Reserch of Ultra-High Gradient Laser-Plasma Accelerator

与东京大学和日本原子能研究所合作，研究了激光与等离子体相互作用和激光加速直线加速器试验光束。采用东京大学电子直线加速器的KEK T-CUBE激光器。在这些研究的基础上开展了国际合作。此外，还与BNL合作研制了激光-阴极枪，在激光-等离子体相互作用的研究中取得了一些新的发现：光通道的形成、入射激光的反常蓝移和气体射流的形成。它们很难用现有的理论来解释。来自俄罗斯和美国的游客进行了分析和模拟研究，为了加速直线加速器光束，必须使皮秒直线加速器光束和飞秒激光光束同步。BNL和LBL的经验有助于建立这一技术。在加速实验中，观察到了300 MeV的能量增益，远远大于假设衍射限制加速长度的预测。为了弄清其物理机制，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波场探测器，激光阴极枪由我们设计并由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.