Elementary processes in the active medium of an iodine photodissociation laser

A theoretical analysis is made of the elementary processes occurring in the active medium of an iodine photodissociation laser and affecting its emission spectrum. An estimate is obtained of the cross sections of the transitions between the hyperfine structure components within the group ²P_3/2 and excited ²P_1/2 states of atomic iodine, which occur because of collisions with various particles in the active medium. It is shown that typically the mixing of the hyperfine structure components of the state ²P_3/2 is very fast in collisions with any particles, whereas the mixing of the sublevels of the state ²P_1/2 is primarily due to collisions with iodine atoms in the ground state. Broadening of the stimulated emission line is considered.