Triple-axis spectrometry (TAS, three axis spectroscopy) is a technique used in conjunction with
inelastic neutron scattering. The instrument is referred to as triple-axis spectrometer (also called TAS). It allows measurement of the
scattering function at any point in
energy and
momentum space physically accessible by the spectrometer.
History
The triple-axis spectrometry method was first developed by
Bertram Brockhouse at the National Research Experimental
NRX reactor at the
Chalk River Laboratories in Canada. The first results from the prototype triple-axis spectrometer were published in January 1955 and the first true triple-axis spectrometer was built in 1956. Bertram Brockhouse shared the 1994
Nobel Prize for Physics for this development, which allowed elementary excitations, such as
phonons and
magnons, to be observed directly. The Nobel citation was "for pioneering contributions to the development of neutron scattering techniques for studies of condensed matter" and "for the development of neutron spectroscopy".