title: Excitation wavelength dependence of water-window line emissions from boron-nitride laser-produced plasmas.
abstract: We investigated the effects of laser excitation wavelength on water-window emission lines of laser-produced boron-nitride plasmas. Plasmas are produced by focusing 1064 nm and harmonically generated 532 and 266 nm radiation from a Nd:YAG laser on BN target in vacuum. Soft x-ray emission lines in the water-window region are recorded using a grazing-incidence spectrograph. Filtered photodiodes are used to obtain complementary data for water-window emission intensity and angular dependence. Spectral emission intensity changes in nitrogen Ly-α and He-α are used to show how laser wavelength affects emission. Our results show that the relative intensity of spectral lines is laser wavelength dependent, with the ratio of Ly-α to He-α emission intensity decreasing as laser wavelength is shortened. Filtered photodiode measurements of angular dependence showed that 266 and 532 nm laser wavelengths produce uniform emission.
authors.forename: M
authors.initials: M
authors.lastname: Crank
authors.forename: S S
authors.initials: SS
authors.lastname: Harilal
authors.forename: S M
authors.initials: SM
authors.lastname: Hassan
authors.forename: A
authors.initials: A
authors.lastname: Hassanein