Silicon Microstrip Detectors Research Articles

A single photon resolution integrating chip for silicon microstrip sensors (SSDROC) in High Energy Photon Source

Single-photon counting silicon microstrip detectors play a crucial role in X-ray powder diffraction experiments due to their high sensitivity and low dead-time. The High Energy Photon Source (HEPS) is poised to become a world-leading facility for high-energy synchrotron radiation. The storage ring, being constructed in China, will operate at an electron energy of 6 GeV and an emittance of less than 0.06 nm rad, thereby providing an exceptionally bright synchrotron light beam.Consequently, there is a requirement for detectors at HEPS to possess enhanced photon counting capabilities. Our team developed a dedicated Application-Specific Integrated Circuit (SSDROC) and a readout electronics system for one-dimensional X-ray detection. To resolve the issue of inconsistent photon response across different channels, a novel secondary calibration method has been applied. The detector has undergone various performance tests, and the results show that the entire system has good linearity, high energy resolution, and a high count rate.

Common-mode noise analysis of silicon microstrip detectors

Silicon microstrip detectors are widely used in space astronomy experiments owing to their high spatial resolution and long-term operational stability. The silicon microstrip detector is affected by bias voltage fluctuations, causing simultaneous changes in the pedestal of all channels under the same power supply. The noise generated by this variation is referred to as common-mode noise (CN). Precisely subtracting the CN can improve the charge resolution of light nuclei. In this study, we investigate the calculation method and sources of CN using the on-orbit data from DAMPE and test beam data of HERD. Our findings confirm that the CN in DAMPE’s silicon microstrip detector primarily arises from fluctuations in the power supply. Furthermore, through the combination of test beam results and SPICE simulations, we have discovered that capacitance-induced charge sharing also contributes to the CN, which increases with the particle charge.

Characteristics of thin p-MCz Si Microstrip Detector Irradiated upto a mixed fluence of 1017neq./cm2for the FCC

Silicon microstrip detectors can be used for the precise particle tracking in the inner tracking region of the detector used in the future high luminosity collider experiment. In the future experiments, hadron collider provides higher luminosities on the strip detector, and therefore, a detector requires very high radiation hardness. Within CERNRD50collaboration, MCz Si is identified as a prime radiation hard material for the fabrication of the p-Si microstrip detector. In this paper, we have used the experimentally verified four level deep-trap mixed irradiation model for p-MCz Si to investigate the effect of heavy irradiations up to a mixed fluence of 1017n eq./cm2 on the full depletion voltage, leakage current, and charge collection efficiency using SRH and CCE modelling.The changes in the characteristics were evaluated, and effect of the traps on the macroscopic performance of the detectors and possible improvement in the design and semiconductor technology of the p-Mcz silicon microstrip detector.

Simulation of DAMPE silicon microstrip detectors in the Allpix[formula omitted] framework

Silicon strip detectors have been widely utilized in space experiments for gamma-ray and cosmic-ray detections thanks to their high spatial resolution and stable performance. For a silicon micro-strip detector, the Monte Carlo simulation is recognized as a practical and cost-effective approach to verify the detector performance. In this study, a technique for the simulation of the silicon micro-strip detector with the Allpix2 framework is developed. By incorporating the electric field into the particle transport simulation based on Geant4, this framework could precisely emulate the carrier drift in the silicon micro-strip detector. The simulation results are validated using the beam test data as well as the flight data of the DAMPE experiment, which suggests that the Allpix2 framework is a powerful tool to obtain the performance of the silicon micro-strip detector.

Quality Assurance Test System for Assembly of STS Modules for the BM@N Experiment

The Silicon Tracking System (STS) of the BM@N experiment will be based on modules with Double-Sided microstrip Silicon Detectors (DSSD) which have been initially developed for the CBM experiment at FAIR. Each module consists of a DSSD, two front-end boards with 8 ASICs each, and a set of low-mass aluminum microcables. During the module assembly the microcables are tab-bonded to the sensor and readout ASICs. The module has 1024 channels on each side of the sensor. For the quality assurance of the ultrasonic bonding process a dedicated procedure based on the noise per channel measurements with a Pogo Pin test device was developed.

