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temperature_measurements_icc07.pdf | 2007-02-26 13:16:34 | Raymond Golingo |
Temperature Measurements on the ZaP Experiment
Author: Raymond P. Golingo
Requested Type: Poster Only
Submitted: 2006-12-18 20:47:00
Co-authors: U. Shumlak, B.A. Nelson, D.J. Den Hartog, and the ZaP team
Contact Info:
University of Washington
120 AERB bo 352250
Seattle, WA 98195-2
USA
Abstract Text:
The ZaP Flow Z-Pinch Experiment is presently studying the effect of sheared flow on gross plasma stability. During a quiescent period in the magnetic mode activity, a dense Z-pinch with a sheared flow is observed on the axis of the machine. The velocity shear agrees with the threshold predicted by linear theory. A better comparison between the experimental and analytic results can be made once the pressure profile is known. The present results are from deconvolutions of chord integrated measurements. The plasma density is measured with a HeNe interferometer and holographic interferometery. The ion temperature is measured with Doppler broadening. The electron temperature is found with coronal equilibrium. The total temperature can be found with pressure balance. Zeeman splitting measurements have confirmed the assumed magnetic field magnitude and the edge of the Z-pinch. Thomson scattering is capable of measuring the electron temperature and density at a point in the plasma. A single point Thomson scattering system is being installed to directly measure the local electron temperature in the Z-pinch. The system has a 3 mm radial resolution and can collect scattered light up to 4 cm off of the axis of the machine. (The Z-pinch has a 1 cm characteristic radius.) The expected Thomson signal has been calculated to be 10 times the measured background radiation level. Initially the system will measure the electron temperature at a single point in the plasma. The design and hardware allow for the system to be upgraded to a multipoint Thomson scattering system which would measure the pressure profile of the Z-pinch. The design of the system and initial results will be presented.
Characterization: A2
Comments:
