J. Phys. IV France 11 (2001) Pr2-225-Pr2-231
Study of innershell photo-ionization-pumped L23M1 transition in Ca for the development of femtosecond X-ray laserD. Kim1, S.H. Son1, J.H. Kim1, Cs. Toth2 and C.P.J. Barty2
1 Pohang University of Science and Technology, Pohang 790-784, Republic of Korea
2 University of California, San Diego, La Jolla, CA 92093-0339, U.S.A.
A new physical scheme for femtosecond X-ray lasers, where the upper lasing is pumped by X-ray photons and the lower lasing level is depopulated via a Coster-Kronig radiationless transition, is analyzed for Ca. The transition wavelength is 4.1 nm, which is inside the water window. The peak spectral brightness of the X-ray laser output at 4.1 nm is predicted to be as large as 5 x l025 photons/sec./(mm2 mrad2 0.1% bandwidth), which is 4 to 5 orders of magnitude brighter than a typical undulator radiation in the similar spectral region. In addition to the high flux, the expected duration of X-ray lasing of ~ 3 fs. will be useful for the study of fast dynamics in physical and biological sciences.
© EDP Sciences 2001