Malik Defends MS July 7
Mr. Talal Ahmed Malik will defend his MS Thesis in a Zoom Meeting chaired by Dr. Mark Gilmore on Tues, July 1 at 11 am.
The title of Mr. Malik's Thesis is "Secondary Electron Yield Measurements on Materials of Interest to Vacuum Electron Communication Devices."
The Abstract for Malik's Thesis is shown below:
Microwave vacuum electron devices are a critical part of communication satellite payloads. The phenomenon of multipactor breakdown (MPB) can cause the performance of these devices to deteriorate, including partial or total destruction of the device. MPB depends on a number of factors, including the secondary electron yield (SEY) of material used within the device. The process of electron multiplication, which leads to breakdown, initiates with the impact of primary electrons on target surfaces, and resonance of free electrons within an oscillating electromagnetic field under vacuum conditions. Therefore, it is of interest to find materials and cleaning protocols that exhibit low SEY. This thesis work describes controlled measurements of SEY in the low energy regime (10 eV to 1000 eV) from several materials of interest to space electronic system. Materials include on copper (Cu), (as a baseline material), silver, stainless steel, aluminum 6061 (Al), monel, nickel/cobalt and invar. In addition, different surface treatment methods adopted in this study are described, which illustrate that SEY is a surface-sensitive process.