Studies and measurements on cavity beam position monitors for novel electron linacs

Beam Position Monitors (BPM) are the most frequent non-intercepting diagnostics used at nearly all Linacs, cyclotrons and synchrotrons. Their main purpose is to measure the position of the center of mass of the beam. There are many types of BPMs, which have different design, developed by taking into accounts the beam characteristics and the level of accuracy and resolution wanted. One of the most recent types, which is now used world-wide, is the Cavity Beam Position Monitor (cBPM). The latter became popular mainly because they can achieve the highest measurement resolution of all types of BPMs (up to tens of nanometers) even for low charge beams. Moreover, they can also be used to give information on the beam charge. The trade-off is that the mechanical design is complex and that high frequency read-out electronics is typically needed, which could increase the overall cost of the system. This dissertation is focused mainly on Cavity Beam Position Monitors and their application on novel electron LINACS. The research performed is particularly focused on the resolution of such devices and it also takes into consideration the read-out electronics, that for many aspects is the most critical part of the system. The techniques used to measure the resolution are explained, as well as all the experiments performed both in laboratory and in presence of beams.