Previous experiments dealt with launching whistler waves into a density striation and measuring direct-converted lower hybrid waves. In the original experiments, only magnetic fields were measured. These results were published in JGR and PRL; for more information on these experiments, click here. As a follow-up to this original set of experiments, wave electric fields were measured directly. These results have been submitted to GRL Letters.

The abstract is for this paper is presented below.

Abstract Previous experiments at the Large Plasma Device (LAPD) at UCLA provide evidence that whistler waves incident on a field-aligned density striation will produce lower hybrid waves via a linear mode-coupling mechanism [Bamber, et. al, 1994; Bamber, et. al, 1995]. These experiments were limited in that only the magnetic fields of the waves were measured. Recent experiments at the LAPD directly measure the whistler and lower hybrid wave electric fields. By comparing the relative magnitude of the different mode's electric fields, we can make some estimates about the conversion efficiency of the linear conversion mechanism.

You can view the entire preprint, Electric Field Measurements of Directly Converted Lower Hybrid at a Density Striation, with a pdf viewer like Adobe Acrobat 3.0 or higher.

Current experiments involve launching lower hybrid waves into a density striation

The basic idea of ongoing experiments is to recreate the physics of the auroral ionosphere in our machine. Obviously we can't recreate the ionosphere, but by we can maintain the ratios of some key parameters. Of particular importance is the requirement that the lower hybrid frequency be density dependent. At low magnetic fields or high density, the lower hybrid wave is field dependent. Therefore, we perform our experiments in high fields, B = 1650 Gauss, and at low densities, n = 6 e11/cc. Right now, I'm analyzing about 1GB of data. There are some interesting features in the data, but it will take some more analysis to make any definitive statements. And I'm already planning my next data run to fill in some gaps in the existing data and find out some new things.

For the current publications, click here