Hybrid Magnet - Setup and mode of operation

This stack can withstand high currents and forces. Cooling water is pumped through holes penetrating the stack. Heat generated in the resistive coil has to be dissipated by a high-pressure cooling water circuit. The pure water circuit of the magnet transfers heat via a heat exchanger to the cooling water circuit of the cooling facilities. Cooling towers, chillers, and a water storage tank of approx. 300 cubic meters are located in this circuit.The sample for the neutron scattering experiment sits in the horizontal 50 mm diam. central bore of the magnet system located between conical openings at both sides of the magnet. These chambers are evacuated in order not to attenuate the neutron beam by air scattering.

A new additional building to accommodate all the peripheral systems had to be erected for the high-field magnet. This "Technikum“, as it is known, will accommodate all facilities for the supply of cooling and energy. The magnet system will be installed in Neutron Guide Hall 2 at the Extreme Environment Diffractometer EXED.

A sophisticated control system protects the entire hybrid magnet against operating errors and equipment failures. A major potential failure of the superconducting coil could occur if part of the winding exceeds the admissible operating temperature and looses its superconductivity. This could result in a high production of energy due to ohmic heating, which can damage the coil. For this reason, if such an event (called a “quench”) occurs, the magnet current has to be immediately reduced to zero (fast discharge). This is achieved by the magnet protection system. A main component of the system is a dump resistor that, in case of a failure, absorbs the energy stored in the magnet, while the connection from the power supply to the magnet is interrupted by circuit breakers. Independent detection electronics with an uninterruptible power supply have the sole task of detecting such a quench as fast and reliably as possible.

Learn more about magnetism in the "Magnet Academy“ by NHMFL.