Compact high-resolution monochromators for the wavelength range of 110–160 Å

Abstract: We consider monochromators designed for operation with a point-like soft X-ray laser-plasma radiation source and intended for characterizing mirrors and other X-ray optical elements, including multilayer X-ray optics. Three compact (∼0.6 m) high-resolution monochromators are calculated: a Hettrick–Underwood scheme with a plane VLS grating for the range from 110 to 160 Å, a single-element monochromator with a translatable plane VLS grating (120–155 Å), and a single-element monochromator with a classical spherical Rowland grating (110–160 Å). The spectral resolution of the configurations is assessed using numerical ray tracing. The capabilities of these monochromators are compared with the capabilities of monochromators using the three-element Czerny–Turner scheme. The “throughput” factor is used as a comparative criterion (figure of merit), provided that the spectral resolving power is sufficiently high (conventionally λ/δλ∼500 or higher).

Keywords: soft X-rays, laser-produced plasma, reflectometer, VLS monochromator, resolving power, Hettrick–Underwood scheme, single-element monochromator, Czerny–Turner monochromator, Rowland grating monochromator.

Received: 23.07.2023
Revised: 18.10.2023