The FPA activity has been waiting for a best fit to be chosen which would best meet the design criteria and minimize interference.  At  a meeting this afternoon, it was decided that the best fit really depends on the interaction between all three VVSA segments and their matching spool pieces.  Therefore it makes more sense to wait for the 3 VVSA’s to arrive and be measured before choosing “THE BEST” fit.  This can be accommodated by placing only the “generic” loops in place on the VVSA #1 and, if time warrants, VVSA #2.  This will allow us time to receive the three VVSAs and scan them.  Then we can truly come up with a best fit based on all 6 parts which make up the vacuum vessel.  This best fit will allow us to move forward with the most confidence about the final configuration of the vacuum vessel; realizing that this look forward is the best expected configuration prior to welding all the ports on and the vessel itself together.  Of course these final activities may further distort the vessel shape.  However, this configuration with all 6 vessel parts is the best we would have available to base the precision diagnostic loop positions.  Therefore the precision diagnostic loops as well as any prerequisite loops to the precision loops will be saved for after the final best fit is determined.  Cooling tube studs may be installed during the diagnostic coil layout however the actual tubing installation will be deferred until after all diagnostic loops are installed.

 

Thanks,

Mike Viola, PPPL, (609) 243 3655