Resonance cavity as an education tool in PlasmaLab@CTU

Abstract

PlasmaLab@CTU is a laboratory at the Czech Technical University in Prague dedicated to train new fusion physicists and engineers in plasma physics and technology with focus on the plasma diagnostics. The resonance cavity is one of the devices which train students in handling microwaves together with vacuum and plasma physics. The contribution will present the design of the resonance cavity, and measurements of the density as the function of the pressure in different gases. It will also present this experiment as an educational tool for the fusion community.The resonance cavity is a metal cylinder placed inside a glass container. It can be evacuated via holes in the top lid. Plasma is generated between an electrode inserted inside and the cylinder itself by RF source with the frequency of 13.5 MHz, and the power of roughly 70 W. Two antennas are placed inside the resonator in the bottom lid to launch and measure the resonant modes in the cavity. Plasma density can be estimated from the shift of the resonance peaks with/without plasma.The experiment can operate with five gases. It can be remotely controlled via its own interface through the internet. The remote control is an important feature of the PlasmaLab@CTU. It aims in continuing in the tradition of educational events already established by the GOLEM tokamak.