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Fast electronic readout for high-channel density scintillator-based systems is needed for radiation tracking and imaging in a wide range of applications, including nuclear physics, nuclear security and nonproliferation. Programmable electronics, like FPGAs and ASICs, provide a fast way of conditioning and processing the signal in real time. In this paper, we present a pulse shape discrimination (PSD) method based on the shaping circuit of a commercially available ASIC, the Citiroc1A by CAEN Technologies. We used two different shaping times per detector channel to calculate a shaping parameter that enables PSD. Using our new method, neutron and gamma-ray pulses detected by a d 12 -stilbene scintillator can be effectively discriminated at light output values greater than 0.15 MeVee. While not achieving the PSD performance of traditional offline charge integration, our method does not require the transfer of data to a separate system for further processing and enables the direct deployment of high-channel density multi-particle detection systems. Moreover, the availability of a wider range of shaping times than those on the Citiroc1A can potentially further improve the PSD performance. [ABSTRACT FROM AUTHOR]

Both monolithic and semi-monolithic scintillator positron emission tomography (PET) detectors can measure the depth of interaction with single-ended readout. Usually scintillators with a thickness of 10 mm or less are used since the position resolutions of the detectors degrade as the scintillator thickness increases. In this work, the performance of a 20 mm thick long rectangular semi-monolithic scintillator PET detector was measured by using both single-ended and dual-ended readouts with silicon photomultiplier (SiPM) arrays to provide a high detection efficiency. The semi-monolithic scintillator detector consists of nine lutetium–yttrium oxyorthosilicate slices measuring 1.37 × 51.2 × 20 mm3 with erythrocyte sedimentation rate foils of 0.065 mm thickness in between the slices. The SiPM array at each end of the scintillator detector consists of 16 × 4 SiPMs with a pixel size of 3.0 × 3.0 mm2 and a pitch of 3.2 mm. The 64 signals of each SiPM array are processed by using the TOFPET2 application-specific integrated circuit individually. All but the edge slices can be clearly resolved for the detectors with both single-ended and dual-ended readouts. The single-ended readout detector provides an average full width at half maximum (FWHM) Y (continuous direction) position resolution of 2.43 mm, Z (depth direction) position resolution of 4.77 mm, energy resolution of 25.7% and timing resolution of 779 ps. The dual-ended readout detector significantly improves the Y and Z position resolutions, slightly improves the energy and timing resolution at the cost of two photodetectors required for one detector module and provides an average FWHM Y position resolution of 1.97 mm, Z position resolution of 2.60 mm, energy resolution of 21.7% and timing resolution of 718 ps. The energy and timing resolution of the semi-monolithic scintillator detector in this work are worse than those of the segmented scintillator array detector and need to be further improved. The semi-monolithic scintillator detector described in this work reduces costs as compared to the traditional segmented scintillator array detector and reduces the edge effect as compared to the monolithic scintillator detector. [ABSTRACT FROM AUTHOR]

The Circular Electron Positron Collider (CEPC) is a proposing electron–positron collider in China, which aims for generating high center-of-mass energy colliding above 250 GeV. The high-granularity electromagnetic calorimeter (ECAL) is included in a calorimeter system, which is mainly responsible for the measurement of photon. A particle flow algorithm (PFA)-based ECAL solution will utilize about 400k channels/m3. Here, we present the design and development status of readout electronics based on SPIROC2b for the CEPC ECAL with high-granularity scintillants and silicon photomultipliers (SiPMs). The readout electronics consists of front-end electronics (FEE), data interface (DIF) board, and data acquisition (DAQ) board. The front-end board (FEB) carries SiPMs (S12571-010P), scintillants (PSD), and FEB application-specific integrated circuit (ASIC) (SPIROC2b). Two electronics were designed in this paper, one is for ASIC functionality and performance only, and the other is used as a single layer of a further prototype of ECAL. Electronic test and cosmic ray test have been done to electronics. The results indicate that a charge dynamic from 62 fC to 300 pC at S/N = 2 is successfully achieved, and the minimum ionizing particles (MIPs) are separated from the pedestal. [ABSTRACT FROM AUTHOR]

We designed a CMOS frontend for the readout of scintillators coupled with silicon photodiodes for nuclear physics experiments. The preamplifier features a continuous-reset feedback and an input pMOS transistor. The designed input dynamic range is 90-MeV silicon equivalent. The frontend has been integrated in single channel and multichannel versions up to 16-channel application specific integrated circuits (ASICs) in the C35B4C3 AMS technology. The measured integral-non-linearity over the whole dynamic range is below 0.5%. The intrinsic rise time (10%–90%) of the preamplifier is of the order of 3 ns over the entire dynamic range and is below 50 ns when coupled with a 130-pF photodiode. We qualified the spectroscopic performance by acquiring spectra of a mixed nuclei \alpha source and of different \gamma sources (137Cs and 60Co) with a CsI(Tl) scintillator crystal 3.2~\text cm\times 3.2~\text cm\times 6~\text cm coupled with a 18~\text mm\times 18~\text mm silicon p-i-n diode 300- \mu \textm -thick readout by the developed ASIC. [ABSTRACT FROM AUTHOR]

