Speaker
Description
Gaseous photomultiplier tubes (gas-PMTs) based on micro-pattern gaseous detectors for visible light detection have been widely investigated due to their compelling advantages. These include cost-effective large-area coverage, high spatial and time resolution, and resistance to magnetic fields. However, visible light photocathodes are highly chemically reactive and suffer from severe degradation when subjected to excessive ion bombardment.
To address these challenges, we designed a triple micromesh gaseous structure (TMM) capable of achieving an unprecedented ion backflow (IBF) ratio of 3×10^−5 at gas gains exceeding 1×10^5. Based on this structure, a novel visible light gas-PMT prototype coupled with a bialkali photocathode was developed. This was achieved by exploring fabrication techniques relying entirely on inorganic materials, such as ceramics and metals, and utilizing a ppb-level gas purification system. We measured the gain and quantum efficiency (QE) of the prototype, and evaluated the long-term stability of the photocathode in a gaseous environment.
| Name of the speaker | Kunyu Liang |
|---|---|
| Eligible for the Georges Charpak Young Scientist Award. | yes |