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Chapter 9 Nuclear Radiation. 9.3 Radiation Measurement. Geiger Counter. A Geiger counter detects beta and gamma radiation uses ions produced by radiation to create an electrical current. Units for Measuring Radiation. Units for measuring radiation activity include
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Chapter 9 Nuclear Radiation 9.3 Radiation Measurement
Geiger Counter A Geiger counter • detects beta and gamma radiation • uses ions produced by radiation to create an electrical current
Units for Measuring Radiation Units for measuring radiation activity include • Curie –measures activity as the number of atoms that decay in 1 second • rad (radiation absorbed dose)– measures the radiation absorbed by the tissues of the body • rem (radiation equivalent) – measures the biological damage caused by different types of radiation
Measuring Radiation Activity Often the measurement for an equivalent dose is in millirems (mrem). One rem is equal to 1000 mrem. The SI unit is the sievert (Sv). One sievert is equal to 100 rem.
Radiation Exposure Exposure to radiation occurs from • naturally occurring radioisotopes • medical and dental procedures • air travel, radon, and smoking cigarettes • cosmic rays
Radiation Sickness LD50 • is the amount of radiation to the whole body that is the lethal dose for one-half the population • varies for different life-forms, as Table 9.6 shows
Learning Check A typical intravenous dose of I-125 for a thyroid diagnostic test is 100 Ci. What is this dosage in megabecquerels (MBq) (3.7 1010 Bq = 1 Ci)? A. 3.7 MBq B. 3.7 106 MBq C. 2.7 102 MBq
Solution A typical intravenous dose of I-125 for a thyroid diagnostic test is 100 Ci. What is this dosage in megabecquerels (MBq) (3.7 1010 Bq = 1 Ci)? 100 Ci 1 Ci 3.7 1010 Bq 1 MBq x 1 x 106 Ci 1 Ci 1 106 Bq = 3.7 MBq The answer is A.