Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Fukuda, Yuji; Matsui, Ryutaro; Iwata, Natsuyo*; Kishimoto, Yasuaki
no journal, ,
In order to investigate the underlying physical mechanism of high power laser interaction with cluster medium, we have performed simulations using EPIC3D (Extended Particle based Integrated Code), which includes key atomic processes and relaxation processes self-consistently in fully relativistic three dimensional configuration, and systematically investigated the interaction processes of medium of carbon clusters embedded in helium gas. We found that the synergetic interplay of different mechanisms such as (1) acceleration of ions due to Coulomb explosion of individual carbon clusters, (2) compression and acceleration of background helium gas due to the Coulomb explosion of clusters, (3) magnetic vortex generation and associated pinching near the rare surface, and (4) sheath acceleration at the interface between the medium and vacuum, could play an important role in realizing the particle acceleration observed in the experiments.
Kado, Masataka; Ishino, Masahiko; Kishimoto, Maki; Tamotsu, Satoshi*; Yasuda, Keiko*; Shinohara, Kunio*
no journal, ,
Intense soft X-ray emissions are very useful for X-ray microscopy to observe living biological specimens. Increasing the photon flux in the range of wavelength 2.3 nm to 4.4 nm, so-called "water window", is a key issue for the soft X-ray microscopy. We have proposed to use ultra-thin foiled targets to limit the target mass to be heated by an intense pulsed laser. Thin foiled gold targets with various thicknesses from 10 nm to 50 
m were irradiated with an intense laser pulse at the wavelength of 1.053 m generated from a Nd:glass laser system with 20 J output energy in 600 ps pulse duration. The soft X-ray emissions from the laser-produced plasmas were measured with a soft X-ray spectrometer and a soft X-ray plasma camera. The X-ray flux increased as the target thickness decreased and reached the maximum at the target thickness of 20 nm. We have observed living biological cells with the soft X-ray emissions generated from the thin-foiled gold targets.