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

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

Technical news

• GPS:
  
  • Molten Pb target installed for  IS598 (Windmill and Isoltrap)
  • Users report again that the working sets do not refresh until prompted in case of crashes. Under investigation.
  • Intervention in scanner 482 did not find any mechanical problems.
• HRS:
  
  • Most of the ISCOOL electrodes where replaced last week. The ground electrode and one of the extraction electrodes where cleaned and will be replaced at a later stage (wrong drawings).
  • ISCOOL continuous-mode transmission now degrades slowly at 40 kV and disappears above that energy. 30 kV will be used for now. Under investigation.
  • New SiC installed for IS507 (²⁰Mg). Yield checks were performed by Jochen for IS507 on Wednesday and Thursday.
• RILIS:
  
  • .
• REX/HIE-ISOLDE:
  
  • The first HIE-ISOLDE cryo-module will be installed this Saturday.
• Target group reports that the tape station deflector sometimes needs 1600 V for tune instead of the usual 2300 V. Deflector being investigated.
• The last valve in LA2 got stuck half closed. The repair will be postponed to at least Monday, May 4^th.
• Users report the LA2 does not have a spare controller box for traveling experiments’ faraday cups. It will be investigated.
• ISOLTRAP users report the CC0 faraday cup wasn’t working, reading 0 when inserted.
  
  •  An inspection was attempted but there was equipment blocking the access.
  • The group leader reminds that the space between lines must be kept clean for easy access.
• IDS users found the CB0 (?) faraday cup with the pressurized air disconnected. Fixed.
• Users request that the chemicals cabinet is moved out of the ISOWORK extension into the main hall.
• IDS users remind that end of beamlines lines are not equipped with Penning pressure gauges. In addition, the operation of the last valves has to be always on forced mode on LA1, IDS and COLLAPS, although the threshold should correspond to a pirrani reading.

Safety

• The coordinator reminds the group that the SAS doors in the ISOWORK area must be closed at all times.
• Eating and drinking are only allowed in B508 kitchen.
• The coordinator reminds the group that the RP current limit on ISOLDE targets is 2 uA.

Schedule           

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

IS598 report

• Scientific goal: measure the charge radii of neutron deficient and neutron rich Hg isotopes.
  
  • The measurement of neutron deficient 177-183Hg will explore shape coexistence in the region
  •  In the neutron rich region the charge radius transition observed at N=126 will be investigated.
• Laser ionization in source using a three laser scheme in the VADIS ionization chamber.
• Confirmed previous measurements for ^181-185Hg, new measurements of ^178-180Hg. Reference measurement of ^202,2-3Hg, new results from ^206,207,208Hg, including mass measurements using the MR-TOF+ISOLTRAP.

IS507 report

• Scientific goal: study of the beta-delayed proton emission in ^20,21Mg.
  
  • Identify the proton/gamma widths for states of astrophysical interest.

AOB

-B508 has only one phone in the data room. New phones will be installed this week.

-CERN is moving their cellular coverage to a new company. The switch will be done June 24^th. Please see the attached document for more information. (updated 8/5/2015, the documentation will be provided closer to the date of the switch)

-The next meeting will take place at 14:00 Wednesday next week (29^th April 2015) followed by a seminar by Thomas Duguet on "Non-observable nature of the nuclear shell structure: meaning, illustrations and consequences" (https://indico.cern.ch/event/374812/)                                                                                               

Minutes taken by MMF