1. There were no comments to last week’s minutes.
2. Main Technical News
a. On GPS, target #484 had been left on and heated for RILIS re-alignment after the successful intervention in the GPS20-section (cp. minutes 15.8.). The vacuum is again below 10-6 mbar.
b. On Monday, target #485 UCx (cold plasma) was installed and setup. Yield checks of 6He are within expectations, the release characteristics were determined. The beam is planned for users before the weekend after REX setup.
c. On HRS, the used target #477 UCx (surface) was installed for 30Mg-beam to REX. After some vacuum problems last Wednesday, the beam was delivered still on Wednesday night to users (IS 526) with yields comparable to the data base ones.
d. On Sunday, the CRIS experiment IS 471 took over.
e. In the coming days, tests of ISCOOL and of the new RF amplifier are planned. In the case of successful testing, the new amplifier will be installed, the old one will remain available as spare.
3. Other Technical News:
a. The diagnostics problems from last week on HRS.FC690 and CAO.FC30 have been solved, the FC in the REX beam line remains broken.
4. REX/RILIS:
a. FC prototype for HIE-ISOLDE fulfilling special geometric constraints has been tested with stable beam and exhibit some problems in the secondary electrons suppression.
b. The setup of REX for 6He is challenging because of the light mass. Presently, REX is being set-up by shooting through REXtrap. Hydrogen as cooler gas is being prepared as a back-up solution.
c. The damaged o-ring at the GPS RILIS window has been successfully exchanged.
d. The dye-aging problem at the end of the Mg run was due to a wrong chemical delivered by the chemical stores.
e. The Ti:Sa laser is presently tested in narrow-band mode for scanning Fr isotopes.
5. Physics and Schedule:
a. Within IS 526, the levels of 31Mg were investigated by proton elastic resonance reactions using the REX scattering chamber (cp. minutes 8.8.) to study the structure of Mg within the island of inversion.
b. Within IS 471, the spectroscopy of Fr isotopes reaching A=203 was successful. The efficiency of the CRIS method was 1:100 close to the expectations within the proposal.
c. Within IS 505 the 10-6 (E > 500 keV) beta-deuteron branch of 6He will be studied using an optical time projection chamber at REX 2ndline. The energy of decay products will be measured using a gaseous detector with the aim to explore low energy delayed deuterons
d. In the last few weeks, three new experimental techniques (CRIS, tilted-foils beta NMR, beta NMR for liquids) have been successfully realized. The three are connected with the thesis work of in-house students.
6. Safety:
a. The chemical store at CERN provided acetone instead of ethanol. Please pay attention to deliveries!
b. The GPS ALARA3 intervention went well (cp. minutes 15.8.). Much lower doses than expected.
c. It is planned to use hydrogen gas at REX, appropriate safety measures will be taken.
7. AOB:
a. There will be a visit of about 40 Swedish high-school students on 13.9. People who can help with the visit should contact Magda.
b. The transparent trays next to the printer 26-1033-HPW have been emptied. Please use them to store uncollected print outs. Everybody is reminded to quickly recuperate prints.
c. Building 115 needs some cleaning, will be organized by Karl within the next fortnight.
d. Please keep the workshop clean and in working conditions for the next user.
e. The meeting was followed by the summer-student talks of Fatima Raihan on“Nuclear Spin Polarization with the Tilted Foil Method” (supervisor: Magda), Amalia Hadjitheodorou on “Probing Soft Matter with β-NMR Spectroscopy” (supervisor: Monika), and Elise Wursten on “Study of the ion temperature in the WITCH Penning traps” (supervisor: Martin).
Minutes taken by SK