No Comments to the minutes of the ISOLDE Physics Group Meeting of the 07.11.2012:
GPS:
- On Monday 12/11, target #497 (CaO-helicon) has been installed on GPS;
- Some problems occurred during the operations of installation:
1. The robot got stuck, eventually it worked fine;
2. The target was put in the wrong place on the table in front of the front-end: a manual intervention was needed to place it in the correct position;
3. The cooling water circuit did not start immediately (probably because GPS is not used since a long time); Fixing the problem caused the HRS water system tripped and the HRS line and target heating went down;
4. Problems also occurred with the gas injection due to a failure in the PLC card (solved on Tuesday);
5. Other software problems were experienced not at the general INCA level but at the local level of FESA;
6. Finally GPS.FC20 is not going in, so we are missing a diagnostic piece
- Proton scan successfully done on Tuesday evening and yield checks followed;
- Yields measurement done but they reveal a loss of two order of magnitude in the intensity. Clearly the beam is not properly/fully transported to the tape-station.
The reason is not yet clear: one possibility can be the additional extraction electrode in this type of target, which has a wrong polarity or the front-end extraction electrode that cannot be moved. Having the GPS.FC20 out of order does not help in diagnostic.
- At the moment, the target team is trying to change the polarity of a second electrode since also this can be the cause of the bad transmission to the tape-station.
HRS:
- It is in good shape, it has worked fine over the last week with UC-Re target;
- Last Tuesday-Wednesday delayed collections on Ag and Rb were performed and REX was setup for the IS536 run: users had beam 1 day in advance;
- Friday morning few hours without beam due to vacuum problems caused by emptying one of the ISOLDE balloons: unfortunately the ISOLDE operator was not informed that it was going to occur.
- On Friday evening, following the request of the MINIBALL users to have more beam, the target group heated up the target. The result was no beam after the ISCOOL.
- Miguel eventually found out that decreasing the gas flow in the ISCOOL allows to have more beam.
- The MINIBALL users were finally happy to have 2.5 times more intensity than before but the reason why the ISCOOL was performing better with a reduced gas flow is not yet understood.
- On Monday – Tuesday : target cool down;
- During the target cool-down period several beam diagnostic tests have been done:
1. Emittance measurement in LA1: but more intensity is needed;
2. Transmission test along the beam line up to MISTRAL: the beam line, not used since a long time, was debugged: several magnetic elements were found not working or disconnected. The preliminary transmission achieved was 60%.
3. Beam diagnostics tests along the REX-LS20 line where some weeks ago new diagnostic devices have been installed: these checks are in the framework of HIE-ISOLDE development.
- Target change today morning: #495, Ca-VADIS
- Starting from today, the separator and ISCOOL are setup for WITCH run on 35Ar (IS433) and some night studies of 31Ar (IS476);
- This evening stable beam tuning to LA2 (yields measurement of 31Ar)
- Tomorrow, Thursday, proton scan, yields check, REX setup;
- On Friday, WITCH will start. Given the uncertainties on the GPS, it is very probable that WITCH will run on HRS, but the situation is still evolving.
REX:
- From last Wednesday to Monday morning, REX run on 98Rb for IS536 experiment;
- on Monday morning, Frederik has carried out some tests on in-EBIS decay: analysis on-going;
- Local REX-trap source repaired on Monday and being used by WITCH;
- REX.TRAP.FC10 got stuck last week and is not moving correctly: do not use it!
RILIS
Setting up for the Mn run next week
GENERAL ISOLDE: beam line survey:
This week and next week, two CERN surveyors are checking the alignment of the ISOLDE beam lines. This is in the framework to have a survey of the general status of the lines. Please, for their safety, inform them when you know that radioactive beam is transported along the beam lines that they measure: they wear an active dosimeter but they are not experienced in working in place under risk of radiation.
PHYSICS AND SCHEDULE
- From last Wednesday to Monday morning, IS536 experiment with MINIBALL and T-REX setup: aim of the experiment was to test the possibility to excited high-energy, high-spin states in nuclei produced in incomplete-fusion reaction. The test reaction was 98Rb+Li7 (the original proposal asked for 98Kr); Users very happy and satisfied both on how the experiment went on and on the obtained data; Due to the short half-life of 98Rb (quite challenging for the REX-TRAP, REX-EBIS complex) they worked with unusual tuning to minimize the in-EBIS decay; Nevertheless the beam composition was 25% 98Rb and 98Sr 75% (98Sr produced by beta-decay of 98Rb);
- WITCH (IS433) is ready to take beam. The data from last year, showed a couple of problems that have been already investigated and solved. The new run will be carried out with improved experimental conditions.
- LA2: hopefully measurements of 31Ar decay (IS476) for astrophysical interest.
SAFETY:
- Safety shoes: next Monday 19/11/2012: try different models of shoes from 10 to 12 in the ISOLDE meeting room;
- Anyone is free to buy/wear his/her own safety shoes;
- Eye-scan: The dosimeter service is asking to register the chip on the dosimeter. During such operation the users have been sometimes asked for an iris scan. For anyone knowledge: this is not required at ISOLDE. So, if you feel uncomfortable in giving a picture of your eye, you can refuse it. Magda will follow up why the dosimeter service sometimes asks for an iris scan: it must be a communication problem.
AOB:
- New student joins ISOLTRAP for the next three months: Anton Kirch comes from Posdam (close to Berlin), he is a bachelor student, he will make the bachelor thesis at ISOLDE;
- Congratulations:
1. Christopher, ISOLTRAP PhD student, defended his thesis last week in Heidelberg;
2. Monika got a CERN fellow for Biophysics and Medical studies;
3. Our associate’s researcher (M. Pfutzner) was prolonged by 4 months and the corresponding’s associate contract, who will come next year, was prolonged by 2 months.
- Ronald Garcia, PhD student from KULeuven in the group of Gerda Neyens, will spend one year in ISOLDE working on COLLAPS and CRIS;
- Many abstracts received for the ISOLDE workshop: 18 of them could not be accommodated in the program. For the ones not accepted for an oral contribution, a special poster session will be organized on Monday 17/12 evening.
- VIP’s visit at ISOLDE: a Korean delegation will visit ISOLDE next Monday afternoon. Please be ready from 5 p.m at your setup to give a nice and positive description and answer to the visitors questions. The group consists of an accelerator physicist and a particle physicist working on Dark Matter. The visit is in the framework of the Korean project to build a radioactive beam facility in Korea.
- On Monday 26th, VIP Canadian delegation will visit ISOLDE: from 10:45 a.m. be ready at your setup to give the usual nice and positive presentation;
- From Thursday on during two weeks, the main corridor of the ISOLDE offices will be painted: remove your posters, they can be back afterwards.
- New chart of nuclides are available in Jennifer office: the folded ones will be distributed as one per ISOLDE experiment setup, the posters are for the official places. The old posters from 2006 will become available.
- No final decision on building 105 and 507 has been yet taken.
The meeting was followed by the seminar of Etienne Liennard, from PLC, CAEN, on “Beta-neutrino correlation measurements with LPCTrap”.
Michael Tandecki, ex PhD student at KULeuven working in Witch and now PostDoc at Triumf, will give a seminar tomorrow at 11 o’ clock.
Seminar next week - Bradley Cheal: http://indico.cern.ch/conferenceDisplay.py?confId=209162