Study of radiative recombination into deuterium Rydberg states

Biedermann, C.; Gao, Hui; Schuch, R.; Zong, W.; Asp, S.; DeWitt, D. R.; Kuiper, H.

doi:10.1088/0953-4075/28/3/020

Cited by 13 publications

(3 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…T , and the measured RR rates are very sensitive to T ⊥ . The sensitivity of the RR rates has been examined in detail by Biedermann et al (1995). It was noted that possible enhancement of the RR rates is possible with T ⊥ closer to the value for T , where usually T ⊥ T .…”

Section: Radiative Recombinationmentioning

confidence: 99%

Electron - ion recombination processes - an overview

1997

View full text Add to dashboard Cite

Extensive theoretical and experimental studies have been carried out for the past 20 years on electron-ion recombination processes, as they are applied to the analysis of astrophysical and laboratory plasmas. We review the basic understanding gained through these efforts, with emphasis on some of the more recent progress made in recombination theory as the recombining system is affected by time-dependent electric fields and plasma particles at low temperature. Together with collisional ionization and excitation processes, recombination is important in determining ionization balance and excited-state population in non-equilibrium plasmas. The radiation emitted by plasmas is usually the principal medium with which to study the plasma condition, as it is produced mainly during the recombination and decay of excited states of ions inside the plasma. This is especially true when the plasma under study is not readily accessible by direct probes, as in astrophysical plasmas. Moreover, external probes may sometimes cause undesirable disturbances of the plasma.Electron-ion recombination proceeds in several different modes. The direct modes include three-body recombination (TBR) and one-step radiative recombination (RR), all to the ground-and singly-excited states of the target ions. By contrast, the indirect resonant mode is a two-step dielectronic recombination (DR), which proceeds first with the formation of doubly-excited states by radiationless excitation/capture. The resonant states thus formed may relax by autoionization and/or radiative cascades. For more exotic modes of recombination, we consider off-shell dielectronic recombination (radiative DR = RDR), in which an electron capture is accompanied by simultaneous radiative emission and excitation of the target ion. Some discussion on attachment of electrons to neutral atoms, resulting in the formation of negative ions, is also given.When resonance states involve one or more electrons in high Rydberg states, presence of an external or intrinsic electric field in the vicinity of the target ions can seriously affect the ionic states involved and the resulting reaction rates. Such perturbative fields can be intrinsic, as in the case of the plasma ion field, or externally imposed. A proper theoretical treatment of this difficult problem is crucial in understanding the recombination process which takes place in a field contaminated environment. The simple off-shell dressing procedure of high Rydberg states by a time-dependent field is reviewed, and the possibility of an anomalously large enhancement in the rates, due to the momentum coherence effect (MCE), is discussed.

show abstract

Section: Radiative Recombinationmentioning

confidence: 99%

Electron - ion recombination processes - an overview

1997

View full text Add to dashboard Cite

show abstract

“…where q is the charge state, v i the ion beam velocity, and B the magnetic field strength in the unit of T. In this experiment, the n dip is estimated to be 165 corresponding to the magnetic rigidity value of 1.17 Tm of the dipole magnet. We note that rather sophisticated and detailed studies on the re-ionization of high excited states in magnetic fields have been reported [51][52][53] pointing out the relevance of low-l levels at high Rydberg states which are not field ionized. Indeed even in our current experiment related cascade transitions could be possible during flight time of ions to the dipole magnet.…”

Section: The Experimentsmentioning

confidence: 83%

X-ray emission associated with radiative recombination for Pb$^{82+}$ ions at threshold energies

Zhu,

Gumberidze,

Over

et al. 2022

Preprint

View full text Add to dashboard Cite

For bare lead ions, decelerated to the low beam energy of 10 MeV/u, the x-ray emission associated with radiative recombination (RR) at "cold collision" conditions has been studied at the electron cooler of CRYRING@ESR at GSI-Darmstadt. Utilizing dedicated x-ray detection chambers installed at 0°and 180°observation geometry, we observed for the very first time for stored ions the full x-ray emission spectrum associated with RR under electron cooling conditions. Most remarkably, no line distortion effects due to delayed emission are present in the well resolved spectra, spanning over a wide range of x-ray energies (from about 5 to 100 keV) which enable to identify fine-structure resolved Lyman, Balmer as well as Paschen x-ray lines along with the RR transitions into the K-, L and M-shell of the ions. To compare with theory, an elaborate theoretical model has been applied. By considering the relativistic atomic structure of Pb 81+ , this model is based on a sophisticated computation of the initial population distribution via RR for all atomic levels up to Rydberg states with principal quantum number n = 165 in combination with cascade calculations based on timedependent rate equations. Within the statistical accuracy, the experimental x-ray line emission is in very good agreement with the results of the theoretical model applied. Most notably, this comparison sheds light on the contribution of prompt and delayed X-ray emission (up to 70 ns) to the observed X-ray spectra, originating in particular from Yrast transitions into inner shells.

show abstract

“…Some of the more recent studies of this type have been performed at the Test Storage Ring at Heidelberg [158] and at the CRYRING storage ring in Stockholm [192,193]. It has been found that at least for singly charged ions, the rates of atom production, even into quite highly excited states [194], can be adequately described by equation (9).…”

Section: Radiative Recombination In Storage Ringsmentioning

confidence: 99%

Ultra-low energy antihydrogen

Holzscheiter

Charlton

1999

Rep. Prog. Phys.

View full text Add to dashboard Cite

The study of CPT invariance with the highest achievable precision in all particle sectors is of fundamental importance for physics. Equally important is the question of the gravitational acceleration of antimatter.In recent years, impressive progress has been achieved at the Low-Energy Antiproton Ring (LEAR) at CERN in capturing antiprotons in specially designed Penning traps, in cooling them to energies of a few milli-electron volts, and storing them for hours in a small volume of space. Positrons have been accumulated in large numbers in similar traps, and low-energy positron or positronium beams have been generated. Finally, steady progress has been made in trapping and cooling neutral atoms. Thus the ingredients to form antihydrogen at rest are at hand. This report will describe the techniques available to produce, decelerate, and accumulate antiprotons at low energy, how to generate high-density plasmas of low-energy positrons, and how to combine these two species into antihydrogen.Once antihydrogen atoms have been formed, they can be captured in magnetic gradient traps and standard spectroscopic methods applied to interrogate their atomic structure with extremely high precision for comparison with the hydrogen atom. In particular, the 1S-2S transition, with a lifetime of the excited state of 122 ms and thereby a natural linewidth of five parts in 10 16 , offers in principle the possibility to directly compare matter and antimatter properties at a level of one part in 10 18 . Other quantities of interest, such as the hyperfine structure splitting of the ground state, will also be discussed.Finally, we will give a brief outlook into the future and comment on some of the possible antiproton facilities which could be used to continue this field of research well into the next century.

show abstract

Study of radiative recombination into deuterium Rydberg states

Cited by 13 publications

References 14 publications

Electron - ion recombination processes - an overview

Electron - ion recombination processes - an overview

X-ray emission associated with radiative recombination for Pb$^{82+}$ ions at threshold energies

Ultra-low energy antihydrogen

Contact Info

Product

Resources

About