Wavelength determination of curved spectral lines with planar crystal spectrometer

For the need of X-ray wavelength determination of laser plasma, a novel method was presented for wavelength determination by using curved spectral line measured with planar crystal spectrometer. In normal reference line method, the wavelength of more than two reference lines should be determined before wavelength determination. By using curved spectral line method, no reference line was used to determine wavelength. In this paper, curved image of Heα self-emission spectrum of aluminum plasma was recorded in experiment, and the uncertainty of this method using the present spectrometer was about 2 × 10^-4 nm in theory. (authors)