An electromagnet having a conical bore. The conical bore is created by wrapping a conductor around a conically-offset helix. The cross sectional area of the conductor can be varied in order to maintain a desired current carrying capacity along the helix. A single element can be used as the conductor. The conductor can also be created by stacking a series of specially-shaped plates analogous to prior art Bitter-disks.
1. An electromagnet capable of creating a conical magnetic field, comprising:
a. a center axis running from a first end of said electromagnet to a second end of said electromagnet;
b. a central cavity, lying within said electromagnet and running along said center axis;
c. wherein said central cavity includes a first conical portion defined by a conical profile;
d. a single helical conductor, wrapped around said first conical portion, wherein said single helical conductor is formed by a plurality of 360 degree turns;
e. wherein said single helical conductor has a pitch and a cross section;
f. wherein said pitch of said single helical conductor varies across said first conical portion;
g. wherein said cross section of said single helical conductor has an inner edge, an outer edge, a height, and a width;
h. wherein said outer edge lies upon an outer radius measured from said center axis, with said outer radius being constant;
i. wherein said inner edge lies upon an inner radius measured from said center axis, with said inner radius being variable within said first conical portion, so that said radius lies on said conical profile within said first conical portion, thereby smoothly varying said width of said cross section within said first conical portion; and
j. wherein said height of said cross section is also smoothly varied within said first conical portion in order to maintain a desired cross sectional area for said cross section.
2. The electromagnet as recited in claim 1 , wherein said pitch and said cross section are varied in order to maintain a constant cross sectional area of said helical conductor.
3. The electromagnet as recited in claim 2 , wherein said pitch and said cross section of said helical conductor are varied to minimize the variation in said cross sectional area of said helical conductor throughout said first conical portion.
4. The electromagnet as recited in claim 3 , further comprising:
a. wherein said first conical portion has a first end wherein said inner radius is relatively large and a second end wherein said inner radius is relatively small;
b. a second conical portion within said central cavity;
c. wherein said second conical portion has a first end wherein said inner radius is relatively large and a second end wherein said inner radius is relatively small; and
d. wherein said second end of said first conical portion lies proximate said second end of said second conical portion.
5. The electromagnet as recited in claim 2 , further comprising:
a. wherein said first conical portion has a first end wherein said inner radius is relatively large and a second end wherein said inner radius is relatively small;
b. a second conical portion within said central cavity;
c. wherein said second conical portion has a first end wherein said inner radius is relatively large and a second end wherein said inner radius is relatively small; and
d. wherein said second end of said first conical portion lies proximate said second end of said second conical portion.
6. The electromagnet as recited in claim 1 , wherein said helical conductor has an outward facing surface, and wherein said outward facing surface lies along a single cylinder running parallel to said center axis.
7. The electromagnet as recited in claim 1 , further comprising:
a. wherein said first conical portion has a first end wherein said inner radius is relatively large and a second end wherein said inner radius is relatively small;
b. a second conical portion within said central cavity;
c. wherein said second conical portion has a first end wherein said inner radius is relatively large and a second end wherein said inner radius is relatively small; and
d. wherein said second end of said first conical portion lies proximate said second end of said second conical portion.
8. The electromagnet as recited in claim 7 , wherein said central cavity includes a cylindrical bore positioned between said first and second conical portions.