arXiv subjects

Suyu Xiao

Publications and source records attributed to Suyu Xiao.

18 recordsLinked to original sources

arXiv2026

Time Resolution of a Novel Ultra-fast Graphene-Optimized 4H-SiC PIN

Silicon carbide detectors exhibit good detection performance such as fast time resolution, high radiation tolerances, high breakdown voltage and low temperature sensitivity and have been studied for detection applications. Meanwhile, transient current technique (TCT) is a direct and effective method to evaluate the time resolution of semiconductor detectors. Conventional metal electrodes for TCT testing employ window structures, which lead to non-uniform electric field distribution and deteriorated time resolution. Graphene features high optical transmittance, ultrahigh carrier mobility, and excellent radiation resistance, making it an ideal transparent electrode material for semiconductor detectors. In this work, a graphene-optimized ring electrode (G/RE) 4H-SiC PIN detector and a reference ring electrode (RE) 4H-SiC PIN detector are fabricated. TCT measurements demonstrate that graphene integration improves the time resolution consistency, reducing the time resolution from 38 ps (reference RE detector) to 21 ps (G/RE detector) at the maximum scanning distance, while also achieving effective noise suppression. The graphene integration improves the stability of time resolution by 87% compared to the reference detector. Notably, the achieved time resolution of 21 ps is comparable to that of state-of-the-art 4H-SiC low-gain avalanche detectors (LGADs), which typically exhibit time resolutions better than 35 ps under single minimum ionizing particle (MIP) equivalent injection conditions, further validating the effectiveness of graphene-based electrode design.

physics.ins-det↗

arXiv2026

A Telescope System for Charge and Position Measurement of High Energy Nuclei

A high-granularity telescope system with a large sensitive area and low material budget has been developed for high-energy heavy ion beam tests. The telescope consists of nine layers of silicon microstrip detectors (SSDs), whose performance was validated through a heavy ion beam test at the CERN SPS. A hybrid machine learning algorithm is proposed to address the challenges of nuclear charge measurement with SSDs. The system achieves a spatial resolution of $\mathcal{O}(1) \,$\SI{}{\micro\metre} and a charge resolution better than 0.16 charge units for nuclei from $Z = 1$ to $Z = 29$, with a sensitive area of $8 \times 8 \, \mathrm{cm}^2$. To the best of our knowledge, this represents the most precise charge and spatial resolution simultaneously achieved by a silicon telescope to date.

physics.ins-det↗

arXiv2026

Beam Test Characterization of Silicon Microstrip Detector Flight-Model Ladders for the AMS-02 Upgrade

The AMS-02 experiment plans to install a new silicon microstrip tracker layer (Layer-0) on top of the existing detector, increasing the cosmic-ray acceptance by a factor of 3. Layer-0 employs a design in which multiple silicon microstrip detectors (SSDs) are connected in series to form long detector ladders. We present a detailed performance study of the flight-model ladders using a 350~GeV mixed hadron beam at the CERN SPS. The study focuses on the following aspects: (i) the performance of ladders with different numbers of SSDs, for which the intrinsic spatial resolution at normal incidence varies from $9.5~\mu\mathrm{m}$ to $11.4~\mu\mathrm{m}$ for ladders composed of 8 to 12 SSDs; (ii) the response consistency for particles impacting on the \emph{Head} and \emph{Tail} regions of the ladder; and (iii) the dependence of the detector performance on the particle incidence angle.

physics.ins-det↗

arXiv2026

Stability of Charge Collection Efficiency and Time Resolution in 4H-SiC PIN Diodes Under X-ray Irradiation

This study evaluates the radiation tolerance of a 4H-SiC PIN detector under X-ray irradiation up to \SI{2}{MGy} (Si) at \SI{160}{keV}. The detector features a fully epitaxial vertical PIN structure with mesa terminations and field plates. Comprehensive pre- and post-irradiation characterization includes I-V/C-V measurements, charge collection efficiency (CCE) and timing resolution tests using $\beta$-particles ($^{90}$Sr). After \SI{2}{MGy} irradiation, the reverse leakage current remains at an ultralow level of $\sim 10^{-11}$ \si{A/cm^2} at \SI{-300}{V} with negligible degradation. C-V characteristics are basically consistent, with full depletion at \SI{~130}{V}. CCE for $\beta$-particles decreases by less than 5\%. The detector maintains good timing resolution: \SI{21}{ps} before and \SI{31}{ps} after irradiation, with jitter increasing moderately. These results demonstrate stable performance under extreme X-ray exposure, highlighting the detector's potential for radiation-hard applications in high-energy physics, space missions, and nuclear reactor monitoring.

