| 主权项 |
1. A magnet system that generates a highly stable magnetic field at a sample location, the magnet system comprising:
a magnet cryostat housing a first superconducting magnet coil and a second magnet coil co-axial to said first magnet coil which second magnet coil is during operation of the magnet system short-circuited in a superconducting persistent mode; and an external power supply that during operation supplies current to the first magnet coil via a current lead thereby generating a first magnetic field at the sample location that fluctuates according to a current noise of the power supply, wherein the second magnet coil is positioned and dimensioned in a way that it inductively couples to the first magnet coil such that it generates at the sample location a second magnetic field that compensates the fluctuations of the first magnetic field caused by the current noise of the power supply, wherein the first magnet coil and the second magnet coil are arranged on a common sample holder and the second magnet coil is arranged radially inside the first magnet coil and is axially shorter than the first magnet coil, the second magnet coil thereby having an inner radius which is smaller than an inner radius of the first magnet coil. |
