3D characterization of thin glass x-ray mirrors via optical profilometry

Abstract

In this paper we present the "Characterization Universal Profilometer" (CUP), a new metrological instrument developed at the Brera Observatory for the 3D surface figure mapping of X-ray segmented mirrors. The CUP working principle is based on the measure of the the distance between the surface under test from a rigid reference dish. This approach is made possible by the coupled use of two sensors, the CHRocodile® optical device and the SIOS triple beam interferometer, mounted onto a proper system of x-y-z stage of translators. In this paper we describe the working principle of the new instrument. We will also present the results of the commissioning performed for a CUP breadboard developed at the Brera Observatory. The CUP offers the possibility to perform an high accuracy metrology of thin glass segments produced via hot slumping, to be used in future segmented X-ray mirrors like those foreseen aboard IXO or other projects that will make use of active X-ray mirrors.

X-ray optical units made of glass: achievements and perspectives

“…With respect to the final X-ray calibration, the 20 meters focal length of the model posed some constrain in the facility schedule, as an extension of the normal set-up has to be mounted [12]. Intra-focal measurements have been performed in 2013 and results have been reported in [13]. In-focus measurements were not possible for PoC#2 up to beginning of 2014. .…”

“…The metrology of the integrated glass is performed with the CUP [13] available at INAF/OAB. As a consequence of the stacking procedure, the external layer is the only one accessible with our metrological device, which scans a square grid of points on the glass surface.…”

Design and manufacturing of a compact two-mirror system for multispectral imaging applications

“…Fig. 4B shows the mirror under characterization by the optical profilometer [3] after the grinding. At this stage, the surface was not yet of optical grade and appeared opaque.…”

“…Our solution consists in a very compact two-mirror telescope, designed to meet the strict payload requirements for airborne remote sensing of environment. The overall system needs to be included into a maximum volume of 200 x 200 x 300 mm 3 , which is the volume allowance for payloads onboard the C-100 Vulcan, an ultralight aircraft considered as baseline aerial platform for the project. In parallel to the volume constraint, we optimized the weight of the telescope, by designing the rigid structure that supports and integrates the optics and the imaging sensor systems.…”

Direct hot slumping of thin glass foils for future generation x-ray telescopes: current state of the art and future outlooks

“…The slumped glasses are characterized in shape with a Long Trace Profilometer for 1-D profiles and with the Characterization Universal Profilometer (CUP), developed at our laboratories, for 2-D maps [3]. Moreover, their surface roughness is characterized with an Atomic Force Microscope (AFM), a WYKO Phase Shift Interferometer and a Micro-Finish Topographer (MFT) [4].…”