自然伽马测井仪稳定性影响因素分析

本文根据自然伽马测井仪的电路设计、光电倍增管及晶体性能，结合对现用九方仪器伽马短接性能测试的资料，对影响其稳定性的诸多因素进行了细致的分析，找出影响仪器稳定性的主要因素，进而提高自然伽马仪的稳定性。     

气囊对光电倍增管水下内爆影响试验研究

江门中微子试验中使用的光电倍增管需要长时间承受高静水压力作用,由于光电倍增管外壳使用膨化硅玻璃制造,受自身结构微观缺陷影响不可避免的有发生碎裂的可能,并引发光电倍增管的水下内爆(Implosion),对其周围设施造成危害。在可加压密封罐中进行带有气囊的光电倍增管水下内爆试验,使用高速摄像和压力传感器记录实验过程数据。并将试验结果与无气囊条件下的光电倍增管水下内爆相关数据进行对比,探究了使用气囊进行光电倍增管水下内爆防护的可行性,为光电倍增管的水下内爆防护提供新的思路。     

核测量用光电倍增管性能测试方法

从测试的目的、原则、内容、方法、以及测试数据的处理方法5个方面,论述了核测量用光电倍增管的性能测试方法,对多种光电倍增管的性能测试结果表明,这些内容完全满足核测井仪器研制与生产的需要,在分析光电倍增管坪特性影响因素的基础上,结合了射线强度测量的具体特点,提出了改进光电倍增管性能和使用效果的一些建议。     

光电倍增管在全息光盘条形码阅读器中的应用

光电倍增管（ｐｈｏｔｏｍｕｌｔｉｐｌｉｅｒｔｕｂｅ）的应用已有几十年的历史，尽管六十年代固体器件的出现，使光电倍增管一度面临激烈的竞争，但光电倍增管仍以其灵敏度高、时间响应度好、增益高及噪声低等一系列优点，依然应用于要求较严格的场合，如微弱信号处理等。本文就是介绍其在一种微弱信号探测（全息光盘条形码阅读器）中的应用。     

光电倍增管工作特性简述

在光谱分析等领域中,光电倍增管的工作特性至关重要。因为目前使用的管子型号繁多(单美国就生产约550个),而引起这些管子工作特性改变的因素又多种多样,所以在工作中我们应对光电倍增管的工作特性予以高度重视。本文试对常见的光电倍增管工作特性作一简要叙述,供大家参考。一、光谱特性光电倍增管的光谱特性主要由阴极材料、窗口材料决定,同时也受温度,磁场和时间的影响,甚至和入射辐射照射的光电阴极的部位也有关。表1给出了部分美国S系列光阴极材料和窗口材料。图1给出了部分S系列光阴极的光谱响应曲线,图2给出了部分非S系列的     

真空紫外微通道板光电倍增管的研制

主要讨论了真空紫外微通道板光电倍增管的工作原理及设计考虑，介绍了这种新型弱光探测器研制过程中的主要关键技术以及该器件所具有良好性能和广阔的应用前景。     

宽量程弱光照度计的研制

本文介绍了用大面积硅光电二极管和光电倍增管两种光探测器作测光探头的宽量程弱光照度计。详细介绍了两种探测器的Ｖ（λ）修正以及标定结果。照度测量范围为２０００ｌｘ～１×１０－６ｌｘ最低可分辨１０－７ｌｘ，测量不确定度为±３．２％。     

PPM量级纹波系数的光电倍增管恒流源

本文讨论的光电倍增管高压电源是针对其纹波要求较苛刻而工作时间较短的特殊场合而设计的。该电路可提供输出稳定、纹波系数小的直流高压、它能保证光电倍增管在工作时间内的良好工作。实验结果证明该电路确实可行。     

三路负高压稳压电源

三路负高压精密稳压电源是为ＪＳＧ－Ⅰ／Ⅱ型激光速度干涉仪设计的配套仪器，主要用作高精度光电倍增管电源。仪器采用了他激式高频直流变换电路和可调半导体电压基准，用大功率Ｖ－ＭＯＳ管做调整管。实现了输出电压宽范围连续可调，提高了温度稳定性，消除了振荡噪音和开机过冲。     

