Page 182 - Radiochemistry and nuclear chemistry

CHAPTER 7

Radiation Effects on Matter"

Contents

7.1. Energy transfer 167
7.1.1. Charged particles 167
7.1.2. Uncharged radiation 169
7.2. Radiation tracks 169
7.3. Radiation dose and radiation yield 170
7.4. Metals 172
7.5. Inorganic nonmetallic compounds 173
7.6. Water 176
7.7. Aqueous solutions 177
7.8. Organic compounds 180
7.9. Experimental methods 183
7.10. Dose measurements 184
7.11. Large-scale non-biological applications 186
7.11.1. Radiation sources 187
7.11.2. Process criteria 187
7.11.3. Radiation induced synthesis 188
7.11.4. Industrial radiation processing 189
7.12. Technical uses of small dose-rates 189
7.13. Exercises 190
7.14. Literature 190

Soon after the discoveries of X-rays and radioactivity it was learned that radiation could
cause changes in matter. In 1901 P. Curie found that when a radium source was placed on
his skin, wounds were produced that were difficult to heal. In 1902 skin cancer was shown
to be caused by the radioactivity from radium but 5 years later it was learnt that radium
therapy could be used to heal the disease. Large radiation doses were found to kill fungi
and microorganisms and produce mutations in plants.
Glass ampules containing milligrams of radium darkened within a few months and became
severely cracked, allowing the leakage of radon gas. In the early years of the investigation
of radioactivity, emphasis was on radium and its decay products. Among the radiation
effects observed were the fluorescence induced in different salts and the changes in their
crystallographic form. Metals were found to lose their elasticity and become brittle.
Radiation was also found to have a profound effect on the chemical composition of solutions
and gases. Water, ammonia and simple organic substances decomposed into more

This chapter has been revised by Prof. T. Eriksen, Royal Institute of Technology, Stockholm

166