A 10 Tesla cryomagnet on a polarized neutron diffractometer

D3 is a spin polarized hot neutron diffractometer which makes possible the accurate measurement of the magnetization distribution within crystals at the atomic level. When equiped with CRYOPAD, very precise spherical polarimetric scattering measurements can be carried out.

When measuring the magnetization distribution the sample must be saturated by a magnetic field. The greater the proportion of atomic spin aligned with the field axis, the larger the diffraction signal (higher spin dependent intensities). Hence D3 was equiped, in 2001, with a powerful cryomagnet capable of imposing a 10 Tesla magnetic field on large samples and allowing a large access to a lifting neutron detector.

The movie below shows D3 in 2001 equiped with the bulky 10 Tesla cryomagnet. It demonstrates the rotation of the cryomagnet around the omega axis of the diffractometer and the movement of the detector around it.

Click here to download the 328x500 MPEG-4 movie (file size: 300 kb)

©2003-2007, Artechnique & Institut Laue-Langevin.

The movie below was shot in 2001, half a minute after the cryomagnet started to quench due to a mechanical problem separate from the cryomagnet itself. The quench corresponds to the magnet coils losing their superconducting properties, and the circulating current sees electrical resistance; the stored energy is rapidly converted to heat. Quenching is alway very spectacular. There is an explosive noise resulting as the liquid helium is boiled off and is ejected from the cryostat with an explosive noise. This, of course, should never occur "en théorie" as French say!

Click here to download the 240x320 MPEG-4 movie (file size: 800 kb)

©2003-2007, Institut Laue-Langevin.
Featuring: Eddy Lelièvre-Berna, Eric Bourjalamy.

English checked by: Ronen Ghosh, April 2007.
Updates: A.Filhol, 7 May 2007, 9 Sept 2009.