physics.ins-det↗

arXiv2025

Preliminary design and simulation for CEPC fast luminosity monitor detector based on 4H-SiC

The Circular Electron-Positron Collider (CEPC), a next-generation high-luminosity collider, employs a crab waist scheme to achieve ultrahigh $5 \times 10^{34} \, \text{cm}^{-2}\text{s}^{-1}$ luminosity at Higgs mode. Owing to the extremely small beam size, the luminosity is highly sensitive to the stability of final focusing elements, where mechanical vibrations (e.g. ground motion) may induce beam offsets and luminosity degradation. To address this, a luminosity-driven dithering system is implemented for horizontal beam stabilization. In this work, we develop an optimized 4H-SiC fast luminosity detector scheme using an array of radiation detectors with picosecond time resolution positioned at critical locations. By using self-development software RAdiation SEmiconductoR (RASER), we optimize the active area of the detector to achieve 2\% relative precision at 1~kHz. Furthermore, the Total Sample Current (TSC) exhibits a near-linear correlation with luminosity attenuation, enabling real-time luminosity monitoring.

hep-ex↗

arXiv2025

4H-SiC PIN detector for alpha particles from room temperature to 90 {\deg}C

In the field of high-energy particle detection, detectors operating in high-radiation environments primarily face high costs associated with power consumption and cooling systems. Therefore, the development of particle detectors capable of stable operation at room temperature or even elevated temperatures is of great significance. Silicon carbide (SiC) exhibits significant potential for particle detector applications due to its exceptional carrier mobility, radiation hardness, and thermal stability. Over the past decade, significant breakthroughs in silicon carbide epitaxial growth technology and device processing techniques have enabled the development of SiC-based particle detectors, providing a new technological pathway for particle detection in high-temperature environments. In this work, we fabricate a 4H-SiC PIN detector, named SIlicon CARbide (SICAR) and characterize its leakage current, capacitance, and charge collection across varying temperatures. The results indicate that the detector maintains a very low leakage current (< 10 nA) at 90 C, with no degradation in depletion capacitance or charge collection performance. Additionally, it achieves a fast rise time of 333 ps at 90 C, confirming its potential for high-temperature radiation detection applications.

physics.ins-det↗

arXiv2025

The study of 4H-SiC LGAD after proton radiation

Silicon carbide (SiC) is a promising material for radiation monitoring in harsh environments, due to its low dark current, high breakdown voltage, high thermal conductivity, and radiation hardness.~This work investigates a SiC-based Low-Gain Avalanche Detector (LGAD), named SICAR, with a gain factor of~2 to 3, under 80 MeV proton irradiation up to $1\times 10^{14}$~$n_{eq}/cm^{2}$. Electrical characterization via I-V, C-V, and $\alpha$ particle injection reveals an increase in threshold voltage and a 2 to 4 order of magnitude reduction in leakage current, while charge collection efficiency decreases by about 50\%. X-ray diffraction (XRD) and capacitance deep-level transient spectroscopy (C-DLTS) were employed to characterize the lattice structure and deep-level defects before and after irradiation. Deep-level defect characteristics were integrated into TCAD simulations to develop an electrical degradation model for SiC LGADs. A linear defect-flux relationship is established in the model, showing agreement with experimental results.

physics.ins-det↗

arXiv2025

Rise Time and Charge Collection Efficiency of Graphene-Optimized 4H-SiC p-i-n Detector

Silicon carbide detectors exhibit good detection performance and are being considered for detection applications. However, the presence of surface electrode of detector limits the application of low-penetration particle detectors, photodetectors and heavy-ion detection. A graphene-optimized 4H-SiC detector has been fabricated to expand the application of SiC detectors.Its electrical properties and the charge collection performance of {\alpha} particles are reported. The effective doping concentration of lightly doped 4H-SiC epitaxial layer is about 4.5\times10^{13}cm^{-3}, approaching the limit of the lowest doping level by the SiC epitaxial growth technique. The rise time of the graphene-optimized ring electrode detector is reduced by 24% at 200 V, compared to ring electrode detector. The charge collection efficiency (CCE) of graphene-optimized 4H-SiC PIN is 99.22%. When the irradiation dose is 2\times10^{11} n_{eq}/cm^2, the irradiation has no significant impact on the rise time and uniformity of the rise time for the graphene-optimized 4H-SiC detectors. This study proves that graphene has a certain radiation resistance. Graphene-optimized 4H-SiC detectors can not only reduce the signal rise time, but also improve uniformity of signal rise time and stability of charge collection. This research will expand the application of graphene-based 4H-SiC detectors in fields such as low energy ions, X-ray, UV light detection, particle physics, medical dosimetry and heavy-ion detection.

