[en] Discovery of superconducting materials that operate at high temperatures revives interest in the use of rf field for plasma confinement. This paper discusses feasibility of a scheme where resonant rf cavities are attached to the mirror ends of an open system for plasma confinement. 9 refs., 9 figs

[en] The authors present a theoretical study of the isotope separation by means of isotopically selective ion cyclotron resonance plasma heating (ICRH). The special attention is devoted to the separation of gadolinium isotopes. The ions are supposed to pass through the device shown on Fig. 1 where they are heated by the full-turn-loop antenna that excites RF field with azimuthal number m = 0. They calculate the distribution function of ions in a plasma stream at the orifice of the device. A satisfactory separation is achieved for the following values of parameters. The length of heating zone ell = 200 cm, initial temperature of plasma stream T_parallel = 5 eV, T_{perpendicular} = 60 eV, the plasma radius a = 10 cm, plasma density n = 10¹² cm^-3, external magnetic field B = 30 kGs. The energy of resonance ions W = 100 divided-by 200 eV. The latter value is achieved if a current in the antenna loops is equal to 60A with full number of loops N = 150. With the specified parameters, the current in the plasma stream is equal to 15 divided-by 20A. Then the production rate equals to 100 kg of Gd¹⁵⁷ per year. Energy of Gd's ions after pass through the heating zone vs. their axial velocity

[en] In recent experiments ultracold plasmas were produced by photoionizing small clouds of laser cooled atoms. This paper presents the results of molecular dynamic simulations for the early time evolution of such plasmas. Contrary to earlier speculation, no evidence of strong electron-electron correlations is observed in the simulations even if the initial value of the coupling parameter (Γ_e=e²/akT_e) is much larger than unity. As electron-electron correlations begin to develop, the correlation energy is released to heat the electrons, raising the electron temperature to the point where Γ_e∼1 and limiting further development of correlation. Further heating of the electrons occurs as a by-product of three-body recombination. When a model of laser cooling is added to the simulation, the formation of strong ion-ion correlation is observed. Contrary to earlier suggestion, the rate of three-body recombination is observed to be in reasonable agreement with the traditional formula, R=3.9x10^-9 s^-1[n(cm^-3)]²[T_e(K)]^-9/2, but care must be taken to use the correct temporally evolving temperature, T_e. The simulations are challenging because it is necessary to follow three-body recombination into weakly bound (high n quasiclassical) Rydberg states, and the time scale for such states is short compared to that for the plasma dynamics. This kind of problem was faced earlier in computational astrophysics when studying binary star formation in globular clusters and the simulation method used here is adapted from such studies

[en] The ApparaTus for High precision Experiment on Neutral Antimatter and antihydrogen TRAP collaborations have produced antihydrogen atoms by recombination in a cryogenic antiproton-positron plasma. This paper discusses the motion of the weakly bound atoms in the electric and magnetic field of the plasma and trap. The effective electric field in the moving frame of the atom polarizes the atom, and then gradients in the field exert a force on the atom. An approximate equation of motion for the atom center of mass is obtained by averaging over the rapid internal dynamics of the atom. The only remnant of the atom internal dynamics that enters this equation is the polarizability for the atom. This coefficient is evaluated for the weakly bound and strongly magnetized (guiding center drift) atoms understood to be produced in the antihydrogen experiments. Application of the approximate equation of motion shows that the atoms can be trapped radially in the large space charge field near the edge of the positron column. Also, an example is presented for which there is full three-dimensional trapping, not just radial trapping. Even untrapped atoms follow curved trajectories, and such trajectories are discussed for the important class of atoms that reach a field ionization diagnostic. Finally, the critical field for ionization is determined as an upper bound on the range of applicability of the theory

[en] In recent experiments, ultracold plasmas were produced by photoionizing small clouds of laser-cooled atoms. It has been suggested that the low initial temperature of these novel plasmas leads directly to strong correlation and order. In contrast, we argue that rapid intrinsic heating raises the electron temperature to the point where strong correlation cannot develop. The argument is corroborated by a molecular-dynamics simulation of the early-time plasma evolution

[en] Very weakly bound electron-ion pairs in a strong magnetic field are called guiding center drift atoms, since the electron dynamics can be treated by guiding center drift theory. Over a wide range of weak binding, the coupled electron-ion dynamics for these systems is integrable. This paper discusses the dynamics, including the important cross magnetic field motion of an atom as a whole, in terms of the system constants of the motion. Since the dynamics is quasi-classical, quantum numbers are assigned using the Bohr-Sommerfeld rules. Antimatter versions of these guiding center drift atoms likely have been produced in recent experiments

[en] A theory is presented of the separation of isotopes of heavy elements by selective heating of a plasma consisting of the ions of an element of interest. The results are presented from calculations of inductive heating of a plasma containing Gd ions with the help of a solenoidal antenna that excites a high-frequency field with azimuthal number m=0

[en] The production rate of an ICR isotope separator is analyzed as a function of the ratio between the antenna length and the length of the heating region. The axial dependence is found of the RF field of a full-turn-loop antenna that excites an RF field with the azimuthal number m=0. The fractions are calculated of the isotopes that are collected at the exit of the separator by means of an element with a curvilinear magnetic field