Minutes of the REX integration meeting on Wednesday, 18.05.2004

Participants: Fredrik Wenander, Thomas Sieber, Pierre Delahaye, Luis Fraile, Mats Lindroos (chair), Peter Butler

1. Miscellaneous

* Ivan Deloose contacted for implementation of slow extraction from the EBIS. Will evaluate the problem this week.

* Stable K+ beam injection from trap to EBIS, >13% for K10+.

* The HT for the trap has an unnormal leakage current of 2 uA. Insulators are cleaned, transformer as well. Goes away if the transfer-acceleration-retardation potentials are adjusted. This suggests internal leakage current.

* Severe sparking (>44 kV) in the tube between the trap and the trap ion source prevents operation with the ion source. Michael O'Neil looks into the problem.

* The VME for the REXTRAP keeps stopping and needs rebooting after some hours of operation. Investigation in progress.

* The REXEBIS and Linac will be provided with a separate pulse generator to allow Linac operation also when the Trap process has stopped.

* The sideband and rotating wall cooling tests are postponed until after the run. Romain and Ivan are now analysing the data. Results to be presented at ENAM04.

* Luis' REX-schedule should be included in the REX-ISOLDE homepage.

- The nitrogen in the EBIS spectra is still there, no leaks found yet.

- Water pressure on the return side (whole REX machine) is still too high. Pressure at the moment not sufficient to run complete LINAC.

- The lead shielding for the MINIBALL seems to be not sufficient. An additional lead shielding has to be installed before the next runs.

- RFQ energy beam has poor transmission (60%) to second beamline. Other beams transports will be calculated and tested.

- An Amplifier for the next REX upgrade to 4 MeV/u is available here at CERN from the AB-RF group. It would provide 400 kW at a duty cycle of ~5%. Costs for modifications, power supplies etc: 200 – 300 kCHF.

Notes by Fredrik and Thomas