Pressure broadening and shift of He(2 {sup 3}P{sub 0,1,2})-He(2 {sup 3}S) lines

Journal Article · Sun Feb 01 04:00:00 EST 2004 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.69.022714· OSTI ID:20640737

Vrinceanu, D; Kotochigova, S; Sadeghpour, H R ^[1]

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1. ITAMP, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138 (United States)

The collisional broadening and shift of metastable helium fine-structure lines are calculated within the impact approximation. Ab initio Born-Oppenheimer potential energy curves correlating to He(1 {sup 1}S{sub 0}) and He(2 {sup 3}P{sub j}) atomic levels are obtained using the configuration interaction valence bond method and combined with semiempirically calculated van der Waals interaction terms between these atoms to also study j-specific and j-changing collisions. A long-range van der Waals potential well exists in the {sup 3}{pi}{sub u} potential correlated to the He(1 {sup 1}S{sub 0})+He(2 {sup 3}P{sub j}) limit, whose influence on the scattering phase shift is assessed. At T=310 K, the broadening and shift parameters are practically j independent and have average values of 12.60 and 1.87 MHz/Torr, respectively. The j-changing collisions have cross sections roughly five times smaller than the j-specific cross sections.

• OSTI ID: 20640737
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 2 Vol. 69; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ATOM COLLISIONS
ATOMS
BORN-OPPENHEIMER APPROXIMATION
CONFIGURATION INTERACTION
CROSS SECTIONS
FINE STRUCTURE
HELIUM
LINE BROADENING
METASTABLE STATES
MHZ RANGE
PHASE SHIFT
POTENTIAL ENERGY
POTENTIALS
SCATTERING
SPECTRAL SHIFT
SURFACES
VALENCE
VAN DER WAALS FORCES