Minutes of the SPL steering group

meeting no. 13

date: 19 September 2008

present: E. Ciapala, R. Garoby, F. Gerigk, A. Lombardi, R. Losito, M. Vretenar, W. Weingarten

Agenda

1. General news and facts
2. New Actions
3. Next meeting
4. Comments to the minutes

1. General news and facts

• RG reported on a meeting with the SPC last week. This was triggered by a request from the Council, which wanted to understand the reasoning for the SLHC efforts.
• MV reported that the finance committee has approved the 2 civil engineering contracts for Linac4, which means that the first earth will be moved in October.
• FG reported on the recent *HB'08 workshop*. A summary was given in the recent SPL study group meeting #87. A preliminary list of talks can be found here here. There was a talk on H- laser stripping by Danilov, where he discussed the application of laser stripping for the SPL. At the SPL energy the technology seems to be much closer to realisation than at the SNS energy of 1 GeV. The subject should be followed.
• RG said that at some point we have to answer if a SPL cryo-module, designed for 2K and high-duty cycle, could also operate at 4.5 K for the LP-SPL.
• FG looked at the reflected RF power, when a SPL cavity, matched for 40 mA is operated at 20 mA. Only 11% of the power are reflected, which means that we can use one coupler matching for LP and HP-SPL. See graph:

• WW and VP have visited CEA last week to define a work-package for the construction of a SPL-type cryo-module by CEA. The latest draft already contains comments by all participants and is not expected to change dramatically. It is planned to have a kick-off meeting towards the end of October. A conceptual design report is expected to be ready for end of January'09. The most pressing issue is confirm the choice of the geometric beta of the SPL cavities. Going away from b=1 means a certain effort of re-designing, so it must be clear if this b=0.92 is really the optimum. AL will look into this question. There should be a big meeting with CEA in November, where the basic parameters have to be fixed. Going away from b=1 means a certain effort of re-designing, so it must be clear if this b=0.92 is really the optimum.
• It is not clear if electro-polishing for the b=0.65 cavity can be done at CEA. SC said that we should be able to do this at CERN.
• FG was contacted by S. Wronka from the Soltan institute in Poland on possible collaboration subjects. S. Wronka will become the head of a small accelerator theory group and their work could also include the use of their labs. It was suggested to have a small meeting with him, when he is at CERN, so that all interested parties can understand the possibilities. Possible subjects are: i) simulation work on the cryo-modules, ii) longitudinal momentum collimation of the SPL beam, iii) aspects of the RF distribution network for the SPL, iv) beam dynamics (PS2, SPL),
• AL reported that there was feedback from the Cockroft institute on the subjects of collimation. They seem ready to start on collimation in Linac4, but they have not reacted to the added proposal by RL to write an interface script that allows import/export of particle data between FLUKA and tracking codes. A meeting is proposed at CERN between October 14 and 17.

2. Actions

Assigned to	Start date	Description	State	Result
VittorioParma	2008-09-24	study possibility to operate LP-SPL at 4.5 K	openclosed		edit
RolandGaroby	2008-09-24	organise meeting to review the detailed design of the components in the cryomodule before the end of 2008	openclosed		edit
RolandGaroby	2008-09-24	prepare for the end of 2008 a detailed work plan until end 2011, including request for resources	openclosed		edit
FrankGerigk	2008-09-24	publish summary document on the basic SPL parameters	openclosed		edit
EdmondCiapala, OlivierBrunner	2008-09-24	contribution on RF hardware for SPL summary document on parameters	openclosed	done	edit

3. Next meeting

17 October, 16:00 in 865-1-D17

4. Comments

• test comment -- FrankGerigk - 25 Sep 2008

-- FrankGerigk - 24 Sep 2008

• FutureLS_Danilov.ppt.pps
• Work-package_specification_SPL_cryomodule_Ver1.doc
• Subjects_for_SPL-Vittorio.doc