The invention discloses a gradient
magnetic field device which comprises a guiding
magnetic field for guiding transmission of a high-current
relativistic electron beam; the guide
magnetic field comprises a solenoid coil; the solenoid coil is wound around the high-current
diode so as to form a gradient magnetic field enabling the high-current
relativistic electron beam to generate radial deflection, and the solenoid coil comprises a first sub-coil, a second sub-coil and a third sub-coil; the first sub-coil is wound on the outer side of an
anode of the high-current
diode, the second sub-coil is wound on the outer side of an outer conductor of the high-current
diode, and the third sub-coil is wound on the outer side of the second sub-coil; the guide magnetic field further comprises an adjusting magnetic field; and the adjusting magnetic field is fixedly arranged between the first sub-coil and the second sub-coil, is wound around the high-current diode and is used for adjusting the
radius change speed of the high-current
relativistic electron beam. The invention further discloses a high-current diode based on the gradient magnetic field. The high-current diode comprises the gradient magnetic
field device. The problem that the size of a high-impedance diode is difficult to reduce can be solved.