A change in the strength of the main magnetic field can be caused by
A)cryogen boiloff.
B)external ferromagnetic materials.
C)shim coil failure.
D)all of the above.

Question

Quizplus · Accepted Answer

Cryogen boiloff can cause a change in the strength of the main magnetic field as it affects the cooling of the superconducting coils. External ferromagnetic materials can also cause a change in the magnetic field by altering the magnetic flux density in the region of interest. Shim coil failure can also affect the magnetic field strength since they are used to fine-tune the uniformity of the field. Hence, all the given options can cause a change in the strength of the main magnetic field.

A Change in the Strength of the Main Magnetic Field