Bremsstrahlung emission during α\alpha-decay of 226Ra^{226}{\rm Ra}

We obtained the spectrum of probability of the bremsstrahlung emission accompanying the $\alpha$-decay of $^{226}{\rm Ra}$ (E$_{\alpha}$=4.8 MeV) by measuring the $\alpha$-$\gamma$ coincidences and using the model presented in our previous study on the $\alpha-$decay of $^{214}{\rm Po}$ (E$_{\alpha}$=7.7 MeV). We compare the experimental data with the quantum mechanical calculation and find a good agreement between theory and experiment. We discuss the differences between the photon spectra connected with the $\alpha$-decay of the $^{226}{\rm Ra}$ and $^{214}{\rm Po}$ nuclei. For the two mentioned nuclei we analyze the bremsstrahlung emission contributions from the tunneling and external regions of the nucleus barrier into the total spectrum, and we find the destructive interference between these contributions. We also find that the emission of photons during tunneling of the $\alpha$-particle gives an important contribution to the bremsstrahlung spectrum in the whole E$_{\gamma}$ energy range of the studied $^{226}$Ra nucleus

Multipolar model of bremsstrahlung accompanying proton-decay of nuclei

Emission of bremsstrahlung photons accompanying proton decay of nuclei is studied. The new improved multipolar model describing such a process is presented. The angular formalism of calculations of the matrix elements is stated in details. The bremsstrahlung probabilities for the $^{157}{\rm Ta}$, $^{161}{\rm Re}$, $^{167}{\rm Ir}$ and $^{185}{\rm Bi}$ nuclei decaying from the $2s_{1/2}$ state, the $^{109}_{53}{\rm I}_{56}$ and $^{112}_{55}{\rm Cs}_{57}$ nuclei decaying from the $1d_{5/2}$ state, the $^{146}_{69}{\rm Tm}_{77}$ and $^{151}_{71}{\rm Lu}_{80}$ nuclei decaying from the $0h_{11/2}$ state are predicted. Such spectra have orders of values similar to the experimental data for the bremsstrahlung photons emitted during the $\alpha$-decay. This indicates on real possibility to study bremsstrahlung photons during proton decay experimentally and perform further measurements.Comment: 14 pages, 6 figure

Search for P-odd time reversal noninvariance in nuclear processes

The scheme of search for time reversal noninvariance in nuclear processes based on the measurement of linear polarization of gamma radiation of a sample aligned by a preceding nuclear decay or by cryogenic means is presented