The principal obstacle to long-time operation of silicon detectors at the highest energies in the next generation of experiments arises from bulk displacement damage which causes significant degradation of their macroscopic properties. The analysis of the behaviour of silicon detectors after irradiation conduces to a good or reasonable agreement between theoretical calculations and experimental data for the time evolution of the leakage current and effective carrier concentration after lepton and gamma irradiation and large discrepancies after hadron irradiation and this in conditions where a reasonable agreement is obtained between experimental and calculated concentrations of complex defects. In this contribution, we argue that the main discrepancies could be solved naturally considering as primary defects the self-interstitials, classical vacancies and the new predicted fourfold coordinated silicon pseudo-vacancy defects. This new defect is supposed to be introduced uniformly in the bulk during irradiation, has deep energy level(s) in the gap and it is stable in time. Considering the mechanisms of production of defects and their kinetics, it was possible to determine indirectly the characteristics of the SiFFCD defect: energy level in the band gap and cross section for minority carrier capture. In the frame of the model, the effects of primary defects on the degradation of silicon detectors are important in conditions of continuous long time irradiation and /or high fluences.
Influence of the prolonged irradiation by fission products of 252Cf radionuclide on the operational parameters of silicon-lithium Si(Li) p-i-n detectors, Si surface barrier detectors and Si planar p+n detector was investigated. The obtained results revealed a linear shift of the fission fragment peaks positions towards the lower energies with increase of the irradiation dose for all investigated detectors. The rate of the peaks shift was found to depend strongly on the detector type and the strength of the electric field in the detectors active region, but not on the temperature of irradiation…
We have investigated the effects of X-ray irradiation to doses of 0, 200 Gy, 20 kGy, 2 MGy, and 20 MGy on the Hamamatsu silicon-photomultiplier (SiPM) S10362-11-050C. The SiPMs were irradiated without applied bias voltage. From current-voltage, capacitance/conductance-voltage, -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 20 kGy the performance of the SiPMs is hardly affected by X-ray radiation damage. For doses of 2 and 20 MGy the SiPMs …
Technological tests of Total Ionizing Dose effects are required not only for silicon particle sensors developed in high energy physics experiments, but also for electronic devices and semiconductor elements used in commercial, automotive and space applications. Using x-ray irradiators, these technological tests and studies can be performed not only in facilities explicitly built for this mission, but also in medical or biological research facilities when some minima requirements are satisfied. Generally this irradiation can be performed without interfering with the medical and biological activ…
Stability of Charge Collection Efficiency and Time Resolution in a Novel Ultra-fast Graphene-Optimized Silicon Carbide Detector Under X-ray Irradiation
Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）；Liaoning University（辽宁大学）；Qufu Normal University（曲阜师范大学）；Jilin University（吉林大学）
The Mu2e calorimeter is composed of 1400 un-doped CsI crystals, coupled to large area UV extended Silicon Photomultipliers (SiPMs), arranged in two annular disks. This calorimeter has to provide precise information on energy, timing and position resolutions. It should also be fast enough to handle the high rate background and it must operate and survive in the high radiation environment. Simulation studies estimated that, in the highest irradiated regions, each photo-sensor will absorb a dose of 20 krad and will be exposed to a neutron fluency of 5.5x10^11 n_(1MeV)/cm^2 in three years of runni…
Silicon Photomultipliers with cell-pitch ranging from 12 $μ$m to 20 $μ$m were tested against neutron irradiation at moderate fluences to study their performance for calorimetric applications. The photosensors were developed by FBK employing the RGB-HD technology. We performed irradiation tests up to $2 \times 10^{11}$ n/cm$^2$ (1 MeV eq.) at the INFN-LNL Irradiation Test facility. The SiPMs were characterized on-site (dark current and photoelectron response) during and after irradiations at different fluences. The irradiated SiPMs were installed in the ENUBET compact calorimetric modules and c…
In the future ATLAS Inner Tracker, each silicon strip module will be equipped with a switch able to separate the high voltage supply from the sensor in case the latter becomes faulty. The switch, placed in between the HV supply and the sensor, needs to sustain a high voltage in its OFF state, to offer a low resistance path for the sensor leakage current in the ON state, and be radiation hard up to 1.2e15 neq/cm2 along with other requirements. While GaN JFETs have been selected as suitable rad-hard switch, a silicon vertical HV-JFET was developed by Brookhaven National Laboratory as an alternat…
