Determination of i̇onic cluster sizes i̇n gas detectors using neon-based gas mixtures

Gas detectors are prone to negative effects caused by ions that interfere with their healthy operation. These effects include disruptions in the electric field configuration and electromagnetic induction, which can affect the detector's signal. Although attempts have been made to address this issue, no successful solution has been found to date. Therefore, understanding the behavior of ions in the detector is critical for solving this problem. Although there is a strong opinion in the literature that ions have no effect on the signal, recent scientific publications suggest that these ions significantly affect the signal. When primary electrons are formed in the detector volume, ions are created and turn into ionic clusters until they reach the cathode(Kalkan, 2015). However, the exact size of these clusters is unknown, and theoretical calculations need to be experimentally proven. Scattering experiments with light atoms or photons have been used to estimate the size of ionic clusters. While these studies have attracted the attention of detector physicists, they are insufficient to fully explain the behavior of ions. To address this issue, a laser beam was sent to the region where ions were formed and entrained by the electric field in the detector. By analyzing the scattered beam using Rayleigh scattering, experimental evidence for the existence and size of ionic clusters has been provided. While volume determination using Rayleigh scattering has been used for a long time, the method used in this thesis differs significantly from the literature. For example, the ionic clusters formed do not move by vacuum but by electric field effect, and it is not possible to channel them into a thin nozzle. The aim is to obtain the first experimental results about the dimensions of the ionic clusters formed under the operating parameters of gas detectors, such as pressure, temperature, humidity, and gas mixture used, and to share them with the literature.