Minutes
from REX integration meeting
Present: Mats Lindroos (chair), Pierre Delahaye,
Fredrik Wenander, Peter Butler
1. Planning and general issues
* The ‘final’
schedule for ISOLDE and REX has been released by Luis. To be found at: http://isolde.web.cern.ch/ISOLDE/schedule/issched.html
* As the beam setup
of the LINAC with its new cavity is not done yet, the warming up of the EBIS
cryostat can not be performed before next beam time in mid July. Some support
for the coolant filling has to be organized.
* The EBIS cathode
should be exchanged before the next run. This will be done starting next week.
Thomas should then have beam again around the 16/6.
* Absence:
* David Porret has been asked to attend next REX meeting to explain
what is going on with the REX Simatics system. The
weeks after Ivan Deloose and Nicolas David will be
invited.
* An updated budget
for next week was requested by Mats. Financial posts for the beginning of the
autumn up to 50 kCHF that could be covered by the
collaboration should be identified.
* The REX-team should
start sketching on a document describing the REX-ISOLDE’s
commitments to the users.
2. REXTRAP and REXEBIS
* The VME controlling
the REXTRAP is still stopping after some time. It seems to be network problems
and an exchange of the network adapter will be tried.
* The HV tube
connecting the trap ion source to the trap is sparking to the Faraday cage. A
long-term solution is investigated by Michael O’neil
(Tony Fowler has been consulted), while a quick
solution will be tried by Pierre and Fredrik.
* The TREK steerer supplies for the EBIS have been repaired.
* Ivan Deloose has had a first look on the slow extraction out of
the EBIS. He’ll evaluate the effort needed and thereafter decide if he can do
it.
* A summary of the
last REX run, IS416, from the low-energy team is given below.
1. The setting up of GPS-REXTRAP, trap, Beam transfer
line and EBIS took in total 17 hours (effective time), without major incidents.
This should be kept in mind for future scheduling. (I belive
Thomas needed at least 8 hours to setup the Linac. In
total this gives 3 working days setup for REX.)
2. The GPS to REXTRAP beam setup went well. Reached
80%, then Richard Catherall increased it to 90%. The
support by the EIC for future beam times is appreciated as:
HRS
transport is claimed to be more difficult
REX-team
is in general very busy with setting up trap and EBIS
3. The trap worked with 50% 133Cs. The VME crashed
every ~8 hour, but the process (the timing signals etc) kept on running in most
cases.
4. We could not use the previously found settings for
beam transport from trap to EBIS. The beam was lost in the beam transfer line.
Reason unknown, and worrying. Remanence field in the support structure of the line? For checking the
beam transfer and EBIS injection we'll try Li from the test ion source. K+ and
U+ from ISOLDE are foreseen for Monday 7/6.
5 After beam transfer adjustment we managed to breed
133Cs27+ with a record efficiency of >14%.
Notes by Fredrik Wenander