Langmuir probes are small metal probes that are inserted into the plasma. When the probes are biased to a negative voltage, they collect ions that are bombarding the probe surface. The current that flows to the probe can be used to measure the ion flux.
Charge-exchange spectroscopy is a technique that uses a beam of neutral hydrogen atoms to excite ions in the plasma. When the excited ions relax, they emit light that can be detected by a spectrometer. The intensity of the light can be used to measure the density of the ions.
The new method combines the two techniques to measure the flux of ions that bombard the walls of fusion devices. The Langmuir probes are used to measure the total ion flux, while the charge-exchange spectroscopy is used to measure the density of the ions. This information can be used to calculate the average energy of the ions that are bombarding the wall.
The new method is a significant improvement over previous methods for measuring the ion flux in fusion devices. The previous methods were only able to measure the total ion flux, and they were not able to provide information about the energy of the ions. The new method provides more detailed information about the ion flux, which is important for understanding how fusion devices operate.
The new method will be used to study the ion flux in the ASDEX Upgrade fusion device at the Max Planck Institute for Plasma Physics. The results of these studies will help scientists to better understand how fusion devices operate and how to improve their performance.
