Plasma simulator on distributed computers and its application to microplasma studies

在本研究计划中，我们研究并发展了一个等离子体模拟器用于微等离子体模拟。此外，我们还在以下几个研究领域中试图了解微等离子体物理并寻找微等离子体控制方法。利用微等离子体模拟器对激光粒子加速、惯性聚变等离子体约束、激光等离子体产生辐射等进行了研究。通过使用微等离子体模拟器，用户可以在分布式计算机上通过WEB浏览器进行模拟。用户无需了解分布式计算机的详细信息就可以通过微等离子体模拟器提交任务并检索结果。在微等离子体模拟器中，还开发了电磁粒子单元代码、流体代码和Vlasov代码。在激光电子加速中，采用TEM（1，0）+（0，1）模激光产生高密度短脉冲（阿托秒）电子束。在TEM（1，0）+（0，1）模激光作用下，预加速电子被横向俘获，纵向压缩。采用强短脉冲激光产生准直质子束，在这项研究中，强短脉冲激光照射薄铝箔，它有许多孔在箔靶的后侧。利用该孔靶成功地产生了准直质子束。我们还提出了一种新的控制激光质子束能谱的方法，即采用附加的覆盖层。激光产生的准直离子束可用于离子治癌、材料加工等。在水下放电研究中，我们发现光电离是至关重要的。还产生了用于精细材料加工的毫米半径微等离子体射流。我们还成功地产生了太赫兹辐射，通过使用激光照射透明半导体。

In this research project, we have studied and developed a plasma simulator for microplasma simulations. In addition, we have tried to understand microplasma physics and to find a microplasma control method in the following research areas. We have also studied on laser particle acceleration, inertial fusion plasma confinement, radiation generation by laser produced plasma, etc by the microplasma simulator. By using the microplasma simulator users can perform simulations through a WEB browser on distributed computers. Without knowing detail information of the distributed computers users can submit their jobs and can retrieve results through the microplasma simulator. In the microplasma simulator an electromagnetic particle-in-cell code, a fluid code and a Vlasov code were also developed. In the laser electron acceleration a TEM (1,0)+(0,1) mode laser is employed to produce high-density short-pulse (atto second) electron beam. The pre-accelerated electors are trapped in transverse and compressed in longitudinal by the TEM (1,0)+(0,1) mode laser. An intense short pulse laser is employed to produce a collimated proton beam; in this study the intense short pulse laser illuminates a thin aluminum foil, which has many holes at the rear side of the foil target. By the tailored hole target a collimated proton beam was successfully produced. We have also proposed a new control method of laser-produced proton beam energy spectrum by employing an additional cover layer. The laser-produced collimated ion beam can be used for ion cancer therapy, material processing, etc. In a discharge study under water we found a photoionization is essentially important. A mm-radius microplasma jet was also produced for a fine material processing. We have also succeeded to produce a THz radiation by using a laser-illuminated transparent semiconductor.