Advanced integrated stationary afterglow method for experimental study of recombination of processes of H3+ and D3+ ions with electrons

Binary recombination of para- and ortho-H 3 + with electrons at low temperatures

“…A mixture of He/Ar/H 2 with a typical composition 10 17 /10 14 /10 14 cm −3 flows continuously along the discharge tube. Details of the ion formation reactions are given elsewhere [4,5,27]. 'A parahydrogen generator' prepares samples of para-enriched H 2 ( e H 2 ) [26].…”

“…The discrepancies between measurements of the binary dissociative reaction rate and the theoretical complexity of this seemingly simple reaction led to a great deal of fruitful research on this process. The history of H + 3 recombination studies has been adequately covered in several review articles [3][4][5][6][7][8][9]. Recently, both theory and experiment have converged to a value for the rate of this particular reaction.…”

Storage Ring Experiments with Cold Molecular Ions: the H3+ Puzzle

“…The H 3 + DR puzzle was proclaimed [5] facing the experimental observation of high DR rate coefficients for H 3 + (though not unanimous among the various studies [4,6]), while efficient reaction pathways could not be rationalized theoretically. Much interest arises from the astrophysical implications of the puzzle [1,5]: for the standard astrophysical model parameters, the observational evidence of a high abundance of H 3 + ions in diffuse interstellar clouds is incompatible with the high DR rate coefficients found in several laboratory measurements.…”

State selective study of H3+recombination in Cryo-FALP and SA-CRDS experiments at 77 K

“…In the Cryo-FALP II setup the movable Langmuir probe [26] measures the electron number density along the flow tube and the time evolution of electron density in afterglow plasma (see example in Fig. 1) can be obtained [27][28][29]. A microwave discharge is ignited in helium buffer gas (with a number density [He]~10 16 -10 17 cm −3 ) in the first section of the flow tube kept at room temperature and plasma consisting of helium metastable atoms He m , He + , and He + 2 ions and electrons is formed.…”

“…The kinetics of formation of H + 3 dominated afterglow plasma was described in details in Refs. [27,29]. Formed H + 3 ions are thermalized in subsequent multiple collisions with He and H 2 .…”