光电倍增管特性的研究

光电倍增管特性的研究     

超快速MCP-PMT的时间特性测试方法研究

超快速时间特性的光电倍增管的时间特性研究,对进一步研制国产超快时间响应的微通道板光电倍增管(FPMT)具有重要的指导作用。本文基于高能物理通用的VME测试方案,设计装置采用皮秒激光器的单光子脉冲工作模式,最终实现系统误差为25 ps的FPMT高精度时间测试系统。通过优化FPMT阳极信号读出方式、优化分压器结构及分压比例,对多款FPMT的时间特性进行测试研究。并提出在非单光子工作模式下表征FPMT时间分辨特性的本征时间下限值,用以对比分析各种不同工作状态的FPMT的时间分辨好坏。在对多款FPMT读出方式完成优化结构设计和对比测试后,研究结果表明,目前实验室来自不同生产单位的样管中,最佳的本征时间分辨下限值为30 ps。     

A Method for Calculating Ozone Depth Using the Solar Ultraviolet Fraunhofer Spectrum

Abstract

A technique has been developed for calculating the ozone depth of the atmosphere from measurements of solar u.v. irradiance at turning points in the Fraunhofer spectrum. The technique has been tested using measurements taken with a single-pass u.v. spectroradiometer with a holographic grating and solar-blind photomultiplier. Ozone depths determined with the technique agree closely with standard Dobson spectrometer results.     

Single photon response of photomultiplier tubes

Beta or gamma rays, when directly incident on the window of an optically shielded photomultiplier tube, yield a typical single photon spectrum. The single photons are possibly generated in the glass window of the photomultiplier tube through excitation of atoms in glass by electrons. The coincidence resolving time has also been measured with a ⁶⁰Co gamma source and a pair of optically shielded photomultiplier tubes detecting single photons.     

DUVEX: An X-ray counting system based on YAG:Ce scintillator

A detector system, called DUVEX, has been developed for the soft-x-ray and extreme ultraviolet domain. It consists of a YAG:Ce scintillator coupled to a photomultiplier module working under vacuum in counting mode. The design and the performances of this detector in terms of yield, absolute efficiency, response and noise are reported. Spectra in the soft x-ray range of different elements (W, Ag, Al, Mg, Cu, N, C and B) obtained in WDS mode using this detector are presented. DUVEX appears as a competitive detection tool in terms of cost and easiness of implementation.     

Time resolution study of a CPPM 320 UV microchannel-plate photomultiplier with a BaF2 scintillation crystal

The time resolution has been measured of a BaF₂ scintillator mounted onto an ITL CPPM 320 UV channelplate photomultiplier. We obtained a intrinsic time resolution of 235 ps (fwhm) at 1.3 MeV. Compared to 120 ps for a Pilot U-XP2020 reference detector this result is rather poor. The explanation is found in the relatively poor quantum efficiency of the channelplate photomultiplier.     

Dynamic magnetic shield for the CLAS12 central TOF detector photomultiplier tubes

The Central Time-of-Flight detector for the Jefferson Laboratory 12-GeV upgrade is being designed with linear-focused photomultiplier tubes that require a robust magnetic shield against the CLAS12 main 5-T solenoid fringe fields of 100 mT (1 kG). Theoretical consideration of a ferromagnetic cylinder in an axial field has demonstrated that its shielding capability decreases with increasing length. This observation has been confirmed with finite element analysis using POISSON model software. Several shields composed of coaxial ferromagnetic cylinders have been studied. All difficulties caused by saturation effects were overcome with a novel dynamical shield, which utilizes a demagnetizing solenoid between the shielding cylinders. Basic dynamical shields for ordinary linear-focused 2-in. photomultiplier tubes were designed and tested both with models and experimental prototypes at different external field and demagnetizing current values. Our shield design reduces the 1 kG external axial field by a factor of 5000.     

A waveshifter light collector for a water Cherenkov detector

A device has been developed which is capable of doubling the light collection capability of a 5 inch hemispherical photomultiplier tube. Known as a “waveshifter plate”, its geometry is adaptable to various applications. Its marginal cost is small with respect to that of a phototube, it is readily removable, and it has minimum effect upon dark noise and timing resolution.     

Expanding the dynamic range of a lidar receiver by the method of dynode-signal collection

A method of lidar data collection by simultaneous registration of signals from the anode and several dynodes of the photomultiplier is suggested. The dynamic range of the receiver has been extended as many as 5 orders of magnitude in the case of cloud sensing. The stable operation under strong background illumination is possible without losses in fine signal structure.