Nanosecond pulse height analyzer

Claim 2

A nanosecond pulse height analyzer comprising a detector receiving an input photon signal and providing in response thereto a voltage pulse proportional to said input photon signal, means to amplify said voltage pulse, said means to amplify including a first and second input, said first input receiving said voltage pulse, means to gate off said amplifying means from a normally conductive state, said means to gate off including a first null detector, an off gate, said first null detector and said off gate being connected in sequence in a first series combination, said first series combination being interconnected between the output of said amplifying means and said second input of said amplifying means, a cathode ray tube having a deflection plate, control grid, and face, said cathode ray tube normally being biased negatively to prevent an electron beam therein from striking said face, a multiplicity of sensors arranged on the surface of said face, each of said sensors being at a different preselected position, each of said positions being representative of a predetermined magnitude of sweep of said electron beam, said deflection plate receivinG said amplified voltage pulse causing said electron beam to sweep a distance proportional to said input photon signal, a second null detector providing an output pulse initiated at and representative of the peak height of the input signal thereto, and an on gate providing an output pulse of preselected duration upon receiving an input signal, said second null detector and said on gate being connected in sequence in a second series combination, said second series combination interconnecting the output of said amplifying means and said control grid, said second series combination receiving said amplified voltage pulse simultaneously with said deflecting plate and operating in response thereto to provide an output pulse of preselected duration to charge the control grid positively for a preset time, allowing said electron beam to strike one of said sensors corresponding to the peak voltage of said input photon signal.