T. Yamanaka

Fast heating of super-solid density plasmas towards laser fusion ignition

We have studied fast heating of highly compressed plasmas using multi 100 TW laser light. Efficient propagation of the ultra-intense laser light and heating of the imploded plasmas were realized with a cone-attached shell target. Energy deposition rate of the ultra-intense laser pulse into high-density plasmas was evaluated from neutron measurements. Generation and propagation property of energetic electrons in the ultra-intense laser interactions were also investigated with solid density targets. About 40% of the laser energy converted to mega electron volts energetic electrons in the interactions with solid targets at intensities of 10 19 W cm -2 . These electrons propagated in the high-density plasmas with a divergence of 20-30° or jet-like collimation. Taking account of these experimental results, heating laser spot size is optimized for laser fusion ignition with a simple estimation.

Development of front-end-system using optical parametric chirped pulse amplification for PW glass laser system

Summary form only given. The technique of chirped pulse amplification (CPA) in a laser system has realized ultra-short pulse generation for high intensity interaction. This technique on large scale Nd:glass laser systems at a 1053-nm wavelength has enabled the production of pulse powers that exceed 1 PW with pulse duration of several hundred fs, and focusable intensities that exceeds 10/sup 21/ W/cm/sup 2/. We have been developing the front-end-system in the PW laser system to generate appropriate chirped pulses. We present the experimental study on a stable high gain OPCPA (optical parametric chirped pulse amplifier) system which will be used as a pre-amplifier to replace the regenerative amplifier and multi-pass amplifier in Ti:Al/sub 2/O/sub 3/ laser system at 1 /spl mu/m.

Broadband high-gain pre-amplifier based on OPCPA for PW laser system

A broadband high-gain pre-amplifier using optical parametric chirped pulse amplification in the PW glass laser system has been developed. The output energy of 20 mJ without gain narrowing was obtained in a single pass through two BBO-OPCPA systems with good output stability.

Petawatt laser for fast ignitor and laser matter interaction research

The worlds biggest petawatt laser is constructed for research of the fast ignitor and related ultraintense laser matter interactions above 10/sup 20/ W/cm/sup 2/. The recent experiments of the fast ignitor are also presented.