Experiments on Characteristics and Control of Positron Plasma

经过3年的实验研究，成功形成了正电子等离子体。得到了以下结果：1。通过将研制的“光子-正电子转换器”与大电流linac相结合，以6 × 10^<10> [e+/s]的时间平均产率产生了慢正电子。正电子等离子体是用低温固体氩膜将脉冲慢正电子叠加而成的。提出了一种新的捕获慢正电子的结构，它由许多环形电极组成。稳定的刚性转子等离子体可以被限制在封闭的电位池中。利用高磁场下的回旋辐射冷却得到冷正电子等离子体。从3.7 MBq的22Na中产生的正电子首先被冷电子缓和，并在陷阱中堆叠超过10^4s。由此，在室温下7t磁场下形成了正电子等离子体。在球形非中性等离子体中发现了不同静电波模式之间的非线性模式转换，并观察到射频电场对二极管振荡的抑制作用。

Positron plasmas were successfully formed through experimental research for three years. The following results have been obtained.1.Slow positrons were generated at a time-average production rate of 6x10^<10> [e+/s] by combining a developed "Photon-Positron Converter" and a high current LINAC.2.Positron plasmas were formed by stacking pulsed slow positrons moderated with a cryogenic solid Ar film.3.A new configuration for trapping slow positrons was developed, which consists of a lot of ring electrodes. A stable rigid rotor plasma can be confined in a closed potential cell.4.Cyclotron radiation cooling in a high magnetic field was applied to get a cold positron plasma. Positrons emerging from 22Na of 3.7 MBq were first moderated by cold electrons and stacked in the trap for longer than 10^4s. Thereby, positron plasmas at room temperature in the magnetic field of 7 T were formed.5.Nonlinear mode-conversions among different electrostatic wave modes were found for spheroidal nonneutral plasmas, and also suppression of diocotron oscillations by rf-electric fields was observed.