Method and setup for photodesorption measurements for a nonevaporable-getter-coated vacuum chamber

Abstract

This article describes a method for measurement of the photodesorption yield and sticking probability for a vacuum chamber coated with nonevaporable getter (NEG). This method is based on a three-gauge method of measurement which was developed and used on a specially designed and assembled setup for the photodesorption yield measurements of test chambers. It has been modified for photodesorption measurements of a vacuum chamber with sorbing walls. Although a short description of the installation and the results of the photodesorption measurements with the NEG-coated vacuum chamber have been published [V. V. Anashin, I. R. Collins, R. V. Dostovalov, N. V. Fedorov, A. A. Krasnov, O. B. Malyshev, and V. L. Ruzinov, The 8th European Particle Accelerator Conference, Paris, France, 2002, p. 2550; Vacuum 75, 155 (2004)], the details of the method, the analysis, and the experimental setup are also described in this article. Special attention is paid to define the sensitivity limit of the method and the setup and to reduce electron- and photon-stimulated desorption in the measurement port.