Beam loss monitors
Introduction
At any moment the accelerated particle which undergoes the Lorentz force must accomplish a closed orbit trajectory; otherwise it will be lost. In other words, acceleration and guidance (bending, focusing, defocusing) must be tuned for synchronization.
BLM's are devices used to measure and localize beam losses over an accelerator. A BLM should be able to establish the number of lost particles, the loss position and the time interval during which the loss occurs.
One of the basic principles of loss detection is the proportionality between the signal from the BLM and the number of lost particles. However, the measurement is not absolute.
The measurement of the beam losses is very important itself for correcting the beam trajectories in order to keep the irradiation level of the accelerator components at the lowest possible level. This helps to keep the lifetime of the accelerator components as long as possible.
Example of a SPS ionization chamber.