Which types of particles are identified as having high linear energy transfer (LET)?

High linear energy transfer (LET) refers to the ability of certain types of ionizing radiation to deposit energy densely along their path as they travel through a medium. This characteristic is significant because it often correlates with the biological effectiveness of the radiation in causing damage to cells and tissues.

Alpha particles and protons are identified as having high LET due to their mass and charge. When alpha particles, which are composed of two protons and two neutrons, travel through matter, they interact more strongly with the surrounding atoms because of their greater mass and charge compared to other forms of radiation. This leads to a higher ionization density, allowing them to transfer a larger amount of energy over a shorter distance. Similarly, protons, being charged particles, also exhibit high LET as they create densely ionizing tracks as they interact with biological tissues.

In contrast, types of radiation such as X-rays, gamma rays, and beta particles are classified as low LET. These forms of radiation tend to be more penetrating and can travel longer distances through human tissues without depositing energy as densely, resulting in less localized damage.

Understanding the differences in LET is important in fields such as radiation therapy, where high LET radiation can be more effective in eradicating tumors while possibly sparing surrounding