Performance of a 20-in. photoelectric lens image intensifier tube

TL;DR

This paper evaluates a 20-inch photoelectric lens image intensifier tube designed for high-resolution air-shower imaging, demonstrating its potential to reduce costs and improve imaging capabilities in cosmic-ray detection.

Contribution

The paper presents the design and performance evaluation of the world's largest image intensifier, enabling cost-effective, high-resolution imaging for the Ashra cosmic-ray observatory.

Findings

Large effective photocathode area of 20 inches

Image reduction to less than 1 inch diameter

Potential for lower pixel costs in cosmic-ray detection

Abstract

We have evaluated a 20-in. photoelectric lens image intensifier tube (PLI) to be mounted on the spherical focal surface of the Ashra light collectors, where Ashra stands for All-sky Survey High Resolution Air-shower Detector, an unconventional optical collector complex that images air showers produced by very high energy cosmic-ray particles in a 42$^\circ$-diameter field of view with a resolution of a few arcminutes. The PLI, the worlds largest image intensifier, has a very large effective photocathode area of 20-in. diameter and reduces an image size to less than 1-inch diameter using the electric lens effect. This enables us to use a solid-state imager to take focal surface images in the Ashra light collector. Thus, PLI is a key technology for the Ashra experiment to realize a much lower pixel cost in comparison with other experiments using photomultiplier arrays at the focal surface. In this paper we present the design and performance of the 20-in. PLI.