The Entropy and Complexity of Drift waves in a LAPTAG Plasma Physics Experiment

POSTER

Abstract

Drift waves grow from noise on a density gradient in a narrow (dia $=$ 3 cm, L $=$ 1.5 m) magnetized ( B$_{oz} = $ 160G) plasma column. A two-dimensional probe drive measured fluctuations in the plasma column in a plane transverse to the background magnetic field. Correlation techniques determined that the fluctuations were that of electrostatic drift waves. The time series data was used to generate the Bandt-Pompe/Shannon entropy, H, and Jensen-Shannon complexity, C$_{JS}$. C-H diagrams can be used to tell the difference between deterministic chaos, random noise and stochastic processes and simple waves, which makes it a powerful tool in nonlinear dynamics. The C-H diagram in this experiment, reveal that the combination of drift waves and other background fluctuations is a deterministically chaotic system. The PDF of the time series, the wave spectra the spatial dependence of the entropy wave complexity will be presented. LAPTAG is a university-high school alliance outreach program, which has been in existence for over 20 years.

Authors

  • Henry Birge-Lee

    North Hollywood H.S.

  • Walter Gekelman

    University of California, Los Angeles

  • P. Pribyl

    University of California, Los Angeles, UCLA

  • Joe Wise

    Wildwood Academy

  • Cami Katz

    Harvard Westlake, Harvard Westlake H.S.

  • Bob Baker

    University H.S. (ret)

  • Ken Marmie

    Roosevelt Middle School, Roosevelt Middle H.S.

  • Sam Thomas

    John Marshall H.S.

  • Samuel Buckley-Bonnano

    Harvard Westlake, Harvard Westlake H.S.