We fabricated a readout ASIC with the fully depleted silicon-on-insulator (FD-SOI) technology for the pair-monitor. The pair-monitor is a silicon pixel device that measures the beam profile of the international linear collider. It utilizes the directional distribution of a large number of electron-positron pairs created by collision of bunches, and is required to tolerate radiation dose of about a few Mrad/year. The irradiation might cause the buried oxide layer of SOI to accumulate charges which interfere with intended functions. We thus performed extensive irradiation tests on the prototype …
Silicon photomultipliers (SiPMs) are highly-sensitive photodetectors emerging as the technology of choice for many applications, including large high-energy physics experiments where they often are exposed to high radiation fluences. In recent years, there has been an increasing interest in assessing the performance deterioration of such detectors after the irradiation with proton or neutron, with different fluence levels. In this work, samples of different FBK SiPM technologies, made with different manufacturing technologies, were irradiated at the INFN-LNS facility (Italy) with protons reach…
Radiation effects on surface and bulk properties of ATLAS18 silicon sensors under low- and high-dose gamma irradiation and annealing
Institute of Physics, Academy of Sciences of the Czech Republic（捷克科学院物理研究所）；Santa Cruz Institute for Particle Physics (SCIPP)（圣克鲁斯粒子物理研究所）；UJP Praha a.s.（UJP布拉格有限公司）；Experimental Particle Physics Department, Jožef Stefan Institute（约瑟夫斯特凡研究所实验粒子物理部）；Instituto de Microelectronica de Barcelona (IMB-CNM), CSIC（西班牙国家科学研究委员会巴塞罗那微电子研究所）；Institute of Particle and Nuclear Study, High Energy Accelerator Research Organization (KEK)（高能加速器研究机构粒子核研究部）；Physikalisches Institut, Albert-Ludwigs-Universität Freiburg（弗赖堡大学物理研究所）
Silicon avalanche photodiodes (APDs) are sensitive to operating temperature fluctuations and are also susceptible to radiation flux expected in satellite-based quantum experiments. We introduce a low power voltage adjusting mechanism to overcome the effects of in-orbit temperature fluctuations. We also present data on the performance of Si APDs after irradiation (gamma-ray and proton beam). Combined with an analysis of expected orbital irradiation, we propose that a Si APD in a 400 km equatorial orbit may operate beyond the lifetime of the satellite.
Silicon photomultipliers (SiPMs) have become popular light conversion devices in recent years due to their low bias voltage and sensitivity to wavelengths emitted from common scintillating materials. These properties make them particularly attractive for resource-constrained missions such as space-based detector applications. However the space radiation environment is known to be particularly harsh on semiconductor devices, where high particle fluences can degrade performance over time. The radiation hardness of a particular SiPM, manufactured by ON Semiconductor (formally SensL), has yet to b…
Detectors proposed for the International Linear Collider (ILC) incorporate a tungsten sampling calorimeter (`BeamCal') intended to reconstruct showers of electrons, positrons and photons that emerge from the interaction point of the collider with angles between 5 and 50 milliradians. For the innermost radius of this calorimeter, radiation doses at shower-max are expected to reach 100 MRad per year, primarily due to minimum-ionizing electrons and positrons that arise in the induced electromagnetic showers of e+e- `beamstrahlung' pairs produced in the ILC beam-beam interaction. However, radiatio…
The response of n+p silicon strip sensors to electrons from a Sr-90 source was measured using a multi-channel read-out system with 25 ns sampling time. The measurements were performed over a period of several weeks, during which the operating conditions were varied. The sensors were fabricated by Hamamatsu Photonics K.K. on 200 micrometer thick float-zone and magnetic-Czochralski silicon. Their pitch was 80 micrometer, and both p-stop and p-spray isolation of the n+ strips were studied. The electrons from the Sr-90 source were collimated to a spot with a full-width-at-half-maximum of 2 mm at t…
Hybrid silicon pixel detectors are currently used in the innermost tracking system of the Compact Muon Solenoid (CMS) experiment. Radiation tolerance up to fluences expected for a few years of running of the Large Hadron Collider (LHC) has already been proved, although some degradation of the part of the silicon detector closer to the interaction point is expected. During the LHC upgrade phases, the level of dose foreseen for the silicon pixel detector will be much higher. To face this aspect, dedicated irradiation tests with fluences above $\mathcal{O}(10^{15})$ n$_{\textrm{eq}}$/cm$^2$ have …
A lot of R & D work is carried out in the CERN RD50 Collaboration to find out the best material for the Si detectors that can be used in the harsh radiation environment of HL-LHC, n and p-MCz Si was identified as one of the prime candidates as a material for strip detector that can be chosen the phase 2 upgrade plan of the new Compact Muon Solenoid tracker detector in 2026. For the very first time, in this work, an advanced four level deep-trap mixed irradiation model for p-MCz Si is proposed by the comparison of experimental data on the full depletion voltage and leakage current to the Shockl…
