1. LHC CMS Detector Upgrade Project FPIX Cooling Update Stefan Grünendahl, Fermilab For the FPIX Mechanical Group, 29 January 2015 Stefan Grünendahl, 2015-1-29 CO2 Meeting 1

2. LHC CMS Detector Upgrade Project Done with the overall FPIX cooling loop dimensioning and layout and with the details of the FPIX module (disk) cooling design, incl. testing. Now working on the details of the loop routing in the electronics area of the cylinder and on the electronics cooling mounts. Have a first iteration of a design for the DC/DC converter cooling bridge and CO2 tubing clamp (incl. FEA) (shown during Nov.5 summary; included for reference). We tested the effect of splitting the electronics heat load between input and return lines: allows simplification of tubing layout. Stefan Grünendahl, 2015-1-29 CO2 Meeting 2 FPIX Cooling Status

3. LHC CMS Detector Upgrade Project Stefan Grünendahl, 2015-1-29 CO2 Meeting 3 Study of Return Line Heat Load  Added heater connection to return section of FPIX full loop test system  Compared 60W load on input line to 34W (input section) + 27W (return section)  No difference in main loop temperature P4 P3 P2 P1 T14 T1 Return section: 2.6mm ID, between T13/P2 and T14/P1

4. LHC CMS Detector Upgrade Project  Tested at -20ºC, 2.5 bar pressure drop, 2 g/s flow Stefan Grünendahl, 2015-1-29 CO2 Meeting 4 Return Line Heat Load: Results I

5. LHC CMS Detector Upgrade Project  Pressure sensors:  no significant difference in total pressure drop  No significant pressure drop over return line (2.6mm ID) Stefan Grünendahl, 2015-1-29 CO2 Meeting 5 Return Line Heat Load: Results II

6. LHC CMS Detector Upgrade Project Stefan Grünendahl, 2015-1-29 CO2 Meeting 6 FPIX DC/DC converter mechanical & thermal interface design Dark blue = aluminum cooling bridge under DC/DC converters, and top of tubing clamp (could be PEEK) (as shown in Nov.5 summary)

7. LHC CMS Detector Upgrade Project  FEA results indicate single ended cooling yields acceptable converter temperature (left graph) and tubing wall power density (two-sided example shown in right graph, max. density=21 kW/m^2). Stefan Grünendahl, 2015-1-29 CO2 Meeting 7 FPIX DC/DC Cooling FEA (as shown in Nov.5 summary)