Minutes
from REX integration meeting
Present: Friedhelm Ames, Pierre Delahaye,
Fredrik Wenander, Mats Lindroos,
Peter Butler, Luis Fraille, Lee Neville
First the new RF
technician Lee Neville was welcomed to the team.
1. Miniball
meeting
At the Miniball meeting in
* Higher final beam energy
(the upgrade to 3 MeV/u is welcome)
* Longer pulse
duration from the EBIS. Slow extraction should be implemented. A matter of reprogramming the ramping of the trapping tubes.
* Phil Woods inquired
about the AlF tests. Mats Lindroos
will contact him when ISOLDE and REX are ready.
2. Control system
* O. Kester has been in contact with Mats Lindroos
concerning sending Stephan Emhofer to CERN in
beginning of April to be involved in the re-writing of the control system. The
financing remains to be clarified.
* A technical meeting
with the people involved with the control system was held in the beginning of
the week. The technical solution for upgrading from NT to XP exists. A framegrabber card for the BD computer has to be changed. One
would then run XP to 2006. The computers concerned are the BD, Profibus FE, linac, EBIS, control
room computers.
* The non-working PCs
in the control room have been emptied from useful insert cards (potentiometer
card etc) and recuperated by the IT department.
* A request for a 20
inch screen has been sent to Philippe Potdevin as no
spare screens were available from the ISOLDE controls.
3. REXTRAP
* The trap delivered stable
beam to WITCH last week. At the end of the run no ions were extracted from the
ions source any longer. It has been refilled and some missing dimensions were
retrieved when the source was opened. The remote control of the gas has been repaired
and tested.
* Next week beam
transfer line tests to the EBIS are foreseen. Ivan Podadera
will be invited.
* The preparation for
the emittance measurements have started. The emittance meter will be requested
for test in March. Friedhelm Ames will contact
4. REXEBIS
* The turbo pumps are
under revision. The 2 double stage molecular drag pumps are damaged (vibrating
and blocking, respectively), possibly by overheating. One could be repaired,
the other not. A replace pump of same type would cost 22 kCHF,
so a cheaper and less performing pump will be bought instead. Delivery mid March. Small Alcatel pump still to be revised.
* The gun gate valve
was found to be scratch at the sealing. Sent away for
re-machining.
* Section 0 can now
be pumped again after the fast-shutting valve is permanently connected to a gas
bottle.
* The unwanted switching-off
(two times) of the controller for the electric bender turbo in the separator is
probably caused by problems in the mains line. David Porret
is looking into the issue.
* A spare collector
supply, also to be used at the test bench and for higher electron currents,
will be ordered. An additional expense to the budget of 8400
euro.
* The alignment of
the drift-tube is still pending.
* A number of smaller
jobs under progress.
* A scintillator with PM-tube is under installation at the
dipole magnet in the separator line. Ideas about a Si-detector
after the trap (at WITCH) are being considered.
5. Linac
* The
cost for the repair of the Coulotron MCP is lower
than expected. So also the cost for the cabling and ventilation work for the
200 MHz amplifiers.
* The
energies after the upgrade were clarified. Maximal energy will be 3 MeV/u. There is a discrete step from 2.3 to 3 MeV/u. 3.1 MeV/u is not reached
as the energy spread into the new 9-gap resonator is too large for the then
required 2.3 MeV/u injected beam.
* Misc installation works are on-going in the hall. Tests of
the RFQ.BO30 MSP suggest it is broken. It has been exchanged for a MCP.
6. Schedule
* The startup date of REX is still foreseen for the
end of March.
* A few on-line requests were mentioned: 28Mg, 24Na,
66Ni, 68Ni, Se. Highest priority have AlF and elements
around mass 140 (D. Habs experiment).
* 7 Miniball experiments are
to be scheduled from July to October.
* For future Kr runs (and noble gas runs in general
with high production rate):
1. The trap
efficiency has to be optimised.
2. The trap
roughing pumps have to be shielded or the area surveyed (A. Dorsival
contacted about the matter).
3. Gas
recuperation to the decay balloons. (Not possible this year
according to the vacuum group.)
* A thin delta-E detector will be installed in the Miniball line to quantify the amount of beam contamination
with different Z.
* Updated budget request to be presented to Peter
Butler next week.
Notes by Fredrik Wenander