Conduction cooling systems for linear accelerator cavities
A conduction cooling system for linear accelerator cavities. The system conducts heat from the cavities to a refrigeration unit using at least one cavity cooler interconnected with a cooling connector. The cavity cooler and cooling connector are both made from solid material having a very high thermal conductivity of approximately 1×10 4 W m −1 K −1 at temperatures of approximately 4 degrees K. This allows for very simple and effective conduction of waste heat from the linear accelerator cavities to the cavity cooler, along the cooling connector, and thence to the refrigeration unit.
1. A conduction cooling system for at least one linear accelerator cavity, said system comprising:
at least one cavity cooler operatively interconnecting said at least one linear accelerator cavity and a cooling connector,
wherein said at least one cavity cooler and said cooling connector comprise a material having a thermal conductivity no lower than approximately 1×10 4 W m −1 K −1 at temperatures of approximately 4 degrees K; and
a refrigeration source operatively connected to said cooling connector.
2. The system of claim 1 , wherein said at least one linear accelerator cavity is an SRF cavity having a minimum quality factor of approximately 1*10 8 .
3. The system of claim 2 , wherein said SRF cavity comprises metallic or ceramic material that is superconducting at a cavity operating temperature.
4. The system of claim 1 , wherein an average cross-section A of said cavity cooler and said cooling connector is determined using the equation
A
=
Q
*
L
Δ
T
*
C
wherein Q is a maximum heat load of said at least one linear accelerator cavity, L is an average distance between said at least one linear accelerator cavity and said refrigeration source, ΔT is a maximum allowable temperature rise from said at least one linear accelerator cavity and said refrigeration source and C is a thermal conductivity of said at least one cavity cooler and said cooling connector.
5. The system of claim 1 , wherein said at least one cavity cooler and said cooling connector comprises a material selected from the group consisting of: high-purity aluminum, diamond, and carbon nanotubes.
6. The system of claim 1 , wherein said at least one cavity cooler comprises a plurality of cavity coolers.
7. The system of claim 1 , wherein said at least one cavity cooler is operatively connected to said linear accelerator cavity through a process selected from the group consisting of: direct casting, diffusion bonding, deposition, and mechanical clamping.
8. The system of claim 1 , wherein said at least one cavity cooler is a cooling ring at least partially surrounding said linear accelerator cavity.
9. The system of claim 1 , wherein said at least one cavity cooler is a cooling block at least partially surrounding said linear accelerator cavity.
10. The system of claim 1 , wherein said at least one cavity cooler is a coating at least partially surrounding said linear accelerator cavity.
11. The system of claim 1 , further comprising an intermediate conduction layer between said linear accelerator cavity and said at least one cavity cooler.
12. The system of claim 11 , wherein said intermediate conduction layer is a ductile material having a thermal conductivity resulting in a thermal resistance between said linear accelerator cavity and said at least one cavity cooler of less than approximately 10% of said thermal resistance of said at least one cavity cooler.
13. The system of claim 11 , wherein said intermediate conduction layer comprises a material selected from the group consisting of: indium and lead.
14. The system of claim 1 , wherein said at least one cooling connecter comprises a plurality of cooling connecters.
15. The system of claim 1 , wherein said at least one cooling connecter is selected from the group consisting of: a bar, a strip, and a cylinder.
16. The system of claim 1 , wherein said at least one cooling connecter is flexible.
17. The system of claim 16 , wherein said at least one cooling connecter is selected from the group consisting of: a braid and a rope.
18. The system of claim 1 , wherein said refrigeration source further comprises a cold tip operatively coupled to said cooling connector such that a thermal resistance between said cooling connector and said cold tip is less than approximately 10% of said thermal resistance of said cooling connector.
19. The system of claim 1 , wherein said refrigeration source is a cryocooler having a power rating of approximately 1 W to approximately 100 W.
20. The system of claim 1 , wherein said refrigeration source is a vessel containing cryogenic fluid.