Silicon photo-multipliers (SiPMs) are detectors sensitive to single photons that are used to detect scintillation and Cherenkov light in a variety of physics and medical-imaging applications. SiPMs ...measure single photons by amplifying the photo-generated carriers (electrons or holes) via a Geiger-mode avalanche. The photon detection efficiency (PDE) is the combined probability that a photon is absorbed in the active volume of the device with a subsequently triggered avalanche. Absorption and avalanche triggering probabilities are correlated since the latter probability depends on where the photon is absorbed. In this article, we introduce a physics-motivated parameterization of the avalanche triggering probability that describes the PDE of a SiPM as a function of its reverse bias voltage, at different wavelengths. This parameterization is based on the fact that in p-on-n SiPMs, the induced avalanches are electron-driven in the ultraviolet (UV) range, while they become increasingly hole-driven toward the infrared range. The model has been successfully applied to characterize two Hamamatsu multi-pixel photon counters (MPPCs) and one Fondazione-Bruno-Kessler (FBK) SiPM, and it can be extended to other SiPMs. Furthermore, this model provides key insight into the electric field structure within SiPMs, which can explain the limitation of the existing devices and be used to optimize the performance of the future SiPMs.
Silicon Photomultipliers (SiPMs) are attractive candidates for light detectors for next generation liquid xenon double-beta decay experiments, like nEXO (next Enriched Xenon Observatory). In this ...paper we discuss the requirements that the SiPMs must satisfy in order to be suitable for nEXO and similar experiments, describe the two test setups operated by the nEXO collaboration, and present the results of characterization of SiPMs from several vendors. In particular, we find that the photon detection efficiency at the peak of xenon scintillation light emission (175-178 nm) approaches the nEXO requirements for tested FBK and Hamamatsu devices. Additionally, the nEXO collaboration performed radio-assay of several grams of bare FBK devices using neutron activation analysis, indicating levels of 40 K, 232 Th, and 238 U of the order of <; 0.15, (6.9 · 10 - 4 - 1.3 · 10 - 2 ), and <; 0.11 mBq/kg, respectively.
After-pulsing and cross-talk in multi-pixel photon counters Du, Y.; Retière, F.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2008, Letnik:
596, Številka:
3
Journal Article
Recenzirano
Multi-pixel photon counters (MPPC) are pixelated Geiger-mode photon manufactured by Hamamatsu photonics. They will be used for reading out all the scintillator elements within the near detector of ...the T2K experiment. Their performances photo-detection efficiency, dark noise and gain, and their insensitivity to magnetic field fulfill the ND280 requirements. On the other hand, two known issues, cross-talk and after-pulsing may adversely impact the detector response. In this paper, cross-talk and after-pulsing are precisely measured by recording waveforms and identifying all the avalanche pulses. At an over-voltage of 2
V, an avalanche generates on an average 0.5 additional avalanches due to after-pulsing, whereas it generates 0.13 at 1
V over-voltage. After-pulses follow two independent time constants of 15 and 82
ns. The cross-talk probability is a factor of 3 smaller than the after-puling probability. Simulating the MPPC response, we find that after-pulsing and cross-talk do not degrade the detector performance significantly within the expected operating conditions of the T2K near detector.
Photo-multiplier tubes (PMTs) and silicon photo-multipliers (SiPMs) are detectors sensitive to single photons that are widely used for the detection of scintillation and Cerenkov light in subatomic ...physics and medical imaging. This paper presents a method for characterizing two of the main noise sources that PMTs and SiPMs share: dark noise and correlated noise (after-pulsing). The proposed method allows for a model-independent measurement of the after-pulsing timing distribution and dark noise rate.
Application of Hamamatsu MPPCs to T2K neutrino detectors Yokoyama, M.; Nakaya, T.; Gomi, S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2009, Letnik:
610, Številka:
1
Journal Article
Recenzirano
Odprti dostop
A special type of Hamamatsu Multi-Pixel Photon Counter (MPPC), with a sensitive area of
1.3
×
1.3
mm
2
containing 667 pixels of size
50
×
50
μ
m
2
each, has been developed for the near neutrino ...detector in the T2K long baseline neutrino experiment. About 60
000 MPPCs will be used in total to read out the plastic scintillator detectors with wavelength shifting fibers. We report on the basic performance of MPPCs produced for T2K.
The calorimeter, range detector and active target elements of the T2K near detectors rely on the Hamamatsu Photonics Multi-Pixel Photon Counters (MPPCs) to detect scintillation light produced by ...charged particles. Detailed measurements of the MPPC gain, afterpulsing, crosstalk, dark noise, and photon detection efficiency for low light levels are reported. In order to account for the impact of the MPPC behavior on T2K physics observables, a simulation program has been developed based on these measurements. The simulation is used to predict the energy resolution of the detector.
The imaging performance of a high-resolution preclinical micro-positron emission tomography (micro-PET) system employing liquid xenon (LXe) as the gamma-ray detection medium was simulated. The ...arrangement comprises a ring of detectors consisting of trapezoidal LXe time projection ionization chambers and two arrays of large area avalanche photodiodes for the measurement of ionization charge and scintillation light. A key feature of the LXePET system is the ability to identify individual photon interactions with high energy resolution and high spatial resolution in three dimensions and determine the correct interaction sequence using Compton reconstruction algorithms. The simulated LXePET imaging performance was evaluated by computing the noise equivalent count rate, the sensitivity and point spread function for a point source according to the NEMA-NU4 standard. The image quality was studied with a micro-Derenzo phantom. Results of these simulation studies included noise equivalent count rate peaking at 1326 kcps at 188 MBq (705 kcps at 184 MBq) for an energy window of 450-600 keV and a coincidence window of 1 ns for mouse (rat) phantoms. The absolute sensitivity at the center of the field of view was 12.6%. Radial, tangential and axial resolutions of (22)Na point sources reconstructed with a list-mode maximum likelihood expectation maximization algorithm were ≤0.8 mm (full-width at half-maximum) throughout the field of view. Hot-rod inserts of <0.8 mm diameter were resolvable in the transaxial image of a micro-Derenzo phantom. The simulations show that a LXe system would provide new capabilities for significantly enhancing PET images.
The fine grained detector readout electronics Retière, F.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2010, Letnik:
623, Številka:
1
Journal Article
Recenzirano
The Fine Grained Detector (FGD) readout electronics was designed to record a snapshot of the detector activity before, during and after the neutrino beam spill produced by the J-PARC accelerator ...complex in Tokai, Japan. The FGD is a key element of T2K near detector currently being constructed. It will act as an active target detecting charged particles produced within its scintillator bars. The original feature of the FGD electronics is to readout Multi-Pixel Photon Counters by recording waveforms using Switch Capacitor Array chips (AFTER ASIC) designed for T2K Time Projection Chamber. In these proceedings, we describe the architecture of the FGD electronics. Beam results show that the physics requirements are met or exceeded. The relatively slow sampling frequency of the AFTER ASIC does not impair the timing resolution significantly. In addition, the very good efficiency of the system for detecting Michel electrons produced by pions or muons decay has been demonstrated.
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