Gamma rays are an ultrahigh-frequency of light that is emitted by radioactive elements, energetic celestial bodies such as black holes and neutron stars, and high energy events such as nuclear explosions and supernovae.
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What is Gamma-ray (γ-ray) Spectroscopy?
Gamma-ray (γ-ray) spectroscopy is a quick and nondestructive analytical technique that can be used to identify various radioactive isotopes in a sample.
A gamma-ray spectrometer (GRS) is an instrument for measuring the distribution of the intensity of gamma radiation versus the energy of each photon.
Principle of Gamma-ray (γ-ray) spectroscopy
- Most radioactive sources produce gamma rays, which are of various energies and intensities.
- When these emissions are detected and analyzed with a spectroscopy system, a gamma-ray energy spectrum can be produced.
- In gamma-ray spectroscopy, the energy of incident gamma-rays is measured by a detector.
- By comparing the measured energy to the known energy of gamma-rays produced by radioisotopes, the identity of the emitter can be determined.
- A detailed analysis of this spectrum is typically used to determine the identity and quantity of gamma emitters present in a gamma source and is a vital tool in the radiometric assay.
- The gamma spectrum is characteristic of the gamma-emitting nuclides contained in the source.
Instrumentation of Gamma-ray (γ-ray) spectroscopy
The equipment used in gamma spectroscopy includes:
- An energy-sensitive radiation detector
The commonly used detectors may be any among the two:
Scintillation detector
- Scintillation is the process by which some material, be it a solid, liquid, or gas, emits light in response to incident ionizing radiation.
- In practice, this is used in the form of a single crystal of sodium iodide that is doped with a small amount of thallium, referred to as NaI(Tl).
- This crystal is coupled to a photomultiplier tube which converts the small flash of light into an electrical signal through the photoelectric effect.
- This electrical signal can then be detected by a computer.
Semiconductor detector
- A semiconductor accomplishes the same effect as a scintillation detector, conversion of gamma radiation into electrical pulses, except through a different route.
- In a semiconductor, there is a small energy gap between the valence band of electrons and the conduction band.
- When a semiconductor is hit with gamma-rays, the energy imparted by the gamma-ray is enough to promote electrons to the conduction band. T
- his change in conductivity can be detected and a signal can be generated correspondingly.
- Germanium crystals doped with lithium, Ge(Li), and high-purity germanium (HPGe) detectors are among the most common types.
- Electronics
It processes detector signals produced by the detector.
For example. A pulse sorter (i.e., multichannel analyzer)
- Associated amplifiers and data readout devices
They help in the generation, display, and storing of the spectrum.
Applications of Gamma-ray (γ-ray) spectroscopy
- They are used extensively in the studies of:
- Nuclear structure
- Nuclear transitions and
- Nuclear reactions
- In space research such as water detection on planets
- Used for the elemental and isotopic analysis of airless bodies in the solar system, especially the moon and mars.
- GRS instruments supply data on the distribution and abundance of chemical elements
References
- https://en.wikipedia.org/wiki/Gamma_spectroscopy
- https://www.physlab.org/wp-content/uploads/2016/04/GammaExp-min.pdf
- https://archive.cnx.org/contents/686b9c8b-1656-49ec-a969-84da62a60eca@1/principles-of-gamma-ray-spectroscopy-and-applications-in-nuclear-forensics
- https://owlcation.com/stem/Gamma-Ray-Spectroscopy
- https://stfc.ukri.org/files/a-bruce-gamma-spectroscopy/
I find gamma spectroscopy for luminescence dating application. Can you suggest me?
Hello,
We are looking to source a Gamma Ray/Semiconductor Detector. Can you please give us some sort of indication of costs and delivery period so we can set our budgets. We are looking for a portable unit.
Dear James,
Sorry I have no idea about this.
Thanks,