Radioactivity: Shielding, Activity, and Decay

Learning Goals:

After this exercise you should be able to:

Use the results of penetration experiments to determine the type of radiation.

model of detection versus distance and explain what it means.

Introduction:

The study of radioactivity provided clues and evidence into the basic structure of matter. There are four main types of particles: the alpha, beta plus, beta minus, and gamma particles. They are characterized by their ability to penetrate materials. The sources of the radiation are characterized by their activity, particles per time, and the rate of change of the activity. We will also do an exercise that shows the relationship between detections and distance from the source.

Activity is decays per unit time; a standard unit of activity is the curie (Ci) where 1Ci = 3.7X10¹⁰disintegrations per second. This is a large number so activity is frequently given in micro (m)or nano(n) curie (Ci). Another common unit is the becquerel (Bq) which is 2.70X10^-11 Ci.

The diameter of the detector is 12.2 mm.