ILC Cryogenics -- Technical Design Report Planning Tom Peterson ILC GDE SCRF meeting at IHEP 8 Dec 2011

ILC cryogenics for the TDR Cryomodule cooling scheme Plant layout Cryogenic unit definitions Heat load assessments Cryogenic plant power and sizing Distribution system sizing Cost estimate update Scope of this work ILC GDE SCRF, Tom Peterson 8 Dec 2011 ILC cryogenics for the TDR

ILC cryogenics for the TDR SRF cryogenics for TDR Main linac cooling scheme is still the same Strings of saturated bath 2 K cooling 5 K - 8 K thermal intercepts with simplified thermal shield 40 K - 80 K thermal intercepts and thermal shield We always said that these temperature levels and the associated pressures would be optimized for integration with a cryogenic plant Thermal shield and intercept flow directions will be optimized Temperatures and pressure may be adjusted for integration with cryogenic plant cycle ILC GDE SCRF, Tom Peterson 8 Dec 2011 ILC cryogenics for the TDR

Cryomodule cooling scheme RDR scheme was essentially unchanged from the TESLA scheme ILC GDE SCRF, Tom Peterson 8 Dec 2011 ILC cryogenics for the TDR

Optimize thermal intercept flow Either in this manner or some similar sort of optimization ILC GDE SCRF, Tom Peterson 8 Dec 2011 ILC cryogenics for the TDR

ILC cryogenic plant and cryogenic unit layout Update these in collaboration with CFS, and main linac integration -- try for 4 each side ILC GDE SCRF, Tom Peterson 8 Dec 2011 ILC cryogenics for the TDR

Update cryogenic unit lengths In reducing the number of cryogenic plants per main linac to 4 from 5 -- 4 cryogenic plants per linac results in about 240 cryomodules per cryogenic unit. Before the 9-8-9 cavity per RF unit concept, we had developed an 8-8-8 cavity per RF unit layout 8-8-8 maximum was 204 cryomodules per cryogenic unit Plant size becomes approximately 25 kW at 4.5 K (5.5 MW installed power), a number we take as a limiting size -- so very large, but still possibly one cryogenic plant Pressure drops and pipe sizes in the cryomodules need to be checked for the higher flow rates and longer distances ILC GDE SCRF, Tom Peterson 8 Dec 2011 ILC cryogenics for the TDR

Plant spacing and lattice Needed: linac lattice distances, total numbers of cryomodules, locations of special items like magnets at the low energy end, other included SC devices like undulators, impact of cryogenic system input such as drift spaces for end boxes (magnets at each end?), etc. This is from the spreadsheet for 8-8-8 cavities per RF unit. ILC GDE SCRF, Tom Peterson 8 Dec 2011 ILC cryogenics for the TDR

ILC cryogenics for the TDR Input parameters for heat load assessments are needed (e.g., input parameters for 5+5 Hz) all cavities active at low gradient RF pulse lengths from CryoPower-PHG-12jan2011.xls RF pulse length = 2180 microseconds from 110120 SFUKUDA DRFS2.ppt slide 11 bin C 16/26 active cavities per RF unit ILC GDE SCRF, Tom Peterson 8 Dec 2011 ILC cryogenics for the TDR

Cryogenic plant power (RDR revised) (15 Nov 2008) Biggest change is 5-8 K dynamic heat from input coupler -- 4.5% effect on cryoplant size ILC GDE SCRF, Tom Peterson 8 Dec 2011 ILC cryogenics for the TDR

Update power for all the plants Reconsider uncertainty factors and plant efficiency assumptions Quantify uncertainty based on data for Q0, dark current estimates, etc. Latest plant efficiency estimates from vendors are a bit lower than at the time of the RDR And assess distribution line sizes and distances These add to the heat loads Update distribution scope and cost estimate Finally update cryogenic system cost estimate ILC GDE SCRF, Tom Peterson 8 Dec 2011 ILC cryogenics for the TDR

Damping ring, RTML, BDS cryo Cryogenics for the sources, damping rings, RTML, and beam delivery system were addressed in the RDR cryogenics chapter Are these now in their respective area chapters? And those groups are writing those details? ILC GDE SCRF, Tom Peterson 8 Dec 2011 ILC cryogenics for the TDR

ILC cryogenics for the TDR How much work is this? Cryogenic system for TDR will be an adjusted version of the RDR Revised and updated for latest layouts, input parameters, and information Collaborative work with CFS, main linac, and the other systems groups to obtain parameters and develop layouts Quantification of the uncertainty factors requires input from other groups Relatively straightforward to reassess the cryogenic system once given all the input parameters I have the spreadsheets and original work, however . . . The design process is iterative with the the other ILC groups Cryo layout requires input and collaboration, and A major effort! Will require significant time ILC GDE SCRF, Tom Peterson 8 Dec 2011 ILC cryogenics for the TDR