Geiger Mode Research Articles

Analytical models of probability distribution and excess noise factor of solid state photomultiplier signals with crosstalk

Silicon Photomultipliers (SiPM), also called Solid State Photomultipliers (SSPM), are based on Geiger mode avalanche breakdown that is limited by a strong negative feedback. An SSPM can detect and resolve single photons due to the high gain and ultra-low excess noise of avalanche multiplication in this mode. Crosstalk and afterpulsing processes associated with the high gain introduce specific excess noise and deteriorate the photon number resolution of the SSPM. The probabilistic features of these processes are widely studied because of its significance for the SSPM design, characterization, optimization and application, but the process modeling is mostly based on Monte Carlo simulations and numerical methods. In this study, crosstalk is considered to be a branching Poisson process, and analytical models of probability distribution and excess noise factor (ENF) of SSPM signals based on the Borel distribution as an advance on the geometric distribution models are presented and discussed. The models are found to be in a good agreement with the experimental probability distributions for dark counts and a few photon spectrums in a wide range of fired pixels number as well as with observed super-linear behavior of crosstalk ENF.

CMOS APD array for multi-function of both sequential and summing mode operations

A sensor is fabricated by a two poly-four metal 0.35 μm CMOS process in order to operate in the Geiger mode. The chip consists of an 8 × 8 array of 67 × 67 μm2 pixels that can be readout in either a summing mode or sequential mode. The features of the CMOS single photon avalanche photodiode (CMOS SPAD) were analyzed. The pixels were then arranged in a 8 × 8 array and the possibility of the summing mode and the sequential mode was verified. The CMOS SPAD pixel has a fill factor of 17.4%. The breakdown voltage of the pixel was at 18.9 V, and the photon detection efficiency was 20% at the 550 nm wavelength. The dead time was 20 nsec, and the dark count rate was 10 kHz at and below the single photon level. The operation of both summing mode and sequential mode function was sucessful in the 8 × 8 array sensor.

Scintillator detectors with long WLS fibers and multi-pixel photodiodes

We have studied the possibility of using Geiger mode multi-pixel photodiodes to read out long scintillator bars with a single wavelength-shifting fiber embedded along the bar. This detector configuration can be used in large volume detectors in future long baseline neutrino oscillation experiments. Prototype bars of 0.7 cm thickness and different widths have been produced and tested using two types of multi-pixel photodiodes: MRS APD (CPTA, Moscow) and MPPC (Hamamatsu). A minimum light yield of 7.2 p.e./MeV was obtained for a 4 cm wide bar.

Avoiding sensor blindness in Geiger mode avalanche photodiode arrays fabricated in a conventional CMOS process

The need to move forward in the knowledge of the subatomic world has stimulated the development of new particle colliders. However, the objectives of the next generation of colliders sets unprecedented challenges to the detector performance. The purpose of this contribution is to present a bidimensional array based on avalanche photodiodes operated in the Geiger mode to track high energy particles in future linear colliders. The bidimensional array can function in a gated mode to reduce the probability to detect noise counts interfering with real events. Low reverse overvoltages are used to lessen the dark count rate. Experimental results demonstrate that the prototype fabricated with a standard HV-CMOS process presents an increased efficiency and avoids sensor blindness by applying the proposed techniques.

Silicon photomultipliers for scintillating trackers

In recent years, silicon photomultipliers (SiPMs) have been proposed as a new kind of readout device for scintillating detectors in many experiments. A SiPM consists of a matrix of parallel-connected pixels, which are independent photon counters working in Geiger mode with very high gain (∼106). This contribution presents the use of an array of eight SiPMs (manufactured by FBK-irst) for the readout of a scintillating bar tracker (a small size prototype of the Electron Muon Ranger detector for the MICE experiment). The performances of the SiPMs in terms of signal to noise ratio, efficiency and time resolution will be compared to the ones of a multi-anode photomultiplier tube (MAPMT) connected to the same bars. Both the SiPMs and the MAPMT are interfaced to a VME system through a 64 channel MAROC ASIC.

