This book was written for students and professionals in radiobiology, medical physics and radiochemistry. It identifies the simpler and practically important aspects of interaction of ionizing radiation with matter. Microdosimetry was developed as a system of concepts as well as physical quantities and their measurement.

I Introduction.- I.1 The Role of Microdosimetry.- I.2 The Transfer of Energy from Ionizing Radiation to Matter.- I.3 Stochastic Quantities.- I.4 Spatial Aspects of Microdosimetry.- I.5 Temporal Aspects of Microdosimetry.- II Microdosimetric Quantities and their Moments.- II 1 Definitions.- II.2 Microdosimetric Distributions and their Moments.- II.3 Representations of Microdosimetric Distributions.- II.4 Experimental versus Calculated Microdosimetric Distributions.- III Interactions of Particles with Matter.- III.1 Overview.- III.2 Quantities and Terms Relating to the Interaction Between Projectiles and Targets.- III.3 Kinematics of the Scattering Process.- III.4 Sources of Charged Particles.- III.5 Microscopic Description of the Electromagnetic Interaction of Charged Particles with Matter.- III.6 The Interaction of Charged Particles with Bulk Matter.- III.7 Appendix: Formal Treatment of the Interaction of Charged Particles with Matter.- IV Experimental Microdosimetry.- IV.I The Site Concept.- IV.2 Fluctuations in Regional Microdosimetry.- IV.3 Measurements in Regional Microdosimetry.- IV.4 Measured Distributions of Lineal Energy.- IV.5 Measurement of Distributions of Specific Energy.- IV.6 Measurement of LET Distributions.- IV.7 Appendix: The V Effect.- V Theoretical Microdosimetry.- V.1 A Diversion in Geometric Probability.- V.2 Monte Carlo Simulation of Charged-Particle Tracks.- V.3 Calculation of Microdosimetric Spectra.- V.4 Methods for Obtaining Proximity Functions.- V.5 The Informational Content of the Moments of the Microdosimetric Distributions.- V.6 Appendix: The Maximum Entropy Principle.- VI Applications of Microdosimetry in Biology.- VI.1 Radiobiology.- V1.2 Radiotherapy.- VI.3 Radiation Protection.- VII Other Applications.- VII.1 Microdosimetry and Radiation Chemistry.- VII.2 Radiation Effects on Microelectronics.- VII.3 Microdosimetry and Thermoluminescence.- References.