An ultraviolet light emitting diode (UV-LED) pulse generator for simulating a scintillator response from neutron time-of-flight detectors as seen on deuterium–tritium fusion experiments at the OMEGA laser facility

A novel ultraviolet light emitting diode (UV-LED) based pulse-shaping module has been developed to characterize and cross-calibrate photomultiplier tubes (PMTs) operating in a variety of configurations on the OMEGA Laser System. This setup provides a relatively inexpensive method for generating synthetic input signals for PMTs that produce waveforms resembling neutron time-of-flight data of OMEGA deuterium–tritium fusion experiments. The system uses an array of UV-LEDs driven by a delay generator whose electrical pulses are shaped with a series of simple circuits. The highly repeatable light pulse produced provides the ability to accurately characterize a PMT’s gain, temporal response, and gate response under experimental conditions. The fairly compact setup also allows for in situ calibrations that incorporate the supporting equipment, such as cabling, oscilloscopes, and splitters, into the characterization process.