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.
Details about the dynamics of gas jet formation, transport and shaping can be found in an article that has now been published in Vacuum. Further information about this project can be found here.