#
64th Annual Gaseous Electronics Conference

## Volume 56, Number 15

##
Monday–Friday, November 14–18, 2011;
Salt Lake City, Utah

### Session JW2: Electron-Molecule Collisions

9:30 AM–12:30 PM,
Wednesday, November 16, 2011

Room: 255E

Chair: Michael Brunger, Flinders University

Abstract ID: BAPS.2011.GEC.JW2.6

### Abstract: JW2.00006 : Low energy electron collision parameters for modeling auroral/dayglow phenomena*

11:00 AM–11:30 AM

Preview Abstract
Abstract

####
Author:

Charles P. Malone

(Jet Propulsion Laboratory)

From the tenuous atmospheres of Pluto and Triton to the higher
pressure
atmospheres of Earth and Titan, electron-collisions with
molecular nitrogen
continue to warrant attention. The airglow emissions of N$_{2}$
from the
atmospheres of Earth and planetary satellites have been extensively
observed. Accurate, consistent cross section data is a necessity for
accurate models of how upper atmospheres behave. This enables
determinations
of solar energy inputs and atmospheric expansion and contraction,
which
influences satellite orbits for instance. Recent work by Lean
\textit{et al.} [1], Stevens
\textit{et al.} [2], and Kato \textit{et al.} [3] appear to
substantiate our $e^{-}$+N$_{2}$ excitation and
emission work (e.g., Johnson \textit{et al.} [4], Malone
\textit{et al.} [5], Young \textit{et al.} [6] and references
therein). Recently, we have focused on the near-threshold-to-peak
region of
N$_{2}$ with the goal of providing low energy collision
parameters of the
$X^{1}\Sigma _{g}^{+}$(0)--$A^{3}\Sigma _{u}^{+}$, $B^{3}\Pi
_{g}$, $W^{3}\Delta _{u}$, $B^{\prime 3}\Sigma _{u}^{-}$,
$a^{\prime 1}\Sigma _{u}^{-}$, $a^{1}\Pi _{g}$, $w^{1}\Delta
_{u}$, $C^{3}\Pi _{u}$, and $E^{3}\Sigma _{g}^{+}$ transitions for
modeling auroral and dayglow phenomena in these N$_{2}$-rich
atmospheres.
The Lyman-Birge-Hopfield (LBH) emissions, from $a^{1}\Pi
_{g}(v^{\prime })$--$X^{1}\Sigma _{g}^{+}(v^{\prime \prime })$
transitions, are `bellwether' measurements for diurnal
Terrestrial Space
Weather variations [7]. However, near-threshold cross section
data is still
lacking for the $a^{1}\Pi _{g}$ state, as well as the
`\textit{slow-cascade}' $a^{\prime
1}\Sigma _{u}^{-}$ and $w^{1}\Delta _{u}$ contributors to LBH
emissions. In addition, Vegard-Kaplan (VK) emissions, from the
$A^{3}\Sigma _{u}^{+}(v^{\prime })$--$X^{1}\Sigma
_{g}^{+}(v^{\prime \prime })$ transitions, recently observed in
Titan's
thermosphere [2], require further improved monoenergetic laboratory
measurements. New electron energy-loss measurements, along with
direct
excitation (integral) cross sections, are presented for
excitation of the
lower states of N$_{2}$, with finely-spaced impact energy
increments in the
threshold-to-peak region. Our recent work, including
vibrationally resolved
excitation, addresses these atmospheric data needs.\\[4pt]
[1] Lean \textit{et al.}, 2011, JGR, 116, A01102. $\quad \quad
\quad \quad \quad \quad \,$
[4] Johnson \textit{et al.}, 2005, JGR, 110, A11311. \newline
[2] Stevens \textit{et al.}, 2011, JGR, 116, A05304. $\quad \quad
\quad \quad \quad $ [5]
Malone \textit{et al.}, 2009, J. Phys. B, 42, 135201. \newline
[3] Kato \textit{et al.}, 2010, PRA, 81, 042717. $\quad \quad
\quad \quad \quad \quad
\;\;\,{\kern 1pt}$ [6] Young \textit{et al.}, 2010, J. Phys. B,
43, 135201. \newline
[7] Ajello \textit{et al.}, 2011, UV Molecular Spectroscopy from
Electron Impact for
Applications to Planetary Atmospheres and Astrophysics, Book
Chapter 28,
published in ``Charged Particle and Photon Interactions with
Matter'' Recent
Advances, Applications, and Interfaces-Eds., Hatano \textit{et
al.}, Taylor {\&} Francis,
Boca Raton, FL.

*Support from NASA's PATM, NSF-RUI, and NSF-Aeronomy programs are gratefully acknowledged.

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2011.GEC.JW2.6