Survival guide for JT Coolers SDW Roger Smith

Survival guide for JT Coolers SDW Roger Smith, 1 2017 Survival Guide for JT Coolers Roger Smith Scientific Detector Workshop 2017 – Baltimore & Michael Feeney

Motivation Concept Usage, tips Test Setup Performance Maintenance Procurement Survival guide for JT Coolers SDW Roger Smith, 2 2017 Outline ① Motivation for in-house capability ② Basic concept (dis)advantages ③ How to use tips, diagnostics, pitfalls ④ How to test ⑤ Performance ⑥ Maintenance prevention and cure ⑦ Procurement alternate sources of parts: faster, cheaper Scientific Detector Workshop 2017 – Baltimore

Motivation Concept Usage, tips Test Setup Performance Maintenance Procurement Why do we like them ? • Continuous unattended operation • Long service life with low maintenance. • Low vibration Scientific Detector Workshop 2017 – Baltimore Survival guide for JT Coolers SDW Roger Smith, 3 2017

Motivation Concept Usage, tips Test Setup Performance Maintenance Procurement Downsides • Compressed gas lines in cable wraps. • Slower cool-down than LN 2. • Long delivery times. • Poor customer service. Scientific Detector Workshop 2017 – Baltimore Survival guide for JT Coolers SDW Roger Smith, 4 2017

Motivation Concept Usage, tips Test Setup Performance Maintenance Survival guide for JT Coolers SDW Roger Smith, 5 2017 Procurement JT cooler basics Cooling by adiabatic expansion in capillary which restricts flow 380 psi 30 -50 psi Counter-flow heat exchanger Flexible hoses with self sealing couplings Air cooled HX Cold head in vacuum T a n k Oil Recovery Compressor Scientific Detector Workshop 2017 – Baltimore Cold head

Motivation Concept Usage, tips Test Setup Performance Maintenance Survival guide for JT Coolers SDW Roger Smith, 6 2017 Procurement JT cooler hardware Brookes Automation, Polycold Compact Cooler Advanced Research Systems, Orca Similar size compressor Compressor Somewhat thicker gas lines Longer Cold Head Hoses Scientific Detector Workshop 2017 – Baltimore Cold Head http: //www. arscryo. com/orca-mixed-refrigerant-co

Motivation Concept Usage, tips Test Setup Performance Maintenance Procurement Survival guide for JT Coolers SDW Roger Smith, 7 2017 Power curves from Polycold Performance determined by refrigerant mix “High performance head” has longer counter flow heat exchanger. Scientific Detector Workshop 2017 – Baltimore

Motivation Concept Usage, tips Test Setup Performance Maintenance Procurement Power curves from ARS Orca Non-flammable refrigerants Longer cold head Scientific Detector Workshop 2017 – Baltimore Survival guide for JT Coolers SDW Roger Smith, 8 2017

Motivation Concept Usage, tips Test Setup Performance Maintenance Procurement Survival guide for JT Coolers SDW Roger Smith, 9 2017 Cooling curves Slower around 250 K Fastest as power peaks around 150 K Final equilibrium < 135 K needed to ge Scientific Detector Workshop 2017 – Baltimore

Motivation Concept Usage, tips Test Setup Performance Maintenance Procurement Survival guide for JT Coolers SDW Roger Smith, 10 2017 Cooling curves – with refrigerant pressure Ethane condensing ? ? ? Methane condensing Scientific Detector Workshop 2017 – Baltimore

Motivation Concept Usage, tips Test Setup Performance Maintenance Procurement Survival guide for JT Coolers SDW Roger Smith, 11 2017 Mixed refrigerant behavior Pressure Relief threshold Something happening here? Peak capacity Scientific Detector Workshop 2017 – Baltimore Refrigerant charge pressure Lowest capacity

Motivation Concept Usage, tips Test Setup Performance Maintenance Procurement How to use ? Scientific Detector Workshop 2017 – Baltimore Survival guide for JT Coolers SDW Roger Smith, 15 2017

Motivation Concept Usage, tips Test Setup Performance Maintenance Survival guide for JT Coolers SDW Roger Smith, 16 2017 Procurement Cooling rate ∂T/∂t = ( Cooling power – load ) / heat capacity PT 16 Brooks Polycold PCC Compact Coolers: Ambient Radiative Loading 35 Fastest here Available cooling power 30 Cooling Power [W] 25 20 PT-16 S/N 1509 CHE 11347 275 psi/75 ft With Radiative Load PT-16 Theoretical 15 Radiation + conduction 10 Final temperature Load example Slowest here, risk of stall 5 0 50 100 150 200 Temperature [K] Scientific Detector Workshop 2017 – Baltimore 250 300

