1. There were no comments to last week’s minutes.
2. Main Technical News
a. On GPS, after the REX setup for 210,212Rn beam was delivered to users (IS 506) on Thursday. Yields remained lower than expected even after an improvement of a factor of 2 by tuning of the Target Group (including Thierry’s help on the weekend). This was probably due to the ion source being faulty. Measurements on 210Rn went well, for 212Rn statistics remained too low, even after several attempts. During one of the attempts, TaO2 was seen in copious amounts instead of 212Rn for unknown reasons (things were checked by Richard on the weekend). This might be similar to the problem of neighboring masses during the run of IS 534 (cp. minutes 16.5.). Also REX settings gave some doubt, so Fredrik came on Saturday to help. The assistance of everybody, especially those helping on the weekend, is highly appreciated!
b. Due to a problem with the PLC controls, which couldn’t be solved quickly by the expert, operation was continued with target/ion source heating and plasma settings in manual mode.
c. During the following experiment on 221,222Rn (IS 475), a vacuum problem in the GPS.20 section appeared and right after, the transfer line developed an open circuit and made the target unusable (just before the users were supposed to stop anyway).
d. GPS.20 vacuum leak: An ALARA 1/2 intervention revealed a leak on the piston of GPS.FC490. The Faraday cup has to be exchanged with an ALARA 3 intervention planned for 7.9.
e. On GPS, a UCx target #488 with surface ionization and LIST will be installed for IS 530 experiment on 34Mg at LA2.
f. On HRS, the HT2 power supply has been checked by Jan Schipper who changed the anode voltage to 17kV. Now, the recovery time is back to the normal value of about 8ms, both HT1 and HT2 power supplies are fine.
g. At 50kV, a transmission through the cooler (to CA0) of 60-65% has been achieved with the UCx-Ta target #487. The setup of LA2 had finished only Monday evening and was followed by proton scan and yield checks for 34Mg tests within IS 530.
h. Earlier tests with target #484 on 34Mg gave a yield of 200/s with laser ionization on a background of 103/s. These results could not be seen so far. On 33Mg, 100 times lower yield is seen with the fast tape station from Strassbourg (used by IS530 at LA2) than by the Target Group (at CA0 tape station).
3. Other Technical News:
a. The new amplifier (cp. minutes 22.8.) is in principle operational, it will be tested again after small modifications before implementation.
4. REX/RILIS:
a. Mg laser beams are prepared; RILIS will switch to Po beams on Monday.
5. Physics and Schedule:
a. CRIS acknowledges all technical assistance during their run 1.5 weeks ago.
b. IS 506 and IS 475 were looking at Coulomb excitation in Rn isotopes. Both experiments studies successfully 1 out of 2 planned isotopes: 210Rn and 221Rn (with new transitions in the latter case). The teams acknowledge the assistance of all technical teams.
c. IS 530 is studying the beta-decay of 34Mg looking for low-lying intruder states in the decay products.
d. The setup for the Po experiment has started at LA1.
e. Magda and Maria will not be here on 7.9. and will be replaced by Thomas.
6. Safety:
a. Joao Batista Lopes will be leaving his department at the end of September. All experiments with ongoing safety inspections should try to finalize their Safety Files before.
b. Karl is in contact with Jonathan Gulley (chemical safety) to discuss safety issues related to the potential carciogenic risk of nano particles.
7. AOB:
a. No-longer-needed equipment of the Bohr-Weisskopf experiment is placed in the middle of bldg. 275 until disposal sometime next week. If you are interested in using some of it, have a look before then.
b. Articles about COLLAPS bio-NMR and CRIS runs will appear in the CERN bulletin in September. ISOLDE-related articles should be coordinated with Maria and distributed over several issues.
c. There will be a CERN-controlled WIFI antenna installed in the ISOLDE visitors’ room to cover all offices in bldg. 3 and 26. Please remove all other WIFI antennas by then as interferences have been observed in equivalent situations in other buildings.
d. Jan is preparing a list of all electronic devices on loan on the ISOLDE account from the electronics pool (202 modules at present). If you use any, please contact Jan. After 15 years of loan, a device becomes the property of the team which paid the rental.
e. The extension of the ISOLDE hall has to be emptied by 17.12. for HIE-ISOLDE work. Please take care of your equipment, any remnants will be moved to long-term storage without extra packing after the dead line.
f. Maria encourages the member of ISOLDE to become first aiders and/or CERN guides.
g. The external garage door of the SAS was found damaged without any measures taken. Please remember to call 77777 or talk to the building supervisor (signs at every entrance to ISOLDE) if you cause or notice any damage.
h. The meeting was followed by a summer-student presentation by Ruben De Grote (supervisor: Kieran) on “Exploring resonant laser ionization”.
Minutes taken by SK