CERN - European Organization for Nuclear Research  

Minutes of the CLIC Meeting - 14 March 2003

Agenda: 
 Progress in the Design of a Damped and Tapered Accelerating Structure for CLIC

Discussion of CLIC friday meeting organization
Speakers:
 Jean-Yves Raguin, Hans Braun, Frank Tecker

Ian Wilson mentioned some points that were discussed at this week's ABMB: career prospects for staff active in R&D, and PAC'03 participation.
For PAC, there are 11 papers related to CLIC, if 5 authors could attend, 9 papers would be covered. The decision will be taken at the next ABMB.
Ian will send a draft CLIC plan for human resources in 2003-08 to all CLIC study members. The plan will detail the work needed to complete CTF3, continue core R&D and have a CDR ready by 2008. This plan  will be send to the DG and R.Aymar. It will also serve as an invitation to participate for external collaborators.

Jean-Pierre Delahaye reported from a meeting at IN2P3, who is investigating in which R&D projects they can participate in collaboration with other european institutes.


Jean-Yves Raguin gave a presentation about 'Progress in the design of a damped an tapered accelerating structure for CLIC'. The previous structure had high surface field (480 MV/m) and high surface heating (ΔT>250 K) for an average gradient of 150 MV/m.
A first approach for a new 2π/3 structure gave Epeak=400 MV/m, ΔT=154 K with transverse wakefields of |Wt| = 90 V/pC/mm/m at the 2nd bunch.
A new structure was designed with lower phase advance of 110° and decreasing iris thickness along the structure that gave for a 83 cell structure: Epeak=355 MV/m, ΔT=122 K and |Wt| = 58 V/pC/mm/m.
A change in the geometry of the coupling wave guide improved this structure (mainly the wakefields) to Epeak=348 MV/m, ΔT=122 K and |Wt| = 45 V/pC/mm/m for a 77 cell structure at an efficiency of 23.8%. These values are still too high for a copper structure but could be envisaged with Molybdenum.
If one would like to stay below a peak surface field of 300 MV/m for a copper structure this would result in an average gradient of 125 MV/m with ΔT=88 K.
Jean-Yves was acknowledged for his excellent work. The study will be continued by A.Grudiev who will do optimization for other materials.


Hans Braun presented the new organization of the CLIC meeting.

Frank Tecker advertised the new web page for the CLIC meeting (since you read this page you have found it already).
The announcement of the meetings and the copies of the transparencies will be published there.
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Frank Tecker  - Last updated  24-03-2003