Reserch of Ultra-High Gradient Laser-Plasma Accelerator

与东京大学和日本原子能研究所合作，研究了激光-等离子体相互作用和激光加速直线试验光束。采用东京大学的KEK t立方激光器和电子直线加速器。在这些研究的基础上开展了国际合作。此外，还与BNL合作开发了激光阴极枪。在激光等离子体相互作用的研究中有了新的发现；它们是光通道的形成、入射激光的异常蓝移和气体射流的形成。现有的理论很难解释它们。来自俄罗斯和美国的参观者进行了分析和模拟研究。为了加速直线激光束，我们必须同步皮秒直线激光束和飞秒激光束。BNL和LBL的经验有助于该技术的建立。在加速实验中，观测到的能量增益为300MeV，远远大于假设衍射限制加速长度的预测。为了弄清物理机制，我们正在尝试由德克萨斯大学和巴黎大学的同事开发的尾流场检测。激光阴极枪由我们设计，由BNL-UCLA团队加工。

Laser-plasma interaction and acceleration of linac test-beams by the laser was studied in collaboration with Tokyo University and Japan Atomic Energy Research Institute. A KEK T-cube laser ana an electron linac of Tokyo University were used. International collaboration has been carried out based on these studies. Besides this, laser-cathode guns have been developed under the cooperation with BNL.There discoveries were made in the study of laser-plasma interaction ; they are formation of optical channel, anomalous blue shift of incident lasers and gas jet formation. They are hard to explain by the existing theory. Analytical and simulation studies were made by visitors from Russia and US.In order to accelerate the linac beams, we have to synchronize the picosecond linac beams and femtosecond laser beams. Experiences of BNL and LBL were helpful in establishing this technique.In the acceleration experiments, an energy gain of 300MeV was observed, which is far larger than the prediction assuming the diffraction-limited acceleration length. In order to clarifty the physical mechanism, we are now trying the wakefield detection developed by the colleagues of University of Texas and University of Paris.The laser cathode guns were designed by us and machined by BNL-UCLA team.