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Related papers: Nuclear Reaction Rates in Dense Plasmas

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In fusion reactions, the Coulomb barrier selects particles from the high-momentum part of the distribution. Therefore, small variations of the high-momentum tail of the velocity distribution can produce strong effects on fusion rates. In…

Nuclear Theory · Physics 2009-11-11 Massimo Coraddu , Marcello Lissia , Giuseppe Mezzorani , Piero Quarati

Detailed calculations of the contribution from off-shell effects to the quasiclassical tunneling of fusing particles are provided. It is shown that these effects change the Gamow rates of certain nuclear reactions in dense plasma by several…

Statistical Mechanics · Physics 2009-10-31 V. I. Savchenko

The problem of determining the effects of the surrounding plasma on nuclear reaction rates in stars is formulated ab initio, using the techniques of quantum statistical mechanics. We derive a result that expresses the complete effects of…

Astrophysics · Physics 2008-11-26 Lowell S. Brown , R. F. Sawyer

The standard theory of nuclear fusion rates in a strongly interacting plasma can be (correctly) derived only when the energy release, Q, is large compared to other energies in the problem. We exhibit a result for rates that provides a basis…

Solar and Stellar Astrophysics · Physics 2010-05-25 R. F. Sawyer

We analyze the effect of plasma screening on nuclear reaction rates in dense matter composed of atomic nuclei of one or two types. We perform semiclassical calculations of the Coulomb barrier penetrability taking into account a radial mean…

Solar and Stellar Astrophysics · Physics 2009-08-20 A. I. Chugunov , H. E. De Witt

We compare Path Integral Monte Carlo calculations by Militzer and Pollock (Phys. Rev. B 71, 134303, 2005) of Coulomb tunneling in nuclear reactions in dense matter to semiclassical calculations assuming WKB Coulomb barrier penetration…

Astrophysics · Physics 2008-11-26 A. I. Chugunov , H. E. DeWitt , D. G. Yakovlev

Nuclear reaction rates in plasmas depend on the overlap (contact) probability of the reacting ions. Path integral Monte Carlo (PIMC) calculations are used here to determine these contact probabilities, g(0), for the one component plasma…

Statistical Mechanics · Physics 2007-05-23 B. Militzer E. L. Pollock

The Coulomb barrier is in general much higher than thermal energy. Nuclear fusion reactions occur only among few protons and nuclei with higher relative energies than Coulomb barrier. It is the equilibrium velocity distribution of these…

Nuclear Theory · Physics 2007-05-23 Jian-Miin Liu

Energy and momentum of the elementary excitations become independent variables in medium: energy and momentum statistical distributions are not identical. The momentum distribution and not the energy distribution is relevant for barrier…

Nuclear Theory · Physics 2016-11-23 M. Coraddu , M. Lissia , G. Mezzorani , P. Quarati

A study is made of the power-law tail effect in the quantum particle distribution over momentum on the nuclear fusion reactions. Our results do not support the idea of averaging the fusion reaction cross-section over the momentum…

Astrophysics · Physics 2008-05-29 Alexander L. Zubarev

This article illustrates how very small deviations from the Maxwellian exponential tail, while leaving unchanged bulk quantities, can yield dramatic effects on fusion reaction rates and discuss several mechanisms that can cause such…

Astrophysics · Physics 2009-11-13 Marcello Lissia , Piero Quarati

We argue that the Maxwellian approximation can essentially underestimate the rates of some nuclear reactions in hot plasma under conditions very close to thermal equilibrium. This phenomenon is demonstrated explicitly on the example of…

Plasma Physics · Physics 2009-11-13 Makoto Nakamura , Victor T. Voronchev , Yasuyuki Nakao

Explosive nuclear burning in astrophysical environments produces unstable nuclei which again can be targets for subsequent reactions. In addition, it involves a large number of stable nuclides which are not fully explored by experiments,…

Nuclear Theory · Physics 2017-08-23 T. Rauscher , C. Froehlich , K. H. Guber

Non-Maxwellian distributions are commonly observed across a wide range of systems and scales. While direct observations provide the strongest evidence for these distributions, they also manifest indirectly through their influence on…

Statistical Mechanics · Physics 2024-12-17 Kamel Ourabah

Nuclear reactions proceed differently in stellar plasmas than in the laboratory due to the thermal effects in the plasma. On one hand, a target nucleus is bombarded by projectiles distributed in energy with a distribution defined by the…

Solar and Stellar Astrophysics · Physics 2014-11-20 T. Rauscher

The effects of the highly damped modes in the energy and reaction rates in a plasma are discussed. These modes, with wavenumbers $k \gg k_{D}$, even being only weakly excited, with less than $k_{B}T$ per mode, make a significant…

Astrophysics · Physics 2008-11-26 Merav Opher , Luis O. Silva , Dean E. Dauger , Viktor K. Decyk , John M. Dawson

We study two different physical scenarios of thermonuclear reactions in stellar plasmas proceeding through a narrow resonance at low energy or through the low energy wing of a wide resonance at high energy. Correspondingly, we derive two…

Nuclear Theory · Physics 2009-11-10 F. Ferro , A. Lavagno , P. Quarati

A new general expression is derived for nuclear electron capture rates within dense plasmas. Its qualitative nature leads us to question some widely accepted assumptions about how to calculate the effects of the plasma on the rates. A…

Solar and Stellar Astrophysics · Physics 2011-07-04 R. F. Sawyer

The extremely small probability of quantum tunneling through an almost classical potential barrier may become not small under the action of the specially adapted nonstationary field. The tunneling rate has a sharp peak as a function of the…

Nuclear Theory · Physics 2007-05-23 Boris Ivlev

Plasmas in which there is a threshold for a dominant reaction to take place (such as recombination or attachment) will have particle distributions that evolve as the reaction progresses. The form of the Boltzmann collision term in such a…

Plasma Physics · Physics 2008-10-13 D A Diver , L F A Teodoro , C S MacLachlan , H E Potts
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