共查询到19条相似文献,搜索用时 78 毫秒
1.
考虑电子的相对论效应,根据电磁学理论和相对论公式建立了电子磁谱仪的原理;按照该原理设计了电子的磁谱仪,用补偿磁路改善了磁场的均匀性;按照磁谱仪的结构对其进行了测试和标定;以LiF热释光探测器作为记录元件,可获得相对论电子的能量分布.实验上典型的测量结果与国外计算机模拟的结果较好地一致,从而证明电子磁谱仪的可靠性. 相似文献
2.
3.
4.
5.
6.
7.
8.
9.
10.
用平场光栅谱仪现场标定5FW X光底片 总被引:2,自引:1,他引:1
采用像散模式的平场光栅谱仪作为分光元件,点状镁激光等离子体X射线源为原始光源,获得均匀线性单色较X射线再生源,在此基础上,用多阶梯衰减膜为相对曝光强度标尺,现场标定了上海感光胶片厂生产的5FW无保护膜X光底片,给出了5.0nm~8.0nm间的底片响应特性。 相似文献
11.
We demonstrated the interaction of a gold cone target with a femto second(fs) laser pulse above the relativistic intensity of 1.37×10 18 μm 2 W/cm 2.Relativistic electrons with energy above 2 MeV were observed.A 25%-40% increase of the electron temperature is achieved compared to the case when a plane gold target is used.The electron temperature increase results from the guiding of the laser beam at the tip and the intense quasistatic magnetic field in the cone geometry.The behavior of the relativistic electrons is verified in our 2D-PIC simulations. 相似文献
12.
S Chakraborty 《Pramana》1985,25(3):275-280
A theoretical study of theL-shell ionization of atoms by relativistic electrons is made for atomic numbers in the range 47 to 92. A new potential model
recently proposed by Das and Chakraborty dealing with atomic screening effect in a better way has been used. The results are
in satisfactory agreement when compared with some available experimental results and also with the theoretical results of
Scofield. 相似文献
13.
光子与相对论麦克斯韦分布电子散射的描述及能谱角度谱计算非常复杂且费时.本文提出了一种光子与相对论麦克斯韦速度分布电子散射的蒙特卡罗(MC)模拟方法,该方法能够细致模拟高温等离子体中任意能量光子与任意温度电子的Compton和逆Compton散射问题.对于散射后光子的能谱和角度谱参数,可以根据电子温度抽样若干不同状态的电子,分别模拟其与光子发生散射,可以得到各次散射后的光子能量和偏转角度,取统计平均后的结果即可获得该光子与该温度电子散射的能谱和角度谱分布.根据该方法编写了光子与相对论电子散射MC模拟程序,开展了高温全电离等离子体中光子与相对论电子散射的能谱角度谱计算和分析,分析结果显示:热运动电子将展宽出射光子能谱,且低能光子与高温电子散射后的蓝移现象明显;出射光子的角度谱很复杂,其决定于入射光子能量、出射光子能量及电子温度.基于该方法计算并以数表形式给出的光子-相对论电子散射能谱角度谱数据,可以供辐射输运数值模拟程序使用. 相似文献
14.
15.
The triple differential cross-section for K-shell ionization of silver and copper atoms by relativistic electrons have been
computed in the coplanar symmetric geometry with the inclusion of exchange effects following the multiple scattering theory
of Das and Seal [1] multiplied by suitable spinors. Present computed results are marginally improved in some cases from the
previous computed results [2]. Present results are compared with measured values [3] and with previous computation results
[2]. Some other theoretical computational results are also presented here for comparison.
相似文献
16.
The magnetic proton recoil(MPR)spectrometer is a novel diagnostic instrument with high perfor-mance for measurements of neutron spectra in inertial confinement fusion(ICF)experiments and high power fusion devices.A compact MPR-type spectrometer dedicated to the research of pulsed deuterium-tritium(DT)neutron spectroscopy of special experimental conditions is currently under design.Analyses of the main parameters and performance of the magnetic analysis system through 3-D particle transport calculations and MonteCarlo simulations and calibration of the system performance as a test using CR-39 solid track detector and α particle from 239pu and 226Ra radioactive sources are presented in this paper.The results indicate that the magnetic analysis system will achieve a detection efficiency level of 10-5-10-4 at an energy resolution of 1.5%-2.1%,and fulfills the design goals of the spectrometer. 相似文献
17.
The magnetic proton recoil(MPR)spectrometer is a novel diagnostic instrument with high perfor-mance for measurements of neutron spectra in inertial confinement fusion(ICF)experiments and high power fusion devices.A compact MPR-type spectrometer dedicated to the research of pulsed deuterium-tritium(DT)neutron spectroscopy of special experimental conditions is currently under design.Analyses of the main parameters and performance of the magnetic analysis system through 3-D particle transport calculations and MonteCarlo simulations and calibration of the system performance as a test using CR-39 solid track detector and α particle from 239pu and 226Ra radioactive sources are presented in this paper.The results indicate that the magnetic analysis system will achieve a detection efficiency level of 10-5-10-4 at an energy resolution of 1.5%-2.1%,and fulfills the design goals of the spectrometer. 相似文献
18.
19.
Stability and instability of relativistic electrons in classical electromagnetic fields 总被引:3,自引:0,他引:3
Elliott H. Lieb Heinz Siedentop Jan Philip Solovej 《Journal of statistical physics》1997,89(1-2):37-59
The stability of matter composed of electrons and static nuclei is investigated for a relativistic dynamics for the electrons
given by a suitably projected Dirac operator and with Coulomb interactions. In addition there is an arbitrary classical magnetic
field of finite energy. Despite the previously known facts that ordinary nonrelativistic matter with magnetic fields, or relativistic
matter without magnetic fields, is already unstable when a, the fine structure constant, is too large, it is noteworthy that
the combination of the two is still stableprovided the projection onto the positive energy states of the Dirac operator, whichdefines the electron, is chosen properly. A good choice is to include the magnetic field in the definition. A bad choice, which always
leads to instability, is the usual one in which the positive energy states are defined by the free Dirac operator. Both assertions
are proved here.
This paper is dedicated to Bernard Jancovici on the occasion of his 65th birthday. 相似文献