TY - JOUR

T1 - Analysis of the Causes of the Inverse Population of Atomic Argon Levels in Condensing Supersonic Flows of Mixtures

AU - Зарвин, Александр Евгеньевич

AU - Мадирбаев, Виктор Жумагазыевич

AU - Дубровин, Кирилл Алексеевич

AU - Яскин, Александр Сергеевич

N1 - This study was supported by the Russian Science Foundation, project no. 22-11-00080.

PY - 2023/12

Y1 - 2023/12

N2 - The features of argon radiation mixed with molecular and atomic additives in condensing supersonic jets are analyzed. Mixtures of argon (95%) with methane (5%) and argon (95%) with monosilane (5%) are used. The mixture’s particles are activated by a well-focused electron beam. The dependence of the radiation intensity of individual argon lines on the gas-dynamic parameters in the jet is studied. In a certain pressure range, different various compositions of mixtures, not only anomalously intense emission was recorded on individual spectral lines of argon (ArI) in mixtures with methane and monosilane, but also the role of clusters of a certain size and composition was revealed. At the same time, a similar effect is not detected in the spectrum of argon (ArII) ions. It is established that the cause of the anomaly is a highly efficient molecular cluster mechanism of the selective excitation of the individual levels of argon atoms, which is absent in noncondensing jets and weakens at the stage of the formation of large clusters. The main channels of energy transmission are reviewed and discussed. Based on the data obtained, an empirical model of the excitation-emission process is proposed.

AB - The features of argon radiation mixed with molecular and atomic additives in condensing supersonic jets are analyzed. Mixtures of argon (95%) with methane (5%) and argon (95%) with monosilane (5%) are used. The mixture’s particles are activated by a well-focused electron beam. The dependence of the radiation intensity of individual argon lines on the gas-dynamic parameters in the jet is studied. In a certain pressure range, different various compositions of mixtures, not only anomalously intense emission was recorded on individual spectral lines of argon (ArI) in mixtures with methane and monosilane, but also the role of clusters of a certain size and composition was revealed. At the same time, a similar effect is not detected in the spectrum of argon (ArII) ions. It is established that the cause of the anomaly is a highly efficient molecular cluster mechanism of the selective excitation of the individual levels of argon atoms, which is absent in noncondensing jets and weakens at the stage of the formation of large clusters. The main channels of energy transmission are reviewed and discussed. Based on the data obtained, an empirical model of the excitation-emission process is proposed.

KW - electronic excitation of radiation

KW - mixed clusters

KW - molecular beam mass spectrometry

KW - molecular-cluster energy exchange

KW - supersonic jet

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85188524655&origin=inward&txGid=fdff3986d38381a44fd1434fee7c38fd

UR - https://elibrary.ru/item.asp?id=65321964

UR - https://www.mendeley.com/catalogue/3c675d9d-ce87-3a54-804f-1c109b6f36c9/

U2 - 10.1134/S0015462823602747

DO - 10.1134/S0015462823602747

M3 - Article

VL - 58

SP - 1668

EP - 1683

JO - Fluid Dynamics

JF - Fluid Dynamics

SN - 0015-4628

IS - 8

M1 - 23

ER -