Super-6T2, a new position-sensitive detector polarized neutron diffractometer

Abstract : A new polarized neutron diffractometer has been commissioned at the ORPHEE reactor in Saclay. Thermal neutron beam of 1.4 Å is obtained by a vertically focusing graphite monochromator. Polarization of the beam is achieved by a supermirror bender of 800 mm length and working cross-section 20×50 mm2 installed in the monochromator shielding. An additional supermirror focusing condensor can be inserted in the RF adiabatic flipper, when small samples are used. Position-sensitive detector Bidim26, developed at the ILL, covers angular range of 24°×24° in vertical and horizontal directions, which allows to perform measurements of flipping ratios for several reflections simultaneously. The polarization of the incident beam is 97%. The flux at the sample position was found to be more than an order of magnitude higher than that of the 5C1 polarized neutron diffractometer at LLB. Data acquisition and data treatment programs have been developed. Possibilities of multi-crystal experiments and studies of powder samples are now under consideration. Ensemble of these measures should boost the data acquisition rate of magnetization densities by a factor of 20–30.