The performance of thin shell adaptive optics for high angular resolution x-ray telescopes

Abstract

The Smart X-ray Optics project is a UK based consortium of five institutions investigating active/adaptive X-ray optics for both large and small scale applications. The large scale application is aimed towards future X-ray telescopes for X-ray astronomy. The work presented here includes the modelling and the testing of the new large scale prototype thin shell optic which incorporates piezoelectric devices to enable the surface to be actively deformed aiming to achieve an angular resolution better than that currently available (e.g. Chandra 0.5"). As the shell is thin, a high degree of nesting is possible such that very large collecting areas can be provided in combination with the high angular resolution. The results from the testing campaign for this prototype in the X-ray beam line at the University of Leicester will be presented. The effect of the actuated piezoelectric devices on the detected image and software development for control of the system are discussed. Improvement of the Full width Half Maximum of the focus spot of up to 25% was seen but as yet this has not been completed in a controlled way. The surface figure achieved with a given set of voltages is stable, but an apparent interaction or coupling between the piezoelectric devices was detected and is still unexplained.

Toward active x-ray telescopes

“…Laser alignment of the mirrors found that the NEMO2 exhibited the smaller focal spot; however, it had a focal length too long to be x-ray tested in the TTF. Consequently, x-ray testing in 2010 was possible for only the NEMO1 26,25 .…”

Nested grazing incidence optics for x ray detection

“…Chandra is sensitive to x-ray sources 100 times fainter than any previous x-ray telescope, enabled by the high angular resolution (0.5 ) of its four layer mirrors, which are made of microcrystalline glasses coated with irdium (Ir), where the film thickness is about 30 nm. The Chandra observatory is constructed based on the type of Wolter-I, [4,5] its focal length is 10.07 m and it works from 0.2 keV-10 keV. The European Space Agency's x-ray Multi-Mirror Mission [6,7] (XMM-Newton) was launched by Ariane 504 on December 10, 1999.…”

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

“…In particular, in the context of the AHEAD (Integrated Activities in the High-Energy Astrophysics Domain) project, proposed to the European Community in the context of the FP7 funding program and at the time being still under evaluation, it has been proposed to develop a X-ray telescope system prototype formed by of a thin shell segment, which incorporates piezoelectric actuators as an integral part of the thin shells. The final goal is to provide a telescope of several square meters of collecting area and with an angular resolution better than 0.5 arcsec HEW 6 . This could be achieved by adjusting the reflecting surfaces in order to achieve and maintain the high angular resolution.…”