Author/Authors :
Kato، نويسنده , , M. and Saito، نويسنده , , N. and Tanaka، نويسنده , , T. and Morishita، نويسنده , , Y. and Kimura، نويسنده , , H. and Ohashi، نويسنده , , H. and Nagasono، نويسنده , , M. and Yabashi، نويسنده , , M. and Tono، نويسنده , , K. and Togashi، نويسنده , , T. and Higashiya، نويسنده , , A. and Ishikawa، نويسنده , , T.، نويسنده ,
Abstract :
The pulse energy of an extreme-ultraviolet free-electron laser (EUV-FEL) has been directly measured using a cryogenic radiometer installed in an experimental station. The laser provided 21.0, 18.0, and 19.5 μ J / pulse at wavelengths of 51, 55, and 61 nm, respectively. The contribution of higher harmonics was estimated by measuring the attenuation of the average pulse energy with increasing Ar gas pressure in a gas cell. The ratio of the intensity of the higher harmonics to that of the fundamental was estimated to be about 1%.
Keywords :
Free-electron laser , Pulse energy , Cryogenic radiometer , Higher-order harmonics
