共查询到18条相似文献,搜索用时 140 毫秒
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不同工作气体对PPAC性能的影响 总被引:2,自引:0,他引:2
描述了为RIBLL研制的一种双维位置灵敏PPAC在不同工作气体下的性能测试.位置读出采用电荷分除法.在7mb气压和C3F8工作气体时阳极在+595V,对于3组分α粒子,位置分辨为0.64mm.使用异丁烷气体,阳极在+500V,位置分辨为0.76mm.PPAC在两种气体中探测效率均为99.1%.C3F8气体质量厚度和能量损失较大,信号幅度较高,适合探测较高能量较轻粒子.异丁烷气体能损较小,适合探测较重粒子. 相似文献
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描述一种可用于兰州放射性束流线(RIBLL)上的ΔE探测器——横向场气体电离室. 对其性能进行了测试, 包括它的坪曲线、探测效率和能量分辨. 测试结果显示, 在混合气Ar(80%)+CO2(20%)的不同气压下, 此电离室具有较长的工作坪区, 较小的坪斜. 相对于Si的探测效率为99.31%.在118mbar的气压下, 对能损为4.94MeV的α粒子, 其能量分辨率为3.25%. 并在RIBLL上利用50MeV/u的58Ni轰击Ta靶的实验中进行了在束应用. 相似文献
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采用高压电点火进行直接起爆,通过放电过程中电流的输出信号确定起爆能量,实验测定了C2H2-2.5O2气体和加入摩尔浓度为70%氩气的C2H2-2.5O2混合气体直接起爆的临界起爆能量,研究了高浓度氩气稀释对C2H2-2.5O2混合物临界起爆能量的影响。实验测得的混合物临界起爆能量实验值与Lee等人的表面积能量理论值基本吻合。研究表明:C2H2-2.5O2气体和加入摩尔浓度为70%氩气的C2H2-2.5O2混合气体的临界起爆能量均依赖于初始压力,并呈反相关指数关系;在相同实验条件下,高浓度氩气稀释极大提高了混合气体直接起爆的临界起爆能量。分析认为,由于临界起爆能量正比于诱导区长度的3次方,因此在相同初始压力下,高浓度氩气的稀释增加了C2H2-2.5O2混合气体爆轰诱导区长度,并最终导致其临界起爆能量的显著上升。 相似文献
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用泵浦探测技术研究了掺杂CeO2的75TeO2-25Nb2O5-5ZnO玻璃在飞秒激光诱导的瞬态光栅多级自衍射。从拉曼和吸收光谱中研究了玻璃的结构特性,并证明了此玻璃中存在Ce3+离子。这种瞬态光栅起因于光克尔效应,并通过Ce3+离子中1S0?1F3电子能级跃迁形成的激发态粒子数光栅而改善,一级衍射信号的转换效率可达到11%。这些实验结果显示了掺杂CeO2的75TeO2-25Nb2O5-5ZnO飞玻璃在全转换开关中具有广泛应用。 相似文献
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研究了电激励脉冲HF激光工作介质SF6/C2H6混合气体的放电特性。通过对放电等离子体荧光图像和放电波形的测量,分析比较了不同条件下放电稳定性、剩余电压、能量沉积效率等特性参数的变化情况。实验结果表明:混合气体的放电过程存在主放电、剩余电压维持和电弧放电3个阶段,各阶段的放电特性有所差异;提高充电电压有利于放电能量的有效沉积,也会使不稳定的电弧放电提前;增加C2H6原子分数能起到抑制电弧放电的作用;混合气体总压的增加会导致剩余电压的提高以及辉光放电的能量沉积效率的降低;最佳的能量沉积出现在电弧放电阶段与辉光放电阶段即将融合的临界状态。 相似文献
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The degradation of some performances of the drift chambers irradiated with 5 MeV electron beam has been tested. The gas mixtures filled were Ar/CO2, Ar/CH4 and C4H10 in proportion.
