4.7T - 11.7T
Gaven Industries combines its Soldered Copper R.F. Shielded Enclosure with heavy 1006 fully annealed steel plate creating a "Dual Shield" which provides the ultimate combination of very high performance R.F. Shielding and Magnetic Shielding for large bore 7T research MRI magnets. Because of the attention to detail that is used in the construction of the R.F. Shield for this application, R.F. Shielding performance is, as a standard, tested to 140dB of attenuation.
Although others use the Magnetic Shield as the R.F. Shield by welding the seams on the interior of most plates (commonly referred to as a combination shield) Gaven Industries' Dual Shield System is extremely cost competitive.
No welding or heat is applied to the steel plates after annealing or during construction as this can cause a loss of Magnetic Shield performance in the heat affected areas. The Soldered Copper R.F. Shield is installed on wood framing that is attached to the inside of the steel plate eliminating the possibility of an inadvertent ground which is a common problem with combination shielding.
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Before any steel plates are fabricated and annealed, testing is performed on a sample of steel and a B-H curve is plotted after each batch of fabricated plates are annealed. This information is used to verify the consistency of the annealing process, verify the actual shielding properties of the steel plates and to confirm the initial data used in the original Magnetic Shield Design.
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