Abstract A superconducting magnet apparatus comprises an emergency run down unit having a heater power source and a heater circuit switch, a superconducting coil, and a persistent current switch circuit, the persistent current switch connected in parallel to the superconducting coil and including a first persistent current switch connected in parallel to a first protective element of low resistance and a second persistent current switch connected in parallel to a second protective element of high resistance. The second persistent current switch has a persistent switch-heater connected to the heater power source through the heater circuit switch. Thus, when it becomes necessary to demagnetize the superconducting magnet apparatus being operated in a persistent current mode, the second persistent current switch parallel to the second protective element of high resistance is opened, whereby current flowing through the superconducting magnet decays rapidly.
A superconducting magnet apparatus comprising an emergency run down unit having a heater power source and a heater circuit switch, a superconducting coil, and a persistent current switch circuit, said persistent current switch circuit being connected in parallel to said superconducting coil and including a first persistent current switch connected in parallel to a first protective element of low resistance and a second persistent current switch connected in parallel to a second protective element of high resistance, said second persistent current switch having a persistent current switch-heater connected to said heater power source through said heater circuit switch.
Claim 2
Dependent Claim
98 words
A superconducting magnet apparatus comprising an emergency run down unit having a heater power source and a heater circuit switch, a superconducting coil, and a persistent current switch circuit, said persistent current switch circuit being connected in parallel to said superconducting coil and including a first persistent current switch connected in parallel to a first protective element of low resistance and a second persistent current switch connected in parallel to a second protective element of high resistance, said second persistent current switch having a persistent current switch-heater connected to said heater power source through said heater circuit switch.
Claim 3
Dependent Claim
44 words
A superconducting magnet apparatus as defined in claim 1 wherein said second persistent current switch includes a plurality of persistent current switching members connected in series, said switching members connected in series having said second protective element of high resistance connected in parallel therewith.
Claim 4
Dependent Claim
22 words
A superconducting magnet apparatus as defined in claim 2 wherein each of said persistent current switching members has a persistent current switch-heater.