Claims
- 1. A gradient coil for creating a magnet field gradient within a predefined volume having fixed length, depth and width dimensions therein comprising:
- a plurality of turns of flat conductive wire enclosing said predefined volume;
- a means for coupling said turns of wire to a pulsed current supply;
- wherein the numbers of turns, the placement of the turns relative to each other in the coil and dimensions of said turns of wire are such that when a pulsed current is supplied to said turns via said means for coupling to a pulsed current, a magnetic field gradient is created in said predefined volume such that of the magnetic gradients produced by said current the steepest and most homogeneous of said magnetic gradients is produced in said predetermined volume during the time when peak of said pulsed current occurs and further wherein the weakest of a plurality of measured electrical resistances occurs, in said coil during a transition of said pulsed current, and wherein said volume has a gaseous uniform magnetic permeability.
- 2. A gradient coil as in claim 1, wherein said turns of wire have a thickness and a width and further the ratio of thickness to width is equal to or greater than 5.
- 3. A gradient coil according to claim 1 wherein the turns used to form said coil are distributed among symmetrical sets, each comprising two groups of turns made up of conducting strands.
- 4. A gradient coil according to the claim 3 wherein the turns of a group are intertwined with one another, with the two groups intertwined with one another.
- 5. A gradient coil according to the claim 3 or the claim 4 wherein the conductors and/or the groups are adjacent to one another.
- 6. A gradient coil according to claim 5 wherein the coil is designed to produce an oriented field gradient such that a strong field is produced the coil comprising an initial group with one turn and a second group with ten adjacent turns.
- 7. A gradient coil according to the claim 6 further comprising:
- a cylindrical chuck;
- wherein the coil is carried by said cylindrical chuck with a radius R.sub.z, the turns being perpendicular to the cylindrical axis of of said chuck, the abscissa of the projection, onto this axis, from the starting point of the groups being respectively equal to 0.356.R.sub.z and 0.893R.sub.z, the width of the conductors being equal to 0.069R.sub.z.
- 8. A gradient coil according to the claim 5 wherein the coil comprises an initial group with two turns and a second group with five turns.
- 9. A gradient coil according to the claim 8 wherein the coil is carried by a cylindrical chuck with a radius R.sub.x, the turns being saddle-shaped on the surface of this chuck and comprising arch-shaped conductor strands of which the projection on the axis ranges respectively from 0.111R.sub.x to 0.249R.sub.x, from 0.568R.sub.x to 0.913R.sub.x and from 2.384R.sub.x to 2.867R.sub.x, the width of the conductors being equal to 0.069R.sub.x.
- 10. A gradient coil according to any one of the claims 1, 2, 3 or 4 comprising turns, powered in series and connected to one another where all the ends to be connected move from the level of one turn to that of another turn.
Priority Claims (1)
Number |
Date |
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85 15510 |
Oct 1985 |
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Parent Case Info
This application is a continuation of application Ser. No. 07/335,935 filed on Apr. 10, 1989, now abandoned, which is a division of application Ser. No. 06/918,882 filed Oct. 15, 1986 and now U.S. Pat. No. 4,847,985.
US Referenced Citations (4)
Divisions (1)
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Date |
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918882 |
Oct 1986 |
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Continuations (1)
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335935 |
Apr 1989 |
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