Experimental studies of the dissociative recombination for CD3CDOD+ and CH3CH2OH2+

• Aims:  Determination of branching fractions, cross sections and thermal rate constants for the dissociative recombination of CD3CDOD+ and CH3CH2OH2+ at the low relative kinetic energies encountered in the interstellar medium. Methods: The experiments were carried out by merging an ion and electron beam at the heavy ion storage ring CRYRING, Stockholm, Sweden. Results: Break-up of the CCO structure into three heavy fragments is not found for either of the ions. Instead the CCO structure is retained in 23 ± 3% of the DR reactions of CD3CDOD+ and 7 ± 3% in the DR of CH3CH2OH2+, whereas rupture into two heavy fragments occurs in 77 ± 3% and 93 ± 3% of the DR events of the respective ions. The measured cross sections were fitted between 1-200 meV yielding the following thermal rate constants and cross-section dependencies on the relative kinetic energy: σ(Ecm[eV]) = 1.7 ± 0.3 × 10−15(Ecm[eV])−1.23±0.02 cm2 and k(T) = 1.9 ± 0.4 × 10−6(T/300)−0.73±0.02 cm3s−1 for CH3CH2OH2+  as well as k(T) = 1.1 ± 0.4 × 10−6(T/300)−0.74±0.05 cm3s−1 and σ(Ecm[eV]) = 9.2 ± 4 × 10−16(Ecm[eV])−1.24±0.05 cm2 for CD3CDOD+.

Ämnesord

NATURVETENSKAP  -- Fysik -- Atom- och molekylfysik och optik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Atom and Molecular Physics and Optics (hsv//eng)

Nyckelord

Astrochemistry - Molecular processes - Plasmas - Methods: laboratory - Methods: N-body simulations - ISM: clouds

Molecular physics

Molekylfysik

kemisk fysik

Chemical Physics

Publikations- och innehållstyp

vet (ämneskategori)

ovr (ämneskategori)