A controllable voltage divider for Hamamatsu R11410-20 photomultipliers for use in the RED 100 emission detector

A control circuit for the operation of Hamamatsu R11410-20 photomultiplier tubes (PMTs), which is intended for use in the RED 100 liquid-xenon emission detector, was developed. To prevent the photocathode degradation due to intense flashes that are associated with signals from high-energy cosmic-ray muons, the circuit forms a voltage pulse that is fed to the PMT photocathode and “blocks” the interelectrode gap between the photocathode and the first dynode. Thus, electron current through this gap is stopped for some time, which suffices for the complete collection of ionization electrons in the RED 100 detector after a cosmic muon passes its sensitive volume. The parameters of the circuit are selected such that the PMT relaxation time after the termination of a blocking pulse, which is determined by the transient processes in the divider, is ～200 μs for a divider with a total resistance of 20 MΩ. This is acceptable for the intended application of the RED 100 detector in an experiment on the search for coherent neutrino scattering off xenon nuclei.     

Single electron response of the scintillator-light guide-photomultiplier detector

The time response of a scintillator-light guide-photomultiplier combination was measured with a time-constant of 3 ns. Single detected electrons were recognizable at the output of the photomultiplier. The distribution of the number of photoelectrons produced by one detected electron and the pulse-height distribution of the photomultiplier output pulses were analysed. Statistical noise computed from these distributions was compared with the noise produced by the dark current of the photomultiplier.     

阻容型高压冲击分压器参数设定及仿真

阻容分压器把阻尼电阻分散在高压臂中,从而对高低频振荡起到阻尼的作用,具有良好的分压特性和精度。文章以测量3000kV雷电冲击电压的低阻尼首末匹配型阻容分压器为例,进行了参数计算及设定,并通过仿真对所设定的参数进行了验证。     

具有动压反馈的配流轴设计方法

径向柱塞泵配流轴摩擦副的静压支承系统,采用动压反馈设计思想增加压力补偿元件,能有效地防止配流轴摩擦副的“抱轴”。     

An inductive voltage divider

A small-sized inductive nanosecond pulse-voltage divider of simple design is described. The divider is used for measuring the voltage at the output unit of the Angara-5-1 facility.     

基于复合左／右手传输线的双频功分器

本文介绍了一种新型的基于复合左／右手（CRLH）传输线理论的双频功分器设计方法,该功分器工作于900MHz和1800MHz。用集总电感和电容元件构成的复合左／右手传输线在900MHz和1800MHz的相移分别是超前和滞后90°。完全可以替代传统功分器中的四分之一波长阻抗变换传输线,且具有占用面积小和可设计工作于任意两个频率的优点。在双频工作的现代无线通信系统中有很广阔的应用前景。     

光电倍增管暗电流的三种简易测试方法

本文介绍了作者对光电倍增管暗电流测试的三种简单实用的方法和设计的该测试装置及具体操作方法。并给出了主要的测试数据及数据处理方法。同时,对光电倍增管暗电流的测试条件、三种简易方法的比较等几个问题进行了讨论。     

Voltage divider resistance for high-resolution of the thermistor temperature measurement

When measuring temperature with a voltage divider, and changing the variation of the thermistor resistance from the temperature to the voltage, the divider resistance greatly impacts the resolution of each ADC step. This work presents a method for determining the divider resistance to minimize the resolution’s maximum value in a given temperature range. Since the function of the resolution strongly depends on the derivative of the thermistor resistance, we also investigated the effect on the resolution when the derivative was calculated by forward and backward finite differences and the Stein–Hart calibration equation. The results showed that the resolution’s maximum calculated by the three methods had only a 5% difference, for the four types of commonly used NTC thermistors. Also, we demonstrated that the divider resistance which minimizes the interval resolution’s maximum can be determined by the thermistor resistance and its derivative at each end of the temperature range.     

A differential high-voltage divider

The design, main design formulas, and test results of a small-size differential high-voltage divider are presented. The conditions determining correctness of using the divider for measuring nanosecond high-voltage signals are obtained. It is shown that the differential voltage divider has some limitations in low- and high-frequency regions. Experiments have been performed on a TэY-500 pulsed electron accelerator with the following characteristics: the accelerating voltage is 350–450 kV, the base pulse duration is 100 ns, the rise time is <5 ns, and the complete pulse electron energy is up to 250 J. The pulse repetition rate is 1–3 pulses/s. To restore the shape of the measured voltage, it is necessary that the output signal from the voltage divider be integrated. The measurement error does not exceed ±10%.     

高精度高压电压表

本文介绍的高精度高压电压表,是以标准电压通过电容系统比较分压电阻的电压降,避免分压电阻表面漏电流对测量精度的影响。电压测量的相对误差<10~(-4)。     

Linearity of the energy scale of a detector based on a LaBr3(Ce) scintillator

The linearity of a LaBr₃(Ce) detector response in the energy range of 0.6–11.0 MeV has been investigated using various PMT voltage divider circuits. A tapered voltage divider circuit is proposed to reduce the nonlinearity.     

