16 November 2011

1. Technical news:

· It was discovered during the WITCH run that changing the heating of the target line (possibly also the target) in a VADIS ion source may cause a change in the plasma potential. This in turn changes the transmission, which can be gained back by tuning the acceleration voltage.

· After the very successful performance of the CaO target yield measurements were scheduled in order to compare its performance before and after use. It turned out the target line developed a short cut some time after the run and before the yield checks, which therefore could not take place.

· The ion beam behind ISCOOL has a ripple, but the faulty power supply was not identified. This didn’t disturb the LA1 run but could be a problem for the COLLAPS run on stable manganese, as beam fluctuations are evident in the fluorescence signal.

· HRS was operated with a resolution of DM/M=1700, which gave a suppression factor for 20Na with respect to 20Mg between 100 and 1000. A higher suppression should be possible when the slits 275 are repaired.

· Due to a slightly thicker target at MINIBALL, REX had to be operated at its highest energy. This caused problems with the 9 gap. Didier and Fredrik request that any frequency change for REX at these energies should be done by them or should be communicated in advance.

2.Physics and schedule:

· WITCH had a successful run on 35Ar and probably first physics results. We are all invited for a reception in room 1-1-025 on Thursday at 3pm to celebrate with them.

· There was another successful run looking for beta-delayed protons from 20Mg. In addition they identified a new decay branch in 21Mg.

· Very good collections took place using 83Rb beam, which benefitted from higher yields due to the rhenium cavity.

· At MINIBALL a g-factor measurement will take place on 74Zn.

· Next week there will be two separator courses followed by an alignment of ISCOOL the following week.

3.Safety:

· There will be a safety visit at CERN on Nov 21-st by tri-partite authorities (the French, the Swiss and CERN). They will most probably also visit ISOLDE. Magda kindly requests that at least one representative per experiment comes to ISOLDE at 1:30 on Thursday (before the WITCH party) in order to help with the cleanup.

4.A.O.B.

· ISOLDE will welcome two new fellows in 2012: Susanne Kreim (ISOLTRAP) and Elisa Rapisarda (MINIBALL).

· The deadline for urgent proposals and addenda to the next INTC meeting will be Friday, Jan 6 at noon.

5. Seminars:

· Dr. Umesh Garg (University of Notre Dame) presented “Nuclear Incompressibility, the Asymmetry Term, and the MEM Effect”.

· For more information and links to the slides please visit the ISOLDE - seminars page.

 

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