Publications by authors named "Paul Zwartek"
Article Synopsis
- This study investigates how residual carbon on p-GaN photocathodes affects their quantum efficiency, emphasizing the importance of a clean surface for achieving negative electron affinity.
- The research utilizes an in-situ X-ray photoelectron spectrometer (XPS) to monitor changes on the photocathode surface during cleaning, activation, and degradation processes.
- Despite the presence of carbon and oxygen contaminants from the manufacturing process, activating p-GaN with cesium allows for the formation of negative electron affinity and reveals the role of cesium carbide in photocathode performance degradation.
Micromachines (Basel)
May 2022
Article Synopsis
- Accelerator scientists require photocathodes with high quantum efficiency (QE) and durability; p-GaN photocathodes, enhanced with cesium, have emerged as promising candidates due to their negative electron affinity surface.*
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- In this study, p-GaN samples were cleaned and activated in an ultra-high vacuum (UHV) chamber, with subsequent analysis of their performance and surface characteristics using various microscopic techniques.*
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- Results indicate that both wet chemical and thermal cleaning processes affect the cathodes' quality, but high QE and long storage life can be achieved at lower cleaning temperatures.*
