Computational Tool for Modeling and Design of Rugged GaAs-based Polarized Electron Sources
- Tech-X Corporation
High-current, high-brightness, spin-polarized electron beams are required for next generation electron-ion colliders (EIC). Proposed cathode designs are based on negative electron affinity (NEA) GaAs. A major limitation of these cathodes is their operational lifetime due to their susceptibility to damage in electron guns. Recent experiments done at Cornell University have demonstrated that a NEA GaAs photocathode can be activated with a protective Cs2Te cap layer leading to a factor of 5 lifetime improvement due to the resistance of Cs2Te to poor vacuum and chemical poisoning. The optimal design parameters for a NEA GaAs photocathode with a protective layer are still to be determined; however, there are no available codes to efficiently explore the large number of possible material design choices. We propose to address this problem by developing software to model both charge and spin transport together with transmission of electrons across cap layer-vacuum interfaces to enable simulations for investigation and design of rugged GaAs-based photocathodes. During the Phase I project, we designed software to model electron spin dynamics in simulation subregions with different material properties. Then, we implemented proof-of-principle prototype code for modeling of spin and charge transport together with electron emission. We ran simulations to test the prototyped models for spin transport across different material layers and emission of spin-polarized electrons. The implementation is fully three-dimensional and tested using parameters derived from recent Cornell University experiments on emission of polarized electrons from a rugged NEA GaAs photocathode with a protective Cs2Te layer.
- Research Organization:
- Tech-X Corporation, Boulder, CO (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Nuclear Physics (NP)
- DOE Contract Number:
- SC0019585
- OSTI ID:
- 1576560
- Type / Phase:
- SBIR (Phase I)
- Report Number(s):
- DE-SC0019585 Final Technical Report
- Country of Publication:
- United States
- Language:
- English
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