Detector development at the ISIS facility

For many years the Rutherford Appleton Laboratory has had a neutron detector development programme. It was undertaken to see if the limitations inherent in conventional He3 detectors (their speed, efficiency at high neutron energies and rigid geometry) could be overcome by scintillator technologies. The detectors developed up to the present date have been based on Li6 doped glass scintillator and have been successfully installed and run routinely. In fact all the present ISIS instruments make use of the Li6 glass scintillator technique within their monitors - which comprise small beads of scintillator supported on fine glass filaments in a reflecting housing and viewed directly by a single photomultiplier tube. To overcome the background and γ sensitivity problems studies have been made of Li6 loaded ZnS scintillator. This has proved so successful that it is likely this technology will form the basis of our detector programme over the next few years. (author)