Minutes from REX meeting 2005-09-07
Present:
General
* Fredrik
is absent for the ICIS05 conf between Sunday
* For the Kr run next week only 88Kr has to be delivered. Probably
as 21 => A/q 4.19. The REX MD is Tue/Wed and the run starts at
Wednesday evening or Thursday morning. Running at HRS.
Maximal intensity is requested, but keep Alexandre Dorsival informed about the radiation level close to the
REXTRAP roughing pumps.
* Mats
will inquire to the vacuum group about the progress of the preparation for the
installation of the gas recovery balloon for REX.
* Mats
and Fredrik will go through the REX budget (this year and next) after the NUPAC
meeting.
* There
will be a review meeting of the control group activities the 23/9. Mats will
give a presentation about ISOLDE and REX. He will suggest the CO group to
finish started activities and not start to migrate the
REXTRAP CS until 2008.
* Romain will transfer his knowledge about the REXTRAP CS to Sylvestre Catin before (if) he
leaves.
TRAP and EBIS
* The
trap and EBIS have been optimized with 6,7Li beams and Ne
and Ar buffer gases have been tested. For Ne buffer gas the trap efficiency is 20% and with Ar it drops to 5%. For the EBIS the Li3+ efficiencies are 13%
and 8%, respectively.
* The Be run is challenging with low beam intensities, short
half-life for 12Be, stripper foils, and RILIS using frequency tripling.
* Romain and Richard will take care of the LN2 filling of
trap and EBIS and LHe filling of the EBIS next week.
Trap last filled this Tuesday.
* The roughing pump of the REXTRAP is now
surrounded by lead brics.
* Ulli Koester has
quickly arranged 20Ne to be used as buffer gas in the trap to avoid
contamination on top of the 11Be beam. The small quantity will only be used
when 11Be is run.
LINAC
* The LINAC has been pre-tuned for A/q=3.6666
(11Be3+) and 3 (12Be4+). 80-90% transport efficiency to the last cup before the
experimental setup. Only 60% transmission through their
collimator.
* A radiation warning sign should be placed
next to the 7-gap resonators when the linac is
operated at 100 Hz due to the increased x-ray level.
* The 200 MHz amplifier has been successfully
repaired by the RF group and is now fulfilling its specifications. That is it
can be run at 100kW, 100 Hz repetition rate and with 900 us pulse length. Some
minor tests remain to be carried out. The fundamental problem was a circular
resonance in the anode capacitor. By adding three slots in the central plate
the resonance condition was broken. The inductive ferrite blocks were then
removed.
Minutes taken by Fredrik Wenander