Optimum design of a grazing-incidence flat-field spectrograph with a spherical varied-line-space grating

Abstract

A grazing-incidence spectrograph is designed by use of the flat-field image-focusing property of a spherical varied-line-space grating. Optimum grating parameters for mechanical ruling are selected by application of genetic algorithms. Two gratings, one for 2-5-nm and the other for 5-20-nm spectral regions, are designed, and their fabrication tolerances are analyzed.

Tungsten spectroscopy in the EUV range observed at a high-temperature superconducting electron-beam ion trap

“…Due to the aluminum L absorption edge, only wavelengths longer than 171Å can pass through this foil. For the present experiment, a Shimazdu varied-line-spacing (VLS) grating (1200 L/mm, part number 001-0659) [19][20][21] was used, and an Andor CCD camera (model number DO936N-00W-#BN) was placed at different positions to record different wavelength regions. Tungsten ions were obtained by injecting W(CO) 6 , a volatile compound with a high vapor pressure at room temperature [22].…”

Spectrograph for solar imaging in the XUV domain

“…The free parameters are: the incidence angle on the parabolic and hyperbolic mirrors p2 , h2 , the separation between these two optics , and the exit arm p". The connections between these four driving parameters and the other parameters of the telescope are provided by (1)(2)(3)(4)(5). In these equations, and are the angles formed with the optical axis respectively by the central ray between the two mirrors and by the central ray on the focal plane, p' is the virtual entrance arm of the hyperbolic mirror, fp and fh are the focal lengths respectively of the parabolic and hyperbolic mirrors.…”

“…The core of the spectrograph is a spherical variable-line-spaced (SVLS) grating giving a focal surface nearly perpendicular to the optical path [4,5]. As a consequence of this, the length of the exit arm of the spectrograph is nearly constant, therefore it is possible to correct for the astigmatism with an auxiliary optics.…”

A new compact soft x-ray spectrometer for resonant inelastic x-ray scattering studies at PETRA III

“…The groove spacing, σ(w), as the function of the position w along the grating is given by 30 ( ) = , (1) where 0 is the groove spacing at the center of the grating, R is the radius of curvature and b 2 , b 3 , b 4 , can be chosen to zero the defocus, coma, and spherical aberrations, respectively. The parameters of the grating given by the manufacturer are = 57680 , 2 = −95.97, 3 = 9.492 × 10 3 and 4 = −9.78 × 10 5 .…”