共查询到20条相似文献,搜索用时 0 毫秒
1.
D. S. Kosolapov B. M. Ovchinnikov V. V. Parusov V. I. Razin 《Instruments and Experimental Techniques》2013,56(6):684-685
A gas electron multiplier with metal electrodes, which is characterized by simplicity and high manufacturing accuracy, reliability, and stability, has been fabricated and tested. 相似文献
2.
A simple technique for manufacturing electrodes of multichannel wire gas electron multipliers was developed. The maximum proportional multiplication factor of ionization electrons K max = 103 was obtained when the chamber containing a multichannel wire gas electron multiplier was filled with a mixture of Ar + 10%C2H4 at a pressure of 1 atm (abs.) and the drift (ionization) gap of the chamber was irradiated with β particles (63Ni). Under irradiation with α particles, K max = 103 at a pressure of 1 atm (abs.) and 3 × 103 at 0.4 atm (abs.). When the chamber was filled with a mixture of Ne + 10%C2H4 at a pressure of 1 atm (abs.) and exposed to β particles, K max = 4 × 103 was obtained. 相似文献
3.
The operation of multichannel wire gas electron multipliers (MWGEMs) with gaps between electrodes δ = 1 and 3 mm, when the
chamber is filled with commercial neon under a 0.4- and 1.0-atm (abs.) pressure and irradiated with α and β particles, is
studied. The following maximal proportional electron multiplication coefficients are obtained: 6 × 103 (α, irradiation, δ = 3 mm, 1 atm, and 20% streamers), 1.2 × 104 (β−, 3 mm, 1 atm, and 50% streamers), 6 × 103 (α, 3 mm, 0.4 atm, and 20% streamers), and 105 (β−, 3 mm, 0.4 atm, and 50% streamers). The maximal proportional electron multiplication coefficients are obtained in the MWGEM
and its anode (induction) gap in the sequential electron multiplication mode: 1.08 × 105 (β−, 1 mm, 0.4 atm, 50% streamers), 2 × 106 (β−, 3 mm, 0.4 atm, 20% streamers), and 1.12 × 105 (α, 3 mm, 0.4 atm, 50% streamers). 相似文献
4.
J. HEJNA 《Journal of microscopy》2008,232(2):276-281
A discrete dynode electron multiplier with radial flux of electrons was built and tested in the range of low‐voltage scanning electron microscopy as a backscattered electron detector of topographic contrast. The multiplier collects backscattered electron emitted in a specific range of take‐off angles and over the whole azimuth angular range enabling large solid collection angle. Multipliers with different dynode shapes were studied theoretically with the use of the software for particle optics and three assemblies were built and tested experimentally. The gain estimation, assessment of the type of detected electrons (secondary electron or backscattered electron), imaging the spatial collection efficiency and signal‐to‐noise measurements were performed. 相似文献
5.
Simonetto A Sozzi C Garavaglia S Fessey JA Nowak S;JET-EFDA Contributors 《The Review of scientific instruments》2011,82(11):113506
A Martin Puplett interferometer for electron cyclotron emission (ECE) measurements from JET tokamak plasmas was extended to multichannel operation for simultaneous radial and oblique ECE measurements. This paper describes the new optics and the instrument's performance. 相似文献
6.
Stickel RE Kellert FG Smith KA Dunning FB Stebbings RF 《The Review of scientific instruments》1980,51(3):396
We report a measurement of the absolute efficiency of a Johnston Laboratories MMl electron multiplier for detection of 2-4 keV Ne(+). The measured detection efficiency depends both on ion impact energy and on the magnitude and direction of an externally applied electric field near the first dynode. 相似文献
7.
1概述4应用效果2系统介绍3现场样气采样点的微机控制图1微机系统框图WSP -4000型多通道气相色谱仪是针对我国中小型化肥厂合成氨生产中质量控制的需要而设计研制的专用气相色谱仪。该仪器既能进行生产中气体的常规分析 ,又能作为氮氢比例调节的前置机 ,实现化肥厂氮氢比调优的计算机集散控制 ,从而提高合成氨的质量与产量。一经操作人员设定完参数后 ,分析过程可全部实现自动化。微机系统用来控制五道气体的自动转道 ,自动柱切换进样 ,自动打印谱图及五道样品分析结果报告 ,同时对检测室温度、柱温、净化器温度进行控制。WSP… 相似文献
8.
This article discusses an electron energy analyzer with a cylindrically symmetrical electrostatic field, designed for rapid Auger analysis. The device was designed and built. The best parameters of the analyzer were estimated and then experimentally verified. 相似文献
9.
J. N. Brown 《Journal of microscopy》1972,96(3):393-395
A simple capacitor discharge microwelder is described together with a method for the preparation of electron microscope central wire beam-stopping apertures. 相似文献
10.
The fundamental characteristics of the energy distribution of output electrons from a single channel electron multiplier were studied experimentally in detail for a few types of straight channels. The width of the energy distribution curve, ranging from about 50 to 15 eV FWHM, is found to depend on the applied voltage V(A) and the length-to-diameter ratio alpha of the channel, and to vary with output current. The results can be explained in terms of the normalized field strength near the output end of the channel and generalized by a set of universal curves presenting the energy width as a function of output current level for different values of VA/alpha. 相似文献
11.
A source with a spark discharge at the atmospheric gas pressure is described. A multichannel version of the spark discharge
from a single generator with the use of an inductive current divider is realized. The number of the discharge channels and
geometry of their disposition can vary over a wide range, depending on the problems being solved. 相似文献
12.