physics.ins-det↗

arXiv2025

Simulation of radiation damage effect on silicon detectors using RASER

Silicon detectors play a crucial role in high energy physics experiments. In future high energy physics experiments, silicon detectors will be exposed to extremely high fluence environment, which can significantly affect their performance. It is important to understand the electrical behavior of detectors after irradiation. In this study, an irradiation simulation framework is constructed in RASER to simulate leakage current and charge collection effciency. The defect parameters are obtained from the Hamburg penta trap model (HPTM). Based on this work, we predict the similar silicon inner tracker which under a ten-year CEPC Higgs mode run can still maintain over 90% charge collection efficiency.

physics.ins-det↗

arXiv2024

High precision proton beam monitor system concept design on CSNS based on SiC

A high precision beam monitor system based on silicon carbide PIN sensor is designed for China Spallation Neutron Source 1.6 GeV proton beam to monitor the proton beam fluence.The concept design of the beam monitor system is finished together with front-end electronics with silicon carbide PIN sensors, readout system and mechanical system.Several tests are performed to study the performance of each component of the system.The charge collection of the SiC PIN sensors after proton radiation is studied with 80 MeV proton beam for continuous running. Research on the performance of the front-end electronics and readout system is finished for better data acquisition.The uncertainty of proton beam fluence is below 1% in the beam monitor system.

physics.acc-ph↗

arXiv2023

Design and simulation of a novel 4H-SiC LGAD timing device

Silicon-based fast time detectors have been widely used in high energy physics, nuclear physics, space exploration and other fields in recent years. However, silicon detectors often require complex low-temperature systems when operating in irradiation environment, and their detection performance decrease with the increase of irradiation dose. Compared with silicon, silicon carbide (SiC) has a wider bandgap, higher atomic displacement energy, saturated electron drift velocity and thermal conductivity. Simultaneously, the low gain avalanche detector avoids crosstalk and high noise from high multiplication due to its moderate gain, and thus can maintain a high detector signal without increasing noise. Thus, the 4H-SiC particle detector, especially the low gain avalanche detector has the potential to detect the minimal ionized particles (MIPs) under extreme irradiation and high temperature environments. In this work, the emphasis was placed on the design of a 4H-SiC Low Gain Avalanche Detector (LGAD), especially the epitaxial structure and technical process which played the main roles. In addition, a simulation tool--RASER(RAdiation SEmiconductoR) was developed to simulate the performances including the electrical properties and time resolution of the 4H-SiC LGAD we proposed. The working voltage and gain effectiveness of the LGAD were verified by the simulation of electrical performances. The time resolution of the LGAD is (35.0 $\pm$ 0.2) ps under the electrical field of -800 V, which is better than that of the 4H-SiC PIN detector.

physics.ins-det↗

arXiv2023

Characterization of silicon photomultipliers for their application in muon scattering tomography

Muon scattering tomography is a non-destructive technique used to image different materials by utilizing natural cosmic ray muons. Typically it requires position-sensitive detectors with a sub-millimeter resolution to effectively distinguish high-$Z$ materials in a compact system. The plastic scintillating fiber detector is a feasible candidate and is currently being designed with one-dimensional silicon photomultiplier (SiPM) readout. In this work, we constructed experimental setups to characterize three different SiPMs from the NDL, SensL, and HPK manufacturers for optimal performance of the scintillating fiber detector. The breakdown voltage, temperature compensation factor, dark noise, and photodetection efficiency of each SiPM are evaluated and summarized. Among the SiPMs tested, the HPK SiPM demonstrated the lowest dark count rate and crosstalk probability while exhibiting the best photodetection efficiency response at the emission wavelengths of the scintillating fibers. This makes the HPK SiPM particularly well-suited to meet the requirements of the detector and serves as a reference for further customization of the one-dimensional SiPM array.

physics.ins-det↗

arXiv2023

Electric Field Measurement by Edge Transient Current Technique on Silicon Low Gain Avalanche Detector

A novel methodology, named the diffusion profile method, is proposed in this research to measure the electric field of a low gain avalanche detector (LGAD).The proposed methodology utilizes the maximum of the time derivative of the edge transient current technique (edge-TCT) test waveform to quantify the dispersion of the light-induced carriers. This method introduces the estimation of the elongation of the carrier cluster caused by diffusion and the divergence of the electric field force during its drift along the detector. The effectiveness of the diffusion profile method is demonstrated through the analysis of both simulated and measured edge-TCT waveforms. Experimental data was collected from a laser scan performed on an LGAD detector along its thickness direction.A simulation procedure has been developed in RASER (RAdiation SEmiconductoR) to generate signals from LGAD.An assumption of immediate one-step carrier multiplication is introduced to simplify the avalanche process.Simulation results were compared with transient current data at the waveform level and showed a favorable match. Both simulation and experimental results have shown that the diffusion profile method could be applied to certain edge-TCT facilities as an alternative of electric field measurement.

