The 1st video conference meeting for the SPL cavity working groups took place on 11th of January 2010.

The participants were:
At CERN: E. Chiaveri, O. Capatina, M. Schuh, R. Calaga, W. Weingarten, T. Renaglia (part-time), F. Haug (part-time), ), S. Calatroni (from home)
TRIUMF: R. Laxdal
Rostock University: H.W. Glock
CEA Saclay: G. Devanz; J. Plouin; S. Chel
CNRS Orsay: H. M. Gassot
Royal Holloway London: Steve Molloy (part-time) 

The proposed agenda of the meeting was :
-    Approval of agenda
-    Organizational issues of meeting (periodicity, time, minutes, …)
-    Schedule of cavities and accessories manufacture (W.  Weingarten)
-    Damping schemes for SPL cavity (H.-W. Glock)
-    Proposed alternate cavity geometry and comparison with “baseline” geometry (R. Calaga)
-    Fabrication of SPL cavities and required tools (O. Capatina) 
-    AOB
-    Date of next meeting and agenda topics

The following presentations have been carried out, and can be found at http://indico.cern.ch/conferenceDisplay.py?confId=80052  :
-    Preparatory slides, by  Wolfgang Weingarten (CERN)
-    Damping schemes for SPL cavity, by Hans-Walter Glock (Uni Rostock)  
-    Proposed alternate cavity geometry and comparison with "baseline" geometry, by Rama Calaga (BNL)
 
Detailed discussions:
-    Approval of agenda => the agenda was approved

-    Organizational issues of meeting (periodicity, time, minutes, …)
The videoconference meetings will take place every 4 weeks, on Monday at 17h00 GMT + 1. 
Please note that this starting time for the next meetings is delayed by one hour with respect to the 1st meeting that was 16h00 GMT +1. The meeting duration will be of 1h30.

-    Schedule of cavities and accessories manufacture (W.  Weingarten)
No comments.

-    Damping schemes for SPL cavity (H.-W. Glock)
Simulations performed with a beam pipe minimum radius of 50 mm instead of the 40 mm for the actual baseline and 40 mm distance of pickup's inner conductor to beampipe surface to obtain Qext (fundamental mode) > 1012. Taken into account the coax pick-up, the taper but not any material, neither the bellow nor the input coupler. The influence of bellow was not fully understood, especially reflective properties to be confirmed. HWG considers that we could decrease the HOM port diameter from 40 mm to 30 mm but he thinks this is not a good idea, since it may hinder the use of a notch filter.

-    Proposed alternate cavity geometry and comparison with “baseline” geometry (R. Calaga)
SC asked if a round taper instead of straight would be better with respect to multipacting. The answer is not trivial since it depends if this implies other changes such length modification for mechanical purposes for example…

-    Fabrication of SPL cavities and required tools (O. Capatina) => presentation postponed to the next meeting due to lack of time 

-    AOB
o    Wolfgang informed that 2 copper cavities will be manufactured:
    .One by Royal Holloway (S. Molloy).
    .One at CERN presenting the same mechanical tolerances requirements as for the final Nb cavities. The tooling to be developed for this cavity will be re-used for the manufacturing of the Nb cavities.
o    Discussion concerning if 3 mm should be the final or the initial thickness for the Nb. WW thinks that 3 mm should be enough as initial thickness. OC reminds that all the calculations were done for 3 mm as final value. More information should be provided (additional calculations…) for a decision during next meeting.

-    Date of next meeting and agenda topics
The next meeting will take place on 8th of February 2010.