Electronic Variable Delay for Tracing Characteristic Curves of Coincidence Circuits and Time‐to‐Height Converters

Automatic tracing of characteristic curves of coincidence circuits and time‐to‐height converters has been accomplished by utilizing a tunnel diode circuit, which provides an electrically controlled time delay continuously varying from 30 to 65 nsec. An input pulse starts a current ramp through the tunnel diode, which generates an output pulse on triggering. The moment of triggering, however, is programmed by a control voltage which dictates the instantaneous value of the initial current flowing through the tunnel diode. Measurements of the delay vs control voltage relationship show no deviation from linearity greater than the experimental error of ±15 psec. Time jitter, characterized by the full width at half‐maximum of the output‐pulse time distribution, is less than 30 psec. A coincidence resolution curve displayed on the screen of an oscilloscope and a height‐vs‐time curve of a time‐to‐height converter traced by an X‐Y recorder are shown.