microtron UK /ˈmaɪ.kɹə(ʊ)ˌtɹɒn/US /ˈmaɪ.kɹoʊˌtɹɑn/ noun1 •A kind of particle accelerator similar to the cyclotron, but in which the accelerating field is not applied through large D-shaped electrodes but through a linear accelerator structure. formsmicrotrons