Minutes of the LIS Section meeting held on 5^th December 2011

Present: G. Arduini, H. Bartosik, C. Carli, A. Garonna, S. Gilardoni, C. Hernalsteens, A. Lachaize, Y. Papaphilippou, R. Wasef, C. Yu.

General Information (Gianluigi)

• Gianluigi introduce a new member of the team: Adriano Garonna who joined the Section on 1^st December and he is going to work under the supervision of Christian for one year on Medical Applications

• VIA fellows: the contracts should be signed starting from 1^st Janaury 2012.

• Technical and Doctoral students and Fellows: Adrian Ulsroed has been selected to work under the supervision of Yannis on the SPS low gamma transition from 1^st February 2012. Hannes has been selected as fellow to work on SPS Upgrade issues from 1^st April 2012.

• LIU day: during the discussion Gianluigi proposed to test the batch compression scheme proposed by Christian and R. Garoby for the 50 ns beam in the PS as this could give on paper an increase of the brightness by 50 %. The RF hardware should be available for the start-up. Simone noted that this will require some time to set-up and this beam will not be available for operation at the start-up.

• The Evian meeting will take place from 12 to 14 December

• Gianluigi will be absent (on a course) from 6 to 8 December and during the Evian meeting. During Christmas he will be absent from 19/12/2011 to 6/1/2012.

Summary and present status of studies on SPS Q20 optics  (Hannes) - slides

Christian asked whether other (non-adiabatic) bunch shortening scheme were studied. Gianluigi replied in the negative (would this require an additional RF system?)

Measurement of the bunch length stability during the ramp was done with 800 MHz on in both cases (Q20 and Q26) with a 50 ns beam and showed that there is no need for a longitudinal blow-up to stabilize the beam longitudinally for the Q20 optics. The same applies for the 25 ns beams.

The injection efficiency is also improved for the Q20 optics as compared to the Q26 optics. The reproducibility of the Q20 optics transmission efficiency looks poorer as compared to that on the Q26 optics because the cycle was tuned while no tuning was done on the Q26 optics.

A maximum of 2 batches with 25 ns beam could be injected and accelerated with the Q20 optics due to lack of time.

Simone asked whether we have more non gaussian tails with the Q20 as compared to Q26 optics. Hannes replied that the wire scanner measurement data are still being analyzed in detail.

With ions the performance of Q26 is better than the performance of Q20. But the set-up is still ongoing. To be continued.

Round table (all)

Christian

ELENA: some optics issues are still to be addressed. The longitudinal beam parameters at injection and transfer need to be reviewed as well. An external ion source could be useful to commission the machine at low energy.  A proton source could be used (injecting the beam from extraction).

Radiobiology studies: the slow extraction of oxygen from PS did not evidence any show stopper but it looks rather difficult. The radioprotection issues for the operation of LEIR with oxygen should be also addressed as this mode of operation might require installing shielding on top of LEIR.

JB Lallement working on the LBS (measurement) line for LINAC4.

MTE (Simone, Antoine, Cedric)

The hybrid scheme (using the ES septum) has been tested. Some progress has been done but there are still difficulties in the extraction.

Dummy septum: optimization of the trajectories with TOF like beam is ongoing to determine the possible position settings for it and extraction settings for all beams.

The fluctuations in the relative position of the islands as a function of the supercycle composition are minimized when a 26 GeV cycle is executed in front of the MTE cycle and when the figure of eight loop is cycled before the MTE cycle.

The measurement of the island position at 2 GeV is continuing with ions.

There is an issue not yet understood with the correction of the coupling that might point either to a cabling or polarity change.

Next meeting

Monday, 16^th Janauary 2012 at 14:00 in room 6-R-012

Agenda:

• General information (Gianluigi)
• Round Table (all)

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