Compact radiation module for THz spectroscopy using 300 GHz continuous-wave clinotron

Area of Science:

• Physics
• Spectroscopy
• Engineering

Background:

• Dynamic Nuclear Polarization (DNP) enhances Nuclear Magnetic Resonance (NMR) spectroscopy sensitivity.
• High-field DNP systems require specific terahertz (THz) radiation properties.
• Compact and stable THz sources are crucial for advanced NMR applications.

Purpose of the Study:

• To develop a compact radiation module for high-field DNP-NMR systems.
• To investigate the suitability of a 300 GHz continuous-wave (CW) clinotron oscillator for DNP-NMR.
• To evaluate the spectral characteristics and stability of the clinotron radiation.

Main Methods:

• Development of a 300 GHz CW clinotron oscillator and a stable high-voltage (HV) power supply.
• Simulation of clinotron radiation spectra, considering accelerating voltage pulsations.
• Experimental testing of the clinotron module for frequency and spectral linewidth stability.

Main Results:

• A stable 300 GHz CW clinotron oscillator was successfully developed and tested.
• The high-voltage (HV) power supply achieved output voltage stability better than 20 ppm.
• Observed frequency stability was 33 ppm, and spectral linewidth was < 8 MHz at 300 GHz.

Conclusions:

• The developed 300 GHz CW clinotron radiation module meets the stringent spectral linewidth requirements for DNP-NMR spectroscopy.
• The clinotron oscillator is a viable component for advanced DNP-NMR systems.
• The stable operation and precise spectral characteristics enable efficient NMR signal enhancement.