Plasma formation and target preheating by prepulse of PW laser light

POSTER

Abstract

An intense short pulse laser with intensity over $10^{21}$ W/cm$^2$ has become available, i.e. J-KAREN-P at QST. Although the contrast of the short pulse is improved to be of the order of $10^{-11}$, there is an unavoidable prepulse, which has multiple spikes (~ ps) on top of an exponential profile with intensity greater than $10^{14}$ W/cm$^2$ about 50 ps in front of the main pulse. The prepulse preheats the target and also produces tenuous plasmas in front of a target before the main pulse arrives. It is critical to understand such preheating of the target, where the nonlocal heat transport is essential at intensity $> 10^{14}$ W/cm$^2$, since the target condition might totally change before the interaction with the main pulse. Using a hydro code, FLASH, and a collisional particle-in-cell code, PICLS, we study the preplasma formation and target preheating over tens of picoseconds timescale, and discuss the prepulse effects on the main pulse interaction.

Authors

  • Yasuhiko Sentoku

    Institute of Laser Engineering, Osaka University, Osaka, Japan., Institute of Laser Engineering, Osaka University, Osaka, Japan, ILE, Osaka University, Institute of Laser Engineering, Osaka University, Osaka Univ., Univ. of Nevada, Reno, USA

  • Natsumi Iwata

    Institute of Laser Engineering, Osaka University, ILE, Osaka University

  • James Koga

    National Institutes for Quantum and Radiological Science and Technology, National Institutes for Quantum and Radiological Science and Technology (QST), Natl Inst for Quantum & Radiological Science & Tech (QST)

  • Nicholas Dover

    National Institutes for Quantum and Radiological Science and Technology (QST)

  • Mamiko Nishiuchi

    National Institutes for Quantum and Radiological Science and Technology (QST)