Split florida-helix magnet

Abstract

An electromagnet having at least one access port oriented perpendicularly to the electromagnet's central axis. The magnet has a conventional helical winding along its central axis. However, at some point along the length of the axis, the pitch of the helical winding is greatly increased in order to create a region with a comparatively low turn density. One or more ports are provided in this region. These ports provide access from the magnet's central bore to the magnet's exterior. A sample can be placed in the central bore near the ports. A beam traveling down the central bore, or through one of the radial ports, will strike the sample and be scattered in all directions. The ports allow access for instrumentation which is used to evaluate the scattered beam.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a perspective view, showing a conductive helix.

FIG. 2 is a perspective view, showing a prior art Bitter-disk magnet.

FIG. 3 is a detail view, showing a portion of a Bitter-disk magnet.

FIG. 4 is a perspective view, showing a prior art Bitter-disk.

FIG. 5 is a perspective view, showing a prior art Bitter-type conductor turn.

FIG. 6 is a perspective view, showing a prior art Florida-Bitter disk.

FIG. 7 is a detail view, showing a portion of a Florida-Bitter disk.

FIG. 8 is a perspective view, showing a split Florida-helix.

FIG. 9 is a section view, showing internal details of the embodiment of FIG. 8.

FIG. 10 is an elevation view, showing the winding pitch of the embodiment of FIG. 8.

FIG. 11 is a perspective view, showing an elliptical port in a split Florida-helix.

FIG. 12 is a section view, showing internal details of the embodiment of FIG. 11.

FIG. 13 is a perspective view, showing winding pitch variation in a split Florida-helix.

FIG. 14 is a perspective view, showing how a split Florida-helix can be divided into two halves.

FIG. 15 is a hidden-line perspective view, showing a housing configured to allow coolant flow around the ports in a split Florida-helix.

FIG. 16 is a perspective view, showing the assembly of the two halves together in the housing.

FIG. 17 is a perspective view, showing the completion of the assembly of FIG. 16.

FIG. 18 is a perspective view, showing the addition of Florida-Bitter disk stacks to the assembly of FIG. 17.

FIG. 19 is a sectioned perspective view, showing a representative multi-coil magnet constructed of nested Florida-helix and Florida-Bitter coils.

FIG. 20 is a perspective view, showing a prior art approach to the creation of access ports.

FIG. 21 is a graphical view, showing the contribution of the regions of an electromagnet to maximum field strength in the magnet's core.

FIG. 22 is a perspective view, showing a split Florida-helix with the addition of elongated tie rod holes.

FIG. 23 is a detailed perspective view, showing a split Florida-helix with alterations made to optimize the interface surfaces.

FIG. 24 is a detailed perspective view, showing the use of angled cooling slot walls near the interface surfaces.

FIG. 25 is a sectioned perspective view, showing a representative multi-coil magnet constructed of nested Florida-helix and Florida-Bitter coils, and the coolant flow around the access ports.

FIG. 26 is a perspective view with a cutaway, showing the geometry around a radial access port.

FIG. 27 is a detailed elevation view of FIG. 26, showing how coolant lows through a gap around each radial access port.

Claims

1. An electromagnet, comprising: a. a cylinder of conductive material having a central axis, a first end, a second end, a mid plane positioned between said first and second ends, and a central bore passing through said cylinder from said first end to said second end;b. at least one port passing from said central bore to the exterior of said cylinder in a direction substantially perpendicular to said central axis; andc. a gap following a helical path along said central axis from said first end of said cylinder to said second end of said cylinder, wherein said helical gap passes from said central bore to said exterior of said cylinder in a direction substantially perpendicular to said central axis.

2. An electromagnet as recited in claim 1, wherein said at least one port lies on said mid plane.

3. An electromagnet as recited in claim 2, wherein the pitch of said helical path varies.

4. An electromagnet as recited in claim 3, wherein: a. said pitch of said helical path is relatively shallow proximate said first end and said second end; andb. said pitch of said helical path is relatively steep proximate said mid plane.

