Conveners
Session 4: Application Oriented Research: Spin Polarized Sources
- Luca Cultrera (Cornell University)
Many physics experiments at Jlab require high current polarized electron beams and we have been actively engaged in research and development that are intended to improve the existing photocathode performance as well as exploring new photocathodes with the goal to improve the operation capability and the quality of accelerator facilities. Since last P3 workshop, some interesting studies have...
This contribution describes Jefferson Lab polarized electron sources where the world record of high current polarized electron beam was delivered. Polarized GaAs Superlattice photoguns with long lifetime represents a significant challenge for proposed facilities that must operate in excess of tens of mA of polarized average current. Damage due to ion bombardment is the dominant mechanism that...
The quantum efficiency (QE) spectral response of five thin GaAs photocathodes with different active layer thickness and dopant density was experimentally evaluated, and to better appreciate the experimental results, a Monte Carlo model was developed to simulate electron transport and emission. The simulation accurately predicts expected behavior, namely QE is enhanced for thicker GaAs...
We have demonstrated that the SPTEM can provide both TEM images and diffraction patterns. The TEM images were obtained at a spatial resolution of 1 nm with a 30-kV acceleration voltage. The apparatus has an electron beam energy width below 114-meV in the TEM without any monochrometors. The energy width indicates that the temporal coherence is approximately 34 fs. The brightness is measured by...
Using spin-polarized electron beams in a low energy electron microscope provides opportunities to measure microscopic spin structures of domain walls and related spin textures, as SPLEEM permits imaging the vector orientation of the magnetization with high spatial- and angular resolution. This talk outlines key principles of relevant magnetic properties and opportunities in photocathode and...
