Inductive and space charge electric fields in a whistler wave packet

A low-frequency whistler wave packet is excited with a pulsed magnetic loop antenna in a large laboratory plasma (1 m diam×{}2.5 m, nₑ=7×{}10¹¹ cm^-3, kTₑ=1.3 eV, B₀=20 G). Multipoint (10⁴) measurements of the wave magnetic field, B(r,t), and 4D fast Fourier transformation, B(k,{ω}), both verify the dispersion of oblique plane whistler modes and permit the calculation of the wave electric field, decomposed into its rotational (inductive) and irrotational (space charge) contributions, E(r,t)=Eind+Esc. The space charge density, {ρ}(r,t), for a whistler wave is also shown.