A Chronotron for Relativistic Neutron Time-of-Flight Measurements

Neutrons in pulses produced at a 19 mc rate by the circulating beam of the 184-inch cyclotron striking an internal target have kinetic energies from 100 to 800 mev. Circulating-beam bunching limits the time duration of each neutron pulse. Reference signals are produced by a Cherenkov-radiator internal target or the radio-frequency voltage on the cyclotron dee. The chronotron coincidence circuits, capable of a resolving tine of less than 10-9 second, are spaced with increasing time intervals to reduce reflection reinforcement. Saturation of coincidence circuits minimizes the dependence on signal amplitude. The 125-Ω cable is matched at sampling points by a series inductance tapped by tube input capacity.