GB598915A - Radiant energy receiver - Google Patents

Abstract

598,915. Radiation detectors ; discharge apparatus. BENDIX AVIATION CORPORATION. April 16, 1945, No. 9516. Convention date, March 13, 1944. [Classes 39 (i) and 40 (iii)] Apparatus responsive to heat and light radiation comprises a vacuum tube 10 having at one end a sealed window of rock salt 11 and containing adjacent the window 11 a conical holder 13 for a substance 14 such as carbonized vegetable fibres in the form of a fine fluff so that in response to radiant energy waves transmitted through window 11 the substance 14 is activated to release stored gases which flow through vents in the holder 13 to the opposite end of the tube 10 and there become ionized by collision with electrons flowing between a filament 15 and a surrounding grid 18 to thus produce a current flow at an adjacent plate 21. connected in series with a current limiting resistance 23 to a battery 28 so that it is at negative potential with respect to the grid 18. The current impulses from plate 21 are fed to an amplifier 26 and thence to an instrument 27 which is therefore actuated to a degree dependent on the intensity of heat or light radiation impinging on substance 14. A condenser 25 prevents response to slow variations resulting from changes in ambient temperature. In a modification, Fig. 2 (not shown), a glass window formed integrally with the tube 10 is substituted for the rock salt window 11 and the apparatus thus rendered of greater sensitivity to radiant energy within the range 0.5 to 2 microns.