Superconducting Technology Assessment - nitrd

Another issue is the cost of the refrigeration. Buildings and infrastructure may be a major cost factor for large
amounts of refrigeration. Effort should be made to reduce the refrigeration at 4 K and at higher temperatures since
the cost (infrastructure and ownership) is direct function of the amount of heat to be removed.
One key issue is the availability of manufacturers. The largest manufacturer of 4 K coolers is Sumitomo in Japan,
which has bought out all of its competitors except for Cryomech. No American company has made a large helium
refrigerator or liquefier in the last 10 years; the industrial capacity to manufacture large helium plants ended with
the Superconducting-Super-Collider in 1993. Development funding may be needed for U.S. companies to insure
that reliable domestic coolers will be available in the future. Development of an intermediate-sized cooler (between
small laboratory-scale devices and large helium liquefiers) would be desirable to enable a system with multiple
processor modules.
6.4.4 COOLING – ROADMAP AND FUNDING
A roadmap for the development of cryocoolers for an SCE-based, large-scale computer is shown in figure below.
The funding profile needed to maintain development pace is listed in the accompanying table. More details are
presented in Appendix L: Multi-Chip Modules and Boards. (The full text of this appendix can be found on the CD
accompanying this report.)
126
I.
Trade -
offs
1.
Cryo
Req
docum
ent
2. Cryo
Test Bench
Design
2.
Cryo
Test
Bench
3. Cryo
Test Bench
Fabrication
and Qual
3.
Cryo
Test
Bench
qualified
4. Prototype
Design
4.
Prototype
Cryocooler
5. Prototype
Fab and Test
MILESTONES
5.
Prototype
qualified
2006 2007 2008 2009 2010
TABLE 6-6. COOLER DEVELOPMENT COSTS ($M)
Year 2006 2007 2008 2009 2010 Total
Cooler Development 1.3 0.9 1.1 0.6 0.6 4.5
Total Investment 1.3 0.9 1.1 0.6 0.6 4.5