A position-sensitive detector for electrons

A chevron electron multiplier array, followed by a resistive strip collector, has been combined with position-sensitive detector circuitry to provide a detector for particles or photons with position resolution of 0.3 mm in one dimension along a 2 cm strip; the instrument has been applied to a high resolution electron spectrometer. Position resolution appears to be limited only by the capillary spacing of the particular array being used.     

A position-sensitive detector with lithium glass and MaPMT

A position-sensitive detector is designed for neutron detection. It uses a single continuous screen of a self-made lithium glass scintillator, rather than discrete crystal implementations, coupling with a multi-anode PMT (MaPMT). The scintillator is fast and efficient; with a decay time of 34 ns and thermal neutron detection efficiency of around 95.8% for the 3 mm thick screen, and its light yield is around 5670 photons per neutron and 3768 photons per MeV γ rays deposition. The spatial resolution is around 1.6 mm (FWHM) with the energy resolution around 34.7% by using α (5.2 MeV) rays test.     

A variable angle photoelectron spectrometer using a position-sensitive detector

A variable angle photoelectron spectrometer utilizing a position-sensitive multidetector is described. Photoelectron spectra of N₂ obtained using a synchrotron radiation source are presented. The data are acquired using a new technique in which the photoelectron yield is obtained as a function of both wavelength and photoelectron energy, and this gives detailed information on autoionization processes.     

Development of a sub-millimeter position-sensitive gas detector

Position-sensitive thin-gap gas detectors have been developed in the laboratory, based on the ATLAS Thin Gap Chamber. The signal collection structure has been redesigned while retaining other configurations to keep the good time performance of the detector. The position resolution was measured using cosmic muons for two versions of the detector and found to be 409 μm and 233 μm respectively. This paper presents the structure of these two detector prototypes, with the position resolution measurement method and results.     

Study of a position-sensitive scintillator neutron detector

The investigation of a novel thermal neutron detector is developed to fulfill the requirements of the high intensity power diffractometer (HIPD) at the Chinese Spallation Neutron Source (CSNS). It consists of two layers of ⁶LiF/ZnS(Ag) scintillators, two layers of crossed WLSF arrays, several multi-anode photo multiplier tubes (MA-PMT), and the matching readout electronics. The neutron detection efficiency of the scintilltors, the light transportation ability of the WLSF, and the spatial linearity of the readout electronics are measured and discussed in this paper. It shows that the sandwich structure and the compact readout electronics could fulfill the needs of the HIPD. A prototype with a 10 cm×10 cm sensitive area has been constructed to further study the characteristics of the neutron scintillator detector.     

极紫外位置灵敏阳极光子计数成像探测器研究

研制出了应用于月基极紫外成像仪的二维极紫外位置灵敏阳极光子计数成像探测器原形样机,该探测器主要由工作在脉冲计数模式下的微通道板堆、楔条形位置灵敏阳极及相关的模拟和数据处理电路组成。设计和制备了周期为1 mm,直径为30 mm的三电极楔条形位置灵敏阳极,研制了最高计数率为200 kHz的前端模拟和数字电路。测量了探测器的暗计数率、脉冲高度分布及空间分辨率等工作特性。测量结果表明,该探测器的空间分辨率为028 mm,满足月基极紫外成像仪对空间分辨率的要求。     

High pressure,high resolution synchrotron x-ray powder diffraction with a position-sensitive detector

Abstract

We report results of high-pressure experiments with a new diamond-anvil cell in a monochromatic, high-resolution x-ray scattering geometry with alinear position-sensitive detector. The experiments make possible the study of factors controlling line widths of diffraction profiles at pressures in the 100 GPa range, and demonstrate the potential for the use of line profile analysis and Rietveld refinement techniques with high-pressure powder diffraction data. Combined data for various materials indicate that relative contributions to linewidths due to particle size, intrinsic material strength, pressure and state of stress in the sample can be resolved. With light rare-gas solids as pressure-transmitting media, measured FWHMs of the order 0.03? 2 θ corresponding to resolution Δd/d of 2.5 × 10^?3 for 2θ～10-15? are reported. Formation of a high pressure phase appears to involve growth of submicron domains, judging from substantially broadened diffraction peaks under quasihydrostatic conditions. Detailed analysis of complex, non-quenchable high-pressure phases will likely require annealing techniques such as thermal cycling at pressure.

Presented at the IUCr Workshop on ‘Synchrotron Radiation Instrumentation for High Pressure Crystallography’, Daresbury Laboratory 20-21 July 1991     

A simple bakeable particle detector: Ion-electron converter plus solid state electron detector

We describe a simple particle detector using the principle of the ion-electron converter. It detects ions and neutral particles, has low background noise (0.1 counts/s), and is bakeable at 280°C. The energy resolution of the electron detector is better than 2.0 keV, thus allowing the frequency distribution of the electron groups to be observed directly in the pulse height spectrum. The marked differences between the electron statistics for ions and for metastable neutrals are used in an application to mass-analysis. An improvement in signal to noise ratio by more than a factor of ten is achieved.     

