New calculations for heavy-ion collisions with super-critical fields

  title={New calculations for heavy-ion collisions with super-critical fields},
  author={Edward Ackad and Marko Horbatsch},
An adaptation of the mapped Fourier grid method for the Dirac equation is applied to the problem of positron production in quasi-molecular collisions between fully stripped heavy ions with super-critical Coulomb fields. The resonance parameters for the 1S? vacancy which dives into the filled negative-energy continuum are calculated on the basis of the two similar analytic continuation methods of smooth exterior scaling and complex absorbing potential with Pad? extrapolation. Previous results in… Expand

Figures and Tables from this paper

Pair production in low-energy collisions of uranium nuclei beyond the monopole approximation
Abstract A method for calculation of electron-positron pair production in low-energy heavy-ion collisions beyond the monopole approximation is presented. The method is based on the numerical solvingExpand
Electron-positron pair production in slow collisions of heavy nuclei beyond the monopole approximation.
Electron-positron pair production in low-energy collisions of heavy nuclei is considered beyond the monopole approximation. The calculation method is based on the numerical solving of theExpand
Calculation of supercritical Dirac resonances in heavy-ion collisions
This resonance is similar in character to other resonances in atomic physics. It is parameterized by its energy and its lifetime. A numerical discretization technique, the mapped Fourier grid methodExpand
Calculation of electron-positron production in supercritical uranium-uranium collisions near the Coulomb barrier
The time-dependent Dirac equation was solved for zero-impact-parameter bare U-U collisions in the monopole approximation using a mapped Fourier grid matrix representation. A total of 2048 statesExpand
How to Observe the Vacuum Decay in Low-Energy Heavy-Ion Collisions.
It is shown that the vacuum decay can nevertheless be observed via impact-sensitive measurements of pair-production probabilities and the possibility of such an observation is demonstrated using numerical calculations of pair production in low-energy collisions of heavy nuclei. Expand
Implementation and validation of the relativistic transient absorption theory within the dipole approximation
A relativistic transient absorption theory is derived, implemented and validated within the dipole approximation based on the time-dependent Dirac equation. In the non-relativistic limit, it is foundExpand


Theory of positron production in heavy-ion collisions
Collisions of very heavy ions at energies close to the Coulomb barrier are discussed as a unique tool to study the behavior of the electron-positron field in the presence of strong extemalExpand
Positron production in heavy-ion collisions. II. Application of the formalism to the case of the U+U collision
The method developed in the preceding paper is applied to the calculation of the spectra of positrons produced in the U + U collision. Matrix elements of the radial derivative operator betweenExpand
Numerical treatment of the time-dependent Dirac equation in momentum space for atomic processes in relativistic heavy-ion collisions.
A numerical method for the solution of the time-dependent Dirac equation to describe atomic processes in relativistic heavy-ion collisions is presented and finds that the enhancement of bound-free pair production as compared to perturbation theory is much smaller than reported previously by others. Expand
Systematic studies of positron production in heavy-ion collisions near the Coulomb barrier
We present the results obtained from systematic studies of positron creation for a series of heavy-collision systems, with united chargeZu=Z1+Z2 ranging fromZu=164 (Pb + Pb) toZu=184 (U+U) atExpand
Positron production in crossed beams of bare uranium nuclei.
Positron creation in crossed-beam collisions of high-energy, fully stripped heavy ions is investigated within the coupled-channel formalism and the positron spectrum is shifted towards higher energies because of the absence of electron screening. Expand
Numerical calculation of supercritical Dirac resonance parameters by analytic continuation methods
170, since the lowest bound state becomes a resonance inthe negative energy continuum. We address the problem of computing the resonance parameters by extendingthe mapped Fourier grid method toExpand
Solution of the time-dependent Dirac equation by the finite difference method and application for Ca20++U91+
The Dirac equation for an electron moving in time-dependent electromagnetic fields is solved by the method of finite differences. For simplicity the solution is restricted to problems with aExpand
A new scaling law for electron emission in intermediate-energy heavy ion collisions
Abstract A new scaling law is presented for the emission of electrons in intermediate-energy heavy ion collisions. An improved formula is obtained which correctly describes electron emission also inExpand
Observation of Positron Creation in Superheavy Ion-Atom Collision Systems
We report the first observation of position in high-energy /sup 208/Pb + /sup 208/Pb collisions and establish that a dominant fraction of the positron yield is from nonnuclear origins. The excessExpand
Numerical solution of the Dirac equation by a mapped Fourier grid method
An efficient numerical method is developed to solve the relativistic hydrogenic Coulomb problem. Combining a pseudospectral method and a change of coordinates, a matrix representation of theExpand