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arXiv · 1407.0538

Dissociative recombination measurements of NH$^+$ using an ion storage ring

O. Novotný·M. Berg·D. Bing·H. Buhr·W. Geppert·M. Grieser·F. Grussie·C. Krantz·M. B. Mendes·C. Nordhorn·R. Repnow·D. Schwalm·B. Yang·A. Wolf·D. W. Savin
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Abstract

We have investigated dissociative recombination (DR) of NH$^+$ with electrons using a merged beams configuration at the TSR heavy-ion storage ring located at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany. We present our measured absolute merged beams recombination rate coefficient for collision energies from 0 to 12 eV. From these data we have extracted a cross section which we have transformed to a plasma rate coefficient for the collisional plasma temperature range from $T_{\rm pl} = 10$ to $18000$ K. We show that the NH$^+$ DR rate coefficient data in current astrochemical models are underestimated by up to a factor of $\sim 9$. Our new data will result in predicted NH$^+$ abundances lower than calculated by present models. This is in agreement with the sensitivity limits of all observations attempting to detect NH$^+$ in interstellar clouds.

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O. Novotný, M. Berg, D. Bing, H. Buhr, W. Geppert, M. Grieser, F. Grussie, C. Krantz, M. B. Mendes, C. Nordhorn, R. Repnow, D. Schwalm, B. Yang, A. Wolf, D. W. Savin. 2014-07-02. Dissociative recombination measurements of NH$^+$ using an ion storage ring. https://doi.org/10.1088/0004-637x/792/2/132

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