Barday, R.; Jankowiak, A.; Kamps, T.; Klimm, C.; Knobloch, J.; Siewert, F.; Varykhalov, A.; Senkovskiy, B.; Lagotzky, S.; Müller, G.: Field Emission Studies of Heat Treated Mo Substrates. In: Proceedings of IPAC2014, Dresden, Germany. , 2014. - ISBN 978-3-95450-132-8, p. 2955-2957
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Abstract:
Molybdenum can be used as a substrate for the bi-alkali antimonide photocathodes utilized for the generation of high brightness electron beams in a superconducting radio frequency (SRF) photoinjector cavities. Operation at high field strength is required to obtain a low emittance beam, thus increasing the probability of field emission (FE) from the cathode surface. Usually, substrates are heated in situ before alkali de- position to remove oxide layers from the surface. FE on Mo substrates was measured by means of a field emission scanning microscope (FESM). It turned out that in situ heat treatment (HT) of the Mo surface significantly changes the FE behaviour by activation of new emitters. For a better understanding of the mechanism for enhanced emission after in situ heating a witness Mo sample was investigated using x-ray photoelectron spectroscopy.