  Given that there are 94 clinics and more than 200,000 patients treated
worldwide, proton and carbon are the most used heavily charged particles in
heavy ion therapy. However, there is a recent increasing trend in using new ion
beams. Each heavy ion has a different effect on the target. As each heavy ion
moves through the tissue, they lose enormous energy in collisions, so their
range is not long. Ionization accounts for the majority of this loss in energy.
During this interaction of the heavily charged particles with the target, the
particles do not only ionize, but also lose energy with the recoil. Recoil
occurs by atom-to-atom collisions. With these collisions, crystalline atoms
react with different combinations and form cascades in accordance with their
energies. Thus, secondary particles create ionization and recoil. In this
study, recoil values of boron, carbon, nitrogen and oxygen beams in the water
phantom were computed in the energy range of 2.0-2.5 GeV using Monte Carlo
simulation and the results were compared with carbon. It was observed that
there is a regular increase in the recoil peak amplitude for carbon and boron
ions, unlike oxygen and nitrogen where such a regularity could not be seen.
Moreover, the gaps in the crystal structure increased as the energy increases.
