Microstrip Detectors Research Articles

Development of a sapphire microstrip detector for gamma beam monitoring

Artificial sapphire gained interest as radiation detector in the recent years, as an alternative to diamond. The research and development campaign to design, build and characterize a radiation-hard detector for gamma beam monitoring takes place in the scientific context of the Laser Und XFEL Experiment (LUXE) at DESY. The experiment requirements of beam profile reconstruction with micro-metric precision and radiation hardness led to a proposed sapphire microstrip detector design. This work introduces the scientific context for a sapphire microstrip gamma beam profiler (GBP) and describes the experimental campaign for sapphire characterization from early prototypes to the final development of a 192-strip detector.

From 3D to 5D tracking: SMX ASIC-based double-sided micro-strip detectors for comprehensive space, time, and energy measurements

We present the recent development of a lightweight detector capable of accurate spatial, timing, and amplitude resolution of charged particles. The technology is based on double-sided double-metal p+ – n – n+ micro-strip silicon sensors, ultra-light long aluminum-polyimide micro-cables for the analogue signal transfer, and a custom-developed SMX read-out ASIC capable of measurement of the time (Δt ≲ 5 ns) and amplitude. Dense detector integration enables a material budget > 0.3 % X 0. A sophisticated powering and grounding scheme keeps the noise under control.In addition to its primary application in Silicon Tracking System of the future CBM experiment in Darmstadt, our detector will be utilized in other research applications.

The data acquisition system for the PANDA Micro-Vertex Detector

The PANDA (antiProton ANnihilation at DArmstadt) experiment will study the strong interaction in annihilation reactions between an antiproton beam and a stationary cluster jet target. The PANDA detector will be composed of several sub-detectors designed for tracking, particle identification and calorimetry. The Micro-Vertex Detector (MVD) is the innermost part of the tracking system surrounding the interaction region, which is designed for precise vertex and tracking detection. It consists of silicon pixel and double-sided microstrip detectors. For the readout of the microstrip sensors an ASIC called ToASt (Torino Asic for Strip readout) is being developed in 0.11 μm CMOS technology at INFN Turin. The ASIC takes advantage of both Time-over-Threshold and Time-of-Arrival methods to accurately measure the event's energy and timestamp. To sustain the acquisition of the microstrip sensors a MDC (Module Data Concentrator) ASIC is under development at KIT. Up to eight ToASt front-ends' data streams are multiplexed, read out and processed by one MDC. The data of several MDCs are collected and processed by the off-detector readout card MMB (MVD Multiplexer Board), also under development at KIT. The processed data is then transferred via 100 GbE optical links to the computing nodes. The ToASt chips have been integrated with the FPGA implementation of the MDC to form the first fully functional detector module. Beam tests have been performed at the COSY facility in Jülich. This paper focuses on the design of MDC ASIC and MMB board, the integration with the ToASt and presents preliminary beam test results.

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.

Study of Proton Radiation Damage Effects in Si microstrip Detector for New and Fast Tracking System of pCT

A new and fast radiation hard p-Si micro strip detector requires for the high proton imaging performance using the Proton Computed Tomography (pCT) system. Silicon trackers of the pCT have been measured the actual proton dose delivered to the cancer patient during the medical treatment. In this paper, several proton cancer doses up to 9.62x 1014 neq,/cm2 are used for the SRH modelling of the full depletion voltage and leakage current at 293 K of the Si micro-strip detector using microscopic radiation damage model. Radiation hard thin (150μm) p-type MCz Si micro strip detector design is proposed for the pCT that can work up to 800V for very high-irradiated proton cancer doses.

TCAD Simulation of X-ray irradiated Si microstrip detector : Impact on full depletion voltage and leakage current

In the intense x-ray radiation environment at synchrotron sources, it is reported that the performance of the silicon pixel detectors degrades with an increasing x-ray dose up to 10 MGy. To study the impact of x-ray irradiation effects in the n-Fz Si microstrip detector, the microscopic radiation damage parameters of x-ray radiation were extracted from the current–voltage, and capacitance-voltage experiments on test Si microstrip detector. The damage parameters are implemented in Synopsys TCAD. In this paper, we have irradiated the test structure up to 10 MGy, and the results on full depletion voltage, and leakage current are compared with the TCAD simulation results. A very good agreement in between experimental and simulation results is observed in the leakage current for the non-irradiated, and 1 MGy irradiated detectors, where for high doses up to 10 MGy, experimental leakage current was fifty times higher than the simulated leakage current at full depletion voltage. The full depletion voltage in 0 MGy detector is also well matched with the simulation result, and further, it shows the full depletion voltage performance of x-ray irradiated detector. Finally, the new detector design specifications and process parameters are proposed for the optimum performance of the radiation hard p+n Si pixel detector equipped with guard rigs at cut edge for the next generation photon science applications.

Atomic Diffusion Mechanism in BF2+ Implanted and Annealed n-Fz Si junction using Analytical Approach: Comparison with 2-D TCAD Process Simulation Result

Ion implantation controls the diffusion of the dopants inside the n-Fz Si bulk of the p+n Si microstrip detector. In order to understand about the diffusion mechanism of BF2 + molecules/dopants into the n-Fz Si bulk of Double Sided Silicon Strip Detector (back side) for the R3B Silicon Tracker, it is essential to know the precise information about the microscopic defect introduces inside the Si lattice of the detector for the next phase upgrade of the R3B experiment. The purpose of this paper is to present the atomic transport and electrical activation behavior of implanted BF2+ molecules/dopants at an energy of 80 KeV and a dose of 1015 ion/cm2 into the n-Fz Double Sided Silicon Strip Detector for the R3B Silicon Tracker after annealing at 400 °C - 1350 °C.The result shows the amorphous-crystalline interface position and recrystallization temperature using the results revealed from the 2-D TCAD process simulation of the Si 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.

