Abstract
Microscopic calculations have been made of the probabilities of radiationless E1, E2 and E3 transitions in a muonic atom of 238U. The results obtained are compared with the experimental values for those transitions, the experimental probabilities are available for (2p to 1s, 3p to 1s and 3d to 1s). A considerable probability (10-15%) is predicted in actinoid atoms of E3 radiationless transitions 3d to 2p accompanied by excitation of low-lying electric octupole resonance (LEOR).