Summation of pulses in γ-ray spectra

It is shown that peaks formed in -ray spectra by summing the pulses due to cascades can be used to determine both the activity of the radiation source and the efficiency of detecting the rays. Possible sources of errors in determining these quantities were investigated. This method may be used to measure the cross sections of nuclear reactions, to analyze the background radiation when searching for rare decays, and in other applications.Translated from Pribory i Tekhnika Eksperimenta, No. 1, 2005, pp. 58–61.Original Russian Text Copyright ¢ 2004 by Gromov, Fominykh, Chumin, Samatov.     

Development of a technique for high-speed γ-ray spectrometry

A technique for high-speed γ-ray spectrometry was developed for γ-ray diagnostic experiments on the ITER tokamak and tested at the Ioffe Physico-Technical Institute on the cyclotron and the GLOBUS-M and TUMAN-3M tokamaks. This technique was used to upgrade the γ-ray diagnostic system of the JET tokamak. It was shown by the tests that the new technique compares favorably to the traditional one in that it allows the limiting counting rate of the spectrometer to be increased by at least an order of magnitude without noticeable deterioration of its energy resolution.     

On quantitative determination of radon concentration by γ-ray spectrometry of aerosol filters

The problem of determining the ²²²Rn concentration in air from γ-ray spectra of radon progeny is solved using the aerosol filters method. The systematic error of the method due to incomplete collection of radon progeny is determined. It is shown that, when comparing the filter activity to the analytical calculation, the use of a 20-cm-diameter 20-cm-tall NaI(Tl) crystal and a 4−π geometry makes it possible to measure radon concentration with an accuracy of 20-30%. Original Russian Text ? A.Kh. Khokonov, M.B. Masaev, Yu.V. Savoiskii, 2009, published in Pribory i Tekhnika Eksperimenta, 2009, No. 1, pp. 142–144.     

High resolution silicon detectors — status and future developments of the MPI/TU-Munich group

Some of the recent work on high resolution silicon strip detectors by the TU-Munich and MPI-Munich group is presented, in particular:

• •-investigation of the factors limiting the spatial resolution;
• •-use of silicon strip detectors as on-line triggers for the study of charmed particles in hadronic reactions;
• •-development of LSI (large scale integration) readout electronics for strip detectors.

     

Monitoring of <Superscript>235</Superscript>U content of fuel assemblies for nuclear reactors based on neutron and γ-ray scintillation detector systems

A model of the setup for determining the ²³⁵U content of a fuel assembly for WWER-440 reactors is described. The setup operates based on the digital technology for discriminating neutron and photon scintillation responses. An AmLi source is used as an external neutron source. A three-channel system for detecting fission particle coincidences is based on EJ-309 scintillators. A set of digital codes for obtaining and analyzing neutron-neutron (nn), neutron-γ (nγ), and γ-γ (γγ) coincidences has been developed. Dependences of double coincidences have been experimentally obtained and analyzed with the aim of determining the ²³⁵U content of the fuel assembly. It is shown that fission neutrons and coincidences of the nn and nn + γn + nγ types are the best informative parameters for the ²³⁵U content of the fuel assembly.     

Scintillation Parameters of a Phoswich β- and γ-Ray Detector

The effect of the design features of a composite scintillation detector on the value and stability of its light yield under its exposure to both -particles and -rays was investigated. The phoswich detector was manufactured from a NaI(Tl) single crystal and scintillation polystyrene-based plastic. The light yield was measured in the detectors of a differing design. Comparing the experimental results with the simulation data, it was possible to trace the mechanism of light-signal formation in the phoswich. Some proposals were designed that helped improve the following performance data of a scintillation - and -ray detector: the light yield and its stability, pulse-height resolution, and peak-to-valley ratio.     

The 12C(3He,pγ)14N reaction cross section for γ-ray spectroscopy simulation of fusion plasmas

High resolution γ-ray spectroscopy measurements were performed in JET (3He)D plasmas with high energy ion populations driven by radio-frequency (RF) heating. One of the first reactions investigated was 12C(3He,pγ)14N, which was observed at low 3He concentrations. In order to interpret the measurements in this work, cross section data for the 12C(3He,pγ)14N reaction are evaluated. Available data for the population of excited states in 14N up to the eighth level are assessed in the range E(3He) = 0–5?MeV. Discrepancies and gaps in the database have been solved by means of interpolations and consistency analysis. The evaluated cross section data are used to predict the intensity ratio of characteristic 2.31 and 1.63 MeV γ-rays.     

能发射硬X-射线的新型桌面X-射线激光器

X-射线激光器的确存在，甚至桌面型的也存在，但它们通常产生的是“软”X-射线激光，波长约5nm～120nm，比医学X-射线中所用的波长稍长一些，能量只有几百电子伏特。化学、生物学和材料学研究中的新应用呼唤能够产生具有较高能量的“较硬的”X-射线的实验用X-射线激光器。本期Nature报告了向着这个目标所取得的一项进展。这种新的桌面X-射线激光器发射高度标准的、空间相干的X-射线，     

A technique for selecting γ rays with energies above 50 GeV from the background of charged particles in the GAMMA-400 space-based γ-ray telescope

The task of selecting neutral γ rays from the background of charged particle fluxes, which arises in investigation of high-energy (>50 GeV) cosmic rays, is complicated by the presence of the backsplash effect. The backsplash is composed of a great number of low-energy (~1 MeV) particles produced in an electromagnetic shower being developed in the calorimeter of the γ-ray telescope. A technique of charged particle rejection using an anticoincidence system has been developed. A method for discriminating events of charged particle detection from γ-ray detection events accompanied by the backsplash phenomenon is proposed. This method is based on the difference of the signals in time and makes it possible to maintain a high detection efficiency even for high-energy γ rays.     

