Laboratory simulation of the positron-dust interaction and its implication for interstellar dark clouds

0567741 - FZÚ 2024 RIV GB eng J - Journal Article
Wild, J. - Čízek, J. - Nouzák, L. - Pavlů, J. - Šafránková, J. - Němeček, Z. - Vaverka, J. - Nosek, D. - Burian, Tomáš - Wildová, A. - Broulím, J.
Laboratory simulation of the positron-dust interaction and its implication for interstellar dark clouds.
Astrophysical Journal. Roč. 942, č. 1 (2023), č. článku 42. ISSN 0004-637X. E-ISSN 1538-4357
Research Infrastructure: e-INFRA CZ - 90140
Institutional support: RVO:68378271
Keywords : laboratory simulation * interaction of cosmic dust with positrons * possible scenario of interstellar dark clouds charging
OECD category: Astronomy (including astrophysics,space science)
Impact factor: 4.9, year: 2022
Method of publishing: Open access

We report the first laboratory experiment dealing with the interaction of a cosmic dust simulant with positrons emitted from a 22Na radioisotope. Measurements of a charge of micrometer SiO2 dust grains with an accuracy of one elementary charge e revealed +1 e steps due to positron annihilation inside the grain. The observed average rate of these charging events agrees well with prediction of a model based on the continuous slowing down approximation of energetic of positrons inside the grain. Less frequent charge steps larger than +1 e were attributed to emission of secondary electrons during positron slowing down. The determined coefficient of secondary electron emission is approximately inversely proportional to the grain radius. The experimental results led us to the formulation of a possible scenario of interstellar dark clouds charging.
Permanent Link: https://hdl.handle.net/11104/0342108