Minutes of the LII Section meeting held on 19^th February 2007

Present: G. Arduini, J. Barranco, G. Bellodi, E. Benedetto, O. Berrig, C. Carli, M. Chanel, A. Franchi, S. Gilardoni, M. Juchno, A. Lombardi, M. Martini, S. Maury, Y. Papaphilippou, G. Rumolo, B. Salvant, G. Smirnov

General Information (G. Arduini) - slides

Status of the site study for the LINAC4 (S. Maury) - slides1 - slides2

The new study has been triggered at the end of 2006 on request of the AB management in order to choose the position of the LINAC4 compatibly with the expected upgrade programme including SPL and PS2.

In the scheme presently studied a short transfer line connecting LINAC4 either to the PSB or to the SPL is foreseen. A. Lombardi noted that this might not be acceptable if the SPL has to be operated at high intensity. This might imply that commissioning at high intensity of the SPL might not be compatible with PSB operation with injection from LINAC4.  Action: S. Maury to verify with A. Lombardi how this problem can be solved.

S. Maury noted that the connection channels for the passage of the waveguides for LINAC4 will have to be redesigned on request of the RP colleagues to minimize the neutron flux from the LINAC4 tunnel to the klystron gallery.

In the present layout with the SPL injecting at 3.5 GeV into the PS2 and replacing the PS it is not yet clear how the ions will be accelerated, a possibility would consist in using the PS as intermediate acceleration scheme but this would imply maintaining the PS active only for that purpose.

A transfer line from the SPL to ISOLDE has not been integrated yet.

Status of the thin lens PS model and of the loss studies in the PS (J. Barranco) - slides

Only PTC seems to provide the tools for the correct tracking in the presence of edge effects for small radius machines. This would probably imply rewriting part of G. Robert-Demolaize's code and might imply introducing the K2 module (describing the interaction of the proton beam with the collimators) in PTC. The amount of work required is not yet clear. Javier and Yannis are investigating the implications of that.

TT10 optics with emittance exchange. MAD8 vs. PTC  (O. Berrig) - slides

PTC seems to provide Twiss parameters which are very close to those provided by MAD8 although there are small discrepancies of at least 1 %. Tracking an ellipse with parameters given by the initial conditions in TT10 seems to provide an ellipse whose parameters are consistent with the PTC results. G. Arduini asked whether no distortion of the ellipse has been observed (indication of non-linear effects due to fringe fields). O. Berrig replied that no distortion was observed. C. Carli suggested to check whether the resulting ellipse parameters change with the emittance considered. O. Berrig replied that this has been tested and no difference has been observed. O. Berrig added that matching tools have been provided by R. De Maria and are now available in CVS.

G. Arduini asked what is the status of the PSBooster aperture model. O. Berrig replied that it will be completed in approximately one week. M. Chanel noted that this model is important in order to understand the origin of the losses in the PS Booster.

Next meeting

Monday, 5^th March 2007 at 09:00 in room 354-1-001

Agenda

General Information (G. Arduini)

LINAC4 beam parameters (A. Lombardi)

Possible experiment in the PSB (or PS?) to benchmark the space charge codes: what has been done so far, what could be done? (M. Chanel)

What the simulation codes expect for the highest intensity beam we can have in the PSB at intermediate energy (e.g. @ 160 MeV) (M. Martini)

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