title: Lexan coating to eliminate the UV sensitivity of soft x-ray proportional counters with a polypropylene window.
abstract: Lexan coatings on polypropylene windows can eliminate the UV sensitivity of soft x-ray proportional counters. A method is described for coating thin polypropylene films by dipping into and withdrawing from a volatile solution containing Lexan. The x-ray absorption of a typical Lexan coating was only 7% at 44 A which is small compared to that of 2 microm of polypropylene. The Lexan coatings are stable against vacuum cycling in an environment of UV irradiation. As an external, far-UV filter up to wavelengths of 2400 A, Lexan-coated polypropylene is an interesting alternative to metallic films, particularly when large area, high x-ray transmission, and strength are important.
authors.affiliation: Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, Massachusetts 02138, USA.
authors.forename: D G
authors.initials: DG
authors.lastname: Fabricant
authors.forename: R E
authors.initials: RE
authors.lastname: Goddard
authors.forename: F R
authors.initials: FR
authors.lastname: Harnden
authors.forename: P
authors.initials: P
authors.lastname: Gorenstein