Algorithm for precision subsample timing between Gaussian-like pulses.

Area of Science:

• High-energy-density physics
• Experimental diagnostics
• Signal processing

Background:

• National Ignition Facility (NIF) experiments require precise cross-timing between diagnostic instruments.
• Available oscilloscopes offer 6 GHz bandwidths at 20-25 Gsamples/s, with 40 ps sample spacing.
• Existing methods may not meet the stringent timing accuracy requirements (<30 ps).

Purpose of the Study:

• To present a simple midpoint-timing algorithm for precise cross-timing measurements.
• To demonstrate the algorithm's effectiveness for Gaussian-like pulses, such as NIF timing fiducials.
• To determine optimal conditions for achieving high timing precision.

Main Methods:

• Development and simulation of a midpoint-timing algorithm for analyzing pulse data.
• Analysis of Gaussian-like pulses, specifically the 100-ps-wide NIF timing fiducial.
• Experimental validation of the algorithm's performance and precision.

Main Results:

• The midpoint-timing algorithm achieves single-event cross-timing precision of 1 ps.
• Optimal pulse width for the algorithm is approximately 2.5 times the oscilloscope's sample spacing.
• Experimental measurements confirm the algorithm's capability under specific conditions.

Conclusions:

• The midpoint-timing algorithm offers a viable solution for achieving sub-30 ps cross-timing accuracy in NIF experiments.
• Precise timing can be obtained with moderately priced oscilloscopes by applying this analysis technique.
• Understanding the relationship between pulse width and sample spacing is crucial for optimal timing performance.