Gamma radiation does not consist of particles but as short wavelength, high energy electromagnetic radiation emitted from unstable nuclei. It is normally emitted alongside alpha or beta radiation.

Alpha particles, with their high linear energy transfer (LET), cause irreparable double-strand DNA breaks---far more lethal to cancer cells than the single-strand nicks from beta particles.

and that the pulse-height is proportional to the energy of the alpha-particles. It is found in studying the pulses for some beta-radiating substances that there is proportionality between pulse ...

Alpha particles, with their high linear energy transfer (LET), cause irreparable double-strand DNA breaks---far more lethal to cancer cells than the single-strand nicks from beta particles.

Alpha particles come from the nucleus of a radioactive atom. They consist of 2 protons and 2 neutrons; hence have a 2+ charge. A few centimeters of air will stop them. Alpha radiation consists of ...