Characterization of the INFN proton CT scanner for cross-calibration of x-ray CT

Objective. The goal of this study was to assess the imaging performances of the pCT system developed in the framework of INFN-funded (Italian National Institute of Nuclear Physics) research projects. The spatial resolution, noise power spectrum (NPS) and RSP accuracy has been investigated, as a preliminary step to implement a new cross-calibration method for x-ray CT (xCT). Approach. The INFN pCT apparatus, made of four planes of silicon micro-strip detectors and a YAG:Ce scintillating calorimeter, reconstructs 3D RSP maps by a filtered-back projection algorithm. The imaging performances (i.e. spatial resolution, NPS and RSP accuracy) of the pCT system were assessed on a custom-made phantom, made of plastic materials with different densities ((0.66, 2.18) g cm−3). For comparison, the same phantom was acquired with a clinical xCT system. Main results. The spatial resolution analysis revealed the nonlinearity of the imaging system, showing different imaging responses in air or water phantom background. Applying the Hann filter in the pCT reconstruction, it was possible to investigate the imaging potential of the system. Matching the spatial resolution value of the xCT (0.54 lp mm−1) and acquiring both with the same dose level (11.6 mGy), the pCT appeared to be less noisy than xCT, with an RSP standard deviation of 0.0063. Concerning the RSP accuracy, the measured mean absolute percentage errors were (0.23+−0.09)% in air and (0.21+−0.07)% in water. Significance. The obtained performances confirm that the INFN pCT system provides a very accurate RSP estimation, appearing to be a feasible clinical tool for verification and correction of xCT calibration in proton treatment planning.

Analysis of interstrip capacitance of p+n MCz Si microstrip detector using TCAD simulation combining surface and bulk damage effects by mixed irradiation

Interstrip capacitance plays a crucial role on the detector electronic noise performance at the readout electrode of the irradiated detectors in the harsh radiation environment of the high luminosity Large Hadron Collider experiments. The major challenge is to optimize the design of the detector to get the low interstrip capacitance in the real ‘mixed’ irradiation environment of the experiment. A few of experimental studies have been performed within CERN RDD0 collaboration on the n-MCz Si detectors to extract the microscopic parameters for the surface and bulk damage effects especially by mixed irradiations in the detectors. The results on the microscopic parameters are fed into ATLAS TCAD commercial simulation program to compare the experimental data and simulation result. A very good agreement has been recorded between the data and simulation result. In this paper, the microscopic model parameters are used to investigate the effects of mixed irradiation up to a fluence of 8.82× 1014 neq./cm2 on the interstrip capacitance in n-MCz 〈100〉 silicon microstrip detectors. The results are discussed in detail using electric field distribution, electron concentration profile in the irradiated detectors for the different metal overhang width, and an optimized p+n-MCz Si microstrip design is proposed for the future collider experiment.

The new monolithic ASIC of the preshower detector for di-photon measurements in the FASER experiment at CERN

The ForwArd Search ExpeRiment (FASER) is an experiment searching for new light and weakly-interacting particles at CERN’s Large Hadron Collider. FASER is composed of different sub-detectors, including silicon microstrip detectors, scintillator counters and an electromagnetic calorimeter. In this paper, a new preshower detector for the FASER experiment is presented. The new detector, based on monolithic pixel ASICs, will provide excellent spatial and time resolutions and a large charge dynamic range. First results from a prototype chip produced by IHP in 130 nm SiGe BiCMOS technology are shown.

Characterization of 150 μm thick silicon microstrip prototype for the FOOT experiment

The goals of the FOOT (FragmentatiOn Of Target) experiment are to measure the proton double differential fragmentation cross-section on H, C, O targets at beam energies of interest for hadrontherapy (50–250 MeV for protons and 50–400 MeV/u for carbon ions), and also at higher energy, up to 1 GeV/u for radioprotection in space. Given the short range of the fragments, an inverse kinematic approach has been chosen, requiring precise tracking capabilities for charged particles. One of the subsystems designed for the experiment will be the MSD (Microstrip Silicon Detector), consisting of three x-y measurement planes, each one made by two single sided silicon microstrip sensors. In this document, we will present a detailed description of the first MSD prototype assembly, developed by INFN Perugia group and the subsequent characterization of the detector performance. The prototype is a wide area(∼ 100 cm2) single sensor, 150 μm thick to reduce material budget and fragmentation probability along the beam path, with 50 μm strip pitch and 2 floating strip readout approach. The pitch adapter to connect strips with the readout channels of the ASIC has been implemented directly on the silicon surface. Beside the interest for the FOOT experiment, the results in terms of cluster signal, signal-to-noise ratio, dynamic range of the readout chips, as well as long-term stability studies in terms of noise, are relevant also for other experiments where the use of thin sensors is crucial.

