Minutes from the ISOLDE Physics Group meeting on September 23^rd, 2015

No comments to last week’s physics group meeting minutes.

Technical news

• GPS:
  
  • The High Voltage “ramping” cards for the target and transfer line still glitched and ramped down during the IDS run.
    • The cards are designed to not accept commands during protected ramps downs, resulting in long delays to users
    • It is now being considered to remove the cards during the winter shutdown
  • The BTY steerers to the GPS target are back to the normal configuration for proton scans on the converters. Nobody is aware how and when this happened.
  • Users could not reproduce 90% transmission to IDS (RC4) obtained with the automatic tuner system early September. Manually they obtain 70%. Better initial conditions will be investigated.
  • Users ask to have a software alarm when the extraction High Tension is set to a different value than the one defined in the separator magnetic field calculator.
  • During the target optimization users observed a less-than-expected correlation of proton beam intensity and the yield of the less exotic radiogenic Mn isotopes (i.e. when p pulses increased X times, the yield increased < X times).
    • This effect disappeared after a few days, indicating a transitory target effect.
• HRS:
  
  • The UC_X target from the last ISOLTRAP run will be reused for CRIS this week.
• ISCOOL:
  
  • The RFQ was tuned for bunch mode for CRIS at 30 kV, obtaining 50% transmission. At what mass?
• General ISOLDE:
  
  • There will be 2 weeks between the end of protons to ISOLDE until Nov. 27th were ISOLDE will still be operative for stable beams. Fixed setups who wish to take beam from ISOLDE in this period should inform Magda.
• Beam diagnostics:
  
  • The Faraday cups at CA0 and RC2 do not read correct values, and based on the diagnostics of the IDS team, they might not well aligned and cutting the beam. The coordinator askes for quantitative information before passing it to the BI team.
• REX/HIE-ISOLDE:
  
  • The cryomodule coupler heat dissipation is not working as  expected.
    • During the 2015 campaign the module will only be run by the expert team during daytime
    • A solution has been found and will be implemented after the cryo module is taken from the ISOLDE hall
  • Stable beam accelerated with REX has been transported through the unpowered cryo module, only the solenoid on with 70-75% transmission efficiency.

Physics

• Beta-decay of ⁶⁸Mn at IDS:
  
  • Goal: measurement of the lifetime of the ⁶⁸Ni 478 keV gamma transition between the  0⁺₃ and 2⁺ states
  • The yield of ⁶⁸Ni was a factor of 2 better than the values  given in the yield database.

• Ground state properties of neutron-rich Ga isotopes at CRIS:
  
  • Goal: measure the spin parity of the ground state N>50 odd-even Ga isotopes.

Safety

• Users indicate that the Jura side access door to ISOLDE is permanently open. A ticket will be issued to repair the lock.
• Users have seen mice in the ISOLDE hall. A ticket has been opened.
• Four groups of professional fotographers are visiting the ISOLDE hall during Friday. The coordinator reminds users that if beamlines must be opened the visits cannot enter hall.
• The space previously used for the solid state lab at B275 has been cleared by RP. It can be now used for test setups.

Building 508

• A quote from a commercial provider to furnish the kitchen is now with the purchasing office, to be installed in October.

AOB

-The next meeting will take place on Wednesday next week (30^th September 2015) followed by  presentations by Alexandre Obertelly about “In-beam spectroscopy of unstable nuclei from MINOS at the RIBF” (https://indico.cern.ch/event/447555/ ).