PHOTOSENSOR WITH A PHOTOCATHODE IN REFLECTIVE MODE

摘要

A hybrid photon detector with a photocathode in reflective mode where the same vacuum tube components acts both as a perfect incoming light concentrator and as a perfect focusing electron lens and the photoelectrons are electrostatically focused by the same CPC-shape in the opposite direction (i.e., from the small light collection surface towards a point-like region in the middle of the large-area entrance aperture). The CPC is electrically conductive and split into two electrodes by a narrow non-conductive interval positioned in a particular place along the CPC. The photocathode covers the light collection area of the CPC, and the photocathode is operated in the reflective mode such that photoelectrons emerge from the same surface through which the photons enter. Photoelectrons emerging from the entire photocathode are accelerated and focused onto a small electronic sensor placed in the middle of the entrance aperture of the CPC.