TY - JOUR

T1 - The leading correction to the Thomas–Fermi model at finite temperature

AU - Segev, Eyal

AU - Gazit, Doron

N1 - Publisher Copyright:
© 2018 Elsevier B.V.

PY - 2019/3/15

Y1 - 2019/3/15

N2 - The semi-classical approach leading to the Thomas–Fermi (TF) model provides a simple universal thermodynamic description of the electronic cloud surrounding the nucleus in an atom. This model is known to be exact at the limit of Z→∞ i.e., infinite nuclear charge, at finite density and temperature. Motivated by the zero-temperature case, we show in the current paper that the correction to TF due to quantum treatment of the strongly bound inner-most electrons, for which the semi-classical approximation breaks, scales as Z−1∕3, with respect to the TF solution. As such, it is more dominant than the quantum corrections to the kinetic energy, as well as exchange and correlation, which are known to be suppressed by Z−2∕3. We conjecture that this is the leading correction for this model. In addition, we present a different free energy functional for the TF model, and a successive functional that includes the strongly bound electrons correction. We use this corrected functional to derive a self-consistent potential and the electron density in the atom, and to calculate the corrected energy. At this stage, our model has a built-in validity limit, breaking as the L shell ionizes.

AB - The semi-classical approach leading to the Thomas–Fermi (TF) model provides a simple universal thermodynamic description of the electronic cloud surrounding the nucleus in an atom. This model is known to be exact at the limit of Z→∞ i.e., infinite nuclear charge, at finite density and temperature. Motivated by the zero-temperature case, we show in the current paper that the correction to TF due to quantum treatment of the strongly bound inner-most electrons, for which the semi-classical approximation breaks, scales as Z−1∕3, with respect to the TF solution. As such, it is more dominant than the quantum corrections to the kinetic energy, as well as exchange and correlation, which are known to be suppressed by Z−2∕3. We conjecture that this is the leading correction for this model. In addition, we present a different free energy functional for the TF model, and a successive functional that includes the strongly bound electrons correction. We use this corrected functional to derive a self-consistent potential and the electron density in the atom, and to calculate the corrected energy. At this stage, our model has a built-in validity limit, breaking as the L shell ionizes.

KW - Finite temperature

KW - Plasma

KW - Thomas–Fermi model

UR - http://www.scopus.com/inward/record.url?scp=85058018258&partnerID=8YFLogxK

U2 - 10.1016/j.physa.2018.11.010

DO - 10.1016/j.physa.2018.11.010

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AN - SCOPUS:85058018258

SN - 0378-4371

VL - 518

SP - 158

EP - 168

JO - Physica A: Statistical Mechanics and its Applications

JF - Physica A: Statistical Mechanics and its Applications

ER -