Which radiations have high linear energy transfer (LET)?

Which radiations have high linear energy transfer (LET)?

• A. Alpha particles and neutrons
• B. Gamma rays
• C. X-rays
• D. Beta particles

Answer: (A)

Linear energy transfer (LET) is the amount of energy deposited per unit length as radiation travels through tissue. High-LET radiations deliver energy very densely along their paths, causing clusters of ionizations and more complex, harder-to-repair DNA damage. Alpha particles are heavy, doubly charged nuclei, so they interact strongly with matter, lose energy quickly, and produce a high LET with a short range in tissue. Neutrons, though uncharged, create recoil nuclei and other charged secondary particles when they collide with atoms, leading to localized bursts of energy deposition and a high LET in tissue. In contrast, gamma rays and X-rays are photons that interact sparsely, producing ionizations spread over longer paths and thus have low LET. Beta particles are lighter charged particles with less dense energy deposition than alpha radiation, giving them a lower LET.

Linear energy transfer (LET) is the amount of energy deposited per unit length as radiation travels through tissue. High-LET radiations deliver energy very densely along their paths, causing clusters of ionizations and more complex, harder-to-repair DNA damage. Alpha particles are heavy, doubly charged nuclei, so they interact strongly with matter, lose energy quickly, and produce a high LET with a short range in tissue. Neutrons, though uncharged, create recoil nuclei and other charged secondary particles when they collide with atoms, leading to localized bursts of energy deposition and a high LET in tissue. In contrast, gamma rays and X-rays are photons that interact sparsely, producing ionizations spread over longer paths and thus have low LET. Beta particles are lighter charged particles with less dense energy deposition than alpha radiation, giving them a lower LET.