New solid state polarizing bender for cold neutrons

A new S-shaped polarizing bender has been built and tested at the ILL. This compact polarizer, designed using Monte Carlo simulations, consists of a stack of silicon wafers, coated on both sides with a polarizing supermirror and an absorbing layer. Due to the S-shape of the bending, the beam does not change direction on passing through the polarizer. It is ideally suited for cold neutron beams, as shown by the performances measured on the 3-axis spectrometer IN14 at ILL (wavelength 2.4 to 6 angstrom). A transmission of 60-70% of the selected spin state was obtained. Accurate measurements of the degree of polarization of the transmitted beam, using a highly polarized He-3 cell show the high quality of this new device, with polarization efficiency between 98% and 99%. (c) 2006 Elsevier B.V. All rights reserved.