STUDY OF NUCLEAR MICROPROBE BEAM HALO USING IBIC

There are many factors which can give rise to a halo around a focused MeV ion beam, and a method of detecting the distribution and determining the amount of beam current in the halo will help to assess its effect on spatial resolution. This paper describes how the technique IBIC (ion beam induced charge) can be used as an extremely sensitive method of imaging and quantifying the beam halo around focused 3 MeV proton beam current of 200 pA and 0.3 fA. It is also shown how the momentum of the beam fraction in the halo can be calculated from its spatial extent in the IBIC images.