Half-life and radioactive equilibrium with Cobra SMARTsense

Principle

The half-life of a Ba-137 m daughter substance eluted (washed) out of a Ca-137 isotope generator is measured directly and is also determined from the increase in activity after elution.

Tasks

1. To record the counting rate as a function of the counter tube voltage (counter tube characteristic) when the isotope generator activity is constant (radioactive equilibrium).
2. To measure the activity of the isotope generator as a function of time immediately after elution.
3. To measure the activity of a freshly eluted solution of Ba-137 m as a function of time.

Learning objectives

• Parent substance
• Daughter substance
• Rate of decay
• Disintegration or decay constant
• Counting rate
• Half life
• Disintegration product