  We present the first long-duration and high duty cycle 40-tesla pulsed-field
cryomagnet addressed to single crystal neutron diffraction experiments at
temperatures down to 2 K. The magnet produces a horizontal field in a
bi-conical geometry, $\pm$15 and $\pm$30{\deg} upstream and downstream of the
sample, respectively. Using a 1.15MJ mobile generator, magnetic field pulses of
100 ms length are generated in the magnet, with a rise time of 23 ms and a
repetition rate of 6-7 pulses per hour at 40 T. The setup was validated for
neutron diffraction on the CEA-CRG three-axis spectrometer IN22 at the ILL.
