banner image
No data available.
Please log in to see this content.
You have no subscription access to this content.
No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
High-bandwidth polarimeter for a high density, accelerated spheromak
Rent this article for
View: Figures


Image of FIG. 1.
FIG. 1.

PI-1 plasma injector with polarimeter laser chord at the 352 position. Laser passes in between inner and outer electrodes.

Image of FIG. 2.
FIG. 2.

Three-beam heterodyne polarimeter used at GF.

Image of FIG. 3.
FIG. 3.

Polarimeter beam combination and conversion to circular polarization.

Image of FIG. 4.
FIG. 4.

Initial beam combination setup gave poorly circularly polarized beams due to difficulties in aligning the beams with respect to the PRRs.

Image of FIG. 5.
FIG. 5.

Phase shift responses due to beam polarization ellipticity for different setups. Obtained using λ/2 waveplate rotating at about 15 Hz.

Image of FIG. 6.
FIG. 6.

Apparent Faraday rotation during beam alignment by placing a rotating, 14 arc min (0.23°) wedge of ZnSe in the path of the plasma beams. Both signals have bandwidths of 500 Hz. Signal sampled at 10.4 kHz.

Image of FIG. 7.
FIG. 7.

Model toroidal field profile along polarimeter chord for shots 34140 and 34704 at the 352 axial position. The electrodes are located at polarimeter chord positions −0.31 m and 0.31 m, and the magnetic axis at 0 m.

Image of FIG. 8.
FIG. 8.

Measured Faraday rotation compared to expected Faraday rotation from model toroidal field and density profiles. Signal bandwidths are 5 MHz for polarimeter density and 0.5 MHz for Faraday rotation and surface magnetic field. (a) Shot 34140: Poorly aligned beams produce Faraday rotation measurement that does not agree with model. (b) Shot 34704: Beam alignment error significantly reduced. Faraday rotation measurement agrees well with model.

Image of FIG. 9.
FIG. 9.

Spline-fit to surface magnetic probe axial field measurements for shot 34704 at time of peak polarimeter Faraday rotation (488 μs).


Article metrics loading...


Full text loading...

This is a required field
Please enter a valid email address
752b84549af89a08dbdd7fdb8b9568b5 journal.articlezxybnytfddd
Scitation: High-bandwidth polarimeter for a high density, accelerated spheromak