Silicon photomultipliers for high energy physics detectors

In this paper I want to review the current status of development of multi-pixel silicon-based avalanche photo-diodes operated in Geiger mode, also known as Silicon Photomultipliers (SiPM). Particular emphasis is given to the application of this type of photo-sensors in high energy physics detectors.

Improvement of Energy Thresholds for Scintillation Detectors Using a Monolithic 2 ×2 Multi-Pixel Photon Counter Array with a Coincidence Technique

The performance of a large-area, monolithic Hamamatsu multi-pixel photon counter (MPPC) was tested consisting of a 2 ×2 array of 3 ×3 mm 2 pixels. MPPC is a novel type of semiconductor photodetector comprising multiple avalanche photodiode (APD) pixels operated in Geiger mode. Despite its great advantage of signal multiplication comparable to that achieved with the photomultiplier tube (PMT), the detection of weak scintillation light signals is quite difficult due to the severe contamination of dark counts, which typically amounts to ≃1 Mcps/3 ×3 mm 2 at room temperature. In this study, a coincidence technique was applied for scintillation detectors to improve the detection efficiency for low energy gamma-rays. The detector consisted of a 10 ×10 ×10 mm 3 crystals of GSO, BGO, and Pr:LuAG optically coupled with the 2 ×2 MPPC-array. With this technique, we demonstrated that the contamination of dark counts was reduced with a rejection efficiency of more than 99.8%. As a result, 22.2 keV gamma-rays were succ...

Spectral method for characterization of avalanche photodiode working as single-photon detector

In this Letter, a new method for avalanche photodiode characterization, based on the spectral analysis of the photocurrent produced during an avalanche, is proposed. The theory is developed, and an experimental characterization of an avalanche photodiode working in the Geiger mode with CW laser is performed.

Scaleable Single-Photon Avalanche Diode Structures in Nanometer CMOS Technology

Single-photon avalanche photodiodes (SPADs) operating in Geiger mode offer exceptional time resolution and optical sensitivity. Implementation in modern nanometer-scale complementary metal-oxide-semiconductor (CMOS) technologies to create dense high-resolution arrays requires a device structure that is scaleable down to a few micrometers. A family of three SPAD structures with sub-100-Hz mean dark count rate (DCR) is proposed in 130-nm CMOS image sensor technology. Based on a novel retrograde buried n-well guard ring, these detectors are shown to readily scale from 32 to 2 μm with improving DCR, jitter, and yield. One of these detectors is compatible with standard triple-well digital CMOS, and the others bring the first low-DCR realizations at the 130-nm node of shallow-trench-isolation-bounded and enhancement SPADs.

Experimental and TCAD Study of Breakdown Voltage Temperature Behavior in $n^{+}/p$ SiPMs

In this paper, the breakdown voltage in avalanche photodiodes operating in Geiger mode is investigated. In particular, the breakdown voltage dependence on the structural characteristics of n+/p avalanche diodes, such as implant dose and epitaxial layer thickness and doping concentration, as well as the temperature behavior are analyzed. The study includes both experimental data and numerical simulations. The first are acquired in a controlled temperature environment on samples featuring different electrical structures. Simulations are performed both at the technological process as well as at the electrical level using a commercial TCAD software. Agreement between experiments and numerical analysis is found to be quite good and first hints on how to improve the breakdown voltage uniformity and temperature dependence are given. Moreover, with the aid of TCAD simulations, the potential sources of device breakdown voltage fluctuations related to both device process variability and the properties of the starting silicon wafers are investigated.

The features of electronics structure of the multichannel scintillation module for the EMMA experiment

A brief description of the developed structural electric diagrams of 16-channel scintillation module for the underground EMMA experiment, the basic characteristics and parameters of the electrical diagrams of this module are presented. Multi-pixel photodiodes operating in a limited Geiger mode are used for photoreadout of the scintillator de- tectors in 16-channel scintillation module. The method of the automatic tuning of the photosensors gain based on the sta- bilization of an average counting rate of the scintillation de- tectors from gamma rays of a natural radioactive background is described.

