In which type of radiation does the term 'high LET' apply?

High LET, or high linear energy transfer, refers to a type of radiation that has a greater ability to ionize the atoms it interacts with as it travels through a medium. This means that high LET radiation deposits a significant amount of energy over a very short distance, resulting in densely ionizing tracks.

Alpha particles are classified as high LET radiation because they are heavy and carry a double positive charge, which allows them to cause significant ionization in the materials they pass through. Their mass and charge lead them to interact more readily with matter compared to lower LET radiation types. Consequently, alpha particles release their energy in a more concentrated manner, which can lead to more severe biological damage when they interact with biological tissues.

In contrast, gamma radiation, X-rays, and beta particles are considered low to intermediate LET radiation. These forms of radiation are lighter and less ionizing, leading to a broader spread of energy deposition along their paths and less localized biological damage. This distinction is crucial in radiation biology, particularly when assessing the potential health risks and biological effects associated with different types of radiation exposure.