新型金刚石膜微条气体室X射线探测器

以金刚石膜／硅复合材料作为基板．运用微加工技术在金刚石膜／硅衬底上光刻铬／金微条电极．制成了流气式微条气体室探测器。在室温及101．0kPa下,使用微机多道能谱仪及辅助电子学设备在5．9keV^55FeX射线辐照下测量了微条气体室探测器在不同电压下的能谱响应和脉冲信号。结果表明微条气体室探测器具有较高的信噪比,计数率≥10^3Hz,当混合工作气体Ar：CH4=90：10、漂移电压-1000V、阴极电压-650V、阳极0V时,能量分辨率达12．3％。     

矩形截面正比管的等效圆柱形阴极半径

为了考察Tomitani给出的矩形截面正比管的等效圆柱形阴极半径R’_c计算公式与实验符合程度,测量了横截面为5×10mm(2×长边/短边=2x/y=2)和12×70mm(2x/y=5.83)两种矩形正比管分别充以Ar+CO_2(34.2％)和Ar+CH_4(10％、30％、50％和70％)(充气压均～0.1MPa)时的气体放大倍数,以及φ=19.5mm的圆柱形正比管在分别充以与矩形管相同工作气体时的气体放大倍数。结果分析表明:Tomitani公式仅适用于2x/y～1—2;当2x/y=5.83时,计算的R_C值比实验值小一倍。采用我们提出的经验公式计算的等效圆柱形阴极半径R_(CL)=R’_c·x/2,与实验结果在10％内相符。     

THGEM探测器化学抛光及其工作气体优化

采用新的化学抛光方法处理THGEM膜,在不同的气体成分和比例下对THGEM膜的增益和能量分辨进行研究测量。结果表明,以Ar/C_4H_(10)为工作气体的THGEM探测器所需工作电压较低、增益高、能量分辨相对较好。在Ar/C_4H_(10)(95%/5%)的气体条件下,THGEM的增益可达7×10~3。     

小型多丝正比室性能研究

本文着重叙述小型多丝正比室的性能测量结果,包括气体放大、电晕放电、位置分辨率、输出脉冲波形、输出最大幅度、~(55)Fe幅度谱、效率坪曲线以及延迟时间分布等。     

测量~(85)Kr的同轴多丝正比计数器的研制

本文介绍一种用同轴多丝正比计数器测量~(85)Kr的装置。装置探测效率为80％,灵敏度为4—10~(-12)Ci/1。它可以把气体样品密封在计数器内测量,亦可在气体流速小于61/min时进行连续测量。一、引言目前国内外测量~(85)Kr的方法很多,如电离室法、G-M计数器和塑料闪烁计数器测量法,其灵敏度范围为10~(-10)—10~(-11)Ci/1。如果把它们直接用于测量环境中的     

用于低能X射线分析的电荷分配式位置灵敏正比计数器

研制了一种电荷分配式单丝阳极位置灵敏正比计数器．它的效率由近似公式所估价．在感兴趣的4～6．5keV能区内相应效率从65％～25％间变化;它的位置分辨率用宽度50μm(x)的^55FeX射线束测定,可达到0．55mm。并介绍了由这PSPC构成的位置灵敏谱仪两个应用事例。     

平行板气体闪烁正比管

本文简述了气体闪烁正比管的原理、基本结构和制作工艺,对~(55)Fe 5.9keV X射线得到的能量分辨率约为9％。     

二维成像多丝正比室

本文报道了二维多丝正比室成像的研制结果,给出了~(55)Fe源二维成像的清晰照片以及阳极、阴极的空间分辨(FWHM)和线性等结果。     

螺旋阴极位置灵敏正比室

我们研制的螺旋阴极单丝正比室是作为快定时、二维位置灵敏重离子探测系统中的终端计数器。灵敏体积1.2×1.2×10cm~3。在730mmHg的90％Ar 10％CH_4(P10)混合气体下,对5.3MeV的~(210)Poα源,得到能损△E(～1MeV)分辨率12.1％,位置分辨1.2mm(FWHM)。     

研究性重水反应堆排出~(41)Ar 的测量分析

本文详细介绍了重水堆运行时~(41)Ar 的来源和其排放率的研究结果。为监督排出~(41)Ar 对环境的影响,反应堆厂房内设有监测系统,以测量烟囱和工艺房间空气中的放射性气体。从烟囱取出的空气样可连续通过用~(41)Ar 进行标定的电离室。最后指出了降低~(41)Ar 排放量的途径。     

Response of Multiwire Proportional Chambers to Relativistic Heavy Nuclei

Measurements have been carried out at the Lawrence Berkeley Laboratory Bevatron to investigate the response of multiwire proportional chambers to 2. 1 GeV/nucleon C12 and O16 nuclei. The relative gas gain as a function of high voltage was measured for three different gases: 80% Ar/20%CO2, 75% Ar/ 25%C4H10, and 81% Ar/14% Xe/5%CO2. The gas gain obtained with 5.9 KeV X-rays from Fe55 sources was also measured for comparison. Saturation characteristics of the chambers are analyzed and the implications of the results on the use of multiwire proportional chambers as spatial detectors in cosmic ray experiments are discussed. A summary of the results of delta ray calculations and their effect on spatial resolution is also presented.     