5. An electromagnet as recited in claim 4, wherein said at least one port assumes an elliptical form which diverges when proceeding from said central axis toward said exterior of said cylinder.

6. An electromagnet as recited in claim 4, wherein said electromagnet is divided into a first half and a second half, with the division occurring proximate said mid plane.

7. An electromagnet as recited in claim 6, wherein said first half and said second half each include at least two ports separated by at least two interface surfaces, with said first half and said second half meeting at said at least two interface surfaces.

8. An electromagnet as recited in claim 7, wherein each of said at least two interface surfaces includes a stabilizing pin positioned to prevent lateral movement of said at least two interface surfaces with respect to each other.

9. An electromagnet as recited in claim 7, further comprising cooling slots running from said first end to said second end.

10. An electromagnet as recited in claim 9, wherein said cooling slots pass around said at least two interface surfaces.

11. An electromagnet as recited in claim 9, further comprising: a. an inner wall lying within said central bore;b. an outer wall lying outside said exterior of said cylinder;c. at least two bounding walls joining said inner wall to said outer wall, wherein each of said at least two bounding walls lies within one of said at least two ports;d. wherein the exterior surface of each of said bounding walls is smaller than each of said at least two ports in order to form a gap through which coolant can flow around each of said at least two bounding walls.

12. An electromagnet as recited in claim 11, wherein said cooling slots pass around said at least two interface surfaces.

13. An electromagnet as recited in claim 11, wherein each of said at least two interface surfaces includes a stabilizing pin positioned to prevent lateral movement of said at least two interface surfaces with respect to each other.

14. An electromagnet as recited in claim 1, further comprising: a. a first Bitter coil lying proximate said first end of said conductive cylinder and electrically connected thereto; andb. a second Bitter coil lying proximate said second end of said conductive cylinder and electrically connected thereto, so that said first Bitter coil, said conductive cylinder, and said second Bitter coil combine to form a helical electrical current path.

15. An electromagnet as recited in claim 2, further comprising: a. a first Bitter coil lying proximate said first end of said conductive cylinder and electrically connected thereto; andb. a second Bitter coil lying proximate said second end of said conductive cylinder and electrically connected thereto, so that said first Bitter coil, said conductive cylinder, and said second Bitter coil combine to form a helical electrical current path.

16. An electromagnet as recited in claim 3, further comprising: a. a first Bitter coil lying proximate said first end of said conductive cylinder and electrically connected thereto; andb. a second Bitter coil lying proximate said second end of said conductive cylinder and electrically connected thereto, so that said first Bitter coil, said conductive cylinder, and said second Bitter coil combine to form a helical electrical current path.

17. An electromagnet as recited in claim 4, further comprising: a. a first Bitter coil lying proximate said first end of said conductive cylinder and electrically connected thereto; andb. a second Bitter coil lying proximate said second end of said conductive cylinder and electrically connected thereto, so that said first Bitter coil, said conductive cylinder, and said second Bitter coil combine to form a helical electrical current path.

18. An electromagnet as recited in claim 6, further comprising: a. a first Bitter coil lying proximate said first end of said conductive cylinder and electrically connected thereto; andb. a second Bitter coil lying proximate said second end of said conductive cylinder and electrically connected thereto, so that said first Bitter coil, said conductive cylinder, and said second Bitter coil combine to form a helical electrical current path.

19. An electromagnet as recited in claim 7, further comprising: a. a first Bitter coil lying proximate said first end of said conductive cylinder and electrically connected thereto; andb. a second Bitter coil lying proximate said second end of said conductive cylinder and electrically connected thereto, so that said first Bitter coil, said conductive cylinder, and said second Bitter coil combine to form a helical electrical current path.

20. An electromagnet as recited in claim 9, further comprising: a. a first Bitter coil lying proximate said first end of said conductive cylinder and electrically connected thereto; andb. a second Bitter coil lying proximate said second end of said conductive cylinder and electrically connected thereto, so that said first Bitter coil, said conductive cylinder, and said second Bitter coil combine to form a helical electrical current path.