All material exposed to interplanetary space conditions are subject to degradation processes. For obvious reasons there is a great interest to study these processes for materials that are used in satellite construction. However, also the influence of particle and electromagnetic radiation on the weathering of extraterrestrial rocks and on organic and biological tissues is the research topic of various scientific disciplines. To strengthen the comprehensive and systematic investigation of degradation processes a new laboratory, the complex irradiation facility (CIF), has been designed, set up, …
The investigation of the degradation effects on triple-junction (TJ) solar cells, operating in space environment, is of primary importance in view of future space missions towards harsh radiation orbits (e.g. MEO with high particle irradiation intensity) and for the new spacecraft based on electrical propulsion. In the present work, we report the experimental results obtained from the irradiation test campaign carried out both on (InGaP/GaAs/Ge) TJ solar cells and on single junction (SJ) isotype sub-cells (i.e. InGaP top cells, GaAs middle cells and Ge bottom cells). In particular, the electri…
This paper presents the results of the proton irradiation of silicon photomulipliers (SiPMs) by mono-energetic 170 MeV protons with fluence up to 4.6$\times$10$^{9}$ particles/cm$^2$. In our work, three types of silicon photodetectors from Hamamatsu with areas 3$\times$3 mm$^2$ and different subpixel sizes of 25$\times$25 $μ$m$^2$, 50$\times$50 $μ$m$^2$, and 75$\times$75 $μ$m$^2$ were used. The changes in the SiPM dark count rate (DCR) spectrum before and after irradiation in temperatures in the range of 20 $^\circ$C to -65 $^\circ$C are presented. The influence of the DCR changes on the energ…
The collection of charge carriers generated in p+n strip sensors close to the Si-SiO2 interface before and after 1 MGy of X-ray irradiation has been investigated using the transient current technique with sub-nanosecond focused light pulses of 660 nm wavelength, which has an absorption length of 3.5 um in silicon at room temperature. The paper describes the measurement and analysis techniques used to determine the number of electrons and holes collected. Depending on biasing history, humidity and irradiation, incomplete collection of either electrons or holes is observed. The charge losses cha…
In-situ Radiation Damage Study of Silicon Carbide Detectors Subjected to Clinical Proton Beams
Marietta Blau Institute for Particle Physics, Austrian Academy of Sciences（玛丽塔·布劳粒子物理研究所，奥地利科学院）；Institute of Atomic and Subatomic Physics, TU Wien（维也纳工业大学原子与亚原子物理研究所）
For the high-luminosity phase of the Large Hadron Collider (HL-LHC), at the expected position of the innermost pixel detector layer of the CMS and ATLAS experiments, the estimated equivalent neutron fluence after 3000 fb$^{-1}$ is 2$\cdot$10$^{16}$ n$_{eq}$/cm$^2$, and the IEL (Ionizing Energy Loss) dose in the SiO$_2$ 12 MGy. The optimisation of the pixel sensors and the understanding of their performance as a function of fluence and dose makes a radiation damage model for TCAD simulations, which describes the available experimental data, highly desirable. The currently available bulk-damage …
Radiation Hardness of Commercially Available NUV-MT Silicon Photomultipliers
University of Hamburg（汉堡大学）；NCSR “Demokritos（德谟克利特国家研究中心）；Institute of Nuclear and Particle Physics（核与粒子物理研究所）；School of Physics and Astronomy, University of Birmingham（伯明翰大学物理与天文学学院）
The silicon drift detectors are at the basis of the instrumentation aboard the Large Observatory For x-ray Timing (LOFT) satellite mission, which underwent a three year assessment phase within the "Cosmic Vision 2015 - 2025" long-term science plan of the European Space Agency. Silicon detectors are especially sensitive to the displacement damage, produced by the non ionising energy losses of charged and neutral particles, leading to an increase of the device leakage current and thus worsening the spectral resolution. During the LOFT assessment phase, we irradiated two silicon drift detectors w…
A conceptual set-up for measuring the electric field in silicon detectors by electro-optical imaging is proposed. It is based on the Franz-Keldysh effect which describes the electric field dependence of the absorption of light with an energy close to the silicon band gap. Using published data, a measurement accuracy of 1 to 4 kV/cm is estimated. The set-up is intended for determining the electric field in radiation-damaged silicon detectors as a function of irradiation fluence and particle type, temperature and bias voltage. The overall concept and the individual components of the set-up are p…
Radiation damage study of Belle II silicon strip sensors with 90 MeV electron irradiation
Institute of High Energy Physics, Austrian Academy of Sciences（奥地利科学院高能物理研究所）；Aix Marseille Univ, CNRS/IN2P3, CPPM（艾克斯-马赛大学，法国国家科学研究中心/法国原子能和替代能源委员会，粒子与宇宙学实验室）；Indian Institute of Technology Bhubaneswar（布巴内斯瓦尔印度理工学院）；Indian Institute of Technology Madras（马德拉斯印度理工学院）；Malaviya National Institute of Technology Jaipur（斋普尔马拉维亚国立技术学院）；Punjab Agricultural University（旁遮普农业大学）；Tata Institute of Fundamental Research（塔塔基础研究院）；Dipartimento di Fisica, Università di Pisa（比萨大学物理系）
