Bremsstrahlung emission accompanying $\alpha$-decay of $^{210}$Po nucleus

The energy spectrum of bremsstrahlung accompanying the $\alpha$-decay of a $^{210}$Po nucleus has been measured. The probability of emission of bremsstrahlung photons decreases monotonically with an increase in their energy. The data obtained have been compared with the numerical results of calculation within the framework of the classical bremsstrahlung theory and quantum mechanical computation including the subbarrier region of $\alpha$-particle movement.