Claims
- 1. A mold containing a non-uniform cavity surface for forming a laminate tile pole piece for an MRI system, made by the method of:performing a simulation of magnetic flux density between a first magnet of the MRI system and a second magnet of the MRI system; determining an optimum contour of a first surface of the pole piece based on an optimum value of the magnetic flux density between the first magnet and the second magnet; and forming the mold comprising a bottom surface, a side surface and a top surface enclosing a mold cavity, wherein the bottom mold cavity surface contour substantial inverse of the optimum contour of the first surface of the pole piece.
- 2. The mold of claim 1, wherein the non-uniform cavity surface comprises a plurality of cylindrical spacers of non-uniform height.
- 3. The mold of claim 1, wherein the non-uniform cavity surface comprises a solid, non-uniform surface.
- 4. The mold of claim 1, wherein the mold cavity has a circular cross section.
- 5. The mold of claim 4, further comprising a portion of an MRI pole piece located in the mold cavity.
- 6. The mold of claim 5, wherein the pole piece comprises a plurality of trapezoid or annular sector shaped tiles arranged in a plurality of concentric annular arrays.
- 7. The mold of claim 6, wherein the tiles comprise laminate metal tiles.
- 8. The mold of claim 1, further comprising a removable mold cover plate.
- 9. The mold of claim 8, wherein the mold cover plate contains an epoxy inlet opening and an air outlet opening.
- 10. The mold of claim 9, wherein the cover plate is attached to mold walls by bolts or a latch.
- 11. A mold, comprising:a bottom surface, a side surface and a top surface enclosing a mold cavity; and a non-uniform mold cavity surface for forming a tile pole piece for an MRI system, wherein the non-uniform mold cavity surface contour is a substantial inverse of a contour of one surface of the pole piece.
- 12. The mold of claim 11, wherein the mold cavity has a circular cross section.
- 13. The mold of claim 4, wherein the top surface comprises a removable mold cover plate.
- 14. The mold of claim 11, wherein the non-uniform mold cavity surface comprises a plurality of spacers separated by gaps, the spacers being arranged in a plurality of concentric annular arrays.
- 15. The mold of claim 14, wherein the spacers comprise cylinders of various height attached to the mold cavity surface by screws or glue.
- 16. The mold of claim 11, wherein the non-uniform mold cavity surface comprises a solid, non-uniform surface.
- 17. The mold of claim 11, wherein the non-uniform mold cavity surface comprises the bottom surface of the mold.
Parent Case Info
This application is a divisional of application Ser. No. 09/198,507, filed Nov. 24, 1998, now U.S. Pat. No. 6,259,252.
US Referenced Citations (10)
Foreign Referenced Citations (1)
Number |
Date |
Country |
2-246927 |
Oct 1990 |
JP |