| Title |
Modeling of Photoemission and Electron Spin Polarization from NEA GaAs Photocathodes |
| Authors |
- O. Chubenko, A. Afanasev
GWU, Washington, USA
|
| Abstract |
Many nuclear-physics and particle-physics scientific laboratories, including Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (Jefferson Lab) which studies parity violation and nucleon spin structure, require polarized electron sources. At present, photoemission from strained GaAs activated to negative electron affinity (NEA) is a main source of polarized electrons. Future experiments at advanced electron colliders will require highly efficient polarized electron beams, which sets new requirements for photocathodes in terms of high quantum efficiency (QE) (>>1%) and spin polarization (~85%). Development of such materials includes modeling and design of photocathodes, material growth, fabrication of photocathodes, and photocathode testing. The purpose of the present work is to develop a semi-phenomenological model, which could predict photoemission and electron spin polarization from NEA GaAs photocathodes. Detailed Monte Carlo simulation and modeling of physical processes in photocathodes is important for optimization of their design in order to achieve high QE and reduce depolarization mechanisms. Electron-phonon interactions near the surface and influence of the presence of quantum heterostructures on the diffusion length are studied in depth. Simulation results will be compared to the experimental results obtained at Jefferson Lab and can be used to optimize the photocathode design and material growth, and thus develop high-polarization high-brightness electron source.
|
| Funding |
Work supported by The George Washington University and Thomas Jefferson National Accelerator Facility. |
| Paper |
download TUPWA059.PDF [0.878 MB / 4 pages] |
| Export |
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| Conference |
IPAC2015, Richmond, VA, USA |
| Series |
International Particle Accelerator Conference (6th) |
| Proceedings |
Link to full IPAC2015 Proccedings |
| Session |
Tuesday Posters (Washington) |
| Date |
05-May-15 16:00–18:00 |
| Main Classification |
2: Photon Sources and Electron Accelerators |
| Sub Classification |
T02 - Electron Sources |
| Keywords |
electron, scattering, polarization, simulation, photon |
| Publisher |
JACoW, Geneva, Switzerland |
| Editors |
Stuart Henderson (ANL, Argonne, IL, USA); Evelyn Akers (Jlab, Newport News, VA, USA); Todd Satogata (JLab, Newport News, VA, USA); Volker R.W. Schaa (GSI, Darmstadt, Germany) |
| ISBN |
978-3-95450-168-7 |
| Published |
June 2015 |
| Copyright |
|
