Minutes
from REX meeting 2004-10-13
Present:
General issues
* The minutes
from the last meeting were approved.
* Mats is about
to create an email list for the people involved in REX.
* An updated
budget with spending so far 2004 was presented. Approximately 5 kCHF out of 170
kCHF have yet not been used or reserved. It remains to determine what belongs
to consolidation and to operation/maintenance.
* The ISOLDE
server will be changed today Wednesday at
* For the 9,11Li
run the buffer gases from the REXTRAP may cause contamination problems. We have
the possibility to change between Ne and Ar buffer gas. Alternatively we use
installed stripper foils after the Linac to move the charge state distribution
of the contamination away from the 9,11Li.
* The first draft
for REX budget 2005 was discussed internally between Pierre, Thomas and
Fredrik. Priorities were agreed on and Thomas will update the budget once
again. Still lacking input from the beam diagnostics group.
* After a long
delay the repair of the three roughing pumps have commenced. One is
non-repairable, while spare parts are ordered for the other two. The total cost
is estimated to 1 kCHF.
Control system
* Mats will
discuss with Franck di Maio about the involvement of Nikolai Trofimov in the
daily maintenance of the present control system.
*
*
REXTRAP and REXEBIS
*
Beam from GPS has been delivered to Witch via the REXTRAP since Saturday
evening after the Mg run with Miniball was finished. Stable 138Ba and
radioactive 122In. The radiation level was quite high at the trap exit, 300
uS/h.
*
7Li beam from the GPS target has also been taken to setup the low energy part
of REX. A trap efficiency of 38% is reached, while the EBIS efficiency is only
4-5% (20-30% expected). The light mass may cause problems for the timing of the
ramped potentials. To be investigated on Thursday/Friday.
* A
shorter cooling time of 10 ms may be tried for the Li run, or we trigger the
trap to the proton pulses to maximize the throughput of the short lived Li
isotopes.
*
The contamination on A/q=3.6666, the mass-to-charge ratio to be used for the
acceleration of 11Li3+, diminishes to sub-pA within minutes when the Ne gas
inlet to the trap is stopped. If we have time the cooling of K+ using Ar will
be tried on Thursday/Friday.
*
The GPS target is cooled down Wednesday evening.
*
*
One of the turbo pumps in the REX mass separator stopped again last Saturday
morning during the Mg run. That means, the unexplainable stops still remain.
LINAC
* The Linac has been setup
for A/q=3.6666 and 4. A very nice beam spot of 3-4 mm diameter at the target
was obtained. An energy between 2.8 and 2.95 MeV/u will be attainable for the
Li run. A stripper foil is also installed in the beam diagnostics box before
the bending magnet as mentioned above.
* The diagnostics box in the
2nd beam line is repaired. A couple of hours EBIS beam is needed on
Thursday/Friday to check the MCP.
*
The cost (25 kCHF) for the spare buncher amplifier that was ordered 2003 has
been split between the collaboration account and the physics group account.
* Peter
B inquired about the progress of with the ISTC proposal fro the energy upgrade.
Input from the physics community regarding the energy steps and range is
needed. Mats will reestablish the contact with the Russian contact person to
move the project forward.
Minutes
taken by Fredrik Wenander