Partial Photoionization Cross Sections and Angular Distributions for Double Excitation of Helium up to the N=13 Threshold

Journal Article · Fri Dec 09 04:00:00 EST 2005 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.95.243003· OSTI ID:20699671

Czasch, A; Schoeffler, M; Hattass, M; Schoessler, S; Jahnke, T; Weber, Th; Staudte, A; Titze, J; Wimmer, C; Kammer, S; Weckenbrock, M; Voss, S; Grisenti, R E; Jagutzki, O; Schmidt, L Ph.H.; Schmidt-Boecking, H; Doerner, R ^[1]; Rost, J M; Schneider, T ^[2]; Liu, C -N ^[3]

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1. Institut fuer Kernphysik, Universitaet Frankfurt, D-60438 Frankfurt (Germany)
2. Max-Planck-Institut fuer Physik komplexer Systeme, D-01187 Dresden (Germany)
3. Fu Jen Catholic University, Taipei, Taiwan (China); and others

Partial photoionization cross sections {sigma}{sub N}(E{sub {gamma}}) and photoