Development of grazing incidence multilayer mirrors for hard x-ray focusing telescopes

Details Development of grazing incidence multilayer mirrors for hard x-ray focusing telescopes Development of grazing incidence multilayer mirrors for hard x-ray focusing telescopes

Oct 1997

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1997spie.3114..526m&link_type=abstract

Proc. SPIE Vol. 3114, p. 526-534, EUV, X-Ray, and Gamma-Ray Instrumentation for Astronomy VIII, Oswald H. Siegmund; Mark A. Gumm

Astronomy and Astrophysics

Astronomy

2

Scientific paper

We are developing depth-graded, multilayer-coated mirrors for astrophysical hard x-ray focusing telescopes. In this paper, we discuss the primary technical challenges associated with the multilayer coatings, and report on progress to date. We have sputtered constant d-spacing and depth-graded W/Si multilayers onto 0.3 - 0.5 mm thick DURAN glass (AF45 and D263) and 0.4 mm thick epoxy replicated aluminum foils (ERAFs), both of which are potential mirror substrates. We have characterized the interfacial roughness, uniformity, and stress of the coatings. The average interfacial roughness of each multilayer was measured from specular reflectivity scans ((theta) (subscript i) equals (theta) (subscript r)) using Cu K(subscript alpha) x-rays. The thin film stress was calculated from the change in curvature induced by the coating on flat glass substrates. Thickness and roughness uniformity were measured by taking specular reflectivity scans of a multilayer deposited on the inside surface of a quarter cylinder section. We found that interfacial roughness ((sigma) ) in the multilayers was typically between 3.5 and 4.0 angstrom on DESAG glass, and between 4.5 and 5.0 angstrom on the ERAFs. Also, we found that coatings deposited on glass that has been thermally formed into a cylindrical shape performed as well as flat glass. The film stress, calculated from Stoney's equation, for a 200 layer graded multilayer was approximately 200 MPa. Our uniformity measurements show that with no baffles to alter the deposition profile on a curved optic, the layer thickness differs by approximately 20% between the center and the edge of the optic. Interfacial roughness, however, remained constant, around 3.6 angstrom, throughout the curved piece, even as the layer spacing dropped off.

Affiliated with

Also associated with

No associations

Rating

Development of grazing incidence multilayer mirrors for hard x-ray focusing telescopes does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Development of grazing incidence multilayer mirrors for hard x-ray focusing telescopes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Development of grazing incidence multilayer mirrors for hard x-ray focusing telescopes will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1158300