TECHNICAL NEWS
- GPS:
• Still the Ta target on. Currently being used by IDS for stable and radioactive beam tests (until Thursday morning, Aug 14).
• PSB still has problems delivering the nominal 3•1013 protons per pulse (ppp); it is presently several 1012.
• The line/target heating and HV were dropping repeatedly over the last weekend. This turned out to be connected in some of the cases to the faulty front end Penning gauge which suddenly stopped working. Currently a spare one is being used – to be followed up whether or not this would be enough for the rest of the year.
- HRS:
• CRIS finished the data taking on Monday morning, mainly tuning the device and taking data on the long-lived francium isotopes.
• Several mass-control software and hardware related problems have been reported:
a) The new mass control software was not working reliably, giving i.e. not reproducible beam after cycling. This problem turned out to be connected to the fast cycling of the program - slowing it down solved the issue. However, currently mass change takes around 12-15 min.
b) Mass control middle-ware, frontend computer and teslameter were crashing many times and often giving wrong values. The reasons are still unclear. In such situations, the users are encouraged to contact the operator in charge and compare field read-out in the software on the NMR-probe teslameters (next to the entrance to the HRS seperators).
• ISCOOL issues with bunching the beam have been solved. Last weekend the CRIS team measured: 58% of bunching efficiency with 133Cs beam at 50kV, 50% with 221Fr beam at 40kV and 25% with 238U at 40kV.
• The ISCOOL gas valve is temporarily a manual one and therefore the gas inlet regulation cannot be operated remotely from the control room. If needed for beam tuning, only the injection steering can be changed (the quadrupole triplet QP720, QP730 and QS740). For the mass change a slight tuning of the frequency should be done (proportional to 1/sqrt(mass)).
• T1 and the super cycle start signals from the PSB are again available, for both GPS and HRS.
• Target change (UC with quartz transfer line and neutron-converter + RILIS) for the ISOLTRAP experiment is scheduled for tomorrow.
ISOLDE GENERAL
- All users are requested to make detailed notes (especially concerning the observed beam intensities and beam transition) in the e-logbooks for both separators during the course of their experiments.
- The most recent ISOLDE weekly schedules will be placed directly at the ISOLDE webpage: http://isolde.web.cern.ch/experiments/schedules/weekly-schedule. No more emails will be sent around.
Safety:
- Hall division is finally in place. Users and visitors are requested to use the Jura entrance to the hall (access via the CERN cards). Passage through the extension of the hall is allowed by the local physicists who have to move equipment (preferably after 5pm from Mon-Thu and from 13h on Fridays).
Status of the running experiments:
- ISOLDE tape station: the brake has been replaced on Monday and the beta intensities are now reproducible after many tape movements. Gamma and beta detectors have been calibrated. The remaining matter seems to be the wrong readouts of the encoder (light gate measuring tape movement). To be followed up.
- IDS: many interventions on the beam line. The team has been taking the 130Ba beam from GPS since Monday (around 500pA with protons on). RC2 quadrupoles developed a shortcut - once opened it turned out that one of them was grounded by a piece of an aluminium foil. Currently 52% of beam transmission is reached into the setup. The RC4 wire scanner and the FC are being replaced today.
- ISOLTRAP: ready for the beam.
- CRIS: took beam from HRS and ISCOOL later than originally planned. The beam retune had to be done half way through the experiment as a result of which the team could not record reliable absolute yield values. Similar results were recorded like in the past. With the use of stable beam the team demonstrated for the first time the possibility of performing high resolution spectroscopy with CW lasers.
AOB
- Magda has sent around an email summarizing the registration procedure and obtaining access to the hall: http://isolde.web.cern.ch/get-access-isolde-facility
- An ISOLDE DFS folder is available for storing ISOLDE relevant materials. All experiments are asked to send their posters (both PDF and ppt version) to Susanne who will store them in this folder.
- The meeting was followed by one summer student’s seminar of Alexandra LIS (IDS).
- Next week the meeting will take place at the usual day and time and it will be followed by a seminar of four summer students: Jehad Ahmed Alshanty (COLLAPS), Michael Munch (VITO), Maxime Mougeot (SSP) and Markus Kristian Vilen (CRIS).
Minutes taken by MS