Motivation Concept Usage, tips Test Setup Performance Maintenance Procurement Survival guide for JT Coolers SDW Roger Smith, 17 2017 Cool Down Tips • Reduce load until below 250 K where cooling is slowest: • Leave CCDs powered off • Turn off window demister heater • Charcoal getter doesn’t start working until T≤ 180 K, reaching peak efficiency for T≤ 135 K. ØPump while cooling, at least until getter < 150 K. ØAttach cold trap at dewar valve to pump water vapor most efficiently and prevent backflow of contaminants from pump/plumbing. ØGetter must be close to cold head, with separate thermal path. Prefer PT 16 to PT 30 due to lower getter temperature. Scientific Detector Workshop 2017 – Baltimore

Motivation Concept Usage, tips Test Setup Performance Maintenance Procurement Survival guide for JT Coolers SDW Roger Smith, 18 2017 Tips • Unlike LN 2 systems, there is no boil-off rate to serve as a metric for total energy input into the system and provide early warning of poor vacuum. • Use a full range gauge with JT coolers to allow pressure rise rate, thus long term vacuum maintence interval, to be projected. • Granville Phillips Micro-ion plus gauges are reliable but run very hot so we now use Pfeiffer . Ø These work as an ion pump. Ø Small pressure spike are said to be due to cosmic rays. Scientific Detector Workshop 2017 – Baltimore

Motivation Concept Usage, tips Test Setup Performance Maintenance Procurement How to test ? Scientific Detector Workshop 2017 – Baltimore Survival guide for JT Coolers SDW Roger Smith, 19 2017

Survival guide for JT Coolers SDW Roger Smith, 20 2017 Automated test System LN 2 tank Cold head under test heater sensors Getter Radiation shield Vacuum enclosure 1) Change temperature setpoint; 2) Wait for power to stabilize 3) Log power. Dewar on loan from Chas Beichman Scientific Detector Workshop 2017 – Baltimore Compare upward scan to downward scan. Takes about 24 hours to test one cold head. temperature controller

Motivation Concept Usage, tips Test Setup Performance Maintenance Procurement Survival guide for JT Coolers SDW Roger Smith, 21 2017 Typical power curve: PT 14 Retrace of ascending and descending data confirms that settling times were adequate Fully automated since very slow Scientific Detector Workshop 2017 – Baltimore

Motivation Concept Usage, tips Test Setup Performance Maintenance Procurement PT 30 Power Curve: contaminated Contaminated head PTF, Feb 2016 Scientific Detector Workshop 2017 – Baltimore Survival guide for JT Coolers SDW Roger Smith, 22 2017

Motivation Concept Usage, tips Test Setup Performance Maintenance Procurement PT 30 Power Curve: refurbished head Scientific Detector Workshop 2017 – Baltimore Survival guide for JT Coolers SDW Roger Smith, 23 2017

Motivation Concept Usage, tips Test Setup Performance Maintenance Procurement Performance Scientific Detector Workshop 2017 – Baltimore Survival guide for JT Coolers SDW Roger Smith, 24 2017

Motivation Concept Usage, tips Test Setup Performance Maintenance Survival guide for JT Coolers SDW Roger Smith, 25 2017 Procurement Variation between cold heads Cold head variability, PT 16, 275 psi, 25 ft 35 Cooling Power [W] 30 25 20 1602 CHE 1220 0 1509 CHE 1134 7 1509 CHE 1134 6 15 10 5 0 50 100 150 200 Temperature [K] Scientific Detector Workshop 2017 – Baltimore 250 300

Motivation Concept Usage, tips Test Setup Performance Maintenance Survival guide for JT Coolers SDW Roger Smith, 26 2017 Procurement Charge Pressure dependence Brooks Polycold PCC Compact Coolers: Pressure Dependence 1 Brooks Polycold PCC Compact Coolers: Pressure Dependence 2 30 275 psi 25 S/N: 11346 PT-16 S/N 1509 CHE 11346 230 psi/25 ft 20 PT-16 S/N 1509 CHE 11346 250 psi/25 ft 15 10 PT-16 S/N 1509 CHE 11346 275 psi/25 ft 230 psi 5 Cooling Power [W] 35 30 Cooling Power [W] 35 275 psi 25 S/N: 11347 PT-16 S/N 1509 CHE 11347 230 psi/25 ft 20 PT-16 S/N 1509 CHE 11347 250 psi/25 ft 15 PT-16 S/N 1509 CHE 11347 275 psi/25 ft 230 psi 10 PT-16 Theoretical 5 PT-16 Theoretical 0 0 50 100 150 200 250 Temperature [K] Scientific Detector Workshop 2017 – Baltimore 300 50 100 150 200 Temperature [K] What are pressure relief valve settings? Pressure in operation = 400 psi fro 271 psi charge. 250 300

