Effect of rotational excitation of H-2 on isotopic exchange reaction with OD- at low temperatures

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F18%3A10386161" target="_blank" >RIV/00216208:11320/18:10386161 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1051/0004-6361/201833264" target="_blank" >https://doi.org/10.1051/0004-6361/201833264</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/201833264" target="_blank" >10.1051/0004-6361/201833264</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Effect of rotational excitation of H-2 on isotopic exchange reaction with OD- at low temperatures

Popis výsledku v původním jazyce

Aims. This paper presents experimentally obtained rate coefficients for the weakly endothermic reaction OD- + H-2 -&gt; OH- + HD with ortho- and para-hydrogen at astrophysically relevant temperatures between 10 and 300 K. Methods. The reaction was studied with normal and para-enriched (99.5% para-H-2) hydrogen in a 22-pole ion trap. The measured temperature dependencies of reaction rate coefficients are analyzed using a model which assumes that the rotational energies of the two reactants are equivalent to the translational energy in driving the reaction. Results. At room temperature, the rate coefficients of reactions with both nuclear spin variants reach 7 x10(-11) cm(3) s(-1), which is in good agreement with the previous results from ion trap and swarm experiments with normal hydrogen. Cooling down the trap slows down the reaction and leads, at a nominal trap temperature of 11 K, to a rate coefficient below 10(-14) cm(3) s(-1) for paraenriched hydrogen. The fitted reaction endothermicity of 25.3 +/- 2.2 meV agrees well with the literature value calculated in the Born-Oppenheimer approximation, Delta H degrees = 24.0 meV. A simpler evaluation procedure, fitting the data with Arrhenius functions, results in (p)k = 16.8 x10(-11) exp(-234 K/T) cm(3) s(-1) for pure para-hydrogen and degrees k= 9.4 x 10(-11) exp(-101 K/T) cm(3) s(-1) for pure orthohydrogen.

Název v anglickém jazyce

Effect of rotational excitation of H-2 on isotopic exchange reaction with OD- at low temperatures

Popis výsledku anglicky

Aims. This paper presents experimentally obtained rate coefficients for the weakly endothermic reaction OD- + H-2 -&gt; OH- + HD with ortho- and para-hydrogen at astrophysically relevant temperatures between 10 and 300 K. Methods. The reaction was studied with normal and para-enriched (99.5% para-H-2) hydrogen in a 22-pole ion trap. The measured temperature dependencies of reaction rate coefficients are analyzed using a model which assumes that the rotational energies of the two reactants are equivalent to the translational energy in driving the reaction. Results. At room temperature, the rate coefficients of reactions with both nuclear spin variants reach 7 x10(-11) cm(3) s(-1), which is in good agreement with the previous results from ion trap and swarm experiments with normal hydrogen. Cooling down the trap slows down the reaction and leads, at a nominal trap temperature of 11 K, to a rate coefficient below 10(-14) cm(3) s(-1) for paraenriched hydrogen. The fitted reaction endothermicity of 25.3 +/- 2.2 meV agrees well with the literature value calculated in the Born-Oppenheimer approximation, Delta H degrees = 24.0 meV. A simpler evaluation procedure, fitting the data with Arrhenius functions, results in (p)k = 16.8 x10(-11) exp(-234 K/T) cm(3) s(-1) for pure para-hydrogen and degrees k= 9.4 x 10(-11) exp(-101 K/T) cm(3) s(-1) for pure orthohydrogen.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10305 - Fluids and plasma physics (including surface physics)

Projekt

<a href="/cs/project/GA17-19459S" target="_blank" >GA17-19459S: Reakce iontů s atomárním deuteriem - experimentální studie s astrofyzikálními důsledky</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2018

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Astronomy &amp; Astrophysics [online]

ISSN

1432-0746

e-ISSN

—

Svazek periodika

615

Číslo periodika v rámci svazku

Jul

Stát vydavatele periodika

FR - Francouzská republika

Počet stran výsledku

5

Strana od-do

—

Kód UT WoS článku

000439527100001

EID výsledku v databázi Scopus

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