69 research outputs found
Cooperative internal conversion process by proton exchange
A generalization of the recently discovered cooperative internal conversion
process is investigated theoretically. In the cooperative internal conversion
process by proton exchange investigated the coupling of bound-free electron and
proton transitions due to the dipole term of their Coulomb interaction permits
cooperation of two nuclei leading to proton exchange and an electron emission.
General expression of the cross section of the process obtained in the one
particle spherical nuclear shell model is presented. As a numerical example the
cooperative internal conversion process by proton exchange in is dealt
with. As a further generalization, cooperative internal conversion process by
heavy charged particle exchange and as an example of it the cooperative
internal conversion process by triton exchange is discussed. The process is
also connected to the field of nuclear waste disposal.Comment: arXiv admin note: text overlap with arXiv:1511.07164,
arXiv:1502.0147
Photo-induced nuclear cooperation
Reactions and especially the
reaction , called photo-induced nuclear cooperation and cooperative
spontaneous emission with neutron exchange, respectively, are
investigated theoretically. In the case of photo-induced nuclear cooperation it
is supposed that the energy of photons of the beam is less than the
binding energy of the deuteron. The cross section and the transition
probability per unit time, respectively, are determined with the aid of
standard second order perturbation calculation of quantum mechanics. The
calculations are extended to photo-induced nuclear cooperation and cooperative
spontaneous emission with proton exchange as well. With the aid of
the results obtained, recent observations of nuclear activity of samples of
large deuteron content after irradiation by photon-flux of photon energy
smaller than the deuteron binding energy are discussed
Effect of impurities on nuclear fusion
Modification of nuclear reactions due to impurities in plasma is
investigated. The hindering effect of Coulomb repulsion between reacting
particles, that is effective in direct reactions, can practically disappear if
Coulomb interaction of the reacting particles with impurities embedded in
plasma is taken into account. The change of the wavefunction of reacting
particles in nuclear range due to their Coulomb interaction with impurity is
determined using standard time independent perturbation calculation of quantum
mechanics. The result can be interpreted as if a slow, quasi-free particle
(e.g. a proton) were pushed by a heavy, assisting particle (impurity) of the
surroundings and can get (virtually) such a great magnitude of momentum which
significantly increases the nuclear contact probability density and also the
probability of its capture by an other nucleus. As a sample reaction the
process, called impurity assisted nuclear reaction is investigated and
the rate and power densities produced by the reaction are numerically
calculated. With the aid of astrophysical factors the rate and power densities
of the impurity assisted , , ,
% , ,
, ,
, ,
and
reactions are also estimated. The affect of plasma-wall interaction on the
process is also considered. A partial survey of impurity assisted nuclear
reactions which may have practical importance in energy production is also
presented
Resonance-like nuclear processes in solids: 3rd and 4th order processes
It is recognized that in the family of heavy charged particle and electron
assisted double nuclear processes resonance-like behavior can appear. The
transition rates of the heavy particle assisted 3rd-order and electron assisted
4th-order resonance like double nuclear processes are determined. The power of
low energy nuclear reactions in systems formed in placed in
gas environment is treated. Nuclear power produced by quasi-resonant electron
assisted double nuclear processes in these systems is calculated. The
power obtained tallies with experiments and its magnitude is considerable for
practical applications
Charged particle assisted nuclear reactions in solid state environment: renaissance of low energy nuclear physics
The features of electron assisted neutron exchange processes in crystalline
solids are survayed. It is stated that, contrary to expectations, the cross
section of these processes may reach an observable magnitude even in the very
low energy case because of the extremely huge increment caused by the Coulomb
factor of the electron assisted processes and by the effect of the
crystal-lattice. The features of electron assisted heavy charged particle
exchange processes, electron assisted nuclear capure processes and heavy
charged particle assisted nuclear processes are also overviewed. Experimental
observations, which may be related to our theoretical findings, are dealt with.
The anomalous screening phenomenon is related to electron assisted neutron and
proton exchange processes in crystalline solids. A possible explanation of
observations by Fleischmann and Pons is presented. The possibility of the
phenomenon of nuclear transmutation is qualitatively explained with the aid of
usual and charged particle assisted reactions. The electron assisted neutron
exchange processes in pure and composite systems (in the
Rossi-type E-Cat) are analyzed and it is concluded that these reactions may be
responsible for recent experimental observations.Comment: arXiv admin note: text overlap with arXiv:1312.549
Electron assisted reactions in metals
The electron assisted low energy reactions in deuterized metals are
investigated. It is shown that if a metal is irradiated with slow, free
deuterons then the and \ electron assisted processes will have measurable
probabilities even in the case of slow deuterons. The cross sections and the
yields in an irradiated sample are determined. The results are associated with
the so called anomalous screening effect. It is concluded that the electron
processes have to be taken into account when evaluating the experimental
data of low energy fusion reactions in metals
Near threshold laser-modified proton emission in nuclear photoeffect
The change of the probability of proton emission in nuclear photoeffect due
to an intense coherent (laser) field is discussed near the threshold, where the
hindering effect of the Coulomb field of the remainder nucleus is essential.
The ratio of laser-assisted and laser free differential cross section is
deduced and found to be independent of the polarization state of the
field and the two types of initial nuclear state considered. The numerical
values of this ratio are given at some characteristic parameters of the intense
field.Comment: 4 pages, 4 figure
Electron assisted neutron exchange process in solid state environment
Electron assisted neutron exchange process in solid state environment is
investigated. It is shown that if a metal is irradiated with free electrons
then the
electron assisted neutron
exchange process has measurable probability even in the case of slow electrons
of energy much less than the reaction energy . The transition
probability per unit time, the cross section of the process and the yield in an
irradiated sample are determined in the Weisskopf and long wavelength
approximations and in the single particle shell model. Numerical data for the
and the
electron assisted neutron
exchange reactions are also presented
Nuclear processes in solids: basic 2nd-order processes
Nuclear processes in solid environment are investigated. It is shown that if
a slow, quasi-free heavy particle of positive charge interacts with a "free"
electron of a metallic host, it can obtain such a great magnitude of momentum
in its intermediate state that the probability of its nuclear reaction with an
other positively charged, slow, heavy particle can significantly increase. It
is also shown that if a quasi-free heavy particle of positive charge of
intermediately low energy interacts with a heavy particle of positive charge of
the solid host, it can obtain much greater momentum relative to the former case
in the intermediate state and consequently, the probability of a nuclear
reaction with a positively charged, heavy particle can even more increase. This
mechanism opens the door to a great variety of nuclear processes which up till
know are thought to have negligible rate at low energies. Low energy nuclear
reactions allowed by the Coulomb assistance of heavy charged particles is
partly overviewed. Nuclear and reactions are investigated
numerically. It was found that the leading channel in all the discussed charged
particle assisted reactions is the electron assisted
process
Laser-assisted nuclear photoeffect reexamined
The S-matrix element and the cross section of the laser-assisted nuclear
photoeffect are recalculated in a gauge invariant manner taking into account
the effect of the Coulomb field of the remainder nucleus. The \gamma-photon
energy dependence of the laser free cross section obtained in the plane wave
and long-wavelength Coulomb-Volkov approximations are compared. Numerically the
laser-assisted partial cross sections with laser photon energy 2 keV and some
different polarization states of \gamma-photon of energy 3 MeV are
investigated.Comment: 12 pages, 4 figure
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