Range Straggling of Charged Particles in Be, C, Al, Cu, Pb, and Air

The straggling of the range of charged particles due to fluctuations of the ionization loss has been evaluated for six substances (Be, C, Al, Cu, Pb, and air). The calculations extend up to $\frac{T}{\mu c^2}\sim 100$, where $T$ is the kinetic energy and $\mu$ is the mass of the incident particle. At high energies ($\frac{T}{\mu c^2}\gtrsim 5$), the integral giving the range straggling becomes somewhat dependent on the ratio $\frac{\mu }{m}$, where $m$ is the electron mass. Two separate calculations have therefore been carried out, which apply to protons and $\mu$ mesons, respectively. The results for protons can also be used for $\pi$ and $K$ mesons in the energy range of interest ($\frac{T}{\mu c^2}\lesssim 5$).