A Novel, High-Dynamic-Range, High-Speed, and High-Sensitivity CMOS Imager Using Time-Domain Single-Photon Counting and Avalanche Photodiodes

Avalanche photodiodes used in Geiger mode as single-photon counters have become very attractive imaging tools. High-speed single-photon imaging can be used in very low-light-level applications such as surveillance and security imaging, quantum computing, and biomedical imaging including bioluminescence and fluorescence lifetime imaging. However, a typical avalanche-based single-photon detector cannot offer the high dynamic range that is needed for many biomedical and surveillance applications. In this paper, we show how a single-photon detector can be used in time domain for high-dynamic-range applications. We also discuss novel techniques to implement the time-domain single-photon imager in mainstream deep-submicrometer CMOS technology. The designed imager offers high dynamic range and high sensitivity, while maintaining high-speed operation and low cost.

Development of a large-area monolithic 4×4 MPPC array for a future PET scanner employing pixelized Ce:LYSO and Pr:LuAG crystals

We have developed a new type of large-area monolithic Multi-Pixel Photon Counter (MPPC) array consisting of a 4×4 matrix of 3×3 mm 2 pixels. Each pixel comprises 3600 Geiger mode avalanche photodiodes (APDs) that achieve an average gain of 9.68×10 5 at 71.9 V at 0 °C with variations of only ±7.2% over 4×4 pixels. Excellent uniformity was also obtained for photon detection efficiencies (PDE) of ±6.4%, whilst dark count rates at the single photoelectron (1 p.e.) level amounted to ≃ 2 Mcps / pixel , measured at 0 °C. As the first step toward using the device in scintillation photon detectors, we fabricated a prototype gamma-ray camera consisting of an MPPC array optically coupled with a scintillator matrix, namely a 4×4 array of 3×3 ×10 mm 3 crystals. Specifically, we tested the performance with Ce-doped (Lu, Y) 2(SiO 4)O (Ce:LYSO), Pr-doped Lu 3Al 5O 12 (Pr:LuAG) and “surface coated” Pr:LuAG (Pr:LuAG (WLS)) matrices whereby the emission peak of Pr:LuAG was shifted from 310 to 420 nm via a wavelength shifter (WLS). Average energy resolutions of 13.83%, 14.70% and 13.96% (FWHM) were obtained for 662 keV gamma-rays, as measured at 0 °C with Ce:LYSO, Pr:LuAG and Pr:LuAG (WLS) scintillator matrices, respectively. We confirmed that the effective PDE for Pr:LuAG (WLS) had improved by more than 30% compared to original, non-coated Pr:LuAG matrix. These results suggest that a large-area monolithic MPPC array developed here could be promising for future medical imaging, particularly in positron emission tomography (PET).

Integrated array of 2-μm antimonide-based single-photon counting devices

A 32x32 Sb-based Geiger-mode (GM) avalanche photodiode array, operating at 2 μm with three-dimensional imaging capability, is presented. The array is interfaced with a ROIC (readout integrated circuit) in which each pixel can detect a photon and record the arrival time. The hybridized unit for the 1000-element focal plane array, when operated at 77K with 1 V overbias range, shows an average dark count rate of 1.5 kHz. Three-dimensional range images of objects were acquired.

Time-of-Flight PET Detector Based on Multi-Pixel Photon Counter and Its Challenges

