Cold temperatures invert product ratios in Penning ionisation reactions with argon

被引：11

作者：

Bibelnik, Natan ^{[1
]}

Gersten, Sasha ^{[1
]}

Henson, Alon B. ^{[1
]}

Lavert-Ofir, Etay ^{[1
]}

Shagam, Yuval ^{[1
,3
,4
]}

Skomorowski, Wojciech ^{[2
,5
]}

Koch, Christiane P. ^{[2
]}

Narevicius, Edvardas ^{[1
]}

机构：

[1] Weizmann Inst Sci, Dept Chem & Biol Phys, IL-76100 Rehovot, Israel

[2] Univ Kassel, Theoret Phys, Kassel, Germany

[3] NIST, JILA, Boulder, CO 80309 USA

[4] Univ Colorado, Dept Phys, Boulder, CO 80309 USA

[5] Univ Southern Calif, Dept Chem, Los Angeles, CA 90089 USA

来源：

MOLECULAR PHYSICS | 2019年 / 117卷 / 15-16期

基金：

以色列科学基金会; 欧盟第七框架计划;

关键词：

Branching ratio; cold collisions; merged beam; Penning ionisation; associative ionisation; SCATTERING; AR; MOLECULES; KR;

D O I：

10.1080/00268976.2019.1594421

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

In many chemical reactions with more than one possible outcome, the branching ratio is nearly constant over a wide range of collision energies. In barrierless systems governed by long-range interactions, however, the branching ratio is more sensitive to collision energy, and its dependence on it can be useful for better understanding the dynamics and reconstructing interaction potentials. Here we present the reaction rates of Penning and associative ionisation of metastable neon and helium with argon atoms. We obtain reaction rates in merge beam experiments, over a wide range of collision energies corresponding to that of room temperature, all the way down to a few millikelvins. We observe a change of two orders of magnitude in the branching ratio in the measured collision energy range and explain these changes using theoretical calculations. [GRAPHICS] .

引用

页码：2128 / 2137

页数：10

共 30 条

[1] Observation of enhanced rate coefficients in the H2+ + H2 → H3+ + H reaction at low collision energies [J].