Angular and energy analysis of HeH+ products from the charge exchange excitation reaction

Observation of D2H+ (or H2D+) products in coincidence with excited H* (or D*) atoms in the reaction of D2+ with H2

“…The most important finding is that reactions ͑͑3a͒ and ͑3b͒͒, and more generally ͑2͒, actually exist. Still, the long accumulation times necessary to detect the products show that their differential cross sections are very low, probably lower than that found 7,8 for the production of HeH ϩ ϩH* in reaction ͑1͒. Contrary to that reaction, the products are spread over a few (u,) islands.…”

“…For r 1 ϭr x , the system follows this promoted curve with an average probability of 50% ͑as compared with a nearly 100% probability for the He ϩ ϩH 2 (r e ) system͒. [6][7][8] In the same way as for process ͑1͒ it can thus reach curve crossings leading to charge transferexcitation, excitation, and plausibly to the products of reaction ͑2͒.…”

“…One of the reasons is of course the small values of T , due themselves in particular to small values of the intermolecular distances where PES crossings could arise, at high energy. [6][7][8] We have recently performed one of such studies in the E cm ϭ9 -34 eV range. 7 It concerned the reaction…”

“…[6][7][8] We have recently performed one of such studies in the E cm ϭ9 -34 eV range. 7 It concerned the reaction…”

“…6,7 Reaction ͑1͒ is the outcome of two-electron transitions at the mentioned PES crossings: a charge exchange-excitation takes place first and is then followed by proton transfer. Owing to the existence of these crossings, the measured differential cross section (u,) is strongly localized in the HeH ϩ center-of-mass velocity ͑u͒ and scattering angle ͑͒.…”