Minutes from the ISOLDE Physics Group meeting on October 30, 2014
The minutes for the PG meeting held October 23rd have not been released yet.
Technical news
HRS

•  ISOLTRAP run with UCx target to do Scandium masses.
  • o No FC-level of Sc from mass marker was visible, so RILIS could not be optimized. Also, no radioactive Scandium was observed. Molecular ScO from the mass marker was observed.
  • o Gallium release was observed using RILIS, indicating RILIS path and windows are fine.
  • o Surface ionized Na and n-rich Rb isotopes were observed, indicating the target is OK.
  • o In the past Scandium has only been seen in ISOLDE from a stable mass marker. An enhancement of 400x was observed using RILIS.
  • o No target or line heating drops so far. No HT drops either.
  • o Chromium run to ISOLTRAP using RILIS during the weekend
•  Irradiations of solid state physics samples were performed behind the HRS target using the the MEDICIS monorail system *replacing the RABIT system that existed before).
•  Test of ISCOOL’s bunch width on Friday for development.
•  To come: Collections on Monday. After that heating the target to very high temperature to search of Sc release
•  Faraday cups:
  • o FC490 read 10x less than the next faraday cup. Needs to be confirmed that it was fixed.
  • o One of CC0 cups reads more than the others. Users indicate is not an issue for them.
•  Magnet cycling issues:
  • o New version of the cycling software release Thursday evening. No problems cycling since then.
  • o Alert messages being implemented.
  • o Previous stable versions of the software can be installed in case the last one gives problems.
•  Technical stop of 12 h with no protons on Wednesday was used to update the technical software INCA. No problems after that.
•  The automatic beam tuner was successfully used for the ISOLTRAP run. The process requires optimizing the elements that need to be tuned.
•  The user slit remote control is fixed. Please be mindful that the position might be miscalibrated reading out when they are in (as it was in August).
  • o Left slit can physically go to -32 but the software is limited to -25.
  • o Beam intensity did not change with slits out manually or using the software.
•  ISCOOL was retuned after the magnet multipoles were disconnected.
  • o ISCOOL acceptance is larger than the HRS beam emittance
  • o In the bunching mode (for CRIS and COLLAPs), 25% transmission. to be followed.

GPS

•  Molten salt (NaCl) test target installed.
  • o Readout problems of thermocouples at the beginning. Being investigated.
  • o HV sparks at 23 kV. One of the HV cage’ doors in the HV room was not properly closed. Fixed.
  • o Test of release of 11C and 19O in molecular forms.
•  Faraday cup FC556 leaks compressed air. Fixed.
•  Request to have a compressed-air leak-repair kit available for everybody the ISOLDE hall.

RILIS

•  The most powerful laser shows a a 50% drop in ionization efficiency at maximum power. Believed to be due to thermo lensing effect. The HRS entrance window was found coated. To be investigated further.

Safety

•  Users indicate an ongoing problem of the LN2 refill service missing scheduled dates. Magda will follow up.
•  The west access fence for the tourniquet by b508 is being installed. No electricity for the dosimeter proximity sensor yet.
•  Users observed the electrical workers accessing the permanent experiment areas without warning the people in charge of the experiments. This leads to unsafe activities for the experiments and themselves. Magda will follow up.
•  Please remind external users at LA experiments to respect safety rules and common courtesy with tools and parts from other experiments.

ISOLTRAP measurement of Sc masses

•  After no Sc released was observed from the target ISOLTRAP measured 101-102Sr with the Penning trap and 101-102Rb with the MR-TOF.
•  During the weekend Chromium isotopes will be measured. Looking in Z=24 for the N=32 shell closure observed in Ca isotopes.
•  Preliminary observation of 54V (not confirmed).

Building 508

•  The building was inspected with the construction company on Wednesday October 29th. Inspection of the electrical installation will happen next week.
•  The building needs to be thoroughly cleaned before the laser labs are installed
•  Cooling and ventilation works in principle.
•  All the locks in the first and ground floor will have the same CERN keys. Changing locks will be paid by the collaborations.
•  Pending: Compressed air; control room cables; closed circuit water cooling system; internet; safety inspection of the whole building.

AOB
The next meeting will take place at the same time Thursday next week (2pm, 6th November 2014).
Minutes taken by MMF