Laser Induced Nano and Micro Structures of Molybdenum Surface Applied in Multistage Depressed Collector for Secondary Electron Suppression

Abstract

The laser processing molybdenum metal surface method was first proposed to enhance the efficiency of multistage depressed collectors (MDCs). In this study, the secondary electron yield (SEY), surface geometrical morphologies and chemical states of laser processed Mo metal samples were characterized. For the first time, the effects of laser parameters and incident angle of primary electrons on the SEY property of laser induced nano and micro structures of molybdenum surface were investigated. The influence rule of laser processing patterns, power, pitch spacing, scanning speed on surface morphologies and SEY were systematically explored. A maximum SEY of laser processed Mo metal less than one was achieved. The Mo 3d and O 1s core level spectra of Mo metal before and after laser processing were analyzed in this study. Furthermore, the corresponding oxidation states of Mo as well as the relative distribution were elucidated.

Structural and Secondary Electron Yield Properties of Titanium–Palladium Films with Laser-Treated Copper Substrate for Application in Neutron Generators

“…The decrease in δ max could be ascribed to the porous surfaces formed by laser processing. Porous structures can effectively reduce secondary electron emission because high-density micro- and nano-structures increase the probability of secondary electron capture stimulated from the surface, as described in the literature [ 23 , 24 , 47 ].…”

Suppression of Secondary Electron Emissions on the Graphene-Coated Polyimide Materials Prepared by Chemical Vapor Deposition

“…[8,9]. Therefore, it has become a consensus among researchers in the field of electric vacuum to reduce the SEY of materials in order to prevent the undesirable effects of secondary electron emissions [10][11][12][13].…”