Electron stimulated desorption from the 316 L stainless steel as a function of impact electron energy

Abstract

The electron stimulated desorption (ESD) yields of vacuum chamber wall materials are required as one of the important input parameters in the design of vacuum systems for particle accelerators and many other vacuum systems where energetic electrons hit vacuum chamber walls. In the present study, the ESD yields were measured and analyzed (a) as a function of accumulated electron dose, (b) as a function of the total amount of desorbed gas, and (c) as a function of the energy of electrons bombarding. In this study, three separate 316 L stainless steel samples were bombarded with electrons up to an accumulated electron dose of ∼2 × 1023 e−/m2 at three different corresponding electron energies: 50 eV, 500 eV, and 5 keV. Once the required dose was reached, the ESD yield as a function of electron energy was measured between 10 eV and 6.5 keV. The results obtained by both methods were in agreement showing that ESD yield increases with electron energy. Experimental difficulties and problems with interpretation of data relating to such a study are described and discussed in the paper.