Method for forming neutron images

Abstract

Stimulable phosphor sheets are superposed one upon another. Each stimulable phosphor sheet is provided with a first layer of a substance, which absorbs neutrons and emits secondary particles, and a second layer of a stimulable phosphor, which can store energy from the secondary particles. The stimulable phosphor sheets are exposed to a neutron beam carrying image information, and neutron images are thereby stored on the stimulable phosphor sheets. Image signals representing the neutron images stored on the stimulable phosphor sheets are then obtained. The image signal components of the image signals are then added to each other, which represent corresponding picture elements in the neutron images. An image signal representing the neutron images stored on the stimulable phosphor sheets is thereby obtained. Alternatively, at least one stimulable phosphor sheet for absorbing neutrons, emitting particles, and storing energy of these particles and, a second phosphor sheet for detecting and storing energy from .gamma.-rays, are superposed and exposed to a neutron beam carrying image information. After this exposure, images become stored on each layer of the phosphor sheets. The image signals representing the images stored on each layer are then obtained. The image signal stored in the .gamma.-ray detecting layer is subtracted from the image signal stored on the neutron detecting layer to obtain the neutron image stored on the stimulable phosphor sheets.