Energy loss and straggling of alpha particles

The energy loss (∆E) in an atmospheric gas for light ions such as alpha particles (²⁴¹Am) of energy 5.48 MeV has been experimentally deliberated in a scattering chamber at different pressures of 4 to 7 mbar. The energy loss has also been obtained at variable distances from 4 mm to 32 mm. The energy loss of alpha particles has been exponentially decreased with increasing pressure. The measured energy loss of alpha particles at higher pressure that is at 7 mbar that is more but at lower pressure of 4 mbar is less. The energy loss of alpha particles increases as distance increases from the source to detector in the scattering chamber. The transmitted energy of alpha particles at lower pressure that is at 4 mbar is high but at higher pressure of 7 mbar is less. The transmitted energy increases as distance between sources to detector decreases. The nuclear and electronic energy loss in the energy range of 1 - 5.5 MeV for an alpha particle is given by SRIM 2008. The projected energy of the alpha particles increases the nuclear and electronic stopping powers decreases exponentially. Further the range of alpha particles is being increased by increasing ion energy. The electronic collision dominates in the higher energy region (MeV) and nuclear collision in lower projectile energies (keV). The energy loss straggling has been found to be increased by increasing pressure as well as increasing the distance between the source and detector in the scattering chamber. (author)