High Homogeneity Solenoids
Cryomagnetics has considerable experience in the engineering and manufacturing of high homogeneity magnets. By high homogeneity, we mean superconducting magnets with better than +/- 0.01% (100 ppm) maximum central field variation over a 10mm diameter spherical volume (DSV).
In practice, the actual magnet winding process cannot duplicate the computer-generated magnet design specification. Trim coils (shims) must be added to correct inhomogeneities. Many magnet designs can achieve +/- 0.001% (10 ppm) over a 10mm DSV homogeneity with trim coils wound in series with the main coil. This insures homogeneity specification is maintained throughout the entire field range of the superconducting magnet.
Other applications, such as NMR experimentation, require the superconducting magnet to have 1 ppm or 0.1 ppm homogeneity over a large homogeneous volume. This is accomplished by the addition of separately chargeable superconducting shim coils. First-order shim coils can achieve 1 ppm homogeneity and include the coils X, Y, Z, Z2. Second order shim coils can achieve 0.1 ppm homogeneity and include the coils X2-Y2, XY, ZY, and ZX.
The majority of high-homogeneity superconducting magnets are custom built to your specifications. Contact us with your specifications.
Many high-homogeneity magnets can be manufactured in cryogen-free.
Following are some standard designs for your reference.
| Model | Field | Bore | Homogeneity* | Current | Inductance |
| 70-200-10P | 7.0T | 2.00″ | +/- 10 ppm | 78A | 7.0H |
| 70-250-001L | 7.0T | 2.50″ | +/- 100 ppm | 35A | 15.0H |
| 70-300-001L | 7.0T | 3.00″ | +/- 100 ppm | 58A | 18.2H |
| 80-200-10P | 8.0T | 2.00″ | +/- 10 ppm | 45A | 19.4H |
| 80-250-001L | 8.0T | 2.50″ | +/- 100 ppm | 47A | 36.7H |
| 80-250-10P | 8.0T | 2.50″ | +/- 10 ppm | 77A | 11.6H |
| 90-200-10P | 9.0T | 2.00″ | +/- 10 ppm | 82A | 10.2H |
| 90-250-10P | 9.0T | 2.50″ | +/- 10 ppm | 80A | 17.6H |
| 90-300-10P | 9.0T | 3.00″ | +/- 10 ppm | 79A | 27.0H |
Please check out our NMR & EPR Systems Page for additional information on high homogeneity magnet systems.
* Homogeneity is measured over a 10mm diameter spherical volume (DSV).