The paper describes a wide-angle collimator based on a “Schmidt camera” mirror design, which is intended for resolution measurements of a telescope operating in the 120- to 380-nm wavelength range. The collimator consists of a test pattern, a spherical mirror, and a mirror wavefront corrector (planoid) compensating for spherical aberration and astigmatism. The test pattern is shifted from the optical axis of the collimator using a flat mirror. The main parameters of the device are as follows: working area diameter of the test pattern, 30 mm; aperture ratio, F/3.2; exit pupil diameter, 250 mm; angular resolution measured in “white light,” 1.4 arc sec; and field of view, 2ω=3 deg. The results of the angular resolution measurements of a two-channel Schmidt–Cassegrain mirror telescope, obtained with the use of the collimator, are given.
In the paper is studied the main aspects of using ion-beam etching for finish polishing. It is found that 400 eV is the optimal energy for neon ion etching ensuring slight surface roughness smoothing in the range of incidence angles of ± 40°. The deposition of 200 nm amorphous silicon films onto beryllium and their subsequent etching with the 800 eV argon ions improve the effective surface roughness integrated across the range of the spatial frequencies of 0.025-60 μm-1, from σeff=1.37 nm down to σeff=0.29 nm. The effectiveness of the smoothing technology for x-ray applications, confirmed by the results of the study the reflective properties of the Mo/Si mirrors deposited on the substrate. The reflectivity at a wavelength of 13.5 nm increased from 2% for the substrates with the surface roughness of σeff=2.3 nm (the roughness value corresponds to the as-prepared bulk Be substrates and is taken from the literature) up to 67.5% after the smoothing technology.
We present a laboratory high-aperture monochromator-reflectometer employing laser-plasma radiation source and three replaceable Schwarzschild objectives for a certain range of applications in the soft X-ray spectral waveband. Three sets of X-ray multilayer mirrors for the Schwarzschild objectives enable operation of the reflectometer at the wavelengths of 135, 171 and 304 Å, while a goniometer with three degrees of freedom allows different measurement modes. We have used the facility for a laboratory CCD calibration at the wavelengths specified. Combined with the results of the CCD sensitivity measurements conducted in the VUV spectral waveband, the total outcome provides a more comprehensive understanding of the CCD effectivity in a wide spectral range.
The work is devoted to the method of mounting and surface shape measurement of the primary mirror of ARCA telescope, intended for the Sun observation in EUV wavelength range. Calculation of mirror’s deformation due to weight is carried out and a method of its experimental determination in interferometer is proposed. The method of deformation-free installation of mirror into the telescope is proposed. Impact shocks and vibrations, arising during missile launch, is analyzed, and an optimal size of bridges in the rim is determined. Calculations of the mirror deformation due to temperature difference in the telescope on the Earth's orbit and its influence on the resolution of the telescope are conducted. The stresses arising in epoxy adhesive due to temperature changes and due to starting shocks are simulated.
Based on the analysis of the simplest circuit with a two-mirror objective, the potential performance of the lithographic process of a Maskless X-ray lithographer (MLXL) with a Xe X-ray source at a wavelength of 11.2 nm is consider. It is shown that at a laser power of 1 kW the performance of the lithographer may reach of 22 wafers with a diameter of 300 mm per hour. The main factors that affect the performance are analyzed, and directions for optimization MLXL optical circuit are discussed. Experimental results of studying the roughness and the surface shape, and the Mo / Si multilayer mirror reflectance deposited onto the surface of a commercially available micro-electro-mechanical system (MEMS) with a pixel size of 8 μm are presented. The reflection coefficient at a wavelength of 13.5 nm was about 3%. The reasons of low reflectance are discussed. The conclusion is that at the moment the creation of MEMS with improved characteristics is the key problem, the solution of which depends MLXL prospects.