Detecting a beam – without touching it !
A non-invasive, gas jet-based, beam profile monitor has been developed in the QUASAR Group at the Cockcroft Institute, UK. This new instrument allows on-line measurement of the 2-dimensional transverse profile of particle beams with negligible disturbance to either primary beam or accelerator vacuum. The monitor is suitable for use with beams across a wide range of energies and intensities and hence a very promising device not only for fundamental research, but also for accelerators used for cancer treatment or material implantation.
In this setup a nozzle skimmer system shapes a thin supersonic gas jet into a curtain. This is then crossed with the beam that shall be analysed, causing ionization of the jet’s atoms. These ions are then imaged onto a position-sensitive detector and yield the transverse beam profile.