使用曲面微通道板和感应电荷位置灵敏阳极的软X射线-极紫外光子计数成像探测器研究

本项目对我国空间探测的极紫外(EUV)波段大视场相机所需求的球面光子计数成像探测器的关键技术进行了研究。首先,建立了光阴极材料次级电子产出模型,利用该模型计算了软X射线-EUV波段常用的光电阴极材料—碱卤化物的次级电子产出,分析了微通道板(MCP)的次级电子产出。建立了测量MCP量子探测效率的装置,并推导出MCP量子探测效率的计算公式,测量了MCP在软X射线-EUV波段的量子效率以及MCP量子效率随掠入射角的变化。其次,建立了球面实芯微通道板的制备装置,利用高温热成型方法制备出曲率半径为150 mm球面MCP,利用光刻技术制备出有效直径为48 mm的楔条形感应电荷位置灵敏阳极,在此基础上集成了一套使用球面MCP和感应电荷位置灵敏阳极的两维光子计数成像探测器。再次,研制出包括快速前端模拟电路与后续数字电路的成像读出电路,编制了能矫正图像畸变的图像实时采集和处理软件。最后,建立了MCP探测器空间分辨率、图像线性的检测装置,对研制出的探测器性能进行了检测,检测结果表明:探测器的各项技术指标完全满足要求。     

新型涂硼热中子MWPC探测器的时间信号读出方法

基于10B薄膜的二维灵敏探测器是新近发展起来的热中子探测器,其灵敏面积大,时间和位置分辨好,n/抑制能力高,抗辐射能力强,可二维读出且具有良好的耐计数能力。针对新型的涂硼灵敏热中子多丝正比（MWPC）探测器,在延迟线时间差方法的基础上,提出一种中子击中位置数字信息的读出方法,并设计NIM读出插件用以验证该方法对于二维中子探测位置信息的读出能力。测试结果表明,本方法能完成4通道探测器信号的实时测量,其时间测量精度好于50 ps。结合FPGA片上系统实时数据控制和处理技术,单插件可支持最高1.3MHz的探测计数率。     

A neutron diffractometer with a linear position sensitive detector

A powder diffractometer with a linear position sensitive detector (PSD) has been designed and fabricated at BARC. The system is in operation at Dhruva reactor. The PSD has been tested for the position linearity and the uniformity of efficiency. The resolution Δd/d of the diffractometer has been found to be 1·3%. The data can be analyzed using profile refinement technique.     

Qubit measurements with a double-dot detector

We propose to monitor a qubit with a double-dot (DD) resonant-tunneling detector, which can operate at higher temperatures than a single-dot detector. In order to assess the effectiveness of this device, we derive rate equations for the density matrix of the entire system. We show that the signal-to-noise ratio can be greatly improved by a proper choice of the parameters and location of the detector. We demonstrate that quantum interference effects within the DD detector play an important role in the measurement. Surprisingly, these effects produce a systematic measurement error, even when the entire system is in a stationary state.     

Photon counting with a loop detector

We propose a design for a photon-counting detector that is capable of resolving multiphoton events. The basic element of the setup is a fiber loop, which traps the input field with the help of a fast electro-optic switch. A single weakly coupled avalanche photodiode is used to detect small portions of the signal field extracted from the loop. We analyze the response of the loop detector to an arbitrary input field and discuss both the reconstruction of the photon-number distribution of an unknown field from the count statistics measured in the setup and the application of the detector in conditional-state preparation.     

Analysis of optical signal distortion compensation with a Multiskan position-sensitive photodetector by the quasi-median technique

A mechanism of photocurrent redistribution in a Multiskan photodetector under the action of an intricate synthetic aperture is considered. This mechanism makes it possible to estimate the distorted optical signal position that is closest to the undistorted signal median, which specifies the direction toward the source of the optical signal.     

A satellite cluster as a gravitational-wave detector

The detection of gravitational waves by a cluster of satellites is considered. The detector is an optical interferometer formed of several satellites. The calculations for three spacecraft are given. The complete detector response to the monochromatic gravitational wave generated by a binary star is computed.     

A fast detector system with cooled NaI-scintillators

Detector systems with cooled non-thallium-activated NaI-crystals allow to improve the time resolution in -coincidence experiments. Such a system has been developed and yielded typical time resolutions a factor of 2.5 better than conventional NaI(Tl)-systems. Two examples for possible applications are given.     

狭缝式高灵敏裂变中子探测系统

研制了狭缝-外延式高灵敏大面积PIN裂变中子探测系统. 其对14MeV，2.5MeV中子灵敏度可达10^-16C·cm²，比原有典型的脉冲裂变中子探测系统高4个量级. 采用外延式铅狭缝准直结构，研制灵敏区尺寸为60mm，厚度为200μm—300μm的大面积PIN半导体探测器、以Be膜为衬底，有效直径为60的²³⁵U裂变靶，解决了该探测器研制中的高灵敏度和n/γ分辨难题. 该系统已在实践中获得成功应用. 关键词： 裂变中子探测系统 大面积PIN探测器 大面积裂变靶 高灵敏探测系统