Minutes from the ISOLDE Physics Group meeting on July 8^th, 2015

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

Technical news

• GPS:
  
  • Ta-Nb target with a negative ion source in GPS for Chlorine, Bromine yield tests.
  • Because instabilities on linac 2 protons had to be restarted every 90 min, with 10 min turnaround time. Problems pinpointed on the electron ion source, being investigated.
  • Linac 2 problems require running at 10% less intensity on the PSB.
  • On Wednesday the GPS target was changed to Thorium oxide with a negative ion source. Negative ion yield tests and LoI from RILIS to measure the electron affinity of astatine.
  • Tuning LA1 for negative ions went quickly, achieving 65% transmission efficiency.
• HRS:
  
  • HRS magnet mass cycling problems were fixed when downgrading to a previous version of the software. An updated version of the new software will be improved.
  • The new version of the cycling software is twice as fast changing the field. To be cross tested with stable beam.
• A water leak was observed in the ISOLDE hall wall by CRIS. The leak seems to be coming from the top of the hall. It was observed to be rusty and non-radioactive.
• Beam diagnostics:
  
  • Two diagnostics boxes were replaced last week.
  • The leaking box in front of ISCOOL was repaired and replaced. It was pumped successfully, leak check intervention scheduled for this week.
  • A leak developed on the central beamline diagnostic box to be repaired. A completely new box will be installed and tested on Wednesday.
  •  
• Users ask about the status of the ISOLDE leak detector. It is still with the company under repair. For the moment vacuum group is willing to let us borrow from them.

Safety

• The full safety inspection of the ISOLDE hall was performed last Monday. A report will be issued soon.
• The yearly safety inspection of B508 was passed last week. It was recommended to remove cardboard and wooden boxes out of the building.
• The ISOLDE extension will be cleaned for safety. It will be schedule to coincide with a day where no or little work is done on HIE-ISOLDE and the beamlines.

Schedule          

• The final schedule for after mid October will be released at the end of July.

Test of target-ion source for negative ions

• Goals: Yield tests of Ta-Nb target with surface negative ion source
  
  • Test production of Cl and Br isotopes as requested in users’ letter of intent.
  • Simple beta-decay spectroscopy station at LA1 to take advantage of neutron rich Cl and neutron deficient Cl and investigate new physics.
• Bromine and chlorine yields observed to be lower than previous measurements in 2006. Fluorine, sulfur and Selenium were investigated without success.
• Physics run at LA1 started on Friday on neutron deficient Br isotopes. Large yields close to stability, 10⁴ ions/s observed for ⁷⁸Br.
• Bromine 71 was observed at 5 ions/s on Friday, increased to 100 ions/s on Saturday after optimizing Cs dispenser temperature. No ⁷⁰Br was observed after a full nightshift measuring.
• Neutron rich chlorine were tried after that, with very small yields, 10 ions/s of ⁴⁰Cl, 0.5 ions/s of ⁴²Cl.

AOB

-Users report lasers ordered for B508 were left outside in the car park unprotected.

-The next meeting will take place at 14:00 Wednesday next week (15^th April 2015) followed by a seminar to be announced.

Minutes taken by MMF