Use of fast scopes to enable Thomson scattering measurement in presence of fluctuating plasma light.

Journal Article · Mon Apr 19 00:00:00 EDT 2004 · Review of Scientific Instruments, vol. 75, no. 10, October 7, 2004, pp. 3887

DOI:https://doi.org/10.1063/1.1790051· OSTI ID:892781

McLean, H; Moller, J; Hill, D

The addition of inexpensive high-speed oscilloscopes has enabled higher Te Thomson scattering measurements on the SSPX spheromak. Along with signal correlation techniques, the scopes allow new analyses based on the shape of the scattered laser pulse to discriminate against fluctuating background plasma light that often make gated-integrator measurements unreliable. A 1.4 J Nd:YAG laser at 1064 nm is the scattering source. Spatial locations are coupled by viewing optics and fibers to 4-wavelength-channel filter polychrometers. Ratios between the channels determine Te while summations of the channels determine density. Typically, the channel that provides scattered signal at higher Te is contaminated by fluctuating background light. Individual channels are correlated with either a modeled representation of the laser pulse or a noise-free stray light signal to extract channel amplitudes.

• Research Organization: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 892781
• Report Number(s): UCRL-JRNL-203651; TRN: US0605864
• Journal Information: Review of Scientific Instruments, vol. 75, no. 10, October 7, 2004, pp. 3887, Journal Name: Review of Scientific Instruments, vol. 75, no. 10, October 7, 2004, pp. 3887
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
AMPLITUDES
FIBERS
LASERS
OPTICS
PLASMA
SCATTERING
SHAPE
THOMSON SCATTERING