Abstract
This chapter combines the soft- and hard-collision stopping powers derived in the two previous chapters to yield the total collision stopping power (but still not accounting for the higher-order effects to be studied in Chap. 12). For electron projectiles, we consider the restricted hard-collision stopping power derived in Chap. 9 to provide the restricted stopping power for electrons, a quantity of importance in practical radiation dosimetry evaluations. The main part of this chapter is, however, assigned to the theoretical investigation of the mean energy required to create an ion pair. This is a fundamental quantity not only to practical radiation dosimetry but also to our understanding of the ionisation resulting from the interaction of radiation with matter. We develop the generalised Fowler equation, which is essentially a transport equation, to yield the number of ion pairs created per unit energy transfer.
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Notes
- 1.
The symbol for electric charge used here, Q, is not to be confused with that for energy transfer.
- 2.
This is not the same as the mean excitation energy discussed in earlier chapters.
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McParland, B.J. (2014). Total and Restricted Collision Stopping Powers and Theory of the Mean Energy Expended to Create an Ion Pair. In: Medical Radiation Dosimetry. Springer, London. https://doi.org/10.1007/978-1-4471-5403-7_10
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