Gamma ray spectroscopy is a technique used to measure and analyze the energies of gamma rays emitted by radioactive substances. Each radioactive isotope emits gamma rays at specific, characteristic energies, so by recording these energies, scientists can identify the isotopes present and determine their quantities.
How it works:
- A gamma ray detector, often a scintillation detector (e.g., NaI(Tl)) or a high-purity germanium (HPGe) detector, captures the gamma rays.
- The detector converts the gamma ray energy into an electrical signal proportional to the photon’s energy.
- A multichannel analyzer processes these signals to produce a spectrum — a plot of gamma ray counts versus energy.
- Peaks in the spectrum correspond to specific isotopes, allowing for precise identification.
Uses in research:
- Nuclear physics – Studying nuclear energy levels and decay schemes.
- Environmental science – Detecting and quantifying radioactive pollutants.
- Astrophysics – Observing cosmic gamma rays to study stars, supernovae, and cosmic rays.
- Geology and archaeology – Determining elemental composition and age of samples.
- Medical research – Tracking radiopharmaceuticals in metabolic studies.
In research, it’s valued because it’s non-destructive, highly sensitive, and capable of giving detailed isotope information from very small samples.