In the absence of SK, the minutes were taken by TEC.
No comments on the minutes from previous week.
1. News from the technical group:
· HRS: 2 more night shifts with CRIS were very successful.
· HRS: ISCOOL tests during the day resulting in high performance at 60 kV with the nominal transmission of 80% to Faraday cup HRS.FC748 with mass A=40 after refining the tune on the RFQ injection.
· HRS: target change planned for Thursday: #487, UCx+Ta surface/laser ion source.
· GPS: setting up 6He to REX until Friday.
· GPS: HT interlock on Sunday (not shown in VISTAR). Reason unknown. Wrong mass display on VISTAR. Both software issues due to a communication problem with PLC. Solved on Monday.
· GPS: operation break for 4 hours on Monday for unforeseen PS access. Factor x2 beam loss upon restart, partially recovered by increasing the line temperature and the gas flow to the ion source.
· GPS: Exceptional permission of RP to increase in proton beam intensity limit to 2.5uA from Tuesday morning until Wednesday morning (most of the time the 2.5uA were available). This increase is reserved for exceptional cases.
· GPS: line temperature drop on Tuesday, recovered, no damage to the target. Reason unknown.
· Recovery time tests on ISOLDE HV supplies (in preparation for 34Mg experiment). HT1 has the nominal recovery time (6-8 ms). HT2 has a more problematic behavior: instabilities and 15ms at 30kV, 40ms at 50kV. Timing of the pulsing investigated and fine. The supply itself will be investigated on Monday.
· REX: as expected, difficult 6He setup. Three approaches were tried: set the beam by shooting through REX-TRAP on Wednesday; not a success. Attempted to setup He beam with H2 cooling on Thursday; not a success. Attempted to setup He with 22Ne cooling on Friday; about 0.1% efficiency. Beam was delivered according to schedule.
· REX: EBIS extraction electrode and gun went off on Saturday (due to an interlock). Solved the same day.
· REX had considered using the expensive and rare 3He as pilot beam.. The REX team would like to thank all those who quickly help to realize this approach and made the gas available, even though it was not used in the end. One should keep in mind that setting up light masses is very complicated. Mass A=6 is currently available but not mass A=4.
· The REX team would like to remind the users that changing masses at REX is not trivial. Please inform the operator and the REX team in advance about the masses of interest for your experiment and when you foresee the changes. One member per experiment may be trained at the time of the experiment to manage such changes when no operator is directly available (night/week-end). Changes not discussed beforehand are forbidden.
2. Physics and schedule:
· CRIS continued to have test beam in the nights from last week and observed resonances in 202Fr.
· 6He was studied in an optical TPC at the REX second beam line. Particle decays were observed in spite of the beta-decay background. The experimental team would like to extend its thanks to the operators, the REX team and the PSBooster for the proton availability. The yields observed were only comparable to the tabulated yields, (at the beginning and it dropped considerably during the weekend), in spite of the use of the VADIS ion source (should have given a x10 improvement).
· REX is currently being set up for 2 experiments at MiniBall with Rn beams. The beam should become available from Thursday onwards and run over the week-end.
· 34Mg will be delivered from HRS as of Monday to LA2. The team will later take beam from GPS with the next target (LIST).
· The LIST target has been successfully tested off-line and will now be tested with the lasers. It will then be loaded with the UCx material for installation on Wednesday.
3. Safety:
· Good operation at 2.5uA – no activated-air alarms
· Please keep the ISOLDE workshop clean. J.Thiboud is now in charge of inspecting the workshop regularly and updating its tools in case of needs.
· ISOLDE chemicals should be kept in the chemical cabinet between NICOLE and REX. Please bring back the beakers that are not in use!
· Radioactive sources have been since on their own around the ISOLDE hall. Please return them to the safe as soon as you are finished with them.
4. A.O.B
· MK still searches for 2 guides for the Swedish group on September 13. 22 people only.
· The deadline for submission of abstracts to EMIS is August 31. At the meeting, abstracts by TEC (CRIS & ISOLTRAP), SK (ISOLTRAP) and Hans (tilted foils) were mentioned.
· Crane course scheduled on September 20-21, in French with handouts in English. Please contact MK if you would like to participate.
· There are several ISOLDE communications coming close to one another into the Bulletin. It would be advisable to spread them in the future over the year to maximize the visibility of ISOLDE. Please coordinate any further Bulletin communication via MJB.
· The hyperfine anomaly equipment will NOT be taken by the Russian group who showed interest on it in the past. It could therefore be used by any other group at CERN or simply disposed of.
· Joonas Konki, from JYFL, is joining ISOLDE for a month to help out with MiniBall and with the ISOLDE DAQ.
· Hans and Henry are leaving ISOLDE. A surprise celebration was thrown in their honor.
5. Seminars by summer students:
· Jean-Baptiste Durrive, under the supervision of Elisa Rapisarda, on ‘X-ray emissions measured at MiniBall’.
· Teresia Olsson, under the supervision of Matthew Fraser, on‘3-gradient emittance measurements at ISOLDE’.
· Ioan-Bogdan Magdau, under the supervision of Matthew Fraser, on‘REX-ISOLDE pre-buncher feasibility study’.
Minutes by TEC.