physics.ins-det↗

arXiv2021

The performance of IHEP-NDL LGAD sensors after neutron irradiation

The performances of Low Gain Avalanche diode (LGAD) sensors from a neutron irradiation campaign with fluences of 0.8 x 10^15, 15 x 10^15 and 2.5 x 10^15 neq/cm2 are reported in this article. These LGAD sensors are developed by the Institute of High Energy Physics, Chinese Academy of Sciences and the Novel Device Laboratory for the High Granularity Timing Detector of the High Luminosity Large Hadron Collider. The timing resolution and collected charge of the LGAD sensors were measured with electrons from a beta source. After irradiation with a fluence of 2.5 x 10^15 neq/cm2, the collected charge decreases from 40 fC to 7 fC, the signal-to-noise ratio deteriorates from 48 to 12, and the timing resolution increases from 29 ps to 39 ps.

physics.ins-det↗

arXiv2021

Leakage current simulations of Low Gain Avalanche Diode with improved Radiation Damage Modeling

We report precise TCAD simulations of IHEP-IME-v1 Low Gain Avalanche Diode (LGAD) calibrated by secondary ion mass spectroscopy (SIMS). Our setup allows us to evaluate the leakage current, capacitance, and breakdown voltage of LGAD, which agree with measurements' results before irradiation. And we propose an improved LGAD Radiation Damage Model (LRDM) which combines local acceptor removal with global deep energy levels. The LRDM is applied to the IHEP-IME-v1 LGAD and able to predict the leakage current well at -30 $^{\circ}$C after an irradiation fluence of $ \Phi_{eq}=2.5 \times 10^{15} ~n_{eq}/cm^{2}$. The charge collection efficiency (CCE) is under development.

physics.ins-det↗

arXiv2021

Time Resolution of the 4H-SiC PIN Detector

We address the determination of the time resolution for the $\rm 100~\mu m$ 4H-SiC PIN detectors fabricated by Nanjing University (NJU). The time response to $\rm \beta$ particles from a $\rm ^{90}$Sr source is investigated for the detection of the minimum ionizing particles (MIPs). We study the influence of different reverse voltages, which correspond to different carrier velocities and device sizes, and how this correlates with the detector capacitance. We determine a time resolution $\rm (94\pm1)~ps$ for $\rm 100~\mu m$ 4H-SiC PIN detector. A fast simulation software, termed RASER (RAdiation SEmiconductoR), is developed, and validated by comparing the waveform obtained from simulated and measured data. The simulated time resolution is $\rm (73\pm 1)~ps$ after considering the intrinsic leading contributions of the detector to time resolution.

physics.ins-det↗

arXiv2020

Radiation effects on NDL prototype LGAD sensors after proton irradiation

We study the radiation effects of the Low Gain Avalanche Detector (LGAD) sensors developed by the Institute of High Energy Physics (IHEP) and the Novel Device Laboratory (NDL) of Beijing Normal University in China. These new sensors have been irradiated at the China Institute of Atomic Energy (CIAE) using 100 MeV proton beam with five different fluences from 7$\times10^{14}$ $n_{eq}/cm^2$ up to 4.5$\times10^{15}$ $n_{eq}/cm^2$. The result shows the effective doping concentration in the gain layer decreases with the increase of irradiation fluence, as expected by the acceptor removal mechanism. By comparing data and model gives the acceptor removal coefficient $c_{A}$ = $(6.07\pm0.70)\times10^{-16}~cm^2$, which indicates the NDL sensor has fairly good radiation resistance.

physics.ins-det↗

arXiv2019

Charaterization of the first prototype IHEP-NDL LGAD sensor

The timing measurement of charged particles using silicon detector is widely used in synchrotron source as X-ray detectors, in time-of-flight mass spectrometer and especially in large collider experiment. To reduce the drastically event pile-up of high-luminosity large hadron collider (HL-LHC), a new concept of 4-dimension detector including timing and positon has been proposed. One of the candidates for the 4-dimension detector is a new kind of silicon detector called Low Gain Avalanche Diode (LGAD). In China, Institute of High Energy Physics (IHEP) Chinese Academic Science cooperated with Novel Device Laboratory (NDL) at Beijing Normal University have fabricated a series of LGAD sensors. The characterization of the first prototype of IHEP-NDL sensors is presented including leakage current and sensor capacitance measurement. A test system for the time resolution of jitter term using pico-second laser and fast sampling rate oscilloscope is also setup, and the time resolution of 10 ps can be achieved with these sensors.

physics.ins-det↗