40-TESLA PULSED MAGNET FOR NEUTRON DIFFRACTION

06 January 2020 par Super Administrateur
F.DUC LNCMI-TOULOUSE

A 40-T pulsed magnet for single crystal elastic neutron scattering, featuring an unprecedented high duty cycle, now offers new opportunities to investigate magnetic systems down to 2 K at the Institut Laue Langevin (ILL) in Grenoble (France). This unique experimental setup results from a 4-year collaborative work between the LNCMI-Toulouse, the CEA-Grenoble, and the ILL. The magnet produces a horizontal field in a bi-conical geometry, ±15° upstream and ±30° downstream of the sample. Using a 1.15 MJ transportable generator installed on the triple-axis spectrometer IN22, magnetic-field pulses of 100 ms duration are generated, with a rise time of 23 ms and a rate of 7 pulses per hour at 40 T. Since 2014, this magnet has already generated more than 5000 field pulses, with 70% of them at more than 30 T. They have allowed to investigate various magnetic systems such as heavy-fermion materials and quantum spin systems. This equipment is available to ILL users through a scientific collaboration with the LNCMI.

Figure 1: Overview of the bottom of the cryomagnet. The coil is immersed in liquid nitrogen. The sample is under vacuum and fixed at the end of a cold finger. This finger is cooled down using a flow of helium.