CLIC RF STRUCTURE STUDIES
If we believe our own road map we have about six years (in time for CLIC1) to come up with designs of
both the accelerating and power extraction structures that : (i) have been shown by extensive testing to
meet the required technical specification, and (ii) can also be mass produced at a reasonable cost.
HUGH amount of work involved – cannot be done by present small team.
Still many open questions : best type of structure, material, vacuum, fabrication, testing, cost …..
Time to get more people involved and to take a broader look at the overall problems.
RF specialists, metallurgists and surface physics experts, vacuum and mechanical engineering help, .….
Have a new RF expert (Raguin) starting in October as a fellow, Igor will stay on as Project Associate, and
we have a mechanical engineer (Menshov) who will join us as Sci. Assoc. starting in January.
Some hope of getting a few new staff posts for R&D but in general will have to use existing staff and
service groups (EST – material and surface studies, LHC – vacuum, ….. )
All this work needs coordinating and the decisions that are taken should reflect a consensus of experts.
Would like to create a new Structures Working Group consisting of people who have this expertise.
Task of the group will be to formulate, implement and oversee a comprehensive study and test program.
Over the last 10 years or so – impressive program of work has been carried out – Walter will review the
accelerating structure part of this activity – and Lars should do the same for the PETS at a later date.
For the moment – the study group will initially concentrate on the accelerating structures but will in the
longer term look at all 30 GHz structures and components.
As you are aware – presently going through a crisis due to breakdown levels and unexpected damage.
You are probably less aware of two other major problems that we have recently encountered.
(i) main diamond-machining collaboration partner for >10 years has closed down their facility.
(ii) indications that new 60 mm diameter discs with vacuum, water and waveguides incorporated will
be very difficult and very expensive to machine.
On the structure testing side – need a 30 GHz high power RF source available for the duration of the
studies – this is an unresolved problem – planned to use the CTF2 klystrons and modulators in 2002 for
CTF3 – no alternative source available for testing until 2005.
Focus of CTF2 activities until then has to be on structure and component testing.
Organisation : Ian (Chaiman) Walter (Technical Secretary)
Members : Ian, Walter, Jean-Pierre, Hans, Lars, Erk, Igor, Steffen, Gunther, Gilbert, Daniel, Antonio,
Raguin, Menshov, vacuum expert, surface studies expert.
Mondays at 14:15 - when necessary (at irregular intervals).