Vp. Viitanen et H. Harvela, GAS LEAK THROUGH ULTRATHIN RADIATION ENTRANCE WINDOWS, Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment, 360(3), 1995, pp. 566-570
The permeation rates through an ultrathin radiation entrance window me
mbrane have been measured for several common detector gas components,
as well as for some atmospheric gases, by collecting the permeated gas
into a clean volume equipped with an absolute pressure transducer. Th
e dependence of the leak rate on the differential pressure (1.0 bar in
most of the measurements) has also been discussed. Formulas with the
permeation rate as a function of the molecular diameter or the molecul
ar mass are presented. They give a rough estimate for the dependence o
f the permeation rate on the gas properties. The structure of the wind
ow membranes used in the measurements is presented.