The Network Architecture of the Data-processing System for the Photodetector of an Orbital Detector of Ultra-high Energy Cosmic Rays

An orbital detector of ultra-high energy cosmic rays has been developed by the Skobel’tsyn Institute of Nuclear Physics of the Moscow State University together with the international JEM-EUSO collaboration for mounting on board the International Space Station. Its multichannel photodetector is composed of an array of multianode photomultiplier tubes (MAPMTs) combined into modules with 36 MAPMTs in each and with approximately 10⁵ pixels in total. Since the number of channels is great and the speed of measurements is high, high requirements are set for the system of detection, selection, and analysis of events. The designs of the modular photodetector composition and the network architecture of the data processing system that is capable of performing efficient selection of events with different space?time structures are presented. The network principle is implemented via three types of communications: high-speed links between adjacent photodetector modules, long-distance communications for recording information to the permanent memory, and synchronizing links for timing the operation of individual modules. This digital-processing system of the detector can be designed using the ZYNQ system-on-chip concept that includes a field programmable gate array and a processor system.     

The MONICA Experiment for Investigating the Ion Composition of Solar Cosmic Rays

The MONICA satellite-based experiment is described. In this experiment, fluxes of cosmic-ray ions from H to Ni are investigated near the Earth in the energy range of 10–300 MeV/nucleon. The main scientific objectives of the MONICA experiment are to measure the ion and isotope compositions and the energy spectra of solar cosmic rays for individual solar events and to study the evolution of these characteristics over time. The MONICA experiment will help to investigate the ion and isotope composition of the anomalous component of cosmic rays, galactic cosmic rays, and nuclear fluxes in the Earth’s radiation belt. Observations of ion fluxes will be carried out using the MONICA high-aperture multilayer semiconductor spectrometer–telescope installed on board a spacecraft with a low-Earth circular polar orbit at a height of approximately 600 km. This orbit will make it possible to perform the method for measuring the charge of ions with energies above 10 MeV/nucleon, which is based on the use of the Earth’s magnetic field as a particle- charge separator. The geometric factor of the instrument is 100 cm² sr and the angular resolution is 1°.     

气动式铁轨水平度检测系统研究

铁轨水平度是铁路建设中的一项重要技术指标,对于铁路运行至关重要,该文运用气动检测和传动原理,研究一种气动式铁轨水平度检测系统,能够自动检测出铁轨水平度的变化,并且及时反馈到技术部门采取处理措施,保证列车的运行安全以及人民的生命财产安全。经试验验证,该检测系统检测精度高,自动化程度高,既能检测铁轨横向水平度,又能检测铁轨纵向水平度,避免人工经验误差,减轻劳动强度,有望推广应用到实际生产中。     

A Large and Thin Scintillation Plate as a Charged-Particle Coordinate Detector

A new method of light collection in a scintillation plate with wavelength-shifting fibers is described. Using this method, it is possible to determine the coordinates of charged particles traversing the plate. The spatial resolution of the system is comparable to the scintillation-plate thickness and competitive in comparison with the resolution of wire chambers. The results of the experimental testing are presented.     

MEMS检波器动态参数及测试方法的研究

实际工程勘探中传感器通称检波器,常规的加速度和速度型传感器的检测量是静态参数,而石油勘探等领域检测的是动态参数,也就是频率和波形。MEMS检波器主要动态参数有:频率响应也称频率范围、失真系数、动态范围。本文主要研究MEMS检波器动态参数及测试方法,通过对地震勘探MEMS检波器进行动态性能分析,介绍频率范围、失真度系数、动态范围的测试方法,实际的测量结果证明了测试方法的正确性和可行性。     

A Streak-Camera Monitor for Hard X Rays

The instrument is designed on the basis of a fast scintillator and a high-speed image-converter tube for hard X and rays (10 keV). Using a scintillator, it is possible to obtain an almost constant spectral response over an energy range of 40–1000 keV. The time resolution of the camera is governed by the luminescence decay time in the scintillator and may go as high as 100–150 ps. The instrument is used at the ISKRA-5 facility to detect pulses of hard X rays.     

卧式加工中心工件旋转坐标系的换算

通过对卧式加工中心的回转工作台旋转坐标系建立数学模型,编制宏程序,利用宏程序自动计算工件坐标系偏置值,避免了操作过程中产生的误差.     

卧式加工中心工件坐标系自动补偿的研究

通过分析卧式加工中心机床坐标系与工件坐标系、工作台旋转中心之间的关系，并利用FANUC系统中的宏指令及参变量，开发数控系统功能。实现卧式加工中心机床在零件加工过程中，工作台任意角度旋转后，工件坐标系原点得到自动补偿与设定。     

卧式加工中心工件坐标系自动补偿的研究

通过分析卧式加工中心机床坐标系与工件坐标系、工作台旋转中心之间的关系,并利用FANUC系统中的宏指令及参变量,开发数控系统功能。实现卧式加工中心机床在零件加工过程中,工作台任意角度旋转后,工件坐标系原点得到自动补偿与设定。     

A Position-Sensitive Detector for the Polarized-Neutron Spectrometer

A linear detector of thermal neutrons, developed at the Laboratory for High Energies (Joint Institute for Nuclear Research), is used in the polarized-neutron spectrometer of the -2 reactor (JINR). The data are acquired in the regime of frame-by-frame survey to select neutrons with a wavelength = 1–12 Å by the time of flight. The neutron-detection efficiency is 70% for a wavelength of 2 Å. The detector exhibits a low sensitivity to -rays, a differential nonlinearity of 1.5%, and a spatial resolution of 1.5 mm at counting rates of 10⁵events/s.     

