Abstract
Coherence imaging spectroscopy (CIS) measures the two-dimensional profiles of both ion temperature and ion velocity in plasmas. The interferometric technique is realized by a certain relation between the phase and the wavelength of light emerging from a birefringent crystal. The calibration for the CIS system requires monochromatic and tunable light sources near the He II line (468.6nm) or C III line (465nm) where the CIS measures. In this research, the CIS system has been upgraded by implementing an electron multiplier CCD and a CIS cell. A monochromator validates the linearity of the phase relation on the wavelength near the He II line. As an in situ calibration at the Ring Trap 1 plasma device, two spectral lines of Ti and Zn lamps obtain the accurate dispersion function of phase. It is found that a simple method with two spectral lines is reliable and sufficient for the calibration.
Highlights
Doppler spectroscopy is widely applied to diagnose phenomena as a non-contact method
To understand self-organized plasmas in a dipole confinement device Ring-Trap 1 (RT1), Doppler spectroscopy is utilized in high-beta plasmas to study the heat and particle transports, which imitate a planetary magnetospheric plasma in the laboratory[1,2]
coherence imaging spectroscopy (CIS) is a powerful tool for Doppler spectroscopy, and measures the two-dimensional images of ion temperature and flow velocity, which are more informatic and cost effective compared with spectroscopic measurements with a grating spectrometer
Summary
Doppler spectroscopy is widely applied to diagnose phenomena as a non-contact method. Spectral lamps[8,10] or tunable continuous wave lasers[7,9,11] are mainly used as light sources for calibration When the former is used, the spectral lines of the light source do not match the emission lines of the plasma, so the phase of CIS must be extrapolated[8]. We focus on the upgraded system for field widening and sensitivity and the calibration methods with a monochromator and two light sources The former method with the monochromator verifies the phase linearity of birefringent crystals as a function of the wavelength. The latter method, as practical usage, introduces two light sources of Zinc and Titanium to calibrate the CIS system cost-effectively in between discharges, after the CIS system is implemented in the RT1
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