Characterization of the Microstrip Silicon Detector for the FragmentatiOn Of Target experiment

The main objective of the FOOT (FragmentatiOn Of Target) experiment is the measurement of the double differential cross-sections with respect to kinetic energy and emission angle of fragments produced in nuclear interactions at energies of interest for hadrontherapy (up to 400 MeV/u) (Battistoni et al., 2021) [1].The Microstrip Silicon Detector (MSD) will be one of the key components of the experiment, used to reconstruct the fragments’ tracks needed for momentum reconstruction. The sensors produced were tested throughout the production chain first in the laboratory and then at the accelerators to ensure their operation and performance in terms of noise and signal.

Test of a prototype Microstrip Silicon Detector for the FOOT experiment

The FOOT (FragmentatiOn Of Target) experiment aims to measure the fragmentation cross-section of protons into H, C, O targets at beam energies of interest for hadrontherapy (50-250 MeV for H and 50-400 MeV/u for C ions).Given the short range of the fragments, an inverse kinematic approach requiring precise tracking capabilities in a magnetic volume has been chosen.A key subsystem of this experiment will be the Microstrip Silicon Detector, based on 3 X-Y measuring station, each composed of two 150 μm thick single side microstrip sensors. In this work, we present the results of characterization of the new version of a 64 channel low-noise/low power high dynamic range readout ASIC and subsequent tests of the first 150 um thick sensor prototype.A series of tests were also performed to validate a novel “grazing angle” approach, where it is possible to change the track length below a given strip varying the incoming particle’s incident angle onto the sensor to test the electronics dynamic range without using high Z ions.

Study of the performances of the DAMPE silicon-tungsten tracker after five years of mission

DAMPE (DArk Matter Particle Explorer) is a satellite-based experiment launched in December 2015 and smoothly taking data after five years of mission. The Silicon-Tungsten Tracker (STK) is characterized by 6 double layers of silicon micro-strip detectors, for a total detection area of 7 m2, and three 1 mm thick tungsten plates, placed in the mechanical support structure, aimed to the photon conversion in e± pairs. The STK has a double role: precise reconstruction of the track of charged particles with a spatial resolution around 40 μm for most incident angles of the incoming particles, identification of the charge of the incoming cosmic rays. The STK performances are excellent after five years of continuous operation in space: in this contribution the STK in-orbit calibration and performances during the whole DAMPE mission will be presented.

Investigation of mixed irradiation effects in p-MCz thin silicon microstrip detector for the HL-LHC experiments

A lot of R&D work is carried out in the CERN RD 50 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 for the phase 2 upgrade plan of the new Compact Muon Solenoid Tracker detector in 2026. In this work, 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 Shockley Read Hall recombination statistics results on the mixed irradiated p-MCz Si PAD detector. The effective introduction rate (η eff) of shallower donor deep trap E30K is extracted using SRH theory calculations for experimental N eff and that can show the behavior of space charges and electric field distribution in the p-MCz Si strip detector and compared its value with the η eff of shallower donor deep trap E30K in the nMCz Si microstrip detector. Prediction uncertainty in the p-MCz Si radiation damage mixed irradiation model is considered in the full depletion voltage and leakage current. A very good agreement is observed in the experimental and SRH results. This radiation damage model is also used to extrapolate the value of the full depletion voltage at different mixed (proton + neutron) higher irradiation fluences for the thin p-MCz Si microstrip detector.

The tracking detector of the FASER experiment

FASER is a new experiment designed to search for new light weakly-interacting long-lived particles (LLPs) and study high-energy neutrino interactions in the very forward region of the LHC collisions at CERN. The experimental apparatus is situated 480 m downstream of the ATLAS interaction-point aligned with the beam collision axis. The FASER detector includes four identical tracker stations constructed from silicon microstrip detectors. Three of the tracker stations form a tracking spectrometer, and enable FASER to detect the decay products of LLPs decaying inside the apparatus, whereas the fourth station is used for the neutrino analysis. The spectrometer has been installed in the LHC complex since March 2021, while the fourth station is not yet installed. FASER will start physics data taking when the LHC resumes operation in early 2022. This paper describes the design, construction and testing of the tracking spectrometer, including the associated components such as the mechanics, readout electronics, power supplies and cooling system.