胶带输煤用金属检测器

本文介绍了一种金属检测器的结构、原理,它特别适合应用于胶带输煤系统中。     

Studying the Characteristics and Optimizing the Parameters of a Parallel-Plate Chamber Used As a Detector for Time-of-Flight Measurements

The evolution of a technique for precise and highly efficient time-of-flight measurements of minimum-ionizing particles is described. The technique is based on the use of parallel-plate chambers operating in the avalanche mode of gas amplification. The search for the proper material and design for the detector, the choice of the gas mixture composition, the results from the investigation of the gas discharge in the chamber, and the probability of a spark discharge are discussed, along with the development of fast and low-noise electronics.By optimizing the parameters of a parallel-plate chamber, a simple, reliable, and low-cost time-of-flight detector with a resolution of 200 ps and an efficiency of 90% or higher for minimum-ionizing particles was developed.     

A Start Trigger Detector for the ALICE Spectrometer

A fall-back option of the T0 start trigger detector was developed for the ALICE setup that was intended for the study of quark–gluon plasma with the LHC accelerator (CERN). The Monte Carlo simulation with the PYTHIA program was performed for a detector incorporating two symmetrical arrays of 12 Cerenkov counters, each composed of 26-mm-diameter Hamamatsu R5505 phototubes with fine-mesh dynodes and a quartz radiator 3 cm in length and 26 mm in diameter. Its simulated detection efficiency for p–p collisions exceeded 88%. A prototype Cerenkov counter, consisting of a R3432-01(similar to R5505) phototube and a quartz radiator with dimensions of 25 × 30 × 12 mm, was tested in a beam of pions and protons with a 1.19-GeV/c-momentum. The time resolution in the 1–200 dynamic range was better than 50 ps.     

给学生一个学习的虚拟现实环境 --测试技术课程教学改革及多媒体CAI

结合学科发展、机械工程类课程体系及测试技术课程内容和教学手段的改革,提出尽力为学生创建一个学习的虚拟现实环境,是测试技术课程教改的关键问题,介绍了笔者所创作的多媒体CAI。     

超声探伤仪检波电路的新方案

该文提出了用宽带跨导放大器构成超声探伤仪检波电路的新方法，并将两种用ＭＡＸＩＭ宽带跨地放大器构成的检波器与运放构成的精密检波器和平衡调制／解调器的同步检皮器作了比较。给出了３种检波 ＰＳＰＩＣＥ仿真结果。     

用于材料检测的电脑超声波探伤仪

本文介绍了一种用于金属材料检测的电脑超声波探伤仪的原理和特点，并简述了它的基本功能和主要性能。     

A Z Pinch-Based Source of Selective Soft X Rays

A setup for metrological measurements of X rays in the energy range of 50–1000 eV is described. A Z pinch with a discharge time of a few microseconds is used as the X-ray source. Radiation of a given energy is selected with the help of multilayer X-ray mirrors in combination with special X-ray filters. Along with the tested detector, an absolutely calibrated reference AXUV-5 detector is used to determine the density of incident X-ray flux in each energy range. The measured characteristics of some detectors are presented.     

A Stand for Studying Backscattering of Radio-Frequency Pulses

Instruments and Experimental Techniques - A stand for studying backscattering of radio-frequency (RF) pulses with durations of 1.75–3.1 ns with a variable filling frequency from 5.3 to 8.8...     

多关节坐标测量机的误差模型

按Denavit-Hartenberg方法,建立了多关节坐标测量机末端测头中心相对于机座参考坐标系的测量运动的数学模型。在此基础上,运用矩阵函数的全微分方法,建立起末端测头中心坐标误差与测量运动模型参数误差之间的传递关系。为进一步研究多关节坐标测量机的标定和补偿奠定了理论基础。     

A Self-Organising Fuzzy Logic Controller for a Coordinate Machine

For a 3D coordinate measurement system, the dynamic accuracy of the moving table will influence the measuring accuracy directly. If a classical PID controller were designed for this measuring table without an accurate mathematical model, the gain parameters may need to be regulated frequently by trial-and-error to obtain the precise motion control objective, good adaptability, and robustness. In this paper, a model-free fuzzy controller and a self-organising fuzzy controller (SOFC) were employed to eliminate the above controller design problems and improve the tracking control accuracy. The control performances of these intelligent control strategies were compared, based on the experimental results. The SOFC has the best tracking accuracy and its learning ability significantly reduces the trial-and-error design effort of a traditional fuzzy controller.