IMAT is on a broad-pulse, coupled liquid hydrogen moderator on the ISIS TS-2 source which is operated at 10 Hz, in order to achieve a high cold neutron flux for radiography, tomography, and rapid texture analysis.
Two double-disk choppers prevent frame overlap and a T0 chopper removes fast neutrons and gamma radiation. A supermirror straight neutron guide transports neutrons to an aperture selector at 46 m from the moderator, offering a choice of apertures including one open position for the beam to pass through for diffraction experiments. A single-frame mode with a wavelength bandwidth of 6 Å, and a double-frame mode with a bandwidth of 12 Å, will benefit both imaging and diffraction experiments. For texture and strain analysis IMAT has a high neutron flux at medium resolution, ideal for time-dependent in-situ loading and in-situ processing studies.
The main instrument components for the two operating modes, imaging and diffraction, are summarised in Table 1 and detector/cameras available for white beam imaging as well as time-of-flight bragg edge imaging and their parameters are summarized in Table 2.
[1] G. Burca, W. Kockelmann, J.A. James, M.E. Fitzpatrick, Modelling of an imaging beamline at the ISIS pulsed neutron source, Journal of Instrumentation, 8 (2013), no 10, http://dx.doi.org/10.1088/1748-0221/8/10/P10001
[2] K. Lefmann, K. Nielsen, McStas, a General Software Package for Neutron Ray-tracing Simulations, Neutron News, 10 (3), 20-23, (1999)
[3] P. Willendrup, E. Farhi, K. Lefmann, McStas 1.7 – a new version of the flexible Monte Carlo neutron scattering package, Physica B, 350, 735-737 (2004)
R. Santisteban, L. Edwards, M.R. Daymond, A virtual laboratory for neutron and synchrotron strain scanning, Physica B: Condensed Matter, 350 (1), 743-746 (2004)
[5] J.A. James, L. Edwards, Application of robot kinematics methods to the simulation and control of neutron beam line positioning systems, Nucl. Instr. Meth. A, 571 (3), 709-718 (2007)
[6] W. Kockelmann, T. Minniti, D. E. Pooley, G. Burca, R. Ramadhan, F. A. Akeroyd, G. D. Howells, C. Moreton-Smith, D. P. Keymer, J. Kelleher, S. Kabra, T.-L. Lee, R. Ziesche, A. Reid, G. Vitucci, G. Gorini, D. Micieli, R.G. Agostino, V.Formoso, F.Aliotta, R. Ponterio, S.Trusso, G.Salvato, C. Vasi, F. Grazzi, K. Watanabe, J. W. L. Lee, A. S. Tremsin, J.B. McPhate, D.Nixon, N.Draper,
W.Halcrow, J.Nightingale, Time-of-Flight Neutron Imaging on IMAT@ISIS: A New User Facility for Materials Science, J. Imaging, 4, 47, 1-22, (2018).
