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Related papers: Time scales for fission at finite temperature

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Cross-section and neutron-emission data from heavy-ion fusion-fission reactions are consistent with the fission of fully equilibrated systems with fission lifetime estimates obtained via a Kramers-modified statistical model which takes into…

Nuclear Theory · Physics 2009-12-31 J. P. Lestone , S. G. McCalla

Based on a stochastic model for intermittent fluctuations in the boundary region of magnetically confined plasmas, an expression for the level crossing rate is derived from the joint distribution of the process and its derivative. From this…

Plasma Physics · Physics 2018-05-04 Audun Theodorsen , Odd Erik Garcia

The Kramers problem in the energy-diffusion limited regime of very low friction is difficult to deal with analytically becasue of the repeated recrossings of the barrier that typically occur before an asymptotic rate constant is achieved.…

Statistical Mechanics · Physics 2009-10-31 Jose M. Sancho , Aldo H. Romero , Katja Lindenberg

A known limitation of time-dependent mean-field approaches is a lack of quantum tunneling for collective motions such as in sub-barrier fusion reactions. As a first step toward a solution, a time-dependent model is considered using a…

Nuclear Theory · Physics 2022-02-01 Akira Ono

This paper discusses a modified penetration theory where the time scale for the momentum wall layer is based on the onset of ejections from the wall but the time scale for the thermal layer is based on the unsteady state diffusion of heat…

Fluid Dynamics · Physics 2010-09-14 Trinh Khanh Tuoc

We consider the mean first passage time of a random walker moving in a potential landscape on a finite interval, starting and end points being at different potentials. From analytical calculations and Monte Carlo simulations we demonstrate…

Statistical Mechanics · Physics 2015-06-04 Vladimir V. Palyulin , Ralf Metzler

Coulomb fission mechanism may take place if the maximum Coulomb-excitation energy transfer in a reaction exceeds the fission barrier of either the projectile or target. This condition is satisfied by all the reactions used for the earlier…

We examine what role do collisions with the wall play in neutron-antineutron transitions. The collision time for $n$ and $\bar{n}$ and the phase difference between reflected $n$ and $\bar{n}$ waves are calculated. It is shown that…

High Energy Physics - Phenomenology · Physics 2019-06-26 Boris O. Kerbikov

Cross-section and neutron-emission data from heavy-ion fusion-fission reactions are consistent with a Kramers-modified statistical model which takes into account the collective motion of the system about the ground state; the temperature…

Nuclear Theory · Physics 2008-11-26 S. G. McCalla , J. P. Lestone

We study noise induced thermally activated barrier crossing of a Brownian particle that hops in a periodic ratchet potential where the ratchet potential is coupled with a spatially uniform temperature. The viscous friction is considered to…

Statistical Mechanics · Physics 2016-09-27 Solomon Fekade Duki , Mesfin Asfaw Taye

Thermally activated phenomena in physics and chemistry, such as conformational changes in biomolecules, liquid film rupture, or ferromagnetic field reversal, are often associated with exponentially long transition times described by…

Statistical Mechanics · Physics 2024-09-20 Jingbang Liu , James E. Sprittles , Tobias Grafke

We calculate the time taken by a wave packet to travel through a classically forbidden region of space in space fractional quantum mechanics. We obtain the close form expression of tunneling time from a rectangular barrier by stationary…

Quantum Physics · Physics 2019-08-06 Mohammad Hasan , Bhabani Prasad Mandal

Transient {\it time-domain resonances} found recently in time-dependent solutions to Schr\"{o}dinger's equation are used to investigate the issue of the tunneling time in rectangular potential barriers. In general, a time frequency analysis…

Quantum Physics · Physics 2016-08-16 Gastón García-Calderón , Jorge Villavicencio

The question of how long a particle takes to pass through a potential barrier is still a controversial topic in quantum mechanics. Arguably, the main theoretical problem in obtaining estimates for measurable times is the fact that…

Quantum Physics · Physics 2018-09-19 Ricardo Ximenes , Fernando Parisio , Eduardo O. Dias

Characteristic features of tunneling times for dissipative tunneling of a particle through a rectangular barrier are studied within a semiclassical model involving dissipation in the form of a velocity dependent frictional force. The…

Quantum Physics · Physics 2017-05-15 N. G. Kelkar , D. Lozano Gómez , Edgar J. Patiño

Efficiency of a Brownian particle moving along the axis of a three-dimensional asymmetric periodic channel is investigated in the presence of a symmetric unbiased force and a load. Reduction of the spatial dimensionality from two or three…

Statistical Mechanics · Physics 2009-11-13 Bao-quan Ai , Hui-zhang Xie , Liang-gang Liu

In the scenario of the narrow escape problem (NEP) a particle diffuses in a finite container and eventually leaves it through a small "escape window" in the otherwise impermeable boundary, once it arrives to this window and over-passes an…

Statistical Mechanics · Physics 2020-01-03 D. S. Grebenkov , R. Metzler , G. Oshanin

The first-passage time is proposed as an independent thermodynamic parameter of the statistical distribution that generalizes the Gibbs distribution. The theory does not include the determination of the first passage statistics itself. A…

Statistical Mechanics · Physics 2022-08-22 V. V. Ryazanov

The classical theory of chemical reactions can be understood in terms of diffusive barrier crossing, where the rate of a reaction is determined by the inverse of the mean first passage time (FPT) to cross a free energy barrier. Whenever a…

Statistical Mechanics · Physics 2019-11-22 David Hartich , Aljaz Godec

The mean first-passage time (MFPT) for a Brownian particle to surmount a potential barrier of height $\Delta U$ is a fundamental quantity governing a wide array of physical and chemical processes. According to the Arrhenius Law, the MFPT…

Statistical Mechanics · Physics 2025-11-24 Vishwajeet Kumar , Ohad Shpielberg , Arnab Pal