Limiting noise fraction in PDV measurements

Technical Report · Mon Oct 01 00:00:00 EDT 2018

DOI:https://doi.org/10.2172/1481558· OSTI ID:1481558

Dolan, Daniel H. ^[1]

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1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

The limiting frequency resolution of a PDV measurement is: σf = $$\sqrt\frac{6 η}{fsτ^3π}$$ where f_s is the sample rate, τ is the analysis time duration, and 11 is the noise fraction. Although T is a strong lever for reducing uncertainty, this parameter must be kept small to preserve time resolution. Consider a PDV measurement with sampled at 80 GS/s and analyzed in 1 ns durations. A 1% noise fraction corresponds to 0.87 MHz of frequency uncertainty, which at 1550 nm works out to 0.68 m/s. A 10% noise fraction has a limiting velocity resolution of about 7 m/s; for comparison, a VISAR system with similar response time (0.5 ns delay, 532 m/s fringe constant) would have a limiting uncertainty of 5-6 m/s. Noise fractions of 10-20% or less are desirable for measurements at this time scale.

• Research Organization: Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• DOE Contract Number: AC04-94AL85000; NA0003525
• OSTI ID: 1481558
• Report Number(s): SAND-2018-12312R; 669097
• Country of Publication: United States
• Language: English