Geiger-mode multi-pixel APD is being recognized as the best alternative solid-state photo-sensor to vacuum PMT for various specific applications. Especially, its magnetic field immunity and high gain made it popular in MR/PET detector research. In this paper, we utilized its compactness, high gain and high photon detection efficiency in the design of TOF PET detector. In a typical block detector based on PMT, the full timing capability of both PMT and scintillator could not be achieved due to its light sharing for Anger logic scheme. Since Geiger-mode APD is a solid-state based technology, we can apply one-to-one coupling between a scintillator and the photo-sensor to optimize the signal-to-noise ratio. Also, the high photon detection efficiency of MPPC, Geiger mode APD from Hamamatsu, would help to improve timing resolution. So, we made a block detector based on a 4 × 4 array of 3 × 3 mm2 MPPC coupled to a 4 × 4 array of 3 × 3 × 25 mm3 LYSO crystals to evaluate its performance. We have achieved the average of 9% energy resolution and 314 ps coincidence timing resolution with very good uniformity. This block timing resolution showed no degradation in timing compared to individual single channel timing resolution as expected from one-to-one readout. On top of that, the result proves that the solid-state based photo-sensor can be used for TOF PET detector. During the development and setup of the detector, we recognized that a compact and low power electronics readout scheme is one of the biggest challenges, including its cost, for MPPC or other Geiger-mode APD to be used in products.

SENTIRAD—An innovative personal radiation detector based on a scintillation detector and a silicon photomultiplier

Abstract The alarming personal radiation detector (PRD) is a device intended for Homeland Security (HLS) applications. This portable device is designed to be worn or carried by security personnel to detect photon-emitting radioactive materials for the purpose of crime prevention. PRD is required to meet the scope of specifications defined by various HLS standards for radiation detection. It is mandatory that the device be sensitive and simultaneously small, pocket-sized, of robust mechanical design and carriable on the user's body. To serve these specialized purposes and requirements, we developed the SENTIRAD, a new radiation detector designed to meet the performance criteria established for counterterrorist applications. SENTIRAD is the first commercially available PRD based on a CsI(Tl) scintillation crystal that is optically coupled with a silicon photomultiplier (SiPM) serving as a light sensor. The rapidly developing technology of SiPM, a multipixel semiconductor photodiode that operates in Geiger mode, has been thoroughly investigated in previous studies. This paper presents the design considerations, constraints and radiological performance relating to the SENTIRAD radiation sensor.

一种确定In0.53Ga0.47As/InP单光子雪崩二极管击穿电压的方法

We examine the saturation of relative current gain of In0.53Ga0.47As/InP single photon avalanche diodes (SPADs) operated in Geiger mode. The punch-through voltage and breakdown voltage of the SPADs can be measured using a simple and accurate method. The analysis method is temperature-independent and can be applied to most SPADs.

Equalizing noise characteristics in Geiger mode avalanche photodiodes by using gated operation

The gated operation is proposed as an efficient method to reduce and uniformize noise figures in pixel detectors based on Geiger mode avalanche photodiodes. This idea has been proved by prototyping and characterizing a 3x3 array with the sensor and the front-end electronics monolithically integrated on a single CMOS die fabricated in a conventional CMOS technology.

Low-noise pixel detectors based on gated Geiger mode avalanche photodiodes

The gated operation is proposed as an effective method to reduce the noise in pixel detectors based on Geiger mode avalanche photodiodes. A prototype with the sensor and the front-end electronics monolithically integrated has been fabricated with a conventional HV-CMOS process. Experimental results demonstrate the increase of the dynamic range of the sensor by applying this technique.

Readout electronics for low dark count Geiger mode avalanche photodiodes fabricated in conventional HV-CMOS technologies for future linear colliders

This work presents low noise readout circuits for silicon pixel detectors based on Geiger mode avalanche photodiodes. Geiger mode avalanche photodiodes offer a high intrinsic gain as well as an excellent timing accuracy. In addition, they can be compatible with standard CMOS technologies. However, they suffer from a high intrinsic noise, which induces false counts indistinguishable from real events and represents an increase of the readout electronics area to store the false counts. We have developed new front-end electronic circuitry for Geiger mode avalanche photodiodes in a conventional 0.35 μm HV-CMOS technology based on a gated mode of operation that allows low noise operation. The performance of the pixel detector is triggered and synchronized with the particle beam thanks to the gated acquisition. The circuits allow low reverse bias overvoltage operation which also improves the noise figures. Experimental characterization of the fabricated front-end circuit is presented in this work.