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

2. 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

3. 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.

4. 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

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

6. 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’.

9. Stirling Cycle

10. 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

11. 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

12. 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 DESY @ 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