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Evaluation of a front-end ASIC for the readout of PMTs over a large dynamic range

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Chinese Physics C 2015年第12期39卷 51-56页

作者：邬维浩赵雷梁宇于莉刘建峰刘树彬安琪 State Key laboratory of Particle detection and Electronics University of Science and Technology of China

The Large High Altitude Air Shower Observatory （LHAASO） project has been proposed for the survey and study of cosmic rays. In the LHAASO project, the Water Cherenkov Detector Array （WCDA） is one of the major detectors for searching for gamma ray sources. A Charge-to-Time Convertor （QTC） ASIC （Application Specification Integrated Circuit）, fabricated with GlobM Foundry 0.35 μm CMOS technology, has been developed for readout of photomultiplier tubes （PMTs） in the WCDA. This ASIC provides both time and charge measurement of PMT signals. The input charge is converted to a pulse width based on the Time-Over-Threshold （TOT） technique and linear discharge method; as for time measurement, leading edge discrimination is employed. This paper focuses on the evaluation of this front-end readout ASIC performance. Test results indicate that the time resolution is better than 400 ps and the charge resolution is better than 1% with large input signals and remains better than 15% @1 photoelectron （P.E.）, both beyond the application requirement. Moreover, this ASIC has a weak ambient temperature dependence, low input rate dependence and high channel-to-channel isolation.

关键词： ASIC time measurement charge measurement QTC LHAASO WCDA

Research into the sampling methods of digital beam position measurement

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Nuclear Science and Techniques 2015年第3期26卷 71-76页

作者：邬维浩赵雷陈二雷刘树彬安琪 State Key laboratory of Particle detection and Electronics University of Science and Technology of China

A fully digital beam position monitoring system(DBPM) has been designed for SSRF(Shanghai Synchrotron Radiation Facility). As analog-to-digital converter(ADC) is a crucial part in the DBPM system, the sampling methods should be studied to achieve optimum performance. Different sampling modes were used and compared through tests. Long term variation among four sampling channels, which would introduce errors in beam position measurement, is investigated. An interleaved distribution scheme was designed to address this issue. To evaluate the sampling methods, in-beam tests were conducted in SSRF. Test results indicate that with proper sampling methods, a turn-by-turn(TBT) position resolution better than 1 μm is achieved, and the slow-acquisition(SA) position resolution is improved from 4.28 μm to 0.17 μm.

关键词：采样方法位置测量数字波束上海同步辐射装置束流位置监测系统位置分辨率试验比较抽样方法

Study on the temperature dependence of BGO light yield

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Science China(Physics,Mechanics & Astronomy) 2014年第10期57卷 1898-1901页

作者： WANG PeiLong ZHANG YunLong XU ZiZong WANG XiaoLian State Key laboratory of Particle detection and Electronics University of Science and Technology of China

The temperature dependence of BGO coupled with photomultiplier tube R5610A-01 was studied in the range of-30–30℃. The temperature coefficient of the BGO and R5610 A as a whole was tested to be-1.82%/℃. And the temperature coefficient of the gain of the R5610 A is-0.44%/℃ which was tested in the same situation using a blue LED. Thus the temperature coefficient of BGO's light yield can be evaluated as-1.38%/℃.

关键词： BGO light yield temperature dependence PMT

A cosmic ray test platform based on high time resolution MRPC technology

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Chinese Physics C 2015年第5期39卷 69-72页

作者：陈天翔李澄孙勇杰陈宏芳邵明唐泽波杨荣星周意张一飞 State Key laboratory of Particle detection and Electronics University of Science and Technology of China

In order to test the performance of detector prototypes in a laboratory environment, we design and build a large area （90 crux52 cm） test platform for cosmic rays based on a well-designed Multi-gap Resistive Plate Chamber （MRPC） with excellent time resolution and a high detection efficiency for minimum ionizing particles. The time resolution of the MRPC module used is tested to be -80 ps, and the position resolution along the strip is -5 mm, while the position resolution perpendicular to the strip is -12.7 ram. The platform constructed by four MRPC modules can be used for tracking cosmic rays with a spatial resolution of -6.3 mm, and provide a reference time -40 ps.

