Presentation details
» On going developments on monolithic X-ray optics at the Brera Astronomical Observatory: a status report
Presentation duration: 30 minutes
Presenter: Giovanni Pareschi
Grazing incidence mirrors based on monolithic pseudo-cylindrical configuration have been successfully utilized for past X-ray telescopes. The monolithic configuration, thanks to the cylindrical symmetry, improves the intrinsic stiffness of the mirrors and in general prevents from the aberrations caused by the deformations of the reflecting surface. Excellent angular resolution results (4-0.5 arcsec HEW), paying in terms of a modest throughput, were achieved by the Einstein, Rosat and Chandra optics, all based on relatively thick shells (ten millimiters or more) made in glass or glass-ceramic materials, precisely grinded and superpolished. Thin (1mm – 0. 1mm) mirror shells produced via Ni elctroforming replication, used for SAX, XMM and Swift, are characterized by a less performing (but still very good) imaging capability (HEW 0 15 arcsec at 1 keV), with a large gain in terms of throughput. At the Brera Astronomical Observatory we are involved in a number of technological effort to improve the performances of monolithic mirror shell. In this paper we will report on these on-going activities and, in particular, we will discuss on recent results achieved on thin electroformed optics with multilayer reflecting coating for hard X-ray applications and on the direct figuring of thin glass or ceramic shells for obtaining high resolution and high throughput shells with polynomial profile for surveying purposes.
Coauthors:- S. Basso
- O. Citterio
- M. Civitani
- P. Conconi
- V. Cotroneo
- M. Ghigo
- L. Proserpio
- D. Spiga