A simple method for decay measurements of the charge collection mode (commonly referred to as electron-beam-induced current or EBIC) of an electron probe instrument is presented. The decay, which occurs at continuous electron irradiation, should be distinguished from a decay measurement due to the electron beam blanking. This method could be applied to other modes of an electron probe instrument, e.g., cathodoluminescence, in studying electron-beam-sensitive semiconductors. An example of the decay of the EBIC signal in a hydrogenated amorphous silicon device is presented. 相似文献
13.
New methods which reduce the unfavorable energy spread of output electrons from a single channel electron multiplier are presented. A modified output electrode produces a pronounced narrowing effect on the energy distribution without much affect on the gain. A simplified analysis of the field inside the channel shows that the fixed channel wall potential near the output end is responsible for the narrow energy distributions obtainable. 相似文献
14.
气相色谱仪多通道并行快速分析炼厂气方法的研究 总被引:2,自引:0,他引:2
提出了一种用Agilent 3000便携式气相色谱仪分析炼厂气的新方法。通过选择合适的关联通道,建立了外标(对氢)和扩展校正归一化(对其它组分)并用的定量方法。对进样时间与响应的关系,影响保留时间的因素及重叠峰问题作了讨论。新方法保持了原方法的准确度,最大程度地减少了标气使用量,使分析操作更加便利。 相似文献
15.
G. Belforte 《Tribology International》2009,42(4):600-608
The paper presents an experimental investigation of pneumatic resistances constructed using woven wire cloth. Tests were carried out on commercial Touraille stainless steel wire cloth featuring different mesh sizes.Two types of experiments were performed: (a) Mass flow rate through single resistances was measured with different upstream and downstream pressures and wire mesh sizes. (b) Pressure distribution and mass flow rate were measured on a pneumatic pad with a fine wire mesh feeding system. Two approaches of identification of the single resistances are discussed.Test results can be used as the basis for developing woven wire cloth pneumatic resistances whose conductance is equivalent to that of certain of the calibrated orifices normally used in gas bearings. 相似文献
16.
S. A. Titov R. G. Maev A. N. Bogachenkov 《Instruments and Experimental Techniques》2009,52(5):721-724
A multichannel scanning acoustic microscope, the ultrasonic element of which consists of several focused transducers, is proposed.
In this device, images are generated by the electronic switching of the transducers with simultaneous mechanical translation
of the acoustic element, thus reducing the data acquisition time. The design of the microscope, the acoustic element of which
contains eight transducers with a 100-MHz central frequency, a 6.7-mm focal distance, and a 16° angular aperture, is considered.
The multichannel acoustic element and mechanical scanner are physically combined into a remote smadelay linell-size module,
enabling studies of large-size complex-shaped objects. As an example, acoustical images of the inner structure of spot welds
of aluminum sheets are presented. The comparison of the acoustical images and results of destructive tests has shown that,
based on ultrasonic data, it is possible to estimate sizes of weld cores and detect inner defects. 相似文献
17.
Zhou Y Deng ZC Liu ZT Yi J Tang YW Gao BY Tian CL Li YG Ding XT 《The Review of scientific instruments》2007,78(11):113503
A new multichannel HCN interferometer has been developed on HL-2A tokamak, which is characterized by two techniques: (1) the wave-guide HCN laser with cavity length of 6 m to increase the optical resource power and (2) high response room temperature waveguide Schottky diode detectors to obtain good beat signal. The space resolution is 7 cm by the use of focusing metal mirrors mounted on the vacuum chamber and a compensated optical system. In the 2006 experiment campaign, this new interferometer has been applied for plasma density profile and density sawtooth measurement. 相似文献
18.
B. M. Ovchinnikov V. V. Parusov Yu. B. Ovchinnikov 《Instruments and Experimental Techniques》2011,54(1):43-46
Results of studying multichannel gas electron multipliers with 1-mm-thick metal electrodes, perforated over the entire working
area by 1-mm-diameter holes with a 1.5-mm distance between them, and a 3-mm gap between the electrodes are described. The
influence of N2 and H2O microadditives on operation of the neon-filled multiplier is studied. When β particles (63Ni) were detected, the maximal proportional electron multiplication factor in neon under pressure of 1 atm (abs.) with quenching
additives of (H2O + N2) ≈ 100 mln−1, equal to K
mltcmpl = 3 × 104, is obtained. 相似文献
19.
E. G. Osadchii Ya. I. Korepanov N. N. Zhdanov 《Instruments and Experimental Techniques》2016,59(2):302-304
An electrochemical cell has been developed for determining the thermodynamical activity of a component in a solid solution (alloy) depending on its concentration at a temperature of up to 150°С and atmospheric pressure. A salt solution of glycerin is used as an electrolyte. Measurements can be simultaneously performed on 10–15 different samples in the cell under identical conditions for all compositions of the solid solution studied. This is ensured by using an inert electrode being displaced from sample to sample. In this case, the comparison electrode is common and immobile, thus substantially increasing the accuracy and reliability of experimental results, since this allows one to perform repeated (check) measurements of the EMF at a constant temperature on any sample with a specified composition. 相似文献
20.
The paper describes characteristics and design principles of a multichannel power supply for CW magnetrons with RF power up
to 3 kW. An advanced control system implemented in the power supply has resulted in its good operational properties as well
as allowed providing adaptive procedures for the regulation of magnetron operation. A modular approach based on utilization
of novel electronic components increases reliability and lowers weight and dimensions of the power supply. 相似文献