Active x-ray optics for the next generation of x-ray telescopes

Abstract

The immediate future for X-ray astronomy is the need for high sensitivity, requiring large apertures and collecting areas, the newly combined NASA, ESA and JAXA mission IXO (International X-ray Observatory) is specifically designed to meet this need. However, looking beyond the next decade, there have been calls for an X-ray space telescope that can not only achieve this high sensitivity, but could also boast an angular resolution of 0.1 arc-seconds, a factor of five improvement on the Chandra X-ray Observatory. NASA's proposed Generation-X mission is designed to meet this demand; it has been suggested that the X-ray optics must be active in nature in order to achieve this desired resolution. The Smart X-ray Optics (SXO) project is a UK based consortium looking at the application of active/adaptive optics to both large and small scale devices, intended for astronomical and medical purposes respectively. With Generation-X in mind, an active elliptical prototype has been designed by the SXO consortium to perform point-to-point X-ray focussing, while simultaneously manipulating its optical surface to improve its initial resolution. Following the completion of the large scale SXO prototype, presented is an overview of the production and operation of the prototype, with emphasis on the X-ray environment and preliminary results.

First results from the testing of the thin shell adaptive optic prototype for high angular resolution x-ray telescopes

“…This caused a glue layer with a variable thickness and some print-through, due to stress, was evident on the optical surface. This was seen in scans taken of a second prototype with piezoelectric devices attached, using the LTP as described in Atkins et al 9 and shown in figure 4. The theoretical form of the optic is shown with scans of the mirror with the power supply switched on and 0V applied, the power supply switched off and with the difference between the two.…”

“…The mirror was electroformed at UCL in an in-house facility. 9 Thirty curved piezoelectric actuators designed and manufactured at the University of Birmingham (UoB), were attached to the back of the mirror to allow active manipulation of the surface. The manufacture processes of the mirror are described in Atkins et al 9 are shown in figure 2, where the top graph shows the scanned data with the theoretical form the optic should have had.…”

“…9 Thirty curved piezoelectric actuators designed and manufactured at the University of Birmingham (UoB), were attached to the back of the mirror to allow active manipulation of the surface. The manufacture processes of the mirror are described in Atkins et al 9 are shown in figure 2, where the top graph shows the scanned data with the theoretical form the optic should have had. The lower graph is the data with the theoretical curve subtracted and it is clear that the optic was much flatter than had been expected, which would have elongated the focal length of the device.…”

Thermal shaping of thin glass substrates for segmented grazing incidence active optics

“…The already realized prototype has a dimension of 100 mm x 300 mm x < 1 mm. It is realized with a shell made of Nickel and 30 piezoelectric actuators, 200 μm thick, bonded to the back of this shell [7]. Electroformed Ni plates were considered for easiness of procurement.…”

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

“…A technology development programme entitled Smart X-ray Optics (SXO) has been just successfully completed in the UK, funded by the EPSRC to start development of such optics. The major output from this program, relevant to X-ray telescope optics, is a prototype, single reflection grazing incidence reflector, 100x300x0.4 mm Nickel shell, with 30 piezoelectric actuators of thickness order 200 microns bonded to the back 7 . This will demonstrate the principle and manufacturing techniques required to produce an actively adjustable X-ray mirror shell.…”