Detection and imaging of the spatial distribution of visible or ultraviolet photons
AssigneeAgence Nationale de Valorisation de la Recherche (ANVAR)
InventorsGeorges Charpak, N'Guyen N. Hoan, Armando Policarpo, Fabio Sauli
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Abstract
A gas scintillation proportional counter, with a photosensitive layer, is coupled, through a UV transparent window, to a multi-anode proportional chamber filled with a gas mixture (for instance an argon triethylamine-methane mixture) having a large quantum efficiency for the UV photons. When detecting incident photons, there is obtained the good efficency of photosensitive layers and the satisfactory two-dimensional coordinate localization of multiwire proportional chambers.
Claims7
A device for detection and two-dimensional localization of a field of visible and ultraviolet photons, comprising:
- a first noble gas-filled enclosure defined by a lateral wall, a radiation input window and an output window,
- a photo-cathode layer on the inner surface of said window selected to deliver photo-electrons in response to photons,
- electrode means in said first enclosure to create an electrical field transverse to said input window of a value which imparts additional energy to said photo-electrons and causes far UV production in response to said photo-electrons, without substantial electron multiplication,
- and a second enclosure separated from said first enclosure by said output window of a material transparent to said UV photons,
- a gas mixture including noble gas and an easily ionizable compound in said second enclosure,
- a plurality of electrodes in said second enclosure,
- and circuit means associated with said electrodes for applying voltages to said electrodes selected for causing avalanche processes to occur in said gas mixture responsive to said far UV photons, whereby said enclosure and electrodes constitute a proportional counter for determining the location of said far UV photons.
Dependencies are inferred from the claim text.