Design and first tests of the trapped electrons experiment T-REX

Area of Science:

• Plasma Physics
• Fusion Energy Technology
• High-Power Microwave Devices

Background:

• Gyrotrons are critical for electron cyclotron resonance heating in fusion reactors.
• Instabilities caused by trapped electrons in the magnetron injection gun (MIG) region lead to operational failures.
• Precise manufacturing tolerances for MIG geometry are necessary to mitigate these issues.

Purpose of the Study:

• To understand the physics of electron clouds within gyrotron MIGs.
• To investigate trapped electron behavior in a controlled experimental environment.
• To enhance the performance and reliability of gyrotrons for fusion energy applications.

Main Methods:

• Development of the T-REX experimental setup, replicating MIG geometries and fields.
• Utilizing 2D particle-in-cell simulations with the FENNECS code for comparison.
• Employing a Penning-Malmberg trap-like configuration with coaxial electrodes and a superconducting magnet.

Main Results:

• Presentation of the experimental device and initial findings on current distribution.
• Qualitative comparison between experimental results and FENNECS simulation data.
• Demonstration of a setup capable of mimicking relevant MIG conditions.

Conclusions:

• The T-REX experiment provides valuable data for understanding trapped electron dynamics in gyrotron MIGs.
• Experimental findings align qualitatively with FENNECS simulations, validating the modeling approach.
• This research is crucial for improving the efficiency and reliability of future fusion reactors.