Magnetic-dipole photo-recombination in ultracold hydrogen plasma

Abstract

The cross section of dipole-magnetic photodisintegration of the negative hydrogen ion has been calculated within the framework of an effective-range theory. The dipole-magnetic cross section of photodetachment within the very narrow range of energy near the process threshold dominates over the dipole-electric one. It has been shown that in ultracold hydrogen plasma at temperatures below kT=3.29•10 -4 K the dipole-magnetic photo-recombination becomes a main mechanism of electron capture by hydrogen atoms.

On the production of the positive antihydrogen ion ${{{\rm \bar{H}}}^{+}}$ via radiative attachment

“…In conclusion, we find that rates of + H formation using the radiative attachment approach will be very low, even with optimistic projections on trapped antihydrogen yields and cooling technique development. Inclusion of magnetic-dipole transitions [62] below × − 3 10 4 K will at most double observed rates. Thus, observation of reaction (1) will be difficult unless some way can be found of stimulating the process.…”

“…Recently, Baltenkov [62] has presented calculations of cross sections for the photoionization of H − via the magneticdipole mediated mechanism: these were found, except in a narrow energy region very close to the threshold (at a photon energy of λ hc 0 ), to be much smaller than their electric-dipole equivalents. For instance, the maximum cross section for the photo-magnetic process was found to be around × − 5 10 22 cm 2 at ν = h 1.1 eV (λ ≈ × 11.3 10 3 Å), or around five orders of magnitude lower than the photo-electric cross sections illustrated in figure 1.…”

Influence of electron correlations on double-capture process in proton–helium collisions

“…[2] It also plays a fundamental role in the absorption and emission of partially ionized hydrogen plasmas. [3] The fact that the negative hydrogen ion can be used as an efficient antioxidant in the human body expands the scope of its applications to biology; however, injection of negative hydrogen ions into high energy accelerators is one of its main applications. [4] Moreover, it can be used for the production of neutral beams of energetic hydrogen atoms for fusion devices.…”