Laboratory reflectometer for the investigation of optical elements in a wavelength range of 5–50 nm: description and testing results

Journal Article · Mon May 01 00:00:00 EDT 2017 · Quantum Electronics (Woodbury, N.Y.)

DOI:https://doi.org/10.1070/QEL16300· OSTI ID:22726017

Garakhin, S. A.; Zabrodin, I. G.; Zuev, S. E.; Kas’kov, I. A.; Lopatin, A. Ya.; Nechay, A. N.; Polkovnikov, V. N.; Salashchenko, N. N.; Tsybin, N. N.; Chkhalo, N. I.; Svechnikov, M. V.

We describe a laboratory reflectometer developed at the IPM RAS for precision measurements of spectral and angular dependences of the reflection and transmission coefficients of optical elements in a wavelength range of 5–50 nm. The radiation is monochromatised using a high-resolution Czerny–Turner spectrometer with a plane diffraction grating and two spherical collimating mirrors. A toroidal mirror focuses the probe monochromatic beam on a sample. The X-ray source is a highly ionised plasma produced in the interaction of a high-power laser beam with a solid target at an intensity of 10{sup 11}–10{sup 12} W cm{sup –2}. To stabilise the emission characteristics, the target executes translatory and rotary motions in such a way that every pulse irradiates a new spot. The short-focus lens is protected from contamination by erosion products with the use of a specially designed electromagnetic system. The samples under study are mounted on a goniometer is accommodated in a dedicated chamber, which provides five degrees of freedom for samples up to 500 mm in diameter and two degrees of freedom for a detector. The sample mass may range up to 10 kg. The X-ray radiation is recorded with a detector composed of a CsI photocathode and two microchannel plates. A similar detector monitors the probe beam intensity. The spectral reflectometer resolution is equal to 0.030 nm with the use of ruled gratings with a density of 900 lines mm{sup –1} (spectral range: 5–20 nm) and to 0.067 nm for holographic gratings with a density of 400 lines mm{sup –1} (spectral range: 10–50 nm). We analyse the contribution of higher diffraction orders to the probe signal intensity and the ways of taking it into account in the measurements. Examples are given which serve to illustrate the reflectometer application to the study of multilayer mirrors and filters. (paper)

• OSTI ID: 22726017
• Journal Information: Quantum Electronics (Woodbury, N.Y.), Vol. 47, Issue 4; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-7818
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACCURACY
BEAMS
CONTAMINATION
DEGREES OF FREEDOM
DENSITY
DIFFRACTION GRATINGS
GONIOMETERS
LASER TARGETS
MICROCHANNEL ELECTRON MULTIPLIERS
MONOCHROMATIC RADIATION
PHOTOCATHODES
PROBES
REFLECTION
RESOLUTION
SPECTROMETERS
SPHERICAL CONFIGURATION
TRANSMISSION
WAVELENGTHS
X-RAY SOURCES