Micrometer Gap Distance Dependence on Temperature Changes in a Large Electrode System

Abstract: The purpose of this project is to verify if the so called capacitance method is a sensitive enough method to measure micrometer distance changes in an electrode system. This is done by heating up an electrode system to 60°C and make capacitance measurements during the procedure. With the inverse relationship between the capacitance and the distance between the surfaces the distance is attained. The incitement to find a sensitive measurement method is that in a particle accelerator the temperature is down to 4K and the components of an electrode system will contract which can lead to a breakdown of the system. The change in temperature gives a theoretical change in "gap distance" that is close to the measured change in gap distance, therefore the method is a reliable enough method to measure micrometer distance changes. A possible reason for the small deviation is that the measured temperature is the temperature of the surface of the electrode system. It would be preferable to measure the total temperature of the electrodes, not just the surfaces because it is the whole electrode that expands and contracts with the temperature. This could be done with an IR-camera.