Observation of the plasma channel dynamics and Coulomb explosion in the interaction of a high-intensity laser pulse with a He gas jet

Authors

G.S. Sarkisov, P. N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow, Russia
V. Yu. Bychenkov, P. N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow, Russia
V.T. Tikhonchuk, P. N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow, Russia
Anatoly Maksimchuk, University of MichiganFollow
Shouyuan Chen, University of Michigan, Ann ArborFollow
R. Wagner, University of Michigan, Ann Arbor
G. Mourou, University of Michigan, Ann Arbor
Donald P. Umstadter, University of Nebraska-LincolnFollow

Date of this Version

12-25-1997

Comments

Published by Interperiodica. JETP-Letters, 66, 828-34 (1997); translated from Pis’ma Zh. Eksp. Teor. Fiz. 66, 787-92 (1997). HREF="http://www.maik.rssi.ru/cgi-bin/journal.pl?name=jetplet&page=main "http://www.maik.rssi.ru/cgi-bin/journal.pl?name=jetplet&page=main Published by Am Inst Physics.

Abstract

We report the first interferometric observations of the dynamics of electron–ion cavitation of relativistically self-focused intense 4 TW, 400 fs laser pulse in a He gas jet. The electron density in a channel 1 mm long and 30 mm in diameter drops by a factor of approximately 10 from the maximum value of ~8x10¹⁹ cm²³. A high radial velocity of the plasma expansion, ~3.8x10⁸ cm/s, corresponding to an ion energy of about 300 keV, is observed. The total energy of fast ions is estimated to be 6% of the laser pulse energy. The high-velocity radial plasma expulsion is explained by a charge separation due to the strong ponderomotive force. This experiment demonstrates a new possibility for direct transmission of a significant portion of the energy of a laser pulse to ions.