TY - JOUR
T1 - Characterization of mica crystals as reflectors for an ultracold neutron doppler converter
AU - Crow, M. L.
PY - 1997
Y1 - 1997
N2 - Natural mica crystals have been characterized for use as reflectors for an ultracold neutron source using Bragg scattering of cold (400 m/s) neutrons from a moving mica reflector, recently installed at the Los Alamos neutron science center (LANSCE). In particular, the trioctahedral Mg-rich mica phlogopite has been obtained in large sheets. The structure factor for the first-order Bragg reflection is a factor of four larger than for muscovite, the first variety of mica examined. The observed peak reflectivity for a phlogopite of 0.25 mm thickness is about 8.2% at 1.9 Å, with a mosaic spread of about 0.3° FWHM, in good agreement with the ideally imperfect crystal model. This can be extrapolated to a reflectivity of about 63% at the 17.4 Å operating wavelength of the ultracold neutron source. Improvements are possible by obtaining Fe-rich mica, which should be almost as effective as the alternative approach of using synthetic perfluorinated mica.
AB - Natural mica crystals have been characterized for use as reflectors for an ultracold neutron source using Bragg scattering of cold (400 m/s) neutrons from a moving mica reflector, recently installed at the Los Alamos neutron science center (LANSCE). In particular, the trioctahedral Mg-rich mica phlogopite has been obtained in large sheets. The structure factor for the first-order Bragg reflection is a factor of four larger than for muscovite, the first variety of mica examined. The observed peak reflectivity for a phlogopite of 0.25 mm thickness is about 8.2% at 1.9 Å, with a mosaic spread of about 0.3° FWHM, in good agreement with the ideally imperfect crystal model. This can be extrapolated to a reflectivity of about 63% at the 17.4 Å operating wavelength of the ultracold neutron source. Improvements are possible by obtaining Fe-rich mica, which should be almost as effective as the alternative approach of using synthetic perfluorinated mica.
KW - Mica
KW - Muscovite
KW - Phlogopite
KW - Ultracold neutrons
UR - http://www.scopus.com/inward/record.url?scp=11544338297&partnerID=8YFLogxK
U2 - 10.1016/S0921-4526(97)00525-5
DO - 10.1016/S0921-4526(97)00525-5
M3 - Article
AN - SCOPUS:11544338297
SN - 0921-4526
VL - 241-243
SP - 110
EP - 112
JO - Physica B: Physics of Condensed Matter
JF - Physica B: Physics of Condensed Matter
ER -