The dark current, the pulse height, the energy resolution and the counting rate plateau have been measured during the irradiation. 相似文献
The dark current, the pulse height, the energy resolution and the counting rate plateau have been measured during the irradiation. 相似文献
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HAN Ji-Feng ZHANG Jia-Wen CHEN Jin ZHANG Qing-Min LIU Qian XIE Yu-Guang QIAN Sen MA Lie-Hua 《中国物理C(英文版)》2008,32(5)
The installation of the BESⅢ RPC system has been completed.Cosmic ray test results show that they perform very well in streamer mode and meet the BESⅢ requirements.We have tested several RPCs in the avalanche mode with the addition of extra SF6 in the gas mixture.We find an efficiency plateau that reaches~95%.and a time resolution of 1.8 ns.This demonstrates that the BESⅢ-type RPC can work in the avalanche mode as well. 相似文献
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In this contribution, a new procedure to systematically identify and quantify novel molecular gases with low global warming potential for application in high voltage insulation as gas mixtures is presented. The attention is focused on highly efficient procedures to be able to scan a large number of candidate gases. To identify new molecules, we derived an empirical correlation between the electric strength of a gas and certain molecular properties, like polarizability or dipole moment, which can be calculated by means of density functional theory. The swarm parameters of these pre‐selected molecules in mixtures with buffer gases is then quantified, using a newly set‐up Pulsed Townsend experiment. The setup operates with a high degree of automation to enable systematic evaluation of gas mixtures not to miss possible synergistic effects. Key element of this PT setup is a new photocathode that works with a high quantum efficiency and long lifetime even when exposed to reactive species during the measurements. Moreover, for an automated operation it is important to know precisely in which range the experiment can be operated, i.e. for example to know up to which electron density space charge effects can be neglected. Finally, the measured swarm parameters need to be translated into breakdown voltage strengths of different electrode arrangements and different applied voltage wave shapes. For this, a model of the the streamer to leader transition in SF6 will be applied to other strong electronegative gases in future studies to test if the model is universally valid. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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The effects of surface resistivity of the high voltage provider on the space dispersion of the induced charge of a prototype Resistive Plate Chamber (RPC) have been studied experimentally and theoretically. The results of both experiment and theory agree and confirm that a two-Gaussian function can be used to fit the dispersion of the induced charge of the RPC. It is shown that the Gaussian function with the narrower width is mainly due to the expansion of the avalanche charge in the gas gap of the RPC, and the Gaussian function with the larger width is due to the charge dispersion when it passes through the resistive carbon film. This will be useful in the RPC design when one wants to make an RPC with high position resolution. 相似文献
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The effects of surface resistivity of the high voltage provider on the space dispersion of the induced charge of a prototype Resistive Plate Chamber (RPC) have been studied experimentally and theoretically. The results of both experiment and theory agree and confirm that a two-Gaussian function can be used to fit the dispersion of the induced charge of the RPC. It is shown that the Gaussian function with the narrower width is mainly due to the expansion of the avalanche charge in the gas gap of the RPC, and the Gaussian function with the larger width is due to the charge dispersion when it passes through the resistive carbon film. This will be useful in the RPC design when one wants to make an RPC with high position resolution. 相似文献
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An optical filter is employed to transport a 15-ns light pulse from a high power ruby laser for precise triggering of a gas filed high voltage spark gap. The maximum power density that can be transmitted by the fiber is limited to 6 × 1012 W/m2 above which laser induced damage occurs on the fiber entrance face. The overall throughput efficiency of the optical system was measured as 62 percent. Results are presented for the switching delay time and associated jitter for various mixtures of A and N2 gas, and as a function of the voltage across a pulse-charged Blumlein generator gap. Pulse charging of the Blumlein generator was accomplished by a three-stage Marx generator, resulting in output voltages up to 250 kV. It was conclusively demonstrated that an optical fiber will transport a sufficiently intense laser pulse to evince subnanosecond jitter in the triggering of a pressurized gas switch under the conditions studied. 相似文献