No Comments to the minutes of the ISOLDE Physics Group Meeting of the 14.11.2012.

TECHNICAL NEWS

Since last week, both GPS and HRS have a plasma CaO target.

GPS:

• Target #497-Ca0, helicon (plasma) ion source.
• Proton BTY line was not operational for a few hours due to a short-circuit;
• HV supply of the target has shown a 400V offset, with no voltage applied. However the offset disappears when applying the HV: quite a strange, not understood problem, but not disturbing the operations. Probably it is due to the plasma source.
• After the change in the polarity of a second electrode (actually found wrong) the ion source efficiency was recovered.
• Various measurements of Ar and C yields were taken along the week to characterize the helicon ion source.
• The measured yields of proton-rich C, indirectly estimated as CO⁺, were good and very promising. A rate of 3000/uC for 9C was estimated: the target team is quite satisfied with this value.
• On GPS the yields of ³⁵Ar measured with the tape station, were in agreement with the measurement on the Faraday Cup (no discrepancies as in HRS, see below).
• Wednesday: stable beam planned for emittance studies at LA1
• Thursday, beam transmission to Mistral, before the start of the target change on HRS;
• The next target on GPS will be a ⁴⁴Ti target (source). It is not going to take protons. It is a strong (some MBq) radioactive source of ⁴⁴Ti produced at PSI to be coupled to the ion source to a pure post-accelerated beam.

HRS:

• Target #495-Ca0, VADIS (plasma) target
• Starting from last Wednesday, the separator and ISCOOL are set up for the WITCH run;
• Proton scan and yields check done on Wednesday but there was a discrepancy in the tape-station and Faraday Cup results (FC read 10x more than tape-station) – this would be possible if presence of many contaminants. Yields measured were not satisfying.
• Wednesday evening stable and radioactive beams to LA2 (experiment hunting for ³¹Ar). Yields too low and no ³¹Ar observed.
• On Thursday, after increasing the target heating, measured higher yields. The target heating has started very cautiously by the target beam because of the recent change of the thermocouple and thus a different readout;
• Thursday night: beam to LA2 for a 2nd trial: 100/uc of ³³Ar and 7 x 10⁴/uc of ³⁵Ar, unfortunately no counts of ³¹Ar were observed.
• On Friday, WITCH started and run smoothly till today morning.
• On Monday, the yields measurement showed that the ³⁵Ar has dropped by a factor of 2 at the same target and line temperature. After adjusting the target and line heating they managed to have stable yields till today morning.
• Some numbers: 10⁶-10⁷³⁵Ar in FC before the WITCH setup, 10⁵ Ar trapped (i.e. more than measured at the tape-station). WITCH users were happy with the beam.
• Also happening today: RABBIT irradiation;
• Today afternoon - target change: next target is #492-U_xC Re-surf, already in use some weeks ago (the one giving the uA intensity of mass markers, Rb, Cs and Mn). Now it is ok for the COLLAPS and SSP runs in the next days. Information after the meeting: the target change was postponed to hursday morning.
• Thursday evening stable beam tuning to Collaps and SSP (LA1 and LA2) and from Friday, IS508 experiment (COLLAPS) starts running till next Tuesday morning.

REX:

• From last Friday to today morning, REX-trap preparing ISOLDE beam to WITCH
• Last week: beam from the local EBIS source was used to test the new beam diagnostic devices recently mounted along the REX beam-lines.
• Also the performances of thin stripping-foils made of C were tested;
• It was possible to get beams through the LINAC despite the fact that the WITCH magnet was switched on and on full field.

RILIS

• Mn beam from RILIS starting from Thursday to COLLAPS, and LA1 and LA2 for Solid State physics

GENERAL ISOLDE:

Beam-line survey: still on-going

PHYSICS AND SCHEDULE

• Paul Finlay, on behalf of the WITCH team, presented a short summary of the IS433 run and on the collected data:

o The first few days of beam were used to solve some issues, related to the strong ionization of the He (buffer gas used in the second trap) which produced an unwanted background, difficult to subtract precisely.

o From Monday morning, thanks to the better yields from ISOLDE and a better performing apparatus, they acquired very good data.

o Unfortunately, to reduce the systematic error they need to known very precisely the background in their setup. For this reason, actually only part of the total assigned beam time was used to collect physical data. The rest went for background estimation.

SAFETY:

• Safety shoes: last Monday 19/11/2012 from 10:00 to 12:00, a nice exhibition of safety shoes took place in the ISOLDE meeting room.

o Around 30 persons from ISOLDE chose and bought their shoes; therefore Anna Paula is confident to get very good prices from the selling store.

o To whom has not yet decided which shoes to buy: a few models will be available at the CERN store;

o The debate concerning the wearing of safety shoes and helmet in the ISOLDE hall even after the Long Shutdown (when no construction work will be running) is still on-going. The rule is actually wanted by the DG office.

• Eye-scan: The dosimeter service is still randomly asking the ISOLDE users to have an iris scan. Situation still to be clarified. The eye scan is not needed, but you have to say explicitly that you work at ISOLDE.
• Empty Balloon n.2: Balloon 2 emptied from 2800mbar to 877mbar, starting at 17h00 Friday until 22h50 Saturday. This time, ISOLDE operators have been informed in advance.

AOB:

• Next INTC meeting will take place on 26-27 June 2013. Low and high energy proposals will be covered; The usual February meeting will not take place due to the long shutdown.
• Susanne welcomes suggestions for the invited seminars of next year. The PhD students actually working in ISOLDE will fill the eventual gaps.
• The magazine “Kultur und Technik” of the“Deutsche Museum”, Munich, has recently published a nice article on “working as a scientist at CERN” interviewing part of the ISOLTRAP team.
• Coupure d’urgence planned on 19^th December. More details from Magda in the following weeks.
• The video prepared by the CATHY fellows at ISOLDE for the EU Authorities (for advertising the CATHY project and ITN Actions) has achieved a resounding success. On 5^th December, in the Isolde Meeting room, immediately after the meeting, the projection of the movie will follow (5 minutes long)
• VIP visits at ISOLDE:

1. The VIP Korean visit at ISOLDE, last Monday 19.11., was very successful.

2. Next visiting group comes from Canada and it is scheduled at 10 o’clock, next Monday 26.11. Paul Finlay and Dave Lunney are the official guides of the tour. The other group members are asked to be by their setups between 11 and 12h in case of questions.

• Water theft countermeasure: The big water bottles for the water dispenser in the printer room (26-1-033) keep disappearing. In order to prevent it from happening again Thomas has decided to hide the bottles at the back of the room, behind some cabinets.

The meeting was followed by the seminar of Bradley Cheal, University of Manchester on “The new IGISOL 4 radioactive ion beam facility: beginning a new era of measurements”.

Slides available on http://indico.cern.ch/conferenceDisplay.py?confId=209162

Seminar next week: Christoph Düllmann, "Super-heavy isotopes research at GSI"

On Tuesday 27.11, immediately after the Technical meeting, the seminar of Tim Giles on “Automatic Steering of Isolde beam lines” will follow (please check if confirmed)

Minutes taken by ER