Speaker
Dmitry Fursa
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P5.3012.pdf
Benchmark cross sections for excitation of the X1Σ g+ → b3Σ u+ transition in
molecular hydrogen
M. Zawadzki1, R. Wright2, G. Dolmat2, M. F. Martin2, L. Hargreaves2, D. V. Fursa3,
M. C. Zammit4, L. H. Scarlett3, J. K. Tapley3, J. S. Savage3, I. Bray3, M. A. Khakoo2
1
Gdańsk University of Technology, Gdańsk, Poland
2
California State University, Fullerton, USA
3
Curtin University, Perth, Australia
4
Los Alamos National Laboratory, Los Alamos, USA
We present a joint experimental and theoretical investigation of a fundamental process in atomic
and molecular physics: electron impact excitation of molecular hydrogen’s (H2) most dominant
transition (X1Σg+ → b3Σu+). Excitation of this state is by far the main channel that causes the
dissociation of H2 into H + H atoms at low energies. The Convergent Close-Coupling (CCC)
calculations [1] predicted significant, more than factor of two, disagreements with previously
recommended cross sections [2]. Khakoo et al. [3] have recently designed a novel electron
scattering instrument (an electron time-of-flight spectrometer, TOF), and have measured
differential scattering cross sections for the excitation of the X1Σg+ → b3Σu+ transition, as ratios to
elastic scattering, with high precision. The recently developed TOF spectrometer does not suffer
from transmission problems like conventional spectrometers. Using the present theoretical and
experimental approaches, we have been able to get outstanding agreement between theory and
experiment for the excitation of a molecule for a very important transition in this most basic of
all molecules. This work heralds significant progress in electron-molecule scattering, as well as
promoting our understanding of dissociation processes not found in atoms.
4.0 References
• present exp. [3]
3.5 [1] M. Zammit et al., Phys. Rev. A 95,
▲ Nishimura and Danjo [4]
022708 (2017).
3.0 ♦ Khakoo et al. [5]
ICS (a.u.)
■ Khakoo and Segura [6] [2] J.-S. Yoon et al., J. Phys. Chem. Ref.
2.5 Data 37, 913 (2008).
----- recommended ICS [2]
2.0 ── present CCC [3] M. Zawadzki et al., Phys. Rev. Lett.
1.5
2018, submitted.
[4] H. Nishimura and A. Danjo, J. Phys.
1.0 Soc. Japan 55, 3031(1986)
0.5 [5] M. A. Khakoo et al., Phys. Rev. A 35,
0.0 2832 (1987).
5 10 15 20 25 30 [6] M. A. Khakoo and J. Segura, J. Phys. B:
E0 (eV) Atom. Molec. Phys. 27, 2355 (1994).
Fig.1 Integrated cross sections for excitation of the b3Σu+state of H2.
