Alternative Source for Nominal 20 K Refrigeration At the MTA Barry Norris, Arkadiy Klebaner September 17, 2004

On a recent trip to Vancouver, Canada, Arkadiy Klebaner took a tour of TRIUMF and its cyclotron/associated equipment. One observation: A Stirling ‘turn key’ 20K refrigeration package is used for the vacuum system. Important points to note: Triumf has NO cryogenics people but does have cryogenic needs Triumf has two operational machines; They rotate their usage - 1 machine 28 years old, other is 15 years old Self contained system motor driven

Comments Pasted from Stirling Webpage Stirling Cryogenics & Refrigeration BV is the world’s leading innovator in stand-alone cooling systems. Stirling provides solutions for gas and liquid processes at temperatures ranging from -75ºC to -250 ºC. For over half a century the company has been applying the (Philips) Stirling cycle cryogenerator technology,which enables liquid gases to be produced on-site. Stirling has developed a wide variety of applications like liquid gas production plants, process coolers, gas liquefiers, power coolers and cold cabinets, all based on the stand-alone Stirling cryogenerator technology.

Over 4,000 Stirling cooling systems are already installed worldwide. Customers include artificial insemination centers (livestock improvement), amusement parks, research & development institutes,high-temperature super conducting labs, hospitals, universities, observatories and logistic suppliers. Stirling develops and produces standard as well as customized equipment, and offers a full support package that includes installation, field service and spare parts. Continued Comments Pasted from Stirling Webpage

Stirling Machine at TRIUMF, 400 approx 14K Unit sitting on red pedastal is about 2 meters in length

WHY SEEK AN ALTERNATIVE? Remember: Present plan is to build Tevatron style Helium refrigeration plant capable of running at 4.5K or 14-20K ranges. 1)Would eliminate the resources within AD/Cryogenic Department needed for completion of piping design, installation and operation of Tev system - Stress/Demands on Dept. resources are severe 2) Would possibly limit the manpower needed to operate the plant in a continuous manner to support experimenters We would seek a solution to ‘outsource’ maintenace’.

Stirling Cycle

What We Know to this Point TRIUMF believes cost for 4 stage machine, 400W, 14K machine is about $400,000 (we’ve asked Stirling to verify) TRIUMF comments that if you purchase a used machine from a 3 rd party the cost may be half that of new machine…surplus machines should be available At least in the case of TRIUMF, maintenance requirements are extensive! every 600 hours there is a ‘defrost’ of machine every 2000 hours there is a total overhaul TRIUMPH has dedicated tech for this work Note: TRIUMF has 2 machines they swap out with one another AND a partial 3 rd for spare parts

Technical items: Cooldown time of machine on order of 1 hour Water cooled 5/25 deg C, 3 cubic m/hour, 1.7 bar Induction motor drive…variable speed would give different tune What We Know to this Point - Continued

Concluding Comments -Awaiting response from Stirling on our application - Need to contact other users and understand views on maintenance, reliability, and operation experiences Other users: Nuclear Science Center, New Delhi India Hamburg Germany - If serious about possibilities, trip should be made to TRIUMF to talk details with technician and engineer who work on the equipment daily