High-current conduction cooled superconducting radio-frequency cryomodule

1. A superconducting radio-frequency (SRF) cryomodule for accelerating an electron beam, comprising:

a vacuum vessel;

an SRF cavity within said vacuum vessel;

a coaxial input power coupler extending through said vacuum vessel and connected to said SRF cavity;

a cryocooler having a cold head, said cold head connected to the SRF cavity;

a water-cooled beam pipe higher-order mode absorber for damping of high-order modes;

a thermal shield;

a magnetic shield;

an entrance beam tube and an exit beam tube;

said coaxial input power coupler including an outer conductor having an inner surface; and

said inner surface of said outer conductor of said power coupler includes a section with a layer of high-temperature superconductor.

2. The SRF cryomodule of claim 1 further comprising:

said SRF cavity is selected from the group consisting of niobium (Nb) and metal with thermal conductivity greater than 500 W/(m K) at 4 degrees K;

said RF cavity includes an inner surface;

said inner surface of said SRF cavity is includes a thin film coating for reducing RF losses; and

said thin film coating is a superconductor having a critical temperature greater than 15 K.

3. The SRF cryomodule of claim 2 further comprising:

said thin film coating is 1 to 1.5 μm thick; and

said thin film coating is selected from the group consisting of Nb 3 Sn, Nb 3 Ge, NbN, and NbTiN; and

said cryocooler maintaining said SRF cavity at 4.3 K.

4. The SRF cryomodule of claim 1 further comprising:

said SRF cavity includes an outer surface;

said outer surface of said SRF cavity includes a coating; and

said coating on said outer surface of said SRF cavity is selected from the group consisting of copper and tungsten.

5. The SRF cryomodule of claim 4 wherein said coating on said outer surface of said SRF cavity is deposited on said SRF cavity by vacuum plasma-spraying, electroplating, or by a combination of vacuum plasma-spraying and electroplating.

6. The SRF cryomodule of claim 1 further comprising said high-temperature superconductor having a critical temperature greater than 90 K.

7. The SRF cryomodule of claim 6 further comprising said layer of high-temperature superconductor is applied to said inner surface of said outer conductor by methods selected from the group consisting of physical-chemical vapor deposition, pulsed laser deposition, and a combination of physical-chemical vapor deposition and pulsed laser deposition.

8. The SRF cryomodule of claim 1 wherein said (SRF) cryomodule includes an electron beam current of at least 1 ampere at an energy of 1 to 10 MeV.

9. The SRF cryomodule of claim 1 further comprising:

said entrance beam tube having a diameter and said exit beam tube having a diameter; and

said diameter of said exit beam tube is larger than the diameter of said entrance beam tube.

10. The SRF cryomodule of claim 1 further comprising:

an entrance beamline ultra-high vacuum valve on said entrance beam tube; and

an exit beamline ultra-high vacuum valve on said exit beam tube.

11. The SRF cryomodule of claim 1 wherein said coaxial input power coupler is capable of sustaining a minimum of 500 kilowatt of power.

12. The SRF cryomodule of claim 1 further comprising:

said cryocooler includes a first stage cold head and a second stage cold head;

said first stage cold head of said cryocooler is at a temperature of 50-80 K; and

said second stage cold head of said cryocooler is at a temperature of 4.3-9 K.

13. The SRF cryomodule of claim 1 further comprising:

said magnetic shield including an inner and an outer magnetic shield; and

said inner and outer magnetic shields are constructed of a high permeability metal having high magnetic shielding properties, and

said thermal shield is constructed of oxygen free electronic copper.

14. The SRF cryomodule of claim 1 wherein said water-cooled beam pipe higher-order mode absorber is a ferrite damper.

15. The SRF cryomodule of claim 1 wherein said cryocoolers each provide a cooling power greater than or equal to 1.5 watt at 4.2 K.

16. A superconducting radio-frequency (SRF) cryomodule for accelerating an electron beam, comprising:

a vacuum vessel;

an SRF cavity within said vacuum vessel;

a coaxial input power coupler extending through said vacuum vessel and connected to said SRF cavity;

a cryocooler having a cold head, said cold head connected to the SRF cavity;

a water-cooled beam pipe higher-order mode absorber for damping of high-order modes;

a thermal shield;

a magnetic shield;

an entrance beam tube and an exit beam tube;

a high thermal conductivity strain relief section between said second stage cold head and said SRF cavity; and

said high thermal conductivity strain relief section is selected from the group consisting of copper and tungsten.

17. A method for accelerating an electron beam to an electron beam current of at least 1 ampere at an energy of 1 to 10 MeV, comprising:

providing a superconducting radio-frequency (SRF) cryomodule including a vacuum vessel, an SRF cavity within said vacuum vessel, an coaxial input power coupler extending through said vacuum vessel and connected to said SRF cavity, a cryocooler having a cold head, said cold head connected to the SRF cavity, an entrance beam tube and an exit beam tube, a thermal shield, a magnetic shield, said coaxial input power coupler including an outer conductor having an inner surface; said inner surface of said outer conductor of said power coupler includes a section with a layer of high-temperature superconductor, and a water-cooled beam pipe higher-order mode absorber on said exit beam tube;

cooling said SRF cavity to between 4.3 K and 9 K with said cryocooler;

providing said exit beam tube with a greater diameter than said entrance beam tube to damp high-order modes in said SRF cavity;

further damping high-order modes in said SRF cavity with said water-cooled beam pipe higher-order mode absorber;

removing infrared heat generated by the SRF cavity with said thermal shield; and

removing magnetic flux lines of interfering magnetic fields with said magnetic shield.