Occurrence of half integral diffraction orders in XUV-soft X-ray spectra using a free-standing transmission grating

Article type: Research Article

Authors: Sailaja, S. | Naik, P.A. | Arora, V. | Gupta, P.D.

Affiliations: Plasma Radiation Section, Centre for Advanced Technology, Indore 452013, India.

Note: [] Corresponding author: S. Sailaja, Plasma Radiation Section, Laser R & D Block 'D', Centre for Advanced Technology, Indore, 452013, (M.P), India. Tel.: +91 731 488467; Fax: +91 731 488430; E-mail: [email protected].

Abstract: Effect of distortion in free-standing gold microstructure transmission gratings resulting in appearance of half integral orders in X-ray spectra is reported. XUV-soft X-ray spectra of moderate Z plasmas produced by 2GW, 4 ns/28 ns (FWHM), Nd: glass laser pulses showed low intensity peaks corresponding to half integral orders (up to m=7/2), in addition to the normal diffraction orders. These are explained to occur due to a symmetric distortion in the part of grating structure used, which leads to a periodicity in twice the grating period. Experimentally measured intensity ratios of different diffraction orders are consistent with the theoretical values calculated for the grating structure observed under a scanning electron microscope. This distortion, however, does not affect the spectral resolution of 0.6Å (in the first order) as expected and measured for the undistorted part of the grating structure.

Journal: Journal of X-Ray Science and Technology, vol. 8, no. 4, pp. 231-239, 1998