Calibration of coherence imaging spectroscopy using spectral line sources

Area of Science:

• Plasma Physics
• Spectroscopy
• Optical Diagnostics

Background:

• Coherence Imaging Spectroscopy (CIS) is an advanced diagnostic technique.
• It measures 2D profiles of ion temperature and velocity in plasmas.
• Accurate calibration is crucial for interferometric techniques involving birefringent crystals.

Purpose of the Study:

• To upgrade the Coherence Imaging Spectroscopy (CIS) system with an electron multiplier CCD and a CIS cell.
• To validate the linearity of the phase-wavelength relation using a monochromator.
• To establish a reliable in situ calibration method for CIS at the Ring Trap 1 plasma device.

Main Methods:

• Implementation of an electron multiplier CCD and a CIS cell for CIS system upgrade.
• Utilizing a monochromator to verify phase-wavelength linearity near the He II line.
• Employing two spectral lines from Ti and Zn lamps for in situ calibration and dispersion function determination.

Main Results:

• The upgraded CIS system is operational.
• Monochromator validation confirmed the linearity of the phase-wavelength relation.
• Calibration using two spectral lines from Ti and Zn lamps provided an accurate dispersion function.

Conclusions:

• The implemented calibration method using two spectral lines is simple, reliable, and sufficient for accurate CIS measurements.
• This research contributes to the advancement of plasma diagnostic capabilities.
• The findings support precise characterization of plasma properties like ion temperature and velocity.