1. The following comments were made to last week's minutes
a. Point 5b. LOI88 was supposed to study the possible application of b-NMR technique to “solve biological problems”, independent of the method of spin polarization. The use of the COLLAPS setup is due to the well established experimental technique.
b. Point 4c: only the emittance measurements were performed by CATHI fellows.
c. Point 2f: the fact whether the valve was sealed or not sealed was not brought up in the Technical Meeting.
2. Technical news - GPS
a. On GPS, until Tuesday morning, measurements with UC-W #484 target took place. Record yield of 31Mg was observed at the beginning. For the 27Mg beam, the 27Al contamination was very low.
b. The HV was tripping every few hours at 60kV, so 55kV was used and it tripped only a few times during the run.
The vacuum in the GPS20 sector is deteriorating. It is now between 2-6e-6mbar. The vacuum team found a leak at the RILIS laser window caused by an o-ring damaged by the laser. This problem showed up already on the 24.07 and deteriorated with time, an intervention including o-ring protection - is scheduled for Monday, 20.08
c. On Saturday, the line heating went off for unknown reason. The ramping card made it to go up again quite fast, but it was not damaged.
d. Also on Saturday a problem with the PS-Booster kicker caused problems with protons. On Monday morning (6-9h), there were no protons for the same reason. The COLLAPS beam time was extended by 3h in order to complete the measurement. The Booster and other proton users are thanked for waiting for the planned intervention.
3. Technical news - HRS
a. Target change UC-Ta #477 (already used this year) on Thursday last week, followed by p-scan and yield check on Tuesday and Wednesday.
b. REX setup is being finished, the beam for IS526 expected on Wednesday evening
c. The Faraday cup FC690 located in front of the cooler is not working.
4. Technical news - REX/RILIS
a. REX: Setting up for 30Mg, good performance achieved, different A/q and E values will be tested in order to decrease the level of contamination
b. Over the weekend 1.2 MeV Ne5+ from EBIS beam was provided for emittance measurements for HIE-ISOLDE
c. The hardware and software of the fast EBIS valve has been investigated. It now works as it should.
d. The REX MCPs can provide now information on the beam spot size
e. RILIS was ionizing Mg at GPS and on Tuesday the laser beams were moved to HRS.
f. The scanning of the RILIS Ti:Si laser has not been yet performed. It is now planned during the HRS run.
g. RILIS is also busy in the offline-separator area, preparing for tests of the LIST behaviour with an outgasing carbide target, using an Yb mass marker.
5. Other technical news:
a. FC30 in CA0 line shows 10pA with beam or without it. The diagnostics team will look into it.
6. Physics and schedule
a. COLLAPS run on 31Mg finished on Monday morning with full success, reaching the goal of LOI88. The polarized ion beam was implanted into a liquid drop kept at bad vacuum and beta-NMR resonances were recorded. This proves that the b-NMR technique can be used for studying biological problems. A plate with muffins was offered by Monika to celebrate this exciting result.
b. Online emission channeling at GHM within IS453 took place from Monday to Tuesday morning studies of lattice site location of implanted radioactive 27Mg ions were performed. The assistance of Alex in lowering the 27Al and 27Na was appreciated.
c. IS526 using the REX scattering chamber with 30Mg beam is supposed to start in the afternoon. The goal is the investigation of spin-parity and spectroscopic factors of 31Mg by measuring the excitation function of the elastic scattering.
d. Magda is absent on Monday and Jan will replace her.
7. Safety
a. An ALARA3 intervention has been signed to carry out the change of the GPS RILIS window.
b. An ALARA2 is scheduled for Wednesday, related to a check of the dry-pumps by the vacuum group.
c. For the GPS UC target a 20% higher level of radioactivity was observed in the air, similar to the previous Ta target. The RP group is investigating the cause.
d. Users of the mechanical workshop are requested to leave it clean and good conditions for the next user.
8. AOB
a. Paul Finlay and Andreas Knecht are new post-docs with the WITCH experiment welcome!
b. The meeting was followed by the summer-student talk of Maria Neves entitled “11Be Emission Channeling Experiments at ISOLDE online EC”.
Minutes by jk