0. Comments to the minutes of the ISOLDE Physics Group Meeting of the 24.10.2012:
a. No comments.
1. Technical news from the last 2 weeks– HRS
a. On Thursday 2 weeks ago yield checks finished with the UC target with a new n-converter geometry.
b. ISOLTRAP took over the beam on Friday in order to study n-rich Cu isotopes. After requesting the maximum p-beam intensity the beam was gone and it was discovered that the neutron converter got displaced. It was decided to shoot directly on the target and leave the Cu lasers in stand-by. The team decided to go for the backup plan and investigate n-rich Rb isotopes until Tuesday morning. However, the yields were dropping during the weekend.
c. On Tuesday last week the TA team performed check on the target to see ageing effects.
d. The target was supposed to be used for biophysics (Ag collections) and a short REX run until Friday, but due to low yields and REX problems the cooling of the target started on Tuesday evening.
e. The RP team agreed on changing the target on Thursday afternoon before completing the full cool-down period (43 instead of 48h). A new target was installed (UC-Re) together with new surface mass markers. Some problems with the target clamps faced during the change, it was necessary to use the robot to unclamp the target.
f. On Friday setup of the beam, very strong surface ionised beam observed (150 uA), checks on 93Rb in the evening. It was agreed that this target should be used as little as possible by the solid state and biophysics teams to save it for exotic REX run. During the weekend no beam except the intense stable Rb was seen behind the ISCOOL. It could be due to high stable beam intensities which were influencing the emittance of other beams, so the mass marker was heated to empty it over the weekend. On Monday the beam intensity dropped to the level of nA. In the afternoon Tim performed the cooler tests concluding its proper operation. The radioactive beams were going through properly through the cooler.
g. On Tuesday morning REX setup was partially done, RILIS preparing of Ag ionisation for biophysics measurements. Check of the beam composition at MINIBALL and the EBIS breeding scheduled for Wednesday.
2. Technical news from the last 2 weeks - REX and RILIS
a. Last Tuesday the REX RFQ developed a vacuum leak. Only a small leak was found, which could not explain the problems. After investigation with the leak tester the vacuum recovered to the usual value. Problem not fully understood.
b. On Thursday and Friday the linac was opened in order to install diagnostic systems for the HIE ISOLDE. The emittance meter got moved to LA1.
c. Problems with the fan of the 7-gap amplifier, no slow extraction will be possible before the problem get solved.
d. REXTRAP ion source is being repaired.
e. RILIS is preparing for the Mn beam.
3. Other technical news
a. It is still not clear to which extend electricity will be available in the hall during the Long Shutdown.
b. On HRS the FC20 Faraday cup shows less current than FC490. It might be connected with using long cables and moving the amplifiers far from the Faraday cup. The problem will be further investigated.
c. On Saturday and Monday problems with reading FC490.
d. The fabulous INCA software was disabled for 3 hours.
e. A new RF amplifier for ISCOOL was installed. The amplifier, constructed by CERN rf teams, seems to work fine, a spare unit is available as well. When changing the frequency please remember about adjusting the voltage according to the calibration curve available in the logbook.
4. Physics and schedule
a. ISOLTRAP team measured masses of n-rich Cs and Rb isotopes; several values known from previous measurements got significantly improved.
b. The biophysics team was collecting Ag samples.
c. The new version of the schedule is available.
5. Safety
a. On November 19th from 10.00 to 12.00 in the ISOLDE meeting room there will be a safety shoes try out.
6. AOB
a. The meeting was followed by a seminar by Marek Pfützner.
b. The lecture series on particle radioactivity given by Marek Pfützner are available online
c. On Friday ISOLDE expects a visit of Serbian engineering students.
d. The INTC meeting took place last week: over 30 proposals for HIE ISOLDE experiments got submitted. Over 800 shifts were requested, half of them were awarded (440).
Minutes by jk