSO/LYSO, BGO, and LaBr3. The results of the study are compared to those obtained previously with the older sample of the 12×12mm2 MPPC array made as a monolithic device. TSV MPPC array with the size of 24×24mm2 is one of the first commercially available SiPM with such a large active area and with the dead space between channels minimized to only 0.2 mm. Moreover, in these devices, Hamamatsu introduced trenches between cells to reduce cross-talk. Hence excess noise factor (ENF) was also reduced from a value of 1.7 to 1.2 in comparison to the “old” monolithic sample (data for the same overvoltage of 1.3V). Whereby for the new MPPCs, the optimum operating voltage is higher by about 0.6V. In consequence, this higher optimal overvoltage means a higher photon detection efficiency (PDE) and number of photoelectrons, and leads to improved energy resolution. Energy resolution measured for the 662keV full energy peak in a 137Csγ-source spectrum recorded with 12×12mm2 TSV MPPC and two CsI:Tl scintillators (12×12×12mm3 and 1×1in) equals to 5.8% and 6.8%, respectively. For the “old” MPPC with the same CsI:Tl scintillators energy resolution is equal to 6.4% and 7.1%, respectively. These improved TSV MPPC arrays can be commercially used for scintillation light readout of “large” crystals with a diameter of 1×1in or 2×2in, suitable for gamma spectrometry in a wide range of applications. The combination of new 8×8ch (24×24mm2) TSV MPPC and 2×2in NaI:Tl gives an excellent energy resolution below 8%, despite the incomplete match of the scintillator surface to the active area of MPPC and loss of the part of the light.
2 inch molecular organic glass scintillator for neutron–gamma discrimination Grodzicka-Kobylka, M.; Szczesniak, T.; Moszyński, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
February 2023, 2023-02-00, Letnik:
1047
Journal Article
Recenzirano
Odprti dostop
In this manuscript we report on the scintillation properties and pulse shape discrimination (PSD) performance of new organic glass scintillator. Two cylindrical samples with dimensions of 2 × 2 ...inches were tested. Additionally, this two samples were used in stack configuration in order to measure the PSD characteristics of a sample with a size of 2 × 4 inches. The study covers the measurements of neutron/gamma discrimination capability, emission spectra, photoelectron yield and analysis of the light pulse shapes originating from events related to gamma-rays and fast neutrons. The results were compared to data recorded previously using an EJ-276 plastic scintillator, an EJ-309 liquid scintillator and a stilbene single crystal.
The performance of the large 5x5x10 inch NaI:Tl and 5x5 inch BGO scintillators coupled to the R11833-100 PMT was investigated by gamma spectrometry in comparison with the well-known 5x5x10 inch ...NaI:Tl crystal coupled to the ET9390 PMT and 5x5 inch BGO coupled to the R877 PMT. The tests included measurements of light output in terms of photoelectron number and energy resolution. Time resolution was also measured in coincidence experiments with 511 keV annihilation quanta from a 22Na gamma source.
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