Minutes from the ISOLDE Physics Group meeting on October 21^st, 2015

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

Technical news

• HRS:
  
  • IDS user successful Cadmium measurements with cold quartz line UC_­X target.
    • A non-recoverable leak appeared after physics run when increasing the temperature of the quartz.
  • There was a small two-hour interruption of physics on Friday for intervention in Linac 2.
• GPS:
  
  • There was trouble installing the target for REX/HIE-ISOLDE.
    • The problem seems to be in the pushing piston.
    • No repair will be done before the winter shutdown.
  • Proton scan was finished Tuesday afternoon.
  • RILIS group did the full laser tuning for Zn on Tuesday. Zinc beams are now available.
• RILIS:
  
  • Cadmium campaign ran in on-call mode, very successfully. Only two small interventions to retune the lasers were needed.
  • Zinc ionization requires a UV laser for the first stage. The large power of this first stage induces coating in the windows, requiring periodic cleaning interventions
• General ISOLDE:
  
  •  The safety valves of the 4000 L Liquid Nitrogen tank outside ISOLDE were tested.
    • They were found to leak and operate at pressures higher than safety regulations
    • New valves will be ordered. There is a three week waiting period for delivery.
  • The ISOLDE hall floor is known to have an elevation difference of up to 17 mm between the exit of the magnets and the farthest away lines.
    • A full study of the current situation using beam optics calculations was performed by Elisa Rapisarda.
    • It was found that the current situation is at the limit of the bending power of the ISOLDE optics
    • The group leader informs on this point and would like to hear the opinion of the in house to do this major intervention on the ISOLDE beamlines during the LHC Long Term Shutdown 2 (in 2019).
• REX/HIE-ISOLDE:
  
  • Full tuning of ⁸⁷Rb₂₈₊ was performed from the target to the MiniBall setup.
    • First test was performed with non superconducting RFQ up to 2.85 MeV/u.
    • Superconducting acceleration was achieved up to 3.6-4 MeV/u.
  • The superconducting cavities are expected to hold power steadily for at least 7 h.

Physics

• Beta-delayed neutron emission of Cd isotopes at IDS:
  
  • Goal: measurement of high intensity neutron emission in even-even Cd isotopes.
    • The large neutron branching ratios are linked to “super” allowed Gamow-Teller decay of ¹³²Cd core neutrons.
    • Neutron emission will occur through large high energy quasi resonances.
  • Very successful run of A=132, 9 shifts total at  1 ion/s, for total of 5000 neutrons detected. Neutron emission dominated by a single resonance at 1.2 MeV.
  • Short run of ¹³⁰Cd where no neutrons were observed.
  • Short runs of ^129,133Cd for future proposals.

• Coulomb excitation of even Zn isotopes at MiniBall:
  
  • Goal: measure the transition strength to the 4⁺à2⁺ states and higher in ^74,76,78,80Zn
  • Stable Ne beam was taken at the beginning of the weak for in-beam calibration of the HPGe clusters angles (for Doppler corrections).
  • Beam on target interaction was demonstrated measuring scattered particles in the CD. No scattering was observed with the target removed.

Safety

• Long term storage has been facilitated for ISOLDE.
• Activated or contaminated material found in B275 cannot be stored in there. A new storage location has to be provided meanwhile it will be moved to ISR3 where the target are stored .
• Due to the contamination incident from last week the entrance locks of B275 will be changed.
  
  • An activity report must now be filled prior to entrance to B275.

The group leader asks users to contact Karl or her in order to obtain the new keys for a few hours as the keys need to be shared. key should be given back as soon as the access is not needed

•  In general the person holding the key is responsible that all the rules below are respected and should not give the key to another group of people without your agreement.

The ISOLDE leader has been asked to remind you that:

1. the transport of any material from the ground floor outside of the building or any displacement of material from the ground floor is not allowed without RP assistance. 

2. the laboratory room is not accessible until it is declassified officially by RP.

3. the access to room (275 R - 010) hosting the contaminated material on the ground floor  is strictly forbidden

• The ISOLDE hall will go through a fire inspection at the end of November
  
  • Cardboard and wooden boxes must be moved out of the hall.

Building 508

• The hole used to pass the cables from the ISOLDE hall into the DAQ and the control rooms has been finished with a closing panel.
• The water cooling circuit serving the laser and photoluminescence laboratories has been signed and ordered. Works should start soon.
• The exterior doors in B508 are going to get new crash-bars compatible with the handles.

AOB

- There will be safety simulation/training at the ISOLDE target area on November 16^th in the morning.

- Users ask about the availability of the ISOLDE separator course. It will be arranged around the stable beam tests scheduled at the end of November. It will be most likely a full week around November 16^th or 23^rd.

-The next meeting will take place on Wednesday next week (28^th October 2015) at 13:45 on the auditorium of the IT building, followed by a presentation by Steven Judge about “The international measurement system & the impact of nuclear physics” (https://indico.cern.ch/event/447134/).

Minutes taken by MMF