Minutes from the ISOLDE Physics Group meeting on May 6^th, 2015

The document explaining CERN’s switch of mobile operators referred at last week’s meeting will not be released until closer to the final date.

Technical news

• Automatic tuning software:
  
  • The program is working and available to users.  Still being actively developed, feedback is appreciated (contact Tim Giles and/or Jake Palmer 167108
  • Extension to tuning the separators is under development.
  • The configuration file can be manipulated similarly to equipment array files.
  • The beam line optimization is done on faraday cups, the separators using the scanners.
  • Faraday cups that misread just by a scale factor do not matter as the program maximizes current no matter what the base value is.
  • Limits can be imposed to protect fragile equipment.
  • It allows for defocusing upstream faraday cups to optimize further downstream.
• RFQ:
  
  • The RFQ is still unstable at energies above 30 kV. Causes are under investigation.
  • Half of the injection and extraction optics have been replaced. This caused minor improvements.
  • Operation above 30 kV is currently not recommended.
• HRS:
  
  • Tim’s “secret” of “high-resolution tune”: High resolution tune tweaks correct for ion source effects by re steering the beam close to the source; not working with FEBIAD sources
  • Users report that the separator slits get stuck in some situations. Believed to be caused by software. Under investigation.
  • The HRS fixed grid used for proton scans now behaves correctly (following a recabling work at the startup)
  • IDS users report that re steering of the last RC4 quadrupole was necessary to get good transmission with radioactive beam after having tuned with stable beam. Please keep it in mind when taking stable and radioactive beam to your setups.
• GPS
  
  • Scanner 482 and faraday cup FC490 do not work correctly. Being investigated.

• The faraday cups at CA0/CC0 section will be exchanged early June.
• The coordinator reminds users ISOLDE is only guaranteed 40% of the proton pulses of a given super cycle.
• A power glitch Friday morning crashed the separator control computer. Rebooted successfully.
• The ventilation work in the target area will be finished May 20^th. Uranium Carbide targets can be prepared again once the works finish.

Schedule           

• The second part of the schedule will be most likely released this week. For the weekly releases see http://isolde.web.cern.ch/experiments/schedules/weekly-schedule for more info.

Safety

• The group leader reminds the users that helmets and safety shoes are mandatory in the HIE-ISOLDE work area ().

IS507 report

• Scientific goal: study of the beta-delayed proton emission in ^20,21Mg.
  
  • Identify the proton/gamma widths for states of astrophysical interest.
• Most of the ²⁰Na contamination was removed using the separator slits.
• Increasing the target temperature increased both Na and Mg yields equally.

AOB

-The next meeting will exceptionally take place at 15:30 Wednesday next week (13^th May 2015) followed by the seminar at 16:00 h given by Bertram Blank on "Super-allowed beta decay to study the electro-weak interaction" (https://indico.cern.ch/event/381579/)                                                                                               

Minutes taken by MMF