Supersonic cooling of short-lived molecular states in a pulsed microcavity plasma jet

Su, Rui

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https://hdl.handle.net/2142/90736 Copy

Description

Title

Supersonic cooling of short-lived molecular states in a pulsed microcavity plasma jet

Author(s)

Su, Rui

Issue Date

2016-04-05

Director of Research (if dissertation) or Advisor (if thesis)

Eden, James G.

Department of Study

Electrical & Computer Eng

Discipline

Electrical & Computer Engr

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• microplasma
• supersonic cooling
• molecular spectroscopy

Abstract

"Electronic states of helium diners having potential energy > 24 eV and radiative lifetimes as short as 19 ns have been generated in a micro-plasma jet at super-atmospheric pressure and rotationally cooled by supersonic expansion. Spatial-temporal spectrograms of d^3Σ+u→(b^3)π_g (v', v"") = (0, 0) emission are obtained, which contain the information about the dynamic cooling process during the molecular beam expansion. Analysis shows the spatial-temporal evolution of the rotational temperature to be a damped sinusoid that reaches a minimum value of 100 K, which is attributed to the reflection of electrons from a virtual cathode located downstream of the jet nozzle. Data fitting to the damped sinusoid function yields a spatially-averaged electron density of 10^8 cm^(-3). The experimental setup has the potential to be used in exploration of the spectroscopy and plasma dynamics in various gas molecules."

Graduation Semester

2016-05

Type of Resource

text

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http://hdl.handle.net/2142/90736

Copyright and License Information

Copyright 2016 Rui Su

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