Spin echo small angle neutron scattering using a continuously pumped (3)He neutron polarisation analyser.
We present a new instrument for spin echo small angle neutron scattering (SESANS) developed at the Low Energy Neutron Source at Indiana University. A description of the various instrument components is given along with the performance of these components. At the heart of the instrument are a series of resistive coils to encode the neutron trajectory into the neutron polarisation. These are shown to work well over a broad range of neutron wavelengths. Neutron polarisation analysis is accomplished using a continuously operating neutron spin filter polarised by Rb spin-exchange optical pumping of (3)He. We describe the performance of the analyser along with a study of the (3)He polarisation stability and its implications for SESANS measurements. Scattering from silica Stöber particles is investigated and agrees with samples run on similar instruments.
Centre for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408, USA.
S R
SR
Parnell
Centre for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408, USA.
A L
AL
Washington
Centre for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408, USA.
K
K
Li
Centre for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408, USA.
H
H
Yan
Centre for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408, USA.
P
P
Stonaha
Centre for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408, USA.
F
F
Li
Centre for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408, USA.
T
T
Wang
Department of Chemistry, The University of Sheffield, Sheffield S3 7HF, United Kingdom.
A
A
Walsh
National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
W C
WC
Chen
Department of Physics and Astronomy, The University of Sheffield, Sheffield S3 7RH, United Kingdom.
A J
AJ
Parnell
Department of Mechanical Engineering, The University of Sheffield, Sheffield S1 3DJ, United Kingdom.
J P A
JP
Fairclough
Centre for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408, USA.
D V
DV
Baxter
Centre for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408, USA.
W M
WM
Snow
Centre for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408, USA.
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R
Pynn