电荷除法型位置灵敏探测系统的研究

一、引言电荷除法型单丝位置灵敏探测器与其它定位探测器比较,结构和电子学线路简单可靠、探测的几何长度长,并且具有较好的位置分辨和抗干扰能力,因此它比其它定位探测器有更广泛的应用。     

Use of a Streamer Chamber for Low Energy Nuclear Physics

A small streamer chamber has been implemented for low energy heavy ion reaction studies at the LBL 88" cyclotron. The response of the chamber to light and heavy ions below 35 MeV/nucleon has been examined. The limited sensitivity of light output as a function of ionization works to advantage in recording a wide variety of tracks in the same photograph whose energy loss may vary considerably. Furthermore, as gas targets are attractive for several reasons, we have investigated the suitability of Ar and Xe for use in streamer chambers.     

Study of nonlinear relationship between position and drift time incylindrical-type drift chamber and use of backgammon-shaped cathode pads

A cylindrical-type drift chamber consists of an appropriate array of cylindrical single wire proportional counters and has a simple structure. It is shown that a quadratic function reproduced the space-time relationship in the cylindrical-type drift chamber filled with PR gas (Ar:methane=90:10). The difference in the drift times in pair-cells is simply converted into the incident position of charged particles perpendicular to the anode wire using the quadratic function of the space-time relationship. Furthermore, the quadratic function improves the position resolution. A backgammon pattern is employed for the cathode pad of the cylindrical drift chamber. The cylindrical drift cell with a backgammon-shaped cathode pad gives the position resolution along the anode wire. The position resolution in one sigma along the anode wire is obtained to be 1.7 mm on average. The cylindrical-type drift chamber with a backgammon-shaped cathode pad may be applied to a two-dimensional position sensitive detector with a compact structure and simple signal-processing electronics     

Investigation and application of hollow anode glow discharge ion source

In the present work, a new shape of a glow discharge ion source has been designed, fabricated and constructed at Accelerators and Ion Sources Department, Nuclear Research Center, Egyptian Atomic Energy Authority, Egypt. The discharge and output beam characteristics of the ion source at different operating gas pressures have been measured at the optimum distance between the anode and the cathode (3.5 mm) using hydrogen and nitrogen gases. Furthermore, mixture of different gases was studied, e.g., addition of H₂ gas to N₂ gas with different ratios has been investigated. Finally, as an application of this new ion source, ion beam modification of insulators (glass) which depends on glass structure has been achieved. It has been found that, the transmission of light is decreased by coating the glass surface with Ar ion beam more than coating with plasma of Ar gas at the same pressure and the same exposure time. So we could use this ion source as a coating tool for borate glass surface. The parameters affected the glow discharge ion source efficiency have been examined carefully using a mixture of gases. Using helium gas, the glow discharge is in a turbulent state due to instabilities. An investigated H₂-N₂ mixture has been used in order to obtain an optimum percentage of the mixture of the two gases to increase the electric field necessary for ionization balance.     

Production of Multiply-Charged Ions of Ne, Ar, Kr and Xe by the Electron-Bonbarded Hot Cathode IoN Source of IPCR

Production of multiply-charged ions of Ne, Ar, Kr and Xe has been studied by use of an electron-bombarded hot cathode type ion source of the IPCR 160cm cyclotron, which is similar to Morozov's source. These multiply-charged ions were accelerated by a 3rd harmonics acceleration mode in the cyclotron and detected with a beam probe fixed at the radius of 55cm. Observed multiply-charged ions are Ne2+, Ne3+, Ne4+, Ne5+, Ar3+, Ar4+ Ar5+, Ar6+, Ar7+, Ar8+, Kr6+, Kr7+, Kr8+, Kr9+, Xe9+, Xe10+ and Xe11+. Relative abundance of each charge state of four elements were measured. In case of Kr and Xe , the intensity of observed multiply-charged ions decreased to 1/3 or 1/4 when the charge number is increased by one. Intensities of Ar4+, Ar6+, Ar8+, Kr6+ and Kr8+ were measured as a function of the operation conditions of the ion source, such as arc voltage, arc power and gas flow rate. It was found that a smaller gas flow and a higher arc power brought about a higher yield in all the measured ions. Obtained current intensities of ion source output are 40?A Ar8+, 600?A Kr6+, 40?A Kr9+, 150?A Xe9+ and 10?A Xe11+ respectively.     

WDX-PIXE analysis of low energy X-rays using a microbeam

A high-energy resolution PIXE system developed at a heavy ion microbeam line was used to analyze low energy X-rays below 1 keV. The system is equipped with a plane crystal spectrometer with a gas flow position sensitive proportional counter (PSPC), which enables high-energy resolution PIXE analysis using a microbeam. In order to improve the detection efficiency for the low energy X-rays, the X-ray entrance window of the PSPC was replaced with a thin polymer film supported by a metal grid. As the result, the detectable energy range was extended to carbon K X-rays and chemical effect in Fe and Cu L X-rays could be detected. A preliminary result of high-energy resolution PIXE mapping of Cu mesh (#500) showed that it is possible to obtain the Cu L mapping image using a 2 MeV proton microbeam with the size of 20 × 20 μm.     

球形不锈钢电离室响应实验研究

针对球形不锈钢电离室，开展了一系列实验研究，包括不同充气气体及其不同气压条件下的电离室的能量响应及单位压力灵敏度等。实验气体包括氦气、氮气、氩气、氪气和氙气，原子序数从2到54；充气气压从4kPa到1000kPa；照射射线能量从33keV到1．25MeV。研究结果表明：1）对不锈钢电离室，在充氙气时最灵敏，在相同充气压力下，对137^Cs源和低能射线（83keV）照射，充氙电离室的灵敏度约分别为充氩电离室的5．6倍和55倍；但在实验中发现，对充氙气电离室的灵敏度随压力变化曲线，当射线能量超过205keV时，在计示O．2个大气压处存在拐点，还有待进一步分析。2）从能量响应来看，充氩的最好，充氙的最差，充氦和氮的居中且两者大致相同。