Secondary electron yield reduction of 316L stainless steel prepared by selective laser melting and surface remelting for electron cloud inhibition

Secondary emission (SE) can influence the performance of microwave devices, particle accelerators, etc. Particularly, secondary emission resulting in the formation of electron cloud effect in accelerators can induce various effects, such as the reduction of beam quality, beam lifetime and detector sensitivity. Reducing the Secondary electron yield (SEY) of material surfaces is very important for the inhibition of electron cloud in accelerators. A novel method based on selective laser melting (SLM) and surface remelting is initially proposed in this paper to process metallic materials with low SEY. As a commonly used material in accelerators vacuum pipes, 316 L stainless steel was manufactured by SLM to form surface morphologies with low SEY. The maximum SEY of as-received SLM fabricated and surface remelted SLM fabricated 316L stainless steel are 1.39 and 1.14 (the lowest one in this paper), respectively. On the other hand, the surface resistivities of as-received SLM fabricated (1.371 mu S2 m) and surface remelted SLM fabricated 316L stainless steel (0.893-1.536 mu S2 m) are higher than cast 316L stainless steel (0.78 mu S2 m), which is mainly attributed to their higher surface roughness.