New developments in cold neutron storage with perfect crystals

A second generation cold neutron storage apparatus has been installed at the pulsed neutron source ISIS. The instrument VESTA-II is designed to confine neutrons between two Bragg-reflecting perfect crystal mirrors and to release them in various pulses. A new type of gating has been realized which allows a flexible control of transmission or reflection by the crystal plates. In combination with various other improvements, it creates the potential to extend the scope of its predecessor VESTA-I and facilitate flexible use of the peak intensity of pulsed neutron sources. We discuss the design and concept of the new instrument, present the first experimental results, and review the key elements of the scientific program for the future.