The Microstrip Silicon Detector (MSD) data acquisition system architecture for the FOOT experiment

The FOOT (FragmentatiOn Of Target) multi-detector experiment aims at improving the accuracy of oncological hadrontherapy for tumor treatment. It studies the nuclear fragmentation due to the interactions of charged particle beams with patient tissues employing the inverse kinematic approach to boost the fragments in the laboratory reference system. Hence it is necessary a tracking system in a magnetic field to measure the momentum of the charged fragments. The Microstrip Silicon Detector (MSD) is part of the charged-ions-tracking magnetic spectrometer for the evaluation of the Linear Energy Transfer LET (dE/dx) and the nuclear fragments momentum. Here we describe the MSD architecture and its data acquisition system whose task is to collect and digitize the detectors output, generating a data packet to be sent to the experiment’s central acquisition. This data acquisition system is designed and tested to withstand the trigger rate and detector’s throughput; it has a small size and is easily portable, a necessary feature for an experiment that will move among the available ion beam accelerators and proton therapy treatment rooms.

Beyond the N-Limit of the Least Squares Resolution and the Lucky Model

A very simple Gaussian model is used to illustrate an interesting fitting result: a linear growth of the resolution with the number N of detecting layers. This rule is well beyond the well-known rule proportional to N for the resolution of the usual fits. The effect is obtained with the appropriate form of the variance for each hit (observation). The model reconstructs straight tracks with N parallel detecting layers, the track direction is the selected parameter to test the resolution. The results of the Gaussian model are compared with realistic simulations of silicon micro-strip detectors. These realistic simulations suggest an easy method to select the essential weights for the fit: the lucky model. Preliminary results of the lucky model show an excellent reproduction of the linear growth of the resolution, very similar to that given by realistic simulations. The maximum likelihood evaluations complete this exploration of the growth in resolution.

Silicon Micro-Strip Detectors

Silicon micro-strip detectors are fundamental tools for the high energy physics. Each detector is formed by a large set of parallel narrow strips of special surface treatments (diode junctions) on a slab of very high quality silicon crystals. Their development and use required a large amount of work and research. A very synthetic view is given of these important components and of their applications. Some details are devoted to the basic subject of the track reconstruction in silicon strip trackers. Recent demonstrations substantially modified the usual understanding of this argument.

Computer simulation of the operational characteristics of a microstrip silicon detector

This paper presents the results of preliminary device and technological simulation and optimization of the operational characteristics of semiconductor microstrip detectors. We investigated the influence of heavy charged particles with linear energy transfers of 1.81 MeV cm2 mg−1, 18.8 MeV cm2 mg−1 and 55.0 MeV cm2 mg−1, corresponding to nitrogen 15N+4 ions with an energy E = 1.87 MeV, iron 56Fe+15 ions with an energy E = 523 MeV and xenon 131Xe+35 ions with an energy E = 1217 MeV, as well as the angle of incidence of the particles and the temperature and voltage on the substrate, on the characteristics of the detector. To improve the characteristics of the detector, a screening experiment was carried out and a series of optimization calculations were performed. The results will be used for the manufacture and testing of design parameters for an experimental batch of the investigated devices.

Comparative study of doped and doping less charge plasma silicon microstrip detector

Microstrip silicon detectors are one of the key trackers in particle physics experiment like LHC at CERN. There is a continuous need to improve upon various parameters of detectors like breakdown voltage, leakage current, full depletion voltage, post radiation hardness, charge collection efficiency and low thermal budget. We have introduced new doping less silicon microstrip detector for the very first time and investigated the various parameter of the detector. We have studied and compared the results of doped and dopingless charge plasma silicon microstrip detector. Our study shows improvement in Preradiation breakdown voltage of 2200 V with leakage current of 5.2 pA/um in dopingless charge plasma microstrip detector as compared to 1500 V of breakdown voltage with leakage current of 6.5pA/um as in the case of doped silicon microstrip detector.

Gamma-ray astrophysics in the MeV range

The energy range between about 100 keV and 1 GeV is of interest for a vast class of astrophysical topics. In particular, (1) it is the missing ingredient for understanding extreme processes in the multi-messenger era; (2) it allows localizing cosmic-ray interactions with background material and radiation in the Universe, and spotting the reprocessing of these particles; (3) last but not least, gamma-ray emission lines trace the formation of elements in the Galaxy and beyond. In addition, studying the still largely unexplored MeV domain of astronomy would provide for a rich observatory science, including the study of compact objects, solar- and Earth-science, as well as fundamental physics. The technological development of silicon microstrip detectors makes it possible now to detect MeV photons in space with high efficiency and low background. During the last decade, a concept of detector (“ASTROGAM”) has been proposed to fulfil these goals, based on a silicon hodoscope, a 3D position-sensitive calorimeter, and an anticoincidence detector. In this paper we stress the importance of a medium size (M-class) space mission, dubbed “ASTROMEV”, to fulfil these objectives.