The finite number of pixels in a silicon photomultiplier (SiPM) limits its dynamic range to light pulses up to typically 80% of the total number of pixels in a device. Correcting the non-linear ...response is essential to extend the SiPM's dynamic range. One challenge in determining the non-linear response correction is providing a reference linear light source. Instead, the single-step method used to calibrate PMTs is applied, based on the difference in responses to two light sources. With this method, the response of an HPK SiPM (S14160-1315PS) is corrected to linearity within 5% while extending the linear dynamic range by a factor larger than ten. The study shows that the response function does not vary by more than 5% for a variation in the operating voltage between 2 and 5 V overvoltage in the gate length between 20 and 100 ns and for a time delay between the primary and secondary light of up to 40 ns.
The main consequence of radiation damage on a silicon photomultiplier (SiPM) is a significant increase in the dark current. If the SiPM is not adequately cooled, the power dissipation causes it to ...heat up, which alters its performance parameters. To investigate this heating effect, a measurement cycle was developed and performed with a KETEK SiPM glued to an Al
O
substrate and with HPK SiPMs glued to either an Al
O
substrate or a flexible PCB. The assemblies were connected either directly to a temperature-controlled chuck on a probe station, or through layers of materials with defined thermal resistance. An LED operated in DC mode was used to illuminate the SiPM and to tune the power dissipated in a measurement cycle. The SiPM current was used to determine the steady-state temperature reached by the SiPM via a calibration curve. The increase in SiPM temperature due to self-heating is analyzed as a function of the power dissipation in the SiPM and the thermal resistance. This information can be used to adjust the operating voltage of the SiPMs, taking into account the effects of self-heating. Similarly, this approach can be applied to investigate the unknown thermal contact of packaged SiPMs.
Study of point- and cluster-defects in radiation-damaged silicon Donegani, Elena M.; Fretwurst, Eckhart; Garutti, Erika ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2018, Letnik:
898
Journal Article
Recenzirano
Odprti dostop
Non-ionising energy loss of radiation produces point defects and defect clusters in silicon, which result in a significant degradation of sensor performance. In this contribution results from TSC ...(Thermally Stimulated Current) defect spectroscopy for silicon pad diodes irradiated by electrons to fluences of a few 1014cm−2 and energies between 3.5 and 27 MeV for isochronal annealing between 80 and 280∘C, are presented. A method based on SRH (Shockley–Read–Hall) statistics is introduced, which assumes that the ionisation energy of the defects in a cluster depends on the fraction of occupied traps. The difference of ionisation energy of an isolated point defect and a fully occupied cluster, ΔEa, is extracted from the TSC data.
For the VOi (vacancy-oxygen interstitial) defect ΔEa=0 is found, which confirms that it is a point defect, and validates the method for point defects. For clusters made of deep acceptors the ΔEavalues for different defects are determined after annealing at 80∘C as a function of electron energy, and for the irradiation with 15 MeV electrons as a function of annealing temperature. For the irradiation with 3.5 MeV electrons the value ΔEa=0 is found, whereas for the electron energies of 6–27 MeV ΔEa>0. This agrees with the expected threshold of about 5 MeV for cluster formation by electrons. The ΔEavalues determined as a function of annealing temperature show that the annealing rate is different for different defects. A naive diffusion model is used to estimate the temperature dependencies of the diffusion of the defects in the clusters.
A Python program has been developed which fits a published detector-response model to SiPM charge spectra to characterise SiPMs. Spectra for SiPMs illuminated by low intensity pulsed light with ...Poisson-distributed number of photons and a time spread of order nanoseconds or less, and spectra without illumination can be analysed. The entire spectra, including the intervals in-between the photoelectron peaks, are fitted, which allows determining, in addition to the mean number of detected photons, gain, gain spread, prompt cross-talk, pedestal, and electronics noise, the dark-count rate as well as the probability and time constant of after-pulses. The starting values of the fit parameters are extracted from the charge spectra.
The program performance has been evaluated using simulated charge spectra with the different SiPM parameters varied in a wide range. By analysing 100 simulated spectra for every parameter set, the biases and statistical uncertainties of the individual parameters have been determined. It is found that the parameters are precisely determined and that the entire spectra are well described, in most cases with a χ2/NDF close to 1. In addition, measured spectra for two types of SiPMs for a wide range of over-voltages have been analysed. The program achieves mostly a good description of the spectra, and the parameters determined agree with the values from the producers.
The program can be used for detailed analyses of single spectra, but, as it is compatible with the native Python multiprocessing module, also for the automatic characterisation of large samples of SiPMs.
Overview on calorimetry Garutti, Erika
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2011, Letnik:
628, Številka:
1
Journal Article
Recenzirano
In this paper I want to review the state of the art of calorimeter developments. I will focus on innovative solutions in calorimetry at the technology frontier and I will favor calorimeters for High ...Energy Physics detectors. The field in which calorimeters find their application is so broad that this short review does not do justice to all ongoing projects. Instead, this paper shall be considered as a collection of currently hot topics on the subject.
The EndoTOFPET-US project aims to jointly exploit Time-Of-Flight Positron Emission Tomography (TOFPET) and ultrasound endoscopy with a multi-modal instrument for the development of new biomarkers for ...pancreas and prostate oncology. The paper outlines the functionality of the proposed instrument and the challenges for its realization. The high level of miniaturization and integration poses strong demands to the fields of scintillating crystallography, ultra-fast photon detection, highly integrated electronics and system integration. Solutions are presented to obtain a coincidence time resolution better than 200 ps and a spatial resolution of -1 mm with an asymmetric TOFPET detector. A tracking system with better than 1 mm spatial resolution precision enables the online alignment of the system. The detector design, the production and test status of the single detector components, and the integration plans are discussed.
A new prototype of a tile hadron calorimeter (AHCAL) for the International Linear Collider detector is currently developed within the CALICE collaboration. The aim is to improve the energy resolution ...by measuring details of the shower development and combining them with the data of the tracking chamber (particle flow). The prototype is based on scintillating tiles that are read out by novel Silicon-Photomultiplier (SiPM). This new prototype will take into account all design aspects that are demanded by the intended operation at the ILC It will contain about 2500 detector channels. This is the first calorimeter design which makes full use of the high integration potential of the novel photo-sensor technology. Main focus of this contribution is the mechanical and electrical integration of the front-end electronics into the calorimeter absorber structure, with the aim of maintaining high-density calorimeter. Integration aspects and scalability to an ILC detector are discussed. For the analog calorimeter the proposal of an integrated light-calibration system for calibration and gain monitoring are presented, addressing temperature and bias dependence of the SiPM gain. First results from the measurements with one prototype module at the DESY test beam are presented, which demonstrate the quality of the readout system, and of the light-calibration system.
We have investigated the effects of X-ray irradiation to doses of 0, 200Gy, 20kGy, 2MGy, and 20MGy on the Hamamatsu silicon-photomultiplier (SiPM) S10362-11-050C. The SiPMs were irradiated without ...applied bias voltage. From current–voltage, capacitance/conductance–voltage, capacitance/conductance–frequency, pulse-shape, and pulse-area measurements, the SiPM characteristics below and above breakdown voltage were determined. Significant changes of some SiPM parameters are observed. Up to a dose of 20kGy the performance of the SiPMs is hardly affected by X-ray radiation damage. For doses of 2 and 20MGy the SiPMs operate with hardly any change in gain, but with a significant increase in dark-count rate and cross-talk probability.
PDF