Motivation Concept Usage, tips Test Setup Performance Maintenance Survival guide for JT Coolers SDW Roger Smith, 27 2017 Procurement Line Length Dependence !!! Brooks Polycold PCC Compact Coolers: Line Length Dependence 40 Increasing line length is good! 35 - ü Much faster cool down Cooling Power [W] 30 Stall risk reduced 25 ü Less risk of stall PT-16 S/N 1509 CHE 11347 275 psi/25 ft PT-16 S/N 1509 CHE 11347 275 psi/50 ft 20 Slight increase in equilibrium T PT-16 S/N 1509 CHE 11347 275 psi/75 ft ü Larger power margin @ equilibrium PT-16 S/N 1509 CHE 11347 275 psi/100 ft PT-16 Theoretical 15 Load 10 Final equilibrium 5 0 50 100 150 200 Temperature [K] Scientific Detector Workshop 2017 – Baltimore 250 300 example We plan to explore this further to see how we can harness this effect to get better performance.

Motivation Concept Usage, tips Test Setup Performance Maintenance Survival guide for JT Coolers SDW Roger Smith, 28 2017 Procurement Radiation shielding of coils Brooks Polycold PCC Compact Coolers: Ambient Radiative Loading 40 Aluminized Mylar wrap… 35 ü improves cooling time 30 Cooling Power [W] ü reduces equilibrium 25 PT-16 S/N 1509 CHE 11347 275 psi/75 ft Reduced Radiative Load PT-16 S/N 1509 CHE 11347 275 psi/75 ft With Radiative Load 20 PT-16 Theoretical 15 Load example 10 5 0 50 100 150 200 Temperature [K] Scientific Detector Workshop 2017 – Baltimore 250 300 temperature a few degrees, • no effect on potential for stall.

Motivation Concept Usage, tips Test Setup Performance Maintenance Procurement Survival guide for JT Coolers SDW Roger Smith, 29 2017 Cold head height above compressor Preliminary conclusion could be that height of head above compressor makes no difference …. but this test was not consistent with previous curves Why does this particular cold head behave differently Typical curve Scientific Detector Workshop 2017 – Baltimore

Survival guide for JT Coolers SDW Roger Smith, 30 2017 Two heads on same compressor 40 35 Cooling Power [W] PT-16 S/N 1509 CHE 11347 275 psi/50 ft …. . Greatly diminished capacity PT-16 Dual Head Test 280 psi/50 ft 30 25 20 15 10 5 0 50 100 150 200 Temperature [K] Scientific Detector Workshop 2017 – Baltimore 250 300

Motivation Concept Usage, tips Test Setup Performance Maintenance Procurement Two heads on same compressor As first cooler goes through power peak, resulting increase in return line pressure slows the second cooler Power peak of 2 nd cooler 1 st cooler’s power peak Scientific Detector Workshop 2017 – Baltimore Survival guide for JT Coolers SDW Roger Smith, 31 2017

Motivation Concept Usage, tips Test Setup Performance Maintenance Procurement Two full systems driving one load Scientific Detector Workshop 2017 – Baltimore Survival guide for JT Coolers SDW Roger Smith, 32 2017

Motivation Concept Usage, tips Test Setup Performance Maintenance Procurement Survival guide for JT Coolers SDW Roger Smith, 33 2017 Maintenance and Repair Scientific Detector Workshop 2017 – Baltimore

Motivation Concept Usage, tips Test Setup Performance Maintenance Procurement Survival guide for JT Coolers SDW Roger Smith, 34 2017 Failure modes • Insufficient refrigerant charge pressure Monitor supply and return pressure Pressure relief valve • Low ambient temperature Increase gas charge in winter if needed. • Leak of refrigerant into vacuum Poppet valve on dewar to relieve pressure: Key High Vacuum SRV-25 -125: gette r Thermal link Scientific Detector Workshop 2017 – Baltimore • Work hardening @ flange Thin sheet to constrain head radially, while accommodating axial contraction. KF 25 flange

Motivation Concept Usage, tips Test Setup Performance Maintenance Procurement Survival guide for JT Coolers SDW Roger Smith, 35 2017 Failure modes • Leak when coupling and decoupling hoses: • • Use wrench to hold one side while undoing other Keep straight. Avoid doing this often !!! Keep replacement gas and fixtures on hand. • Cold head contamination (blockage) • Usually due to oil migration from compressor, not contamination when coupling hoses. Ø Replace charcoal adsorbed at compressor every 2 years. Ø Will discuss refurbishment later…. • Compressor wears out ? . . . Not seen in 8 years of continusous operation ! Scientific Detector Workshop 2017 – Baltimore

