5.5 Research and Scientific Applications

Neutron Activation Analysis (NAA)

**Neutron Activation Analysis (NAA)** is a highly sensitive and accurate technique used to determine the elemental composition of a sample. The process involves irradiating a sample with neutrons, which can be absorbed by the sample's atomic nuclei, making them radioactive. The unique gamma rays emitted by these activated nuclei are then measured to identify and quantify the elements present.

• Applications: NAA is used in a variety of fields, including forensics (analyzing trace evidence), geology (determining the composition of rock samples), and environmental science.

Radiocarbon Dating (\(^{14}\)C)

**Radiocarbon dating** is a method used to determine the age of organic materials. Living organisms absorb carbon, including the radioactive isotope Carbon-14 (\(^{14}\)C), from the environment. When the organism dies, the absorption stops, and the \(^{14}\)C begins to decay with a known half-life of approximately 5,730 years.

By measuring the amount of remaining \(^{14}\)C in a sample, scientists can estimate how long ago the organism died. This technique is a cornerstone of archaeology and paleontology.

Particle Accelerators and Synchrotron Radiation

**Particle accelerators** are machines that use electromagnetic fields to propel charged particles to very high speeds. These machines are used for both fundamental research and practical applications.

• Synchrotron Radiation: When charged particles are accelerated in a circular path, they emit a form of electromagnetic radiation called synchrotron radiation. This highly intense and focused light is used to study the structure of materials at the atomic and molecular level, with applications in materials science, biology, and chemistry.
• High-Energy Physics: Accelerators are used to collide particles at high speeds to study the fundamental building blocks of matter and the forces that govern the universe.