Minutes from the ISOLDE Physics Group meeting on July 29th, 2015

No comments to the minutes of the PG meeting held last week.

Technical news

 GPS:
o The UCx target for potassium beams was repaired after the ionising cavity disconnected

when ramping up temperature.
o The HT was run at 40 kV after several trips were observed at higher voltages. To be

investigated.

 HRS:

o HRS magnet short cycling software was tested again last week. The magnets’ field erratic jumps observed during these tests were tracked to the INCA V.3 software update. Version 2 restored, problems in V.3 to be solved. Cycling software is back to the slower version, to be safe.

o UCx target for ISOLTRAP the week before had trouble coupling to the front end. Monday visual inspection of the front end done by a robot showed no anomalies.

o Users report that some recipes of the automatic tuning software include default values (for kickers) that are hardwired and do not automatically scale with beam energy.

•   Maintenance was performed on the RC2/RC4 beamlines. Several quadrupole cables were fixed and the RC2/RC4 kicker power supply was exchanged. There still an offset on some of them, probably due to a software problem.

•   A water leak developed in the proton BTY line on Tuesday afternoon. I was fixed and cleaned by early afternoon Wednesday.

•   RILIS:

o Low ionization efficiency for Cd observed when preparing for IDS experiment.

 Beam diagnostics:
o Faraday cups at CC0 and RC2 still need changing. They will be replaced once the spare

boxes are repaired.

 ISCOOL:

o Vacuum was improved after faraday cups before and behind the cooler were replaced a month ago.

o However, the transmission problems did not improve: normal at 30 kV. Operation at 60 kV still very unstable.

o Tim traced the problem to the extraction electrode area.
o ISCOOL opening scheduled between the IDS and COLLAPS runs in August to identify the

origin of the transmission problems.
o Users ask for the possibility of running HRS with ISCOOL removed. Tim recommends

against it as the RFQ has been observed to improve transmission considerably (6 fold) when transporting to central beamline.

Physics and schedule

•   Mass measurements of neutron rich Ar at ISOLTRAP

•   Goals: mass measurements of 46-48Ar isotopes

o Succesfull measurement of 46,47Ar
o Tried 48Ar but beam contaminants were too high even for the MR-TOF. o Measurement of 97,98Kr instead.

•   Beta decay of neutron rich Potassium isotopes at IDS

•   Goals: beta delayed neutron emission of 51-54K isotopes

o Single particle state evolution in even-odd 51,53Ca, probing new shell closure at N=32 predicted by 3 body forces.

o First measurement of the energy and angular distribution of 2 neutron emission in 51,52K.

o Exploratory measurement of the decay of 54K. Small production observed.

Safety

•   Next week there will be collections of Terbium isotopes. Very active sources at the GLM. GLM and the RILIS cabin stairs will be fenced off next week, specially on the night shifts.

•   The comments of the ISOLDE safety inspection mention mostly containers with chemicals that are either unlabeled, unproperly stored, or both.

o The coordinator reminds people the chemical safety cabinet should be used. The keys are in the traka box. The cupboard is presently in HIE-ISOLDE area, but it will be moved back close to the control room.

•   Next Thursday will be a coordinated action to clean the HIE-ISOLDE area.

•   The coordinator reminds users that visits must be announced in advance to check for the safety

  conditions in the hall, target changes, open beamlines, etc.

•   Users ask for 2 new vacuum cleaners for the ISOLDE hall and B508.

•   The coordinator reminds the ISOLDE hall sources are to be used in the ISOLDE hall and B508

  exclusively. A new yellow radioactive box will be bought to transport sources.

•   Users recommend to include in the ISOLDE online RP course explicitly the rule that two people

  are needed for shifts inside the hall.

  AOB

  -The next meeting will take place at 14:00 Wednesday next week (5th April 2015) followed by a seminar by Etienne Vermeul on “Medical Isotopes at PSI” (https://indico.cern.ch/event/434256/ )

  Minutes taken by MMF