Question from Introduction to Radiological Physics and Radiation Dosimetry Attix Chapter 8

The charged particle has 50 probability of reaching twice its range, While the photon has a probability of f2 = 0.14 of traveling a distance Zip without an interaction. Compare the passage of charged and uncharged particles through matter. What are the approximate probabilities of a single charged particle achieving a path- length equal to twice its range, or of a single photon having a pathlength twice as great as the mean free path l/u? (Assume the photon is totally absorbed in its rst interaction.)