NE-312

Radiation Detection and Measurements Laboratory

Half-Life Lab

Purpose

Irradiate an unknown container in the reactor. Determine which isotope the unknown container contains based on its half-life and energy peaks.

Equipment

• Unknown Sample
• HPGe Detector
• Nuclear Reactor
• Stopwatch
• Computer

Basic Setup

The Lab will be set up when you arrive.

Experimental Procedure

1. The reactor staff will irradiate the unknown sample. After ensuring the sample is safe, it will be placed near the detector. Determine a time interval your group will use between counts (this may be adjusted depending on how long the half-life is).
2. Set the counter to count for one minute. Start the counter and stopwatch simultaneously. Keep the stopwatch running throughout the experiment. After the count is complete, record it along with the time.
3. Continue to take counts and record data until your sample decays through two entire half-lifes. Plot counts against time and extrapolate to determine the half-life of the isotope.
4. Note the major energy peaks in the spectrum.

Using the calculated half-life and energy peak information, determine the identity of your unknown isotope.