关键词： test platform MRPC time resolution cosmic ray tracking

Direct and rapid detection of serum amino acid and monoamine neurotransmitters to assist the diagnosis of panic disorder

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Science China Chemistry 2025年第1期 377-384页

作者： Shiwen Liu Xuerui Wan Meng Zhao Jiaqi Wang Weilan Wu Linlin You Yonggui Yuan Qian Xu Rong Gao Key laboratory of Environmental Medicine Engineering Ministry of Education School of Public Health Southeast University Key laboratory of Modern Toxicology of Ministry of Education Department of Hygienic Analysis and Detection School of Public HealthNanjing Medical University Department of Psychosomatics and Psychiatry Zhongda Hospital School of Medicine Southeast University

The measurement of amino acid and monoamine neurotransmitters（NTs） in serum plays a central role in the identification and monitoring of clinical panic disorder（PD）. However, the strong polarity and chemical heterogeneity of NTs make direct extraction and rapid detection extremely challenging. Herein, we developed a strategy that integrated solid phase extraction based on magnetic Fe3O4coated with polydopamine（Fe3O4@PDA） and direct analysis of mass spectrometry in real time（DART-MS） for quantification of 10 NTs. We systematically investigated the optimal conditions of this strategy to achieve good accuracy and precision. Compared with existing magnetic solid phase extraction methods for NTs detection in biological samples, this strategy could adsorb more targets while having similar adsorption efficiencies, and the total process time was reduced by an average of 69.42%. We rapidly determined the metabolic abnormality of 6 types of NTs in the serum of PD patients and demonstrated their diagnostic accuracy. In addition, an outstanding feature of PD in which tryptophan was more metabolized by the KYN pathway and the 5-hydroxytryptamine pathway was inhibited could be elucidated by this strategy. Our results highlighted the potential ability of Fe3O4@PDA coupled with DART-MS to assist in the clinical diagnosis of PD.

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A probability theory for filtered ghost imaging

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Chinese Physics B 2023年第4期32卷 329-337页

作者：刘忠源孟少英陈希浩 Key laboratory of Optoelectronic Devices and detection Technology College of PhysicsLiaoning UniversityShenyang 110036China

Based on probability density functions,we present a theoretical model to explain filtered ghost imaging(FGI)we first proposed and experimentally demonstrated in 2017[***.425290(2017)].An analytic expression for the joint intensity probability density functions of filtered random speckle fields is derived according to their probability ***,the normalized second-order intensity correlation functions are calculated for the three cases of low-pass,bandpass and high-pass filterings to study the resolution and visibility in the FGI *** simulations show that the resolution and visibility predicted by our model agree well with the experimental results,which also explains why FGI can achieve a super-resolution image and better visibility than traditional ghost imaging.

关键词： ltered ghost imaging probability density function super-resolution

A large-area GEM detector using a novel self-stretching technique

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Chinese Physics C 2015年第4期39卷 51-54页

作者：尤文豪周意李澄陈宏芳邵明孙勇杰唐泽波刘建北 State Key laboratory of Particle detection and Electronics University of Science and Technology of China

A Gas Electron Multiplier （GEM） detector with an effective area of 300 mm×300 mm has been constructed using a novel self-stretching technique, which allows a highly flexible and efficient GEM detector assembly free of glue or spacers. This makes the re-opening and repair of the GEM detectors possible and significantly reduces the scrap rate in the mass production of large-area GEM detectors. With the technique, the assembly time can be limited to a few hours, a factor of ten improvement compared to that using gluing techniques. The details of design and assembly procedure of the 300 mm×300 mm GEM detector are described in this paper. This detector was tested with 8 keV X-rays for the effective gain, energy resolution and performance uniformity. The results show that the typical energy resolution is 20% at an effective gain of about 10-4, with fairly good uniformity.

关键词： GEM self-stretching effective gas gain energy resolution uniformity

Magnetic shielding for DAMPE electromagnetic calorimeter PMTs

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Chinese Physics C 2014年第8期38卷 53-56页

作者：王培龙张云龙汪晓莲许咨宗 State Key laboratory of Particle detection and Electronics University of Science and Technology of China

The magnetic characteristics of R5610A-01 photomultiplier tubes are studied in this paper. The experimental data shows that the gain of R5610A-01 loses about 53% when the magnetic field is 3 Gs along its ＋X axis. A cylinder of one-layer permalloy strip is able to reduce the effect of a 3 Gs magnetic field on the PMT gain to less than 1%.

关键词： photomultiplier tube magnetic shield characteristics

Study on the imaging ability of the 2D neutron detector based on MWPC

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Science China(Physics,Mechanics & Astronomy) 2013年第10期56卷 1882-1886页

作者： TIAN LiChao CHEN YuanBo TANG Bin ZHOU JianRong QI HuiRong LIU RongGuang ZHANG Jian YANG GuiAn XU Hong CHEN DongFeng SUN ZhiJia State Key laboratory of Particle detection and Electronics Institute of High Energy Physics Chinese Academy of Sciences University of Chinese Academy of Sciences Key laboratory of Neutron detection and Electronics China Institute of Atomic Energy

A 2D neutron detector based on 3He convertor and MWPC with an active area of 200 mmx200 mm has been successfully designed and fabricated. The detector has been tested with Am/Be neutron source and with collimated neutron beam with the wavelength of λ=1.37A. The best spatial resolution of 1.18 mm （FWHM） and good linearity were obtained. This is in good agreement with theoretical calculations.

关键词： thermal neutron detector imaging detector two dimensional position resolution