Bertram Brockhouse
1918–2003, Lethbridge, Alberta, Canada, Hamilton, Ontario, Canada
Canadian physicist who shared the 1994 Nobel Prize in Physics for pioneering neutron spectroscopy — measuring energies of crystal excitations with the triple-axis spectrometer he invented.
Born in Lethbridge, Alberta, Brockhouse served in the Royal Canadian Navy during WWII before studying at the University of British Columbia and the University of Toronto (PhD 1950). At the Chalk River Nuclear Laboratories from 1950 he developed 'inelastic' neutron scattering: instead of just counting diffracted neutrons, he measured their energy change to map lattice vibrations. His triple-axis spectrometer (1950s) — crystal monochromator, sample, crystal analyzer — measured the first phonon dispersion curves and generalized to magnons and liquids. He moved to McMaster University in 1962, retiring in 1984.
Nobel-winning work
Brockhouse's triple-axis spectrometer, built at the NRX reactor in the 1950s, let experimenters select incident neutron energy (monochromator crystal), scatter from the sample, then measure outgoing energy (analyzer crystal). Energy conservation then reveals which excitations — phonons, magnons, molecular rotations — the neutron created.
He published the first measured phonon dispersion relations in lead and aluminum (1955–1958), turning neutron scattering from a structure tool into a microscope on the dynamics of matter — complementing Shull's elastic diffraction.
Workplaces: McMaster University, Atomic Energy of Canada, Chalk River
Canada