High-precision Track Detection Of Charged Particle In Gas Detectors

High-energy physics experiments based on particle accelerators are one of the most effective means to study the properties and interaction laws of matter in the micro-world deeper than hadrons.Charged particle track measurement can obtain critical information about the trajectory,interaction vertex,energy,and momentum of a particle.It is a significant part of high-energy physics experiments.With the development of particle accelerators towards higher energy and higher brightness in the future,high-energy physics experiments put forward stringent requirements for the accuracy and reliability of track detection.Gas and semiconductor detectors are the most dominant and the highest spatially resolved track detectors,respectively.Due to the limitations of their working principles and characteristics,they face some challenges in the future demand for high-precision charged particle track detection.The most important ones are the limitations in improving the accuracy of gas detectors and the serious radiation damage effects of semiconductor detectors.According to the high-precision and high radiation resistance requirements of current highenergy physics experiments for charged particle track detection,the paper proposes a new track detection scheme that combines gas detectors with silicon pixel detectors that can directly collect charges.It can use of the advantages of silicon pixel detectors in high spatial resolution and avoid the direct radiation damage of incident charged particles to the pixel detector.On the basis of this scheme,the paper also proposes a new method to locate single-event effects by heavy-ion track measurement and use Topmetal-Ⅱ-to detect low-energy photoelectrons and high-energy heavy ions in gas detectors with high precision.This paper verifies the principle of single-event effect localization detection and realizes the X-ray polarization measurement.The specific research contents and innovations of the paper are as follows:1.The performance study of Topmetal-Ⅱ-is carried out.The paper test the variation of the decay time of different chip pixels with external configuration voltage and the consistency and linearity of decay time and output amplitude of pixels.The expected values and standard deviations of decay time and response amplitude distribution of pixels are given,and the test of the inconsistency of pixel decay time constant caused by the difference of feedback resistance and feedback capacitance at both ends of Charge Sensitive Amplifier(CSA)are also taken.The silicon pixel’s total ionizing radiation dose test is carried out using a 60Co radiation source.The test results show that the chip can meet the 100 Gy total ionizing radiation dose.The paper test the chip by Kr ion microbeam with Linear Energy Transfer(LET)of 18.5 MeV/(mg/cm2)in Si.The test results show that the chip has strong resistance to the single-event effect and prove that the transistors in different pixel parts have different sensitivity to heavy ion irradiation.The tests have important references for improving the pixel chip’s track detection accuracy and radiation resistance.2.The simulation research of high-precision charged particle track detection is proposed.The heavy ion track simulation program is developed,and the simulations of the factors related to the detection accuracy of charged particle track,such as gas ratio,electric field intensity,particle incident height,and energy,are carried out using the program in Ar:CO2.The simulation results show that the greater the spread of the track,the lower the position resolution;the more the average energy loss of heavy ions,the higher the position accuracy;reducing the pixel pitch and increasing the signal-to-noise ratio can also significantly improve the detection accuracy.The simulation study provides valuable references for the formulation and optimization of experimental conditions for high-precision particle track detection.3.The research on single-event effect location detection based on Topmetal-Ⅱ-is carried out.A single-event effect localization method based on high-precision heavy ion track detection scheme is proposed,and the principle prototype is made with Topmetal-Ⅱ-as the localization chip.The localization test of Kr ion beam with energy of 2.15 GeV and cross-sectional area of 5.29 cm2 is carried out on the beam test terminal in HIRFL.A spatial resolution of 4.0 ± 1.48μm and an angle resolution of 0.17 ± 0.063° are obtained in the beam test.The test results verify the feasibility of the single-event effect location detection method.4.The research of X-ray polarization measurement based on Topmetal-Ⅱ-is carried out.In the paper,the Topmetal-Ⅱ-is combined with the gas electron multipliers of Thick Gas Electron Multiplier(THGEM)and Gas Micro-Channel Plate(GMCP)to measure the polarization of 4.35 keV,4.5 keV and 5.9 keV X-rays,and the detector obtains the high-resolution photoelectron tracks and polarization modulation factors of corresponding rays under different experimental conditions.The experimental results show that the quality of photoelectron tracks obtained by GMCP is better than that obtained by THGEM,which is more beneficial to the reconstruction of the initial directions of the photoelectrons.At the same time,it also shows that the structure and multiplication voltage of gas electron multiplier,the type of gas and the track reconstruction algorithm greatly influence the accuracy of X-ray polarization measurement.This research provides valuable references for improving the detection accuracy of photoelectron tracks and the sensitivity of polarization measurements.Compared with the traditional gas detector and semiconductor detector scheme,the charged particle track detection scheme studied in the paper maintains high accuracy.It avoids direct radiation damage to the pixel detector,which can significantly increase the detector’s life and the measurement range of charged particles.At the same time,the scheme provides a superior detection technology for applications that rely on high-precision charged particle track detection,such as single-event effect detection and X-ray polarization measurement,which have an excellent research value and applied prospect.