Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas,a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas.The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface.The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586,respectively.The spectrometer can be used to measure the X-ray lines in the wavelength range of 0.2-0.37 nm,and a LiF crystal(200)(2d = 0.4027 nm) is used as dispersive element covering Bragg angle from 30° to 67.5°.The spectrometer was tested on Shenguang-Ⅱwhich can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm.Photographs of spectra including the 1s2p 1P1-1s2 1S0 resonance line(w),the 1s2p 3P2-1s2 1S0 magnetic quadrupole line(x),the 1s2p 3P1-1s2 1S0 intercombination lines(y),the 1s2p 3S1-1s2 1S0 forbid-den line(z) in helium-like TiⅩⅪ and the 1s2s2p 2P3/2-1s22s 2S1/2 line(q) in lithium-like TiⅩⅩ have been recorded with a X-ray CCD camera.The experimental result shows that the wavelength resolution(λ/Δλ) is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.