S11X-10疏水阀

SIIX-10节能自动疏水阀是根据浮力原理,使阀体内之浮子,随阀体内水位的变化,浮子作升降运动;以达到阀门启闭排水阻气的作用。气体经过压缩机压缩后温度升高,然后随着温度的下降,超过饱和状态的水分就变成水滴,在气罐、油水分离器、管道内析出。另外,为了保证压缩机的正常工作要使用润滑油,有一些润滑油也会随着进入这些部位。油和水会造成许多故障,会使阀类、气缸腐蚀而动作失灵;油和水如从气动工具和管道等处喷出会影响操作人员的正常工作,造成环境污染。因此这些油和水应及时从气罐、油水分离器、管道等处排放出来。     

Testing the neutron attenuator based on <Superscript>6</Superscript>LiH for γ-ray diagnostics of plasmas in the JET tokamak

A ⁶LiH attenuator of a neutron flux incident on a detector is used to reduce the γ-ray background induced by neutrons in the detector material. This attenuator has been tested during experiments with deuterium (DD) plasmas on the JET tokamak. A specimen of the neutron attenuator with dimensions of ?30 × 300 mm has been developed by the Russian Academy of Sciences’ Ioffe Physico-Technical Institute and inserted into a vertical collimator used for γ spectrometry of plasmas. To compare γ-ray spectra recorded with and without the ⁶LiH attenuator being mounted, identical discharges with heating of the DD plasma by a neutral particle beam have been selected. For γ rays with energies of <3 MeV, which are induced by neutrons in the detector material, the suppression factor is found to be ～100. A low attenuation (～2) observed at energies of >3 MeV can be attributed to the transparency of the ⁶LiH attenuator for γ rays. This portion of the spectrum is due to γ radiation of the plasma and γ rays induced by neutrons in the constructional materials of the tokamak. To estimate the efficiency of the ⁶LiH attenuators as a mandatory component of the ITER γ-ray diagnostic system, it is necessary that measurements be taken in deuterium-tritium (DT) discharges.     

HQ45X-10、HQ44X-10系列无磨损球型止回阀问世

国家科委、国家物价局等六个部门联合下达、机电部立项的HQ((44)/(45))10系列无磨损球型止回阀,由成都阀门厂开发成功。并于1992年11月通过鉴定。这项获实用新型的专利。系列球型止回阀,HQ44X-10型为单球密封、HQ45X-10型为多球密封,其设计构思巧妙新颖,利用进口端水介质压力的变化,实现自动断通。     

多晶 X-光衍射仪实验技术

多晶样品的 X 光衍射分析法有很多独特的优点,是一种重要的物理化学分析方法。除用作晶态化合物的鉴别外,在所有涉及物质晶体结构与其物理、化学性质关系的研究中,都有广泛的应用。多晶 X 光衍射仪整机由三个基本部分组成:(1)X 光光源,是一台带有自动稳定系统的强度高度稳定的 X-光发生器;(2)衍     

A New Method and Apparatus for High-Resolution γ-Radiographic Introscopy of Bulk Heavy-Metal Products and Blanks. First Application Results

Russian Journal of Nondestructive Testing - A $$\gamma $$-introscopy method and an installation using “electronic focusing” of $$\gamma $$-quanta transmitted through the studied object...     

普茨迈斯特22X-70混凝土泵车

普茨迈斯特２２Ｘ－７０混凝土泵车的浇注臂结构紧凑，机动性能优良，４段全长为２１６４ｍ，该４段式Ｚ型浇注臂的特点是全长较短，受道路交通及作业高度的影响较小；可以在较低的建筑物下轻易展开。浇筑臂的前端配有伸缩式承力外伸支架，装有一个长１０ｃｍ的传送带，可方便地更换。标准化的弯管接头和输送管为通用零部件，更换便利。为了确保浇筑时的稳定性，浇筑臂的后端配有固定式承力外伸支架，该箱形支架安装在转台上。浇筑臂支架装有一个转动马达转动系统，降低了维修费用，并且有一个开口，可方便地更换转台上的软管。泵车上所有的…     

Characteristics of InP γ-Detectors

The results of investigations of the characteristics of InP detectors manufactured from a bulk iron-doped material are presented. The characteristics were measured in a temperature range from room temperature to –60°C. At room temperature, at a voltage of 400 V, the back current in the InP detectors was under 10 A. The best spectrometric characteristics of the detectors were obtained at temperatures from –50 to –60°C. The spectra of ²⁴¹Am, ¹⁰⁹Cd, ⁵⁷Co, and ¹³⁷Cs sources recorded with InP detectors are presented.     

DS41X-10系列伸缩蝶阀

郑州市上街蝶阀厂是国家定点生产阀门的专业厂家,系河南省一级企业,是获得部级“七五”技术进步奖企业。主要产品有对夹蝶阀、对夹蝶式止回阀、中压蝶阀、蝶式调节通风阀、伸缩蝶阀和伸缩器等10大系列300多个品种     

X-射线荧光光谱仪故障分析与维修

本文通过对3063型X-射线荧光光谱仪的PC探测器和ALC单元电路的组成及原理分析,介绍了这两部分电路的故障分析和处理方法。     

D71X-10对夹式系列蝶阀

郑州市上街蝶阀厂位于上街区南侧,陇海铁路边缘,310国道临门而过,为企业的发展提供了便利的交通条件。工厂始建于1969年,是生产对夹式蝶阀和特种阀门的专业厂,国家明星企业,河南省一级企业和重合同守信誉单位,同时也是省外贸定点出口阀门基地之一。 目前,生产的主要产品有D71X—6、10、16对夹式蝶阀,规格从直径40mm到2800mm达