Energy distributions of He+ and He-2(+) ions formed in ultracold He(2 S-3(1))+He(2 P-3(2)) collisions

Article

Energy distributions of He+ and He-2(+) ions formed in ultracold He(2 S-3(1))+He(2 P-3(2)) collisions

Pieksma, M; Čížek, M; Thomsen, JW; van der Straten, P; Niehaus, A

Phys. Rev. A 66(2), 022703 (2002)

Abstract

Energy distributions of He+ and He-2(+) ions produced in ultracold He(2 S-3(1))+He(2 P-3(2)) collisions are presented. These helium metastable atoms are trapped and cooled in a magneto-optical trap, and have a temperature of 1.1+/-0.2 mK. Initial kinetic energies of the product He+ and He-2(+) ions are analyzed in energy, using a weak electrostatic extraction field in combination with a time-of-flight technique. A pronounced structure is observed in the He+ ion distribution, which can be well explained by a theoretical model that considers the avoided crossings between only three metastable (3)Sigma(g)(+) states of the transient He-2 molecule. The measured He-2(+) distribution has a width that is consistent with the maximum recoil energy of 1.1 meV.

Institute authors

Čížek, Martin

Supported by

GACR 203/00/D111 — Generalisation of non-local resonance theory and calculation of cross sections for resonance processes in small molecules

BibTeX

@article{UTF67,
  author        = {Pieksma, M and Čížek, M and Thomsen, JW and van der Straten, P and Niehaus, A},
  title         = {{Energy distributions of He+ and He-2(+) ions formed in ultracold He(2 S-3(1))+He(2 P-3(2)) collisions}},
  journal       = {Phys. Rev. A},
  publisher     = {AMERICAN PHYSICAL SOC},
  address       = {ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA},
  volume        = {66},
  number        = {2},
  pages         = {022703},
  year          = {2002},
  url           = {http://utf.mff.cuni.cz/\textasciitilde{}cizek/naseclanky/pctsn02.pdf},
}