Present:

Gerard, Jean, Gunn, James

Notes:

With latest injector schedule, we have 2 years to deliver 2 new e-gun fully tested (Sept. 2026)
Gun v4 (proto) is the only one that was built and tested on ECTS
v4 test resulted in good perveance, means electrode geometry is good (may need fine tuning)
However the low ceramic resistance due to high temperature of the ceramic is major limitation
Another weak point: ceramics are exposed directly to the hot cathode outgassing (saw coating of molybdeum, see indico:?)
Solution: adapt Russian design (present AD gun) for ceramics is out of the vacuum and away from the hot cathode
Jean made a concept design of gun v5
Before provide a "final concept design" to MME, we must test it.
For the test purpose, no need to go through long CERN/MME production/aproval process
Cheap and fast outsourcing the ceramic (Kyocera or NTG) and electrodes (CNC24) - cost 10-15 kCHF, time 3 months
So if we order by end of september, we likely have it in Jan.2025, and tested by June 2025 (as compared to MME, where it can take 1 year)
In meantime we proceed tests with v4 that has increased distance of ceramic from cathode

Conclusion: