Jochen Ebert, Uni Karlsruhe1 Powering via cooling pipes very first results

Jochen Ebert, Uni Karlsruhe2 Idea: Combination of cooling pipes, current lead and parts of mechanical support into one single structure. + - ~50A ~1A Problem: every hybrid see´s a different voltage. Solution: combine different cross-sections of alu. The voltage drop partially compensated by similar voltage drop in return line.

Jochen Ebert, Uni Karlsruhe3 Module design by powering via cooling pipes Cooling channels CO2 Powerline=cooling pipe=mechanical support Modules mounted alternately above and under the alu structure Supply and return line for CO2

Jochen Ebert, Uni Karlsruhe4 cooled CO2 bottle in freezer with mounted pressure regulator 2.52 m long ladder with 56 dummy heaters powered via cooling pipes ladder in insulation box Prototype ladder for cooling and powering

Jochen Ebert, Uni Karlsruhe5 liquid CO2 from freezer to flowmeter 1 & 2 (with adjustable valve) left pipe right pipe position of PT1000 sensor 56 dummy heaters 2.52m Layout of ladder ladder is mounted on rohacell 2mm pure aluminum pipe 2 long pipes for environmental heating (no liquid to flowmeters)

Jochen Ebert, Uni Karlsruhe6 thin, flexible capton pcb´s glued on aluminum for good heat conduction to cooling pipes screwed on alu blocks with nylon screws to avoid electric contact between alu blocks and backside of heaters different, pure aluminium power rails mounted on side of blocks to get the cross-sections needed. alu blocks made of two parts, screwed together and surround the cooling pipes detail view of heaters

Jochen Ebert, Uni Karlsruhe7 cross-section and voltage Max. delta V=43 mV Max. delta V=1,89 mV Large difference between simulation and measurement due to contact resistances (24 powerrails screwed to coolingblocks! -> 48 contacts). But still quite good, and gets even smaller with cooling (~ factor 2) Can be avoided by fabrication out of one piece of aluminum.

Jochen Ebert, Uni Karlsruhe8 Cooling heating power: 0W 17W 44W 84W 0W CO2 flow: 2x 400liter/h = 2x 0,7kg/h Heat leak through about 90W Dry-out at the end of the pipe, while the beginning is still cooled properly electrical

Jochen Ebert, Uni Karlsruhe9 Cooling CO2-flow: 2x 800liter/h = 2x 1,5kg/h beginning dry-out heavy dry-out heating power: 44W 84W 110W 140W 187W 230W electrical Heat leak through about 90W

Jochen Ebert, Uni Karlsruhe10 dry-out easy to cool large powers with a little flow of CO2, flow was tested up to 3,7 kg/hour (max. of flowmeters) with negligible pressure drop Even much bigger flow seems possible with tolerable pressure drop

Jochen Ebert, Uni Karlsruhe11 regulating temperature with pressure 11,5bar 8bar 6,5 5,5  very easy to set and hold temperature: just keep pressure constant CO2 pressure in [bar]

Jochen Ebert, Uni Karlsruhe12 Summary CO2 cooling with 2mm ID cooling pipes allows to cool long ladders (tested up to 300 W, needed only 50 W / ladder) Putting a CO2 bottle in a 500 Euro freezer allows a very cheap and efficient CO2 cooling system (CO2 blown into the air). Temperature can be set anywhere between 0 and -50 C by pressure regulator on precooled bottle. Test proofs that long barrel with endcap as inner discs is possible Jochen Ebert, Uni Karlsruhe12

Jochen Ebert, Uni Karlsruhe13 outlook Measure the noise of existing modules while powering via coolingpipes (2,5m long „antennas“). What happens if one module is noisy. Improve contact between powerrails e.g alondining (thin chrom coating) Improve precision of existing measurements.

Jochen Ebert, Uni Karlsruhe14 BACKUP

Jochen Ebert, Uni Karlsruhe15 Strawman with long barrel and discs at small radii Stereo Single Trigger Single Stereo Single

Jochen Ebert, Uni Karlsruhe16 Strixel disk design Outer radius 35 cm 2 outside rings same for each disk Inner ring radius changes with z -> slightly more overlap between sensors if same number and same size of sensor Each ring in two halves with each half built as long ladder Need 3 types of sensor All sensors 10 cm at top

Jochen Ebert, Uni Karlsruhe17 c Alternative: rectangular sensors Can use same sensors as in barrel, if some more overlap allowed. Can have SAME hybrids and same “circular” ladders for each ring Will have middle ring at back of rohacell, so enough space for mounting on cooling rings Note: disks in two halves in order to mount with beam pipe in place Cooling rings

Jochen Ebert, Uni Karlsruhe18 Material budget with small end discs  Material/X 0

Jochen Ebert, Uni Karlsruhe19 Material budget Long Barrel + inner disks