The TOSCA Spectrometer at ISIS: The Guide Upgrade and Beyond

We describe progress to date with the most significant upgrade of the TOSCA spectrometer since it first became operational over fifteen years ago. This major project to boost the incident flux on the instrument by over an order of magnitude has been implemented over the past couple of years and has involved the complete redesign of the primary spectrometer to house a state-of-the-art, high-m neutron guide and associated chopper system. Engineering design and subsequent installation and commissioning efforts have been supported by extensive neutron-transport simulations and baseline studies of neutronic response in the context of the ISIS TS1 Project. Looking further ahead, we also outline ongoing feasibility studies to upgrade the secondary spectrometer, with a view to additional order-of-magnitude gains in neutronic and scientific performance.