Study of heliospheric-relevant magnetic turbulence in a laboratory plasma wind tunnel*

A novel laboratory environment for the study of heliospheric-relavant magnetic turbulence is presented. The Bryn Mawr Experiment (BMX) at the Bryn Mawr Plasma Laboratory (BMPL) is explores magnetically-dynamic turbulence in a wind-tunnel-like apparatus. The turbulence observed here is more akin to space and astrophysical settings such as the solar wind and the magnetosphere that that seen in other plasma turbulence experiments (such as edge-turbulence in fusion reactor experiments) where there is a strong guide field. Magnetized plasmas structures are generated using a coaxial-electrode source and then launched down a cylindrical flux-conserving chamber through a rail-gun-like mechanism. With no background magnetic field, both magnetic field and flow fluctuate freely within the chamber. Simultaneous multi-position magnetic measurements of these structures exhibit broadband spectra with power-law scaling typically steeper than the traditionally Kolmogorov -5/3 scaling. Experimental analyses have mirrored techniques used in spacecraft analysis of solar wind turbulence and comparisons between these regimes and the laboratory environment are made.