Table of experimental nuclear ground state charge radii: An update

Advances in atomic physics, such as cooling and trapping of atoms and molecules and developments in frequency metrology, have added orders of magnitude to the precision of atom-based clocks and sensors. Applications extend beyond atomic physics and this article reviews using these new techniques to address important challenges in physics and to look for variations in the fundamental constants, search for interactions beyond the standard model of particle physics, and test the principles of general relativity.

Search for New Physics with Atoms and Molecules

With the advent of high-energy-density (HED) experimental facilities, such as high-energy lasers and fast Z-pinch, pulsed-power facilities, millimeter-scale quantities of matter can be placed in extreme states of density, temperature, and/or velocity. This has enabled the emergence of a new class of experimental science, HED laboratory astrophysics, wherein the properties of matter and the processes that occur under extreme astrophysical conditions can be examined in the laboratory. Areas particularly suitable to this class of experimental astrophysics include the study of opacities relevant to stellar interiors, equations of state relevant to planetary interiors, strong shock-driven nonlinear hydrodynamics and radiative dynamics relevant to supernova explosions and subsequent evolution, protostellar jets and high Mach number flows, radiatively driven molecular clouds and nonlinear photoevaporation front dynamics, and photoionized plasmas relevant to accretion disks around compact objects such as black holes and neutron stars.

/pdf/experimental-astrophysics-with-high-power-lasers-and-z-2ws0p4rgie.pdf

Experimental astrophysics with high power lasers and Z pinches

One of the most significant developments in computational atomic and molecular physics in recent years has been the introduction of B-spline basis sets in calculations of atomic and molecular structure and dynamics. B-splines were introduced in applied mathematics more than 50 years ago, but it has been in the 1990s, with the advent of powerful computers, that the number of applications has grown exponentially. In this review we present the main properties of B-splines and discuss why they are useful to solve different problems in atomic and molecular physics. We provide an extensive reference list of theoretical works that have made use of B-spline basis sets up to 2000. Among these, we have focused on those applications that have led to the discovery of new interesting phenomena and pointed out the reasons behind the success of the approach.

https://iopscience.iop.org/article/10.1088/0034-4885/64/12/205/pdf

Applications of B-splines in atomic and molecular physics

A consistent set of nuclear rms charge radii: properties of the radius surface R(N,Z) ☆

Spectral lines from the 3s-3p 3 / 2 transitions in Na-like to P-like uranium have been measured at the Lawrence Livermore National Laboratory EBIT-I electron-beam ion trap facility. The measured x-ray energies are among the most accurate spectroscopic data available for highly charged heavy ions and provide important tests of relativistic atomic structure theory as well as bound-state quantum electrodynamic (QED) corrections in strong fields. Relativistic configuration-interaction (RCI) calculations based on the no-pair Hamiltonian with B-spline basis functions have been carried out to study these transitions. Our RCI energies, corrected by many-electron screened QED corrections also calculated here, yield theoretical results in very good agreement with experiment.

Transition energies of the3s−3p3/2resonance lines in sodiumlike to phosphoruslike uranium

Ratios of n=3-->1 intercombination to resonance line intensities for heliumlike ions with intermediate Z values

The formula for computing bound–bound X-ray absorption from unresolved ‘Super’-transition arrays is reformulated in terms of correlated occupation numbers, averaged over subensembles of the ideal grand canonical ensemble. These can be expressed as generalized Fermi factors which depend on the ratio of partition functions. A new algorithm for the computation of this ratio is presented, hybridizing recursion relations starting from full or empty super-shells with an exact relation numerically stable about the average occupation of the supershell.

A revised algorithm for the computation of super-transition array spectra of hot dense plasmas

The distorted-wave approximation and similar weak-coupling methods are frequently used to calculate electron collision cross sections for studies of astrophysical and laboratory plasmas. Autoionizing resonances neglected in these approximations can significantly enhance the calculated rates for collisional excitation of some transitions in highly charged ions. We investigated the effects of such resonances on the excitation rates for n = 2 to n = 2 transitions in fluorinelike Fe, Se, Mo, Ag, Xe, and Eu. The background excitation rates were calculated using a relativistic distorted-wave approximation, and the detailed Auger and radiative rates were calculated using a multiconfiguration Dirac-Fock model. The largest effect is on the electric-dipole-forbidden transitions. The enhancement diminishes with increasing atomic number for all transitions.

M. H. Chen

Papers

Transition energies of the3s−3p3/2resonance lines in sodiumlike to phosphoruslike uranium

Ratios of n=3-->1 intercombination to resonance line intensities for heliumlike ions with intermediate Z values

A revised algorithm for the computation of super-transition array spectra of hot dense plasmas

Resonance enhancement of electron collision rates for fluorinelike ions.

Trapped-Ion Technique for Measuring the Nuclear Charge Radii of Highly Charged Radioactive Isotopes [Phys. Rev. Lett. 76, 1031 (1996)]