Motivation Concept Usage, tips Test Setup Performance Maintenance Procurement Survival guide for JT Coolers SDW Roger Smith, 36 2017 Flammable refrigerants • Non-Flammable refrigerants deliver less power. • PT series refrigerants are same as BBQ gas (propane) and cooking gas (methane), but premixed with Argon (inert). Adopt similar precautions. • Adequate volume for dilution to non-explosive concentration. • Ventilation • Hydrocarbon alarms • Or use Orca Coolers from Advanced Research Systems, which have nonflammable refrigerant and compensate with longer counter-flow heat exchanger Scientific Detector Workshop 2017 – Baltimore

Motivation Concept Usage, tips Test Setup Performance Maintenance Procurement Survival guide for JT Coolers SDW Roger Smith, 37 2017 Cleaning cold heads • Immerse coil and head in ultrasonic cleaner while pumping hot waterdetergent (from bath) through the plumbing. • Need mating connectors to hold self sealing connectors open. • Flush with hot water then de-ionized water, then clean (filtered) compressed dry air. • Bake in vacuum oven with ports open, or evacuate interior while heating exterior. Cold trap to asses whether all water and contaminants are gone. • Recharge with refrigerant. Scientific Detector Workshop 2017 – Baltimore

Motivation Concept Usage, tips Test Setup Performance Maintenance Cleaning hoses • Same as for cold-heads but one needs a really big ultrasonic cleaner. If not available just pump hot water and detergent. • Flush long and well. • Blow plenty of dry air. • Evacuate hose via cold trap to asses whether all moisture is gone. Heat hose (eg in environmental chamber) to hurry process along. • Recharge with refrigerant. Scientific Detector Workshop 2017 – Baltimore Procurement Survival guide for JT Coolers SDW Roger Smith, 38 2017

Motivation Concept Usage, tips Test Setup Performance Maintenance Procurement Survival guide for JT Coolers SDW Roger Smith, 39 2017 Refurbishment of compressor • Most parts are standard refrigeration components. • Make sure heat exchanger is free of dust and fans are working. • Replace internal charcoal adsorber at least every 2 years. Scientific Detector Workshop 2017 – Baltimore

Survival guide for JT Coolers SDW Roger Smith, 40 2017 Internal Adsorber Replacement Internal External • Needed to refurbish all compressors. • Replace after one year of service Part per adsorber: $20 Parker 163 S Filter Dryer $10 Aeroquip couplings (2) + tubing Polycold + soldering internal adsorber assembly: ~$800 Scientific Detector Workshop 2017 – Baltimore

Survival guide for JT Coolers SDW Roger Smith, 41 2017 Gas charging apparatus Picture of charging apparatus Large Gas cylinder Small Gas cylinder Scientific Detector Workshop 2017 – Baltimore

Survival guide for JT Coolers SDW Roger Smith, 42 2017 Gas charging Connect short line from gas cylinder in place of return line from cold head Recharging apparatus (only works between a tank and an Aeroquip interface) Run pump until external gauge reads required pressure (~270 psi) Return line is unconnected (sealed) P Gas cylinder Compressor Scientific Detector Workshop 2017 – Baltimore Cold head

Motivation Concept Usage, tips Test Setup Performance Maintenance Procurement Survival guide for JT Coolers SDW Roger Smith, 43 2017 Alternative Sources of Parts Faster delivery and usually much cheaper Scientific Detector Workshop 2017 – Baltimore

Motivation Concept Usage, tips Test Setup Performance Maintenance Procurement Survival guide for JT Coolers SDW Roger Smith, 44 2017 Cold heads, compressors on e. Bay Delivery in a day or two is much better than 9 months from Polycold COLD HEADs: • Be careful to look at pictures for damage. • “High performance” heads are recognizable form pictures since ~1” longer than standard. • Clean and test incoming heads. COMPRESSORS: • Bigger risk but usually cheap. Buy spares! • Replace adsorber then test. Scientific Detector Workshop 2017 – Baltimore

Motivation Concept Usage, tips Test Setup Performance Maintenance Hoses, etc. • Self sealing connectors • Aeroquip part #, • Supplier • Hose-hose couplings: • Manifolds • Hose suppliers: • Same hoses as Polycold • Slightly thicker hoses Scientific Detector Workshop 2017 – Baltimore Procurement Survival guide for JT Coolers SDW Roger Smith, 45 2017

Motivation Concept Usage, tips Test Setup Performance Maintenance Procurement Survival guide for JT Coolers SDW Roger Smith, 46 2017 Refrigerant • Thus far we have not uncovered any patent claim but… • Air Liquide Inc have an agreement with Polycold not to sell their gas mixtures. • Airgas Inc do not have such an agreement but you will need to figure out what the mixture is. • Those mixing different Polycold gases report that intermediate mixtures give intermediate results mixture does not have to be to accurate. • Pressure vs. temperature curves may reveal approximate ratios. Scientific Detector Workshop 2017 – Baltimore