Bremsstrahlung radiation by a tunneling particle: A time-dependent description

Abstract

We study the bremsstrahlung radiation of a tunneling charged particle in a time-dependent picture. In particular, we treat the case of bremsstrahlung during alpha-decay, which has been suggested as a promissing tool to investigate the problem of tunneling times. We show deviations of the numerical results from the semiclassical estimates. A standard assumption of a preformed particle inside the well leads to sharp high-frequency lines in the bremsstrahlung emission. These lines correspond to "quantum beats" of the internal part of the wavefunction during tunneling arising from the interference of the neighboring resonances in the well.

Accurate numerical solutions of the time-dependent Schrödinger equation

“…Realistic systems need to be solved numerically. Long-time calculations are required for systems which require both nuclear and atomic time-scales such as ionization and bremsstrahlung due to radioactive decay of the nucleus of an atom [2,3,5]. To study the short-time anomalous power law behavior of the decay and the long-time inverse-power law behavior the method of this paper is appropriate.…”

“…Examples of these include the study of nuclear processes such as the decay of unstable nuclei and associated phenomena like atomic ionization [1,2] and bremsstrahlung [3,4,5], the study of fundamental processes necessary for quantum computing [6], the study of mesoscopic physics or nanophysics devices [7], and the motion of atoms in a trap. A reliable and accurate numerical determination of the time-dependent wave function such as we discuss in this paper will no doubt be necessary and/or helpful in making advances in the understanding of a variety of quantum processes.…”

Multipolar Approach for Description of Bremsstrahlung During α -Decay and Unified Formula of the Bremsstrahlung Probability

“…Enough well description of experimental data has already been achieved in such approach, where one can note a resent success in agreement between theory and experiment for the controversial nucleus 210 Po [8,9]. Perspectives are certain in study of dynamics of the α-decay with some analysis of the bremsstrahlung [5,10,11], in study of dynamics of tunneling in the α-decay [12,13,14,15], in research of peculiarities of the polarized bremsstrahlung during α-decay and influence of electron shells on it [16], in effect [17] called as Münchhausen effect which increases penetrability of the barrier due to charged-particle emission during its tunneling and which could be interesting for further study of the photon bremsstrahlung during tunneling in the α-decay. However, the fully quantum approach (starting from [18] and then [19,20]) seems to be the most accurate and motivated from the physical point of view in description of emission of photons, to be the richest in study of quantum properties and new effects.…”

“…Many approaches for description of the bremsstrahlung emission during the α-decay have already been developed where models with semiclassical spherically symmetric description of the α-decay are prevailing (see [3,4,5,6], also calculations of the spectra see in [7]). In comparison with fully quantum approach, the semiclassical one allows to work with characteristics and parameters, physical sense of which is natural that simplifies this task, allowing to understand studied questions easier.…”

New enhanced tunneling in nuclear processes

“…[1,2], and references therein). The recent interest in understanding the processes of underbarrier tunneling [3][4][5][6][7][8][9][10][11] has been stimulated by the calculation of bremsstrahlung radiation in ␣ decay when the ␣ particle is moving under the barrier [12]. In this paper we consider another feature of quantum tunneling: the possible enhancement of nuclear decay due to interactions with low energy charged particles.…”