Nd:Yag Laser Thomson Scattering Diagnostics For A Laboratory Magnetosphere

A new Nd:YAG laser Thomson scattering (TS) system has been developed to explore the mechanism of high-beta plasma formation in the RT-1 device. The TS system is designed to measure electron temperatures (T-e) from 10 eV to 50 keV and electron densities (n(e)) of more than 1.0 x 10(17) m(-3). To measure at the low-density limit, the receiving optics views the long scattering length (60 mm) using a bright optical system with both a large collection window (260-mm diameter) and large collection lenses (300-mm diameter, a solid angle of similar to 68 x 10(-3) str). The scattered light of the 1.2-J Nd:YAG laser (repetition frequency: 10 Hz) is detected with a scattering angle of 90 degrees and is transferred via a set of lenses and an optical fiber bundle to a polychromator. After Raman scattering measurement for the optical alignment and an absolute calibration, we successfully measured T-e = 72.2 eV and n(e) = 0.43 x 10(16) m(-3) for the coil-supported case and T-e = 79.2 eV and n(e) = 1.28 x 10(16) m(-3) for the coil-levitated case near the inner edge in the magnetospheric plasmas. Published by AIP Publishing.