particle radiation

…atom with electrons, protons, alpha particles, or another type of particles. The vacancy also can be created by absorption of X-ray radiation or by nuclear capture of an inner-shell electron as it approaches the nucleus. Often the bombardment is sufficiently energetic to cause the inner orbital electron to be completely…

…and gamma rays, densely ionizing particles—neutrons, protons, mesons, alpha particles, and heavy ions, for example—have been used increasingly to treat cancer and other lesions. Such high-LET radiations (see above The passage of matter rays: Linear energy transfer and track structure) offer potential advantages over conventional X rays and gamma rays…

…the direct detection of charged particle radiations. They are seldom used to detect gamma rays because the low average atomic number of these materials inhibits the full energy absorption needed for spectroscopy. The average atomic number is not greatly different from that of tissue, however, and plastic scintillators have consequently…

Alpha particles, beta particles, neutrons, and positrons are examples of particulate ionizing radiation. Gamma rays and X rays are electromagnetic ionizing radiation.