Temperature and anisotropic-temperature relaxation measurements in cold, pure-electron plasmas
Temperature and anisotropic-temperature relaxation measurements in cold, pure-electron plasmas
复制标题
冷纯电子等离子体中的温度和各向异性温度弛豫测量
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
J. Malmberg
中科院分区：
文献类型：
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作者：
B. Beck;J. Fajans;J. Malmberg
用低温、超高真空、纯电子等离子体陷阱测量了25~2×106K的等离子体温度。在28~3.8×105K和20~60νkg磁场范围内，测量了平行和垂直于外加磁场的温度松弛到公共值的速率 。这个速率ν与等离子体碰撞频率密切相关。当回旋半径Rc大于经典的最接近距离b(Rc/b≫1)时，ν的实测值与传统的碰撞理论相一致。当回旋半径小于经典的最接近距离(Rc/b≪1)时，ν随Rc/b的减小而急剧下降，这与O‘Neil和Hjorth的多电子绝热不变量理论相一致。
Plasma temperatures in the range 25 to 2×106 K have been measured using a cryogenic, ultra‐high vacuum, pure‐electron plasma trap. The rate ν at which the temperatures parallel and perpendicular to the applied magnetic field relax to a common value has been measured over the temperature range 28 to 3.8×105 K and the magnetic field range 20 to 60 kG. This rate ν is closely related to the plasma collision frequency. When the cyclotron radius rc is large compared to the classical distance of closest approach b (rc/b≫1), the measured values of ν are in agreement with conventional collision theory. When the cyclotron radius is small compared to the classical distance of closest approach (rc/b≪1), ν drops precipitously as rc/b is decreased, in agreement with the many‐electron adiabatic invariant theory of O’Neil and Hjorth.