@misc{oai:repo.qst.go.jp:00066965,
 author = {Namba, S. and 岸本, 牧 and John C. and Kakunaka, N. and Matsumoto, Y. and 長谷川, 登 and 錦野, 将元 and Higashiguchi, T. and Ejima, T. and Sunahara, A. and Johzaki, T. and 岸本 牧 and 長谷川 登 and 錦野 将元},
 month = {Nov},
 note = {Water window (WW) soft X-ray (wavelength: 2.3-4.4 nm) is a suitable light source for observing nanometer-size structure of living cells and bio-molecules. Although laser produced plasma has been expected as a bright and short 
pulse X-ray source, the conversion efficiency from driving laser pulse energy to WW radiation is far below 1%, which hinders the realization of a compact and low-cost X-ray microscope. 
Recently, it was found that the WW radiation increased, when an Au target was irradiated by the GEKKO XII laser (1053 nm, 500 ps, 120 J) under low-pressure nitrogen atmospheres up to 400 Pa. 
However, the fact that the laser facility is huge and its repetition rate is very low makes it impossible to apply this X-ray source to the microscope. In order to realize the practical microscope capable of reducing size and cost, The bright X rays generated with a joule class pulsed laser with a high repetition rate is essential. 
Therefore, under N2 atmospheres we measured the WW spectra emitted from Au plasma generated with a commercial nanosecond laser with a low-output energy and 10Hz-repwtition., 2nd Asia-Pacific Conference on Plasma Physics (AAPPS-DPP2018)},
 title = {Anomalous enhancement of water window X-rays emitted from laser produced Au plasma under low-pressure nitrogen atmosphere},
 year = {2018}
}