Greg Blume ÒÁµéÔ°ÊÓƵ
OCNPS 304 Physics Conference Room
Wednesday, November 4, 2026 1:00 pm
Abstract:
This thesis was developed to optimize and evaluate the performance of MOCVD-grown GaAs based distributed Bragg reflector (DBR) strained superlattice (SSL) photocathodes. These photocathodes present the next generation of high QE high polarization electron sources for use in an accelerator environment. Currently, the MOCVD growth process does not permit the fabrication of a protection layer, resulting in the formation of oxides during handling. The removal of these oxides is essential for good performance of an MOCVD-grown photocathode. Thermal desorption is found be an effective method to clean the surface; however, excessive temperature and duration will sublimate desired photocathode material. This sublimation is found to alter the resonance structure introduced via the DBR which may limit photocathode performance. Managing the time and temperature to carefully remove surface oxidation while limiting surface sublimation describe the optimization process for MOCVD-grown DBR photocathodes. The results of this thesis produce a preparation technique that maximizes photocathode performance readying this material for accelerator operations.