Systems and methods for magnetic shielding for a superconducting computing system
A magnetic shielding system that includes a shield that is non-uniform in the axial direction and a shield cap that is non-uniform in the radial direction. Each shield in the system may have a magnetic permeability, thickness, and/or radius that varies in the axial direction to create low-reluctance paths that redirect flux away from a sample towards the ends of the shield. Each shield cap in the system may have a magnetic permeability and/or thickness that varies in the radial direction to create low-reluctance paths that redirect flux away from the sample towards shield walls. An inner shielding layer formed from a material of low permeability and moderate-to-high coercivity may be implemented as the innermost layer of a magnetic shielding system.
1. A magnetic shielding system for use with a superconducting computing system, the magnetic shielding system comprising:
a first and a second shield cap, each shield cap having a thickness that varies in along at least a portion of a lateral direction, a magnetic permeability that varies along at least a portion of the lateral direction, and an opening shaped to accommodate electrical wiring;
a first shield having an inner volume bound by an inner surface of the first shield, the first shield cap, and the second shield cap;
a superconducting shield that is at least partially enclosed in the inner volume of the first shield; wherein
the first shield has a magnetic permeability and a thickness that both vary along an axial direction;
the first shield cap is detachably joined to a first end of the first shield; and
the second shield cap is detachably joined to a second end of the first shield, the second end positioned opposite to the first end.
2. The magnetic shielding system of claim 1 , further comprising a second shield that has an inner volume, wherein the first shield is at least partially enclosed in the inner volume of the second shield, and the second shield is detachably joined to a third shield cap at a first end of the second shield.
3. The magnetic shielding system of claim 2 , further comprising a fourth shield cap that is detachably joined a second end of the second shield, the second end of the second shield positioned opposite to the first end of the second shield.
4. The magnetic shielding system of claim 2 wherein the first shield and the second shield each comprise at least one material selected from the group of: mu metal, permalloy, and ferrite.
5. The magnetic shielding system of claim 1 , wherein the superconducting shield at least partially encloses at least a portion of the superconducting computing system.
6. The magnetic shielding system of claim 1 wherein the thickness of the first shield decreases along the at least a portion of the axial direction as the shield is traversed from the first end to the middle portion of the shield, the thickness sized to minimize reluctance at the first end of the shield.
7. The magnetic shielding system of claim 1 wherein an outer surface of the first shield curves longitudinally inward towards the center longitudinal axis.
8. The magnetic shielding system of claim 1 wherein the first shield comprises a first material selected from a group of: mu-metal, permalloy, and ferrite.
9. The magnetic shielding system of claim 1 wherein the first and second shield caps have a thickness that increases as the first and second shield caps are traversed from the center longitudinal axis to the perimeter, the thickness sized to minimize reluctance at the perimeter.
10. The magnetic shielding system of claim 1 wherein the superconducting shield comprise at least one material selected from the group of: tin, copper, and aluminum.