Multichannel Thomson scattering system for the tokamak TFR based on two-detector spectrum analyzers

Area of Science:

• Plasma Physics
• Fusion Energy Research
• Spectroscopy

Background:

• Accurate measurement of electron temperature (T(e)) and density (n(e)) profiles is vital for tokamak fusion devices.
• Existing methods often require multiple discharges or complex setups, hindering real-time analysis.

Purpose of the Study:

• To develop and validate a simple, single-shot method for measuring electron temperature and density profiles in tokamaks.
• To demonstrate the feasibility of this technique for current and future large tokamak experiments.

Main Methods:

• Utilized Thomson scattering of laser light.
• Deduced electron temperature (T(e)) from the ratio of scattered powers in two spectral intervals.
• Deduced electron density (n(e)) from absolute scattered power in one interval, combined with T(e) knowledge.
• Employed a nine-channel scattering system with two-detector spectrometers for simultaneous measurements.

Main Results:

• Successfully obtained electron temperature (T(e)) and density (n(e)) profiles in a single discharge on the TFR tokamak.
• The method proved effective for real-time profile acquisition.

Conclusions:

• The developed method offers a straightforward and efficient approach for single-shot T(e) and n(e) profile measurements in tokamaks.
• This technique is suitable for application in current and future large-scale fusion research facilities.