title: Windows for small-angle X-ray scattering cryostats.
abstract: To determine the suitability of commonly used windows for small-angle X-ray scattering, a range of materials, including Kapton, (aluminized) Mylar, beryllium, high-purity aluminium foil, mica and silicon nitride have been studied. At small wavevector transfers, Q, in the range 2 x 10(-3) to 0.2 nm(-1), the scattering from Kapton, mica and beryllium is reasonably well described by power laws in Q with exponents of -3.25, -3.6 and -3.9, respectively. There are large variations in the scattering from mica, but a freshly cleaved natural mica window was by far the weakest scatterer. For applications where radiation in the infrared or visible range should be blocked, aluminized Mylar is the most suitable material. Both Mylar and Kapton can be used to make very simple demountable superfluid-tight windows using indium O-ring seals.
authors.affiliation: Department of Physics, Northern Illinois University, De Kalb, IL 60115, USA. llurio@niu.edu
authors.forename: Laurence
authors.initials: L
authors.lastname: Lurio
authors.forename: Norbert
authors.initials: N
authors.lastname: Mulders
authors.forename: Mark
authors.initials: M
authors.lastname: Paetkau
authors.forename: Pete R
authors.initials: PR
authors.lastname: Jemian
authors.forename: Suresh
authors.initials: S
authors.lastname: Narayanan
authors.forename: Alec
authors.initials: A
authors.lastname: Sandy