Rep rate multiplication (RRM) makes Merlin even more competitive
07 Mar 2014



A new chopper system has been installed on Merlin making repetition rate multiplication (RRM) possible for the first time on this instrument.

​Simultaneously measured neutron spectra from a 3g crystal of copper germinate (CuGeO3) measured on Merlin in RRM mode.

RRM involves sending several pulses of different neutron energies onto the sample in a single ISIS timeframe. In single energy mode, users request their desired energy, e.g. 50 meV, and get a single data set in return, whereas in RRM mode, up to 5 separate incident energies can be measured simultaneously, allowing a survey of data sets to be gathered in a fraction of the time.​

The technique has already been used to great effect on LET (Schmidiger, D. et al. Spectrum of a Magnetized Strong-Leg Quantum Spin Ladder. Phys. Rev. Lett. 111, 107202 (2013)) up to a maximum energy of 20meV.  Now RRM on Merlin allows collection of data between ~10 meV and 200 meV.  Significantly the quality of the data produced is state of the art making Merlin highly competitive on the international stage. 

Ross Stewart, leader of the ISIS Excitations group, says, “This development adds new capability to the ISIS neutron spectroscopy suite and shows that despite lower source flux, Merlin can compete with the best in the world.”