Minutes of the LIS Section meeting held on 12 March 2012

Present: G. Arduini,  H. Bartosik, E. Benedetto, N. Biancacci, C. Carli, M. Fitterer, V. Forte, A. Garonna, S. Gilardoni, M. Giovannozzi, C. Hernalsteens, A. Lachaize, E. Métral, A. Molodozhentsev, N. Mounet, A. Ulsroed, R. Wasef, C. Yu

PS model in PTC (Cedric) - slides

Cedric went through the basic principles of PTC and presented the model developed for the PS providing a list of parameters that offer a good compromise between accuracy and acceptable execution time. Scripts to easily select a subset of elements relevant for some of the most common configurations have been provided to reduce the computing time.

In PTC a model including thick multipoles can be used. The strength of the multipoles will be based on the magnetic field simulations performed by M. Juchno. Pole face windings are included as thin lenses.

Round Table (all)

Elena

Elena is studying the impact of the replacing two main PSB dipoles with shorter ones in the injection region. The beta beating produced by this modification seems to be smaller than that due to the chicane or that due to imperfection already present in the ring and contributing to the strength of the Q_V=9 resonance line. The effect of the reduction of the super-periodicity from 16 to 1 should be studied.

Vincenzo

Learning to use ORBIT-PTC. Some issues with the definition of the emittance and dispersion remain to be clarified with Sasha.

Raymond:

He is studying possible means of reducing the space charge tune spread by distorting the optics by powering the PS gamma-jump triplets. A reduction of the space-charge tune spread by 4% could be obtained but the effects resulting by the reduction of the super-periodicity and the possible enhancement of some systematic resonances should be studied.

Chenghui

Wolfgang Bartmann has found a solution for the matching of the BT-BTP line to the PS with the new injection optics studied by Chenghui. A beam test will be organized to see whether this could allow reducing the losses at injection for high intensity beams.

Simone

The CNGS beam is being set-up with chromaticity correction at injection energy. The possibility cycling the magnets at low current to minimize the magnetic history affecting MTE is being considered.

Adriano

Studying stochastic extraction by RF noise.

Adrian

Working on the matching of the PS to SPS transfer line for the low gamma transition optics in the SPS.

Hannes

Preparation of scrubbing run in the SPS with 25 ns beam progressing. No sign of instabilities observed so far. The measurements performed in the new coated chambers without magnetic field seem to indicate the absence of multipacting and that the pressure rise observed in the past in dipoles with a-C coated vacuum chambers was due to multipacting occurring in adjacent uncoated vacuum chambers.

Sasha

The MPI executable file of ORBIT-PTC is corrupted since last Friday at 18:15. The problem is being addressed with the help of F. Schmidt.

Tests with the stripping foils are being performed as Christian noted that no blow-up was induced by the foil.

Next meeting

Monday, 26^th March 2012 at 09:30 in room 6-R-012. Please note the unusual time.

Agenda:

General information (Gianluigi)

Round Table

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