High performance SRF accelerator structure and method

Patent metadata

Field	Value
Publication number	US-10485090-B2
Application number	US-201715411986-A
Country	US
Kind code	B2
Filing date	Jan 21, 2017
Priority date	Jan 22, 2016
Publication date	Nov 19, 2019
Grant date	Nov 19, 2019

Abstract

A high performance accelerator structure and method of production. The method includes precision machining the inner surfaces of a pair of half-cells that are maintained in an inert atmosphere and at a temperature of 100 K or less. The method includes removing thin layers of the inner surfaces of the half-cells after which the roughness of the inner surfaces in measured with a profilimeter. Additional thin layers are removed until the inner surfaces of the half-cell measure less than 2 nm root mean square (RMS) roughness over a 1 mm2 area on the profilimeter. The two half-cells are welded together in an inert atmosphere to form an SRF cavity. The resultant SRF cavity includes a high accelerating gradient (Eacc) and a high quality factor (Q0).

First claim

What is claimed is:

1. A chemical rinse-free method of forming a superconducting radio frequency (SRF) accelerator cavity, comprising:
(a) providing a first and second half-cell of an accelerator cavity having an inner surface and an equator;
(b) adjusting the temperature of the first and second half-cell to 100 K or less;
(c) removing a thin layer of the inner surface of the first and second half-cell while holding the temperature of the first and second half-cell to 100K or less and maintaining the first and second half-cell in a first inert atmosphere;
(d) measuring the roughness of the inner surface of the first and second half-cell with a surface profilimeter;
(e) repeating steps (c) through (d) until the inner surface of the first and second half-cell is less than 2 nm root mean square (RMS) roughness over a 1 mm 2 area; and
(f) welding the two half-cells together in a second inert atmosphere to form a superconducting radio frequency accelerator cavity.

2. The method of claim 1 wherein said half-cells are constructed of niobium.

3. The method of claim 1 wherein said half-cells are constructed of material selected from the group consisting of niobium, copper, vanadium, titanium, technetium, steel, and alloys thereof.

4. The method of claim 1 wherein the accelerator cavity further comprises a quality factor (Q 0 ) of 4×10 10 or greater.

5. The method of claim 1 wherein the accelerator cavity further comprises an accelerating gradient (E acc ) of 45 MV/m or greater.

6. The method of claim 1 wherein the thin layer of the inner surface of the first and second half-cell is removed on a 3D milling machine.

7. The method of claim 1 wherein the second inert atmosphere is selected from the group comprised of argon (Ar), helium (He), neon (Ne), krypton (Kr), and xenon (Xe).

Assignees

• Jefferson Science Ass Llc

Inventors

• Myneni Ganapati Rao

Classifications

• H05H7/20 Primary

  with superconductive walls · CPC title