全球卫星导航系统接收机的正交二分频器设计

将全球卫星导航系统(GNSS)接收机用于手持移动设备必须降低正交二分频器等大功耗模块的功耗,因此,本文提出了工作于1V电压以下的正交二分频器.使用提出的正交二分频器可使电路在各工艺角下高速稳定的工作,并大大降低模块的功耗.首先,介绍已有的高速二分频器.接着,计算了所提出结构的直流静态偏置,并对提岀的锁存器进行小信号建模和分析.最后,根据小信号模型分析得到的条件和GNSS接收机的应用要求,设计了提出的低功耗结构.实验结果表明:提出的二分频器最高工作频率为6.55 GHz,最低可工作到0.25 GHz,消耗电流为0.8mA,占用面积为0.014 4 mm2.提出的电路结构在0.13 μm CMOS工艺上实现,可稳定工作于1V电压下,目前已成功应用于低功耗的移动GNSS接收机中.     

Studying the characteristics of the spectrometric detector based on a LaBr3:Ce crystal and a ФЭУ-184 photomultiplier tube

Results of investigations of the scintillation detector based on a LaBr₃:Ce crystal and a ФЭУ-184 photomultiplier tube are presented. It is shown that, optimizing the ФЭУ-184 photomultiplier tube circuit by reading out the signal from the next to last dynode, it is possible to utilize the spectrometric properties of the LaBr₃:Ce crystal.     

Gas discharge processes in metal channel and standard photomultiplier tubes

The effect of the potential difference at the focusing chamber electrodes of XP2020, FEU-85, FEU-87, and FEU-93 photomultiplier tubes on the intensity of afterpulses resulting from gas discharge processes is investigated. The time distributions of afterpulses in H6780 and R7600U-200 metal channel photomultiplier tubes are also analyzed.     

Dynamics of Synchronous Hydromechanical Drive in Mobile Machine

A mathematical model of the synchronous hydromechanical drive in a mobile machine with a flux divider of choke type is developed on the basis of the theory of the stiffness of a hydraulic system. To obtain the best dynamic characteristics of the system, the properties of the flow divider must be strictly consistent with the dynamic properties of the system.     

某星载功分器大功率隔离电阻器温控方法研究

针对某星载功分器中的大功率隔离电阻器开展温控方法研究。由于该电阻体积小,热耗大,为了解决高热流密度带来的器件高温失效问题,提出采用金属化过孔、焊锡、涂导热胶等方式来降低主要导热路径的热阻。研究表明,实验结果与计算结果符合良好,通过合理的热设计,可以使电阻器温度在严苛的热环境下保持在85 ℃以内的安全范围。     

高压径向柱塞泵配流轴的力学性能分析

目前国产径向柱塞泵的额定压力为28MPa,这样的额定压力使径向柱塞泵的应用场合受到一定的限制。为此,将径向柱塞泵的额定工作压力提高到35MPa,分析配流轴的力学性能。根据配流轴径向受力分析,运用Pro/E及ANSYS Workbench仿真软件对其强度和刚度进行校核。分析结果表明,配流轴的强度和刚度满足设计要求。     

A Maximal Afterpulse Amplitude-to-Main Pulse Amplitude Ratio in a Photomultiplier Tube

An amplitude dependence of afterpulses caused by an ion feedback on the main pulse amplitudes in a photomultiplier tube is studied. It has been found that a maximal afterpulse amplitude-to-maximal main pulse amplitude ratio is inversely proportional to the main pulse amplitude. It has been discovered that the feedback-ion intensities are proportional to the charge released by main pulses at the output of the photomultiplier tube. These facts prove that a detection process of single ions can explain the maximal amplitudes of afterpulses.     

Parameters of the new scintillation detectors

The parameters of two types of scintillation detectors—LGSO + solid state photomultiplier and LaBr₃ + ΦЭУ-184 photomultiplier tube—are experimentally estimated. These detectors are interesting from the standpoint of γ-ray measurements.     

日盲紫外滤光片的带外截止深度测试

针对全日盲紫外滤光片,建立了以窄带光发射二极管（LED）作为基本光源的超大动态范围滤光片带外截止深度测试系统,并分析了系统的测试误差。该系统主要由LED光源,已知衰减系数的标准反射式中性衰减片以及光电倍增管组成。基于替代法,系统测试时将LED光源通过衰减片后的输出电流作为参考电流值替代光源的初始电流值,通过对比运算获得滤光片的带外截止深度。针对系统中的反射式衰减片,文中还提出一种组合衰减片方法,以保证光电倍增管始终工作在线性响应范围内,从而实现对滤光片的超大动态范围的截止深度测试。实验结果表明,在350~800 nm谱段内,该测试系统可测滤光片的带外截止深度延伸至11-OD,不确定度小于2%,相对重复性误差小于0.2%。该系统结构简单,测试谱段范围宽、可测动态范围大且精度高,可广泛用于滤光片的截止深度测试。