Twinning of ion-bombarded single crystals has been investigated for th
e first time. It has been established that bombardment of bismuth sing
le crystals with boron ions stimulates mobility of twinning dislocatio
ns and quenches their sources. This result is explained using the disl
ocation model of a wedge-shaped twin. (C) 1998 American Institute of P
hysics. [S1063-7850(98)01604-8]