Recent SiPM developments, together with improved readout electronics, opened new doors in time of flight positron emission tomography (TOF-PET) and high energy physics (HEP) research with a focus on prompt photon detection with inorganic scintillators. For instance, the relatively high Cherenkov yield of Bismuth Germanate (BGO) upon 511 keV gamma interaction has triggered a lot of interest, especially for its use in total-body PET scanners due to the relatively low production costs of BGO. However, especially in TOF-PET, the electronic readout for BGO still poses unsolved problems. Lab experiments have shown the benefit of Cherenkov detection, with coincidence time resolutions (CTRs) < 200 ps FWHM achieved, but lack system integration due to an unacceptably high power consumption (≫ 30 mW) of the used amplifiers. Therefore it becomes necessary to investigate different readout concepts of modern analog SiPMs, for which we tested several high-bandwidth amplifiers, commercially available, small in dimension, cheap and with a power consumption ranging from 288 mW to only 17 mW. We found that all tested amplifiers showed similar CTR performance of ∼ 100 ps FWHM coupling 3 × 3 × 3 mm 3 LYSO:Ce cubes from EPIC-crystals to S14160-3050HS Hamamatsu SiPMs with 3 × 3 mm 2 active area. The CTR performance with BGO is comparable for all tested amplifiers and the noise contribution to the CTR is found negligible. The results obtained lead to the conclusion that power-efficient SiPM readout solutions can be found, also suitable for Cherenkov light detection with BGO, which opens the door for their implementation in application-specific integrated circuits (ASICs) and systems. [ABSTRACT FROM AUTHOR]

In this paper, the capabilities of a wide-area gamma ray photosensor based on a SiPM array are investigated. For this purpose, we have mounted an array of 144 (12\times12) SiPMs with individual active area of 3 \times 3~\mm^2 and a pitch of 4.2~\mm, thus covering an active area of 50.2 \times 50.2~\mm^2. The measurements were performed by coupling the SiPM array to LYSO crystal arrays of different pixel size (2\times2~\mm^2, 1.5 \times 1.5~\mm^2, and 1 \times 1~\mm^2) and 10–12 mm thicknesses. The SiPM array was controlled by means of three ASICs, and the SiPM signals were multiplexed in order to determine the gamma ray impact position by means of implementing the Anger logic algorithm in the ASIC. The optimum bias voltage and temperature dependence of the gamma ray sensor were determined. An energy resolution as good as 8%, for individual crystal pixels, were reached at 5 V overvoltage. The ASICs design allows one to “activate” different photosensor array areas. This feature has been used to evaluate the detector performance as a function of the crystal pixel size and the photosensor dark noise contribution. In this work we also show the system capability to provide depth-of-interaction (DOI) information by means of implementing a two-layer staggered approach. We have found that accurate DOI information is obtained when the ASICs enabled an SiPM active area as high as 32\times 32~\mm^2(8 \times 8 SiPMs). [ABSTRACT FROM PUBLISHER]

A portable Single Sphere Neutron Spectrometer (SSNS) is designed to measure the neutron energy spectrum in the mixed radiation field. The spectrometer consists of a 30 cm diameter single polyethylene moderating sphere with 19 pieces 6Li and 1-piece 7Li glass scintillator detectors located at the orthogonal X/Y/Z axis. The output signals from each detector are processed and readout by the Silicon Photomultipliers (SiPMs) and the Application Specific Integrated Circuit (ASIC) electronic system. The neutron energy responses of portable SSNS are calibrated in the mono-energetic neutron reference fields (144 keV, 1.2 MeV, 5 MeV, 14.8 MeV) based on the 5SDH-2 tandem accelerator in China Institute of Atomic Energy, which are also simulated from 0.0253 eV to 20 MeV by Monte Carlo simulation. The performance of portable SSNS is tested at different distances in 241Am–Be neutron reference radiation field in National Institute of Metrology, China. The fluence response of SSNS is about 0.28 cm2 for 241Am–Be neutron source. • A portable Single Sphere Neutron Spectrometer (SSNS) is designed to measure the neutron energy spectrum. • The output signals from each detector are processed and readout by the SiPMs and the ASIC electronic system. • The SSNS is calibrated in monoenergetic neutron reference radiation fields. • The neutron energy responses are simulated by Monte Carlo simulation. • The performance of portable SSNS is tested in 241Am–Be neutron reference radiation field. [ABSTRACT FROM AUTHOR]