Photek Ltd. of St. Leonards-on-Sea, UK, has announced that it has produced a prototype 150-mm-diameter zoom image intensifier, which it claims is the largest ever constructed. The device has applications in nuclear particle physics and x-ray crystallography, where a high light-collection efficiency from large objects is desired.

Resulting photoelectrons from the visible light image intensifier's bialkali photocathode are focused onto a 40-mm microchannel plate electron multiplier and phosphor screen assembly. Each input photon produces approximately 1 million visible photons that can be mapped with a charge-coupled device camera. The device is based on the company's family of 80- and 40-mm intensifiers.