# Workshop on LABORATORY ASTROPHYSICS: Interstellar Gas, Dust and Ice

28-30 September 2016
Tagungstätte Schloss Ringberg, Kreuth
UTC timezone
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# Contribution Contributed Talk

Tagungstätte Schloss Ringberg, Kreuth -
MORNING SESSION 1 - GAS PHASE

# Formation of NH$\sf\bf{}_2^+$ and NH$\sf\bf{}_3^+$ at low temperatures - ion trap study.

## Speakers

• Dr. Roucka STEPAN

## Primary authors

• Dr. Roucka STEPAN (Faculty of Mathematics and Physics, Charles University in Prague)

## Content

A possible pathway to gas phase formation of ammonia in interstellar medium is a sequence of hydrogen abstraction reactions of ions with H$_2$, forming NH$_4^+$ from N$^+$. The NH$_4^+$ ions then may recombine with electrons by dissociative recombination towards NH$_3$. The first and last steps of this abstraction sequence, reactions $\rm N^+ + H_2 \to NH^+ + H$ and $\rm NH_3^+ + H_2 \to NH_4^+ + H$, have been studied in detail before. The present study deals with reactions

$\rm NH^+ + H_2 \to NH_2^+ + H,$

$\rm NH_2^+ + H_2 \to NH_3^+ + H.$

We have measured the corresponding reaction rate coefficients in the temperature range 10-300 K using a cryogenic radiofrequency 22-pole ion trap. The parasitic reaction

$\rm NH^+ + H_2 \to H_3^+ + N$

has also been investigated and its rate coefficient will be reported.

## Summary

Rate coefficients of reactions $\rm NH^+ + H_2 \to NH_2^+ + H$ and $\rm NH_2^+ + H_2 \to NH_3^+ + H$ studied in cryogenic 22-pole trap.