Spectrometer Solenoid and RFCC Update Michael S. Zisman Center for Beam Physics Accelerator & Fusion Research Division Lawrence Berkeley National Laboratory MICO Meeting—RAL December 21, 2009
MICO90:Zisman2 Spectrometer Solenoid Status Vendor working on both magnets in parallel —magnet 2 being modified to accommodate additional 1-stage cooler —magnet 1 was modified to accommodate 4 th 2-stage cooler o with room for a single-stage cooler as well, if needed —based on review, some optimism that 4 th 2-stage cooler will not be needed First single-stage cooler at vendor now —order of another one for magnet 1 is under way Lead tests have been prepared but not yet run —small intermittent leaks have been hard to find o new person at vendor assigned to follow up on this Discharge circuit has been fabricated and partially tested —final testing will be done as part of “training” procedure
December 21, 2009MICO90:Zisman3 Magnet 2 Single Stage Cooler Magnet 2 cooler —should handle heat load from HTS leads
December 21, 2009MICO90:Zisman4 Single-Stage Cooler in Place Initial installation has been done —final connections not completed
December 21, 2009MICO90:Zisman5 Single-Stage Cooler Details Internal thermal connection will employ Cu strips, soft soldered and bolted to Cu plate —external bellows utilized for vacuum connection
December 21, 2009MICO90:Zisman6 Cryocooler Connections Cryocooler 2 and 3 connections on magnet 2 —connections from cooler to copper plates getting more instrumentation o connection from copper plate to shield unchanged from previous test –thermal connection is (at best) problematical
December 21, 2009MICO90:Zisman7 Discharge Circuit Fabrication completed for magnet 2 —awaits testing during “training” exercise (January)
December 21, 2009MICO90:Zisman8 Magnet 1 Modifications Changes to permit 4 th 2-stage cryocooler basically complete —based on review, will purchase additional single-stage cooler for this magnet also o at present, this looks like solution of choice –if magnet 2 works well, magnet 1 will surely work even better shield connections on magnet 1 being greatly improved —hope is to have magnet 1 ready soon after magnet 2 is retested o should minimize schedule delay even if magnet 2 changes do not solve all problems –high likelihood of being able to train magnet 2 to full current –no guarantee that magnet 2 will operate without needing “top-up” of cryogens carrying out thermal calculations now to examine this, but real proof awaits testing proposed goal is >6 weeks between top-ups
December 21, 2009MICO90:Zisman9 Magnet 1 Shield Shield will have copper connections from cooler Stage 1 —shield will also be “beefed up” locally to improve heat transfer to edges o this is where cold-mass support intermediate temperature point is connected Improved heat transport to cold-mass supports thermal intercept Improved thermal connection from cooler Stage 1
December 21, 2009MICO90:Zisman10 Schedule Magnet 2 was supposed to be buttoned up by now —late due to illness at vendor o cooler partially installed o build-up of turret under way —expect to be ready to pump after Christmas o leak check probably early in January 2010 —likely mid-January before tests begin o will try to arrive at decision point in January –but early February is more likely o initial cool-down apparatus from Fermilab will be ready when needed –should ship this week
December 21, 2009MICO90:Zisman11 Spectrometer Solenoid Plans Continue with magnet 2 training to reach 270 A or beyond —quantify thermal margin using cold-mass heater Continue work on magnet 1 —about 2 months behind magnet 2 at present —would like results from magnet 2 test before deciding what to do about 4 th two-stage cooler o even if it means delaying magnet 1 progress a bit Evaluate power supplies to test proposed circuit modifications —this is “external” and thus less pressing —expect to do this with magnet 2
December 21, 2009MICO90:Zisman12 RFCC Module (1) All five cavities have been delivered to LBNL —not yet “ready to go” o need processing (electropolish) at LBNL —vendor already pressing for “option” order of five more cavities o this would be a Step 6 commitment Visited HIT two weeks ago to update plans for coupling coils —magnet production contract not yet placed with vendor o hold-up has been lack of complete set of fabrication drawings –resolved remaining issues for cold-mass drawings at meeting last remaining step needed to place contract —some organizational changes o local HIT Project Manager will be Feng-yu Xu o Chief Engineer will be Li Wang (makes all technical decisions) o Prof. Chen (IHEP) will be liaison with Qi Huan Company
December 21, 2009MICO90:Zisman13 RFCC Module (2) Goal to have contract for cold mass fabrication in place by ~March 2010 —considered a “make or break” milestone! o hard to see MuCool CC delivered before next summer o web site for bid process has been set up In parallel, pressing to make HIT test facility operational —cryogenics issue —plan is to o get system modified o complete test of large coil (validates system) o use facility to test and train the three cold masses built by Qi Huan —dates for these still to be negotiated Generating revised Addendum to MOU to formalize plan —magnet cryostats may become U.S. responsibility o depends on results of bid process
December 21, 2009MICO90:Zisman14 Summary Seeing some light at the end of the tunnel —too early yet to tell whether it’s simply an oncoming train o encouraging signs at this point –should be clearer picture at Riverside meeting in March