J. Phys. IV France 11 (2001) Pr2-193-Pr2-196
Ultrahigh-gain Ni-like Kr soft X-ray laser by optical-field-induced-ionization initiated transient excitation schemeY. Nagata1, O. Maya2, M. Obara2, Y. Aoyagi1 and K. Midorikawa1
1 RIKEN, The Institute of Physical and Chemical Research, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
2 Department of Electronics and Electrical Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku, Yokohama 223-8522, Japan
We propose a novel transient collisional excitation scheme for Ni-like Kr (4d1S0-4p1P1) soft-x-ray laser at 32.8 nm. In this scheme, Kr atoms in a differentially pumped cell are longitudinally pumped by a picosecond Nd : glass laser pulse with a focal intensity of [MATH]. Almost 100% of the Ni-like Kr ions are produced by optical-field-ionization, and the ps-pulse efficiently heats the Kr plasma by inverse bremsstrahlung. Numerical calculations predict that an ultrahigh-gain of greater than 1200 cm-1 is possible for the Ni-like Kr transition at 32.8 nm. Preliminary experimental results are also reported.
© EDP Sciences 2001