Gamma Spectroscopy
In this experiment you will use an HPGE detector and a Multi-Channel Analyzer (MCA) to observe the gamma-ray spectra of various "known" isotopes, and then use the same tools to identify some "unknown" isotopes.
This experiment works reliably.
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Reading
- Here is an experiment manual from a different class that describes the experiment.
- There is a chart of the nuclides outside room 123. Learn how to read it.
- This page has a very useful gamma-ray lookup capability which can help determine your unknowns.
- LBNL also has some useful reference tables here.
Questions
- How and why does HPGE have such high energy resolution?
- What is a Multi-Channel Analyzer? Why are you using one here?
- Explain how you will calibrate your MCA.
Location
Room 107.
Equipment needed
- Spectech Multi-Channel Analyzer
- Oscilloscope (Optional, but very useful!)
- Tennelec TC 950 bias supply in NIM bin (Set to 1000 V)
- TC 240 amplifier in same NIM bin
- Small exempt "button" gamma sources for calibration
- Dosimetry badge
- "Unknown" sources
- Liquid nitrogen
Cautions
- The detector cold-finger must be immersed in liquid nitrogen for at least 6 hours prior to turning on the HV supply.
- One student must wear a dosimentry badge in the lab at all times while this experiment is in use.
- The HV should be the last thing you turn on, and the first thing you turn off.