Detector gating system employed in a pulsed neutron logging system

Claim 1

IN A RADIOACTIVITY WELL LOGGING SYSTEM INCLUDING A SUBSURFACE INSTRUMENT, SURFACE MEASURING AND RECORDING EQUIPMENT, AND A LOGGING CABLE HAVING FIRST AND SECOND CONDUCTORS INTERCONNECTING SAID INSTRUMENT AND SAID SURFACE EQUIPMENT. SAID SUBSURFACE INSTRUMENT FURTHER INCLUDING A NEUTRON SOURCE, FIRST AND SECOND NORMALLY UNRESPONSIVE DETECTORS, AND PULSING MEANS FOR INTERMITTENTLY ACTUATING SAID SOURCE TO PRODUCE A SEQUENCE OF BURSTS OF NEUTRONS, THE IMPROVEMENT IN COMBINATION THEREWITH COMPRISING MEANS FOR RENDERING SAID FIRST DETECTOR RESPONSIVE TO INCIDENT RADIATIONS DURING FIRST AND SECOND PRESELECTED PORTIONS OF THE TIME INTERVALS DEFINED BY SAID BURSTS OF NEUTRONS AND FOR RENDERING SAID SECOND DETECTOR RESPONSIVE TO INCIDENT RADIATIONS DURING THIRD AND FOURTH PRESELECTED PORTIONS OF SAID TIME INTERVALS, SAID MEANS INCLUDING FIRST GATING MEANS RESPONSIVE TO SAID PULSING MEANS FOR RENDERING SAID FIRST DETECTOR RESPONSIVE DURING SAID FIRST PRESELECTED PORTIONS OF SAID TIME INTERVALS, SECOND GATING MEANS RESPONSIVE TO SAID FIRST GATING MEANS FOR RENDERING SAID FIRST DETECTOR RESPONSIVE DURING SAID SECOND PRESELECTED PORTIONS OF SAID TIME INTERVALS, THIRD GATING MEANS RESPONSIVE TO SAID PULSING MEANS FOR RENDERING SAID SECOND DETECTOR RESPONSIVE DURING SAID THIRD PRESELECTED PORTIONS OT SAID TIME INTERVALS, FOURTH GATING MEANS RESPONSIVE TO SAID THIRD GATING MEANS FOR RENDERING SAID SECOND DETECTOR RESPONSIVE DURING SAID FOURTH PRESELECTED PORTIONS OF SAID TIME INTERVALS, FIRST SIGNAL SEPARATING MEANS CONNECTED TO SAID FIRST DETECTOR AND RESPONSIVE TO SAID FIRST AND SECOND GATING MEANS FOR SEPARATING AND DISTINGUISHING THE SIGNALS PRODUCED BY SAID FIRST DETECTOR DURING ONES OF SAID FIRST AND SECOND PRESELECTED PORTIONS OF SAID TIME INTERVALS FROM THE SIGNALS PRODUCED BY SAID FIRST DETECTOR DURING THE OTHERS OF SAID FIRST AND SECOND PRESELECTED PORTION OF SAID TIME INTERVALS AND FOR CONNECTING SAID SIGNALS FROM SAID FIRST DETECTOR TO SAID FIRST CONDUCTORS, AND SECOND SIGNAL SEPARATING MEANS CONNECTED TO SAID SECOND DETECTOR AND RESPONSIVE TO SAID THIRD AND FOURTH GATING MEANS FOR SEPARATING AND DISTINGUISHING SIGNALS PRODUCED BY SAID SECOND DETECTOR DURING ONES OF SAID THIRD AND FOURTH PRESELECTED PORTIONS OF SAID TIME INTERVALS FROM THE SIGNALS PRODUCED BY SAID SECOND DETECTOR DURING THE OTHERS OF SAID THIRD AND FOURTH PRESELECTED PORTIONS OF SAID TIME INTERVALS AND FOR CONNECTING SAID SIGNALS FROM SAID SECOND DETECTOR TO SAID SECOND CONDUCTOR.