Proton irradiation effects on a Single-Photon Avalanche Diodes (SPADs) device manufactured using a 150-nm CMOS process are presented. An irradiation campaign has been carried out with protons of 20 MeV and 24 MeV on several samples of a test chip containing SPADs arrays with two different junction layouts. The dark count rate distributions have been analyzed as a function of the displacement damage dose. Annealing and cooling have been investigated as possible damage mitigation approaches. We also discuss, through a space radiation simulation, the suitability of such devices on several space m…
Protons that are trapped in the Earth's magnetic field are one of the main threats to astronomical X-ray observatories. Soft protons, in the range from tens of keV up to a few MeV, impinging on silicon X-ray detectors can lead to a significant degradation of the detector performance. Especially in low earth orbits an enhancement of the soft proton flux has been found. A setup to irradiate detectors with soft protons has been constructed at the Van-de-Graaff accelerator of the Physikalisches Institut of the University of Tübingen. Key advantages are a high flux uniformity over a large area, to …
In this paper results of Edge-TCT and I-V measurements with passive test structures made in LFoundry 150 nm HV-CMOS process on p-type substrates with different initial resistivities ranging from 0.5 to 3 k$Ω$cm are presented. Samples were irradiated with reactor neutrons up to a fluence of 2$\cdot$10$^{15}$ n$_{\mathrm{eq}}$/cm$^2$. Depletion depth was measured with Edge-TCT. Effective space charge concentration $N_{\mathrm{eff}}$ was estimated from the dependence of depletion depth on bias voltage and studied as a function of neutron fluence. Dependence of $N_{\mathrm{eff}}$ on fluence change…
This work focuses on the investigation of radiation induced defects responsible for the degradation of silicon detectors. Comparative studies of the defects induced by irradiation with 60Co- rays, 6 and 15 MeV electrons, 23 GeV protons and 1 MeV equivalent reactor neutrons revealed the existence of point defects and cluster related centers having a strong impact on damage properties of Si diodes. The detailed relation between the microscopic reasons as based on defect analysis and their macroscopic consequences for detector performance are presented. In particular, it is shown that the changes…
Within CERN RD50 Collaboration, MCz Si was identified as a best material for the detector used in the high luminosity collider experiments. The n in p Si detectors were utmost radiation hard detectors, which can be used for the phase 2 upgrade plan of the new Compact Muon Solenoid tracker detector in 2026. The choice of n or p-MCz Si material depends upon the high electrical charge collection efficiency performance of these detectors over n or p-FZSi detectors. The bulk radiation damage model for n, p-MCz Si need to develop for the designing, development and optimization of the advanced detect…
During the scheduled high luminosity upgrade of LHC, the world's largest particle physics accelerator at CERN, the position sensitive silicon detectors installed in the vertex and tracking part of the CMS experiment will face more intense radiation environment than the present system was designed for. Thus, to upgrade the tracker to required performance level, comprehensive measurements and simulations studies have already been carried out. Essential information of the performance of an irradiated silicon detector is obtained by monitoring its charge collection efficiency (CCE). From the evolu…
During the high-luminosity phase of the LHC (HL-LHC), planned to start around 2027, the accelerator is expected to deliver an instantaneous peak luminosity of up to $7.5\times10^{34}$ cm$^{-2}$s$^{-1}$. A total integrated luminosity of $3000$ or even $4000$~fb$^{-1}$ is foreseen to be delivered to the general purpose detectors ATLAS and CMS over a decade, thereby increasing the discovery potential of the LHC experiments significantly. The CMS detector will undergo a major upgrade for the HL-LHC, with entirely new tracking detectors consisting of an Outer Tracker and Inner Tracker. However, the…
We report radiation hardness tests performed at the Frascati Neutron Generator on silicon Photo-Multipliers, semiconductor photon detectors built from a square matrix of avalanche photo-diodes on a silicon substrate. Several samples from different manufacturers have been irradiated integrating up to 7x10^10 1-MeV-equivalent neutrons per cm^2. Detector performances have been recorded during the neutron irradiation and a gradual deterioration of their properties was found to happen already after an integrated fluence of the order of 10^8 1-MeV-equivalent neutrons per cm^2.
The existing ATLAS Tracker will be at its functional limit for particle fluences of 10^15 neq/cm^2 (LHC). Thus for the upgrades at smaller radii like in the case of the planned Insertable B-Layer (IBL) and for increased LHC luminosities (super LHC) the development of new structures and materials which can cope with the resulting particle fluences is needed. N-in-p silicon devices are a promising candidate for tracking detectors to achieve these goals, since they are radiation hard, cost efficient and are not type inverted after irradiation. A n-in-p pixel production based on a MPP/HLL design a…
