Magnetic compound refractive lens for focusing and polarizing cold neutron beams

Journal Article · Thu Mar 15 04:00:00 EDT 2007 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.2709844· OSTI ID:20953399

Littrell, K C; Felcher, G P; Park, S; Kirby, B J; Fitzsimmons, M R ^[1]

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1. Argonne National Laboratory, Argonne, Illinois 60439 (United States)

Biconcave cylindrical lenses are used to focus beams of x rays or neutrons using the refractive properties of matter. In the case of neutrons, the refractive properties of magnetic induction can similarly focus and simultaneously polarize the neutron beam without the concomitant attenuation of matter. This concept of a magnetic refractive lens was tested using a compound lens consisting of 99 pairs of cylindrical permanent magnets. The assembly successfully focused the intensity of a white beam of cold neutrons of one spin state at the detector, while defocusing the other. This experiment confirmed that a lens of this nature may boost the intensity locally by almost an order of magnitude and create a polarized beam. An estimate of the performance of a more practically dimensioned device suitable for incorporation in reflectometers and slit-geometry small angle scattering instruments is given.

• OSTI ID: 20953399
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 3 Vol. 78; ISSN 0034-6748; ISSN RSINAK
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
COLD NEUTRONS
CYLINDRICAL CONFIGURATION
FOCUSING
GEOMETRY
LENSES
NEUTRON BEAMS
PERMANENT MAGNETS
POLARIZED BEAMS
REFRACTIVE INDEX
SMALL ANGLE SCATTERING
X RADIATION