Bolted joint conduction cooling apparatus for accelerator cavities
Methods and systems for bolted joint conduction cooling of accelerator cavities comprises a conduction cooling system. The conduction cooling system comprises mounting at least one cooling ring to a cavity and a conduction link joined to the cooling ring with at least one connection assembly. The materials in the at least one connection assembly can be selected to experience greater thermal contraction than the cooling ring and the conduction link when cooled. A fast conduction cooling system can comprise a cryocooler in thermal communication with a conduction cooling apparatus affixed to a cavity via a conduction path and a thermal switch in the conduction path between the cryocooler and the conduction cooling apparatus wherein a thermal conductance of the thermal switch decreases as a function of temperature.
1. A method for assembling a conduction cooling system comprises:
mounting at least one cooling ring to a cavity;
configuring a conduction link comprising a ring mount configured to engage the cooling ring, a conduction bus, and ear-straps configured to connect the cooling ring to the conduction bus to be joined to the at least one cooling ring with at least one connection assembly comprising a bolt, and a nut; and
selecting materials of the at least one connection assembly to be different from the material of the at least one cooling ring, and the material of the conduction link, wherein the at least one connection assembly experiences greater thermal contraction than the at least one cooling ring and the conduction link when cooled.
2. The method of claim 1 further comprising:
selecting the at least one cooling ring to be made of niobium.
3. The method of claim 1 further comprising:
selecting the conduction link to be made of copper.
4. The method of claim 1 further comprising:
selecting the connection assembly to be made of at least one of:
brass;
bronze; and/or
Be—Cu (beryllium copper).
5. The method of claim 1 further comprising:
connecting the ear-straps to a conduction ring link; and
making thermal contact between the ring link and a conduction mounting bracket.
6. The method of claim 5 further comprising:
pumping cooled fluid through the bus bar.
7. A conduction cooling system comprising:
at least one cooling ring connected to a flexible strap;
a bus bar in thermal contact with the flexible strap; and
a fluidic system configured to pump cooled fluid through the bus bar.
8. The conduction cooling system of claim 7 wherein the fluidic system further comprises:
a conduit for transporting gas;
a cryogenic circulator for driving the gas through the conduit; and
a heat exchanger for cooling the gas flowing through the heat exchanger.
9. The conduction cooling system of claim 7 further comprising:
at least one ring mount with at least one hole pattern that matches a hole pattern on the at least one cooling ring.
10. The conduction cooling system of claim 7 further comprising:
a cold head connected to the bus bar.
11. The conduction cooling system of claim 10 further comprising:
a cryocooler stage and a conduction mounting bracket connecting the cold head and the bus bar.
12. A fast conduction cooling system comprising:
a cryocooler in thermal communication with a conduction cooling apparatus affixed to a cavity via a conduction path; and
a thermal switch in the conduction path between the cryocooler and the conduction cooling apparatus wherein a thermal conductance of the thermal switch decreases as a function of temperature.
13. The fast conduction cooling system of claim 12 wherein the thermal switch comprises:
a gas filled body with at least one fin formed therein.
14. The fast conduction cooling system of claim 12 wherein the thermal switch comprises:
a gas filled body with at least one thermal absorption bed therein.
15. The fast conduction cooling system of claim 12 wherein the thermal switch comprises:
a gas filled body;
a vacuum pump; and
at least one valve wherein the valve can be opened to pump the gas out of the body.
16. The fast conduction cooling system of claim 12 wherein the thermal switch comprises:
a thermal contact plate configured to mechanically engage and disengage the conduction path.
17. The fast conduction cooling system of claim 12 further comprising:
selecting the conduction path to be made of copper.
18. The fast conduction cooling system of claim 12 wherein the cryocooler comprises a first stage and a second stage.
19. The fast conduction cooling system of claim 18 wherein the thermal switch is configured between the first stage and the second stage of the cryocooler.
20. The fast conduction cooling system of claim 19 wherein the first stage is configured to provide cooling power at temperatures greater than 30 K, and wherein the second stage is configured to provide cooling power at temperatures greater than 3K.