MAPS was the world's first time-of-flight crystal spectrometer, designed by Toby Perring at ISIS and built in 1999. Since that time, many new single crystal time-of-flight neutron spectrometers have followed - both at ISIS and elsewhere (SNS, ILL, J-PARC, HZB, etc.). In order to keep pace with these newer instruments, MAPS has had an m=3 neutron guide installed that, together with a modified water moderator on ISIS Target Station One, has led to an order-of-magnitude increase in neutron flux at thermal energies.
Figures 1 & 2: 1) The evolution of the MAPS incident neutron spectrum at various stages of the modernisation project 2) The ratio of the flux on MAPS three years ago to the flux today.
The data shows that experiments previously on MAPS in a week can now be completed in a day (say at an incident energy of ~100 meV).
The conceptual design and calculations for the modernisation were led by Russell Ewings of the ISIS Excitations and Polarized Neutrons Group. The implementation was down to the hard work and dedication of the ISIS Design and Operations Divisions. The guide optics were built and installed by Mirrotron, Budapest.