Система оцінки якості монолітних активних мікропіксельних детекторів

A system for quality assessment of micropixel detectors is presented. The system includes a laser scanning microprobe and a setup for studying the response of micro detectors to minimum ionizing particles. The results of the validation of the developed system indicate its suitability for assessing the quality of the latest monolithic active pixel sensors (MAPS), promising elements of large-area tracking systems for future high-energy physics experiments. Comparison of MAPS with the double-sided microstrip detectors of the CBM experiment (FAIR, Darmstadt) indicates the feasibility of the upgrade of its Silicon Tracking System using MAPS.

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.

Analysis of Bulk and Surface Radiation Damage in n+ in p SFz Si Micro Strip Detectors for the Future High Luminosity Collider Experiments: TCAD Simulation and Measurements

Within the framework of CERN RD50 collaboration, several radiation damage models for n/p-SFz, n-MCz Si have been explored for the better understanding of the experimental results in radiation damage analysis of the irradiated Si detectors. In the present paper, the important review on the microscopic radiation damage model for the p-type SFz Si detector combining the surface and radiation damage effects that can be used to simulate radiation damages effects in the heavily irradiated detectors for the good comparison of the experimental data and simulation result. The surface radiation damage models were extracted from the experimental measurements on the p-MOS capacitor and Gate-Controlled Diodes irradiated by Gamma or X-ray radiations in the range of 10 to 500 Mrad (Si). Whereas, the bulk damage model microscopic parameter was extracted from the experimental (TSC, DLTS) measurements on the n in p-SFz Si microstrip detector. The radiation damage (surface and bulk) models can be fed into the commercial Synopsys TCAD device simulator program for the designing and optimization of the detector, which can be used in the very harsh radiation environment of the HL-LHC, or FCC experiment. The objective of this analysis was to verify the experimental results using the new microscopic radiation damage models on the p-SFz Si for the radiation damage analysis of p- SFz Si detectors irradiated by proton, neutron or mixed at very high fluences. The results were verified by comparison of the experimental data with TCAD simulation.

Element for Matching a Waveguide Transmission Line with a Diode

The article deals with the issues of matching a waveguide transmission line with millimeter wave diodes . The implementation of the transition of a rectangular waveguide to a microstrip switching line in the form of a line of the fin-line type is described . The computer simulation results of the transmission coefficient module of the developed element and the standing wave coefficient by voltage separately for the transition from a rectangular waveguide to a microstrip transmission line and as part of an amplitude detector are shown . A joint application of the developed element with a microstrip detector based on a Schottky diode in the frequency range from 118.1 to 178.4 GHz is proposed . The results of measuring its parameters and the results of determining the sensitivity are given , as well as the evaluation of the results obtained is performed . The obtained results proved the possibility of using the matching element of a waveguide transmission line with a diode in the millimeter wavelength range .

First demonstration of on-chip interpolation using a single photon counting microstrip detector

Despite being used in many X-ray applications, hybrid single photon counting detectors are limited in spatial resolution due to the diffusion of the charge produced by single photons between neighboring electronic channels, also called charge sharing. In this work, we demonstrate that on-chip interpolation can be used to improve the effective spatial resolution in a single photon counting detector without increasing the number and density of interconnects between the sensor and the readout electronics. We describe a digital communication scheme between neighboring channels exploiting charge sharing to obtain a spatial resolution better than the channel pitch, which has been implemented for the first time in the MYTHEN III microstrip detector. The interpolation is achieved directly on-chip at the time the photons are absorbed, limiting the data throughput and the computational effort and allowing a higher photon flux compared to interpolation using analog detectors. Here we show the first results obtained with this interpolation mechanism, characterizing the spatial resolution in terms of modulation transfer function. The spatial resolution of the 50 μm pitch MYTHEN III microstrip detector can be improved from the 20 lp/mm given by the physical strip pitch to an average resolution of approximately 30 lp/mm using the interpolation method.

A Low Noise Readout System for Diamond Microstrip Detectors

Diamond is widely adopted in physics experiments owing to its good radiation hardness. In this paper, a low noise electronics system based on charge sensitive amplifier (CSA) is designed to read out diamond microstrip detectors. Up to 40 channels are implemented in the system, each containing a CSA, a CR — RC 2 shaper, an analog to digital convertor (ADC) and a discriminator used for trigger generation. After calibration and joint test with prototype detector with a size of 4×4×0.5 mm 3, a noise level of less than 845 electrons is realized in all 40 channels. Furthermore, the result with 90 Sr radiation source is consistent with the theory, and a position resolution of 13 um is obtained in laser test which indicates the readout system meets the demand of the future experiment.

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.

TCAD simulation of radiation hard n-MCz and n-Fz Si microstrip detector for the HL-LHC

A radiation hard Si detector is used in the new CMS tracker detector at HL-LHC. It has been observed that n-MCz and n-Fz Si as a material can be used for the Si micro strip detector. The detector design for this material should be simulated and optimized to get high CCE. In order to understand the charge collection behavior of the n-MCz/n-FzSi detector, it is required to simulate and compare the radiation damage effects in the mixed irradiated n-MCz Si and proton irradiated n-Fz Si micro strip detector equipped with metal overhang and multiple guard rings. In this paper, we have done analysis and optimization of the radiation hard n-MCz Si/n-Fz Si strip detector design for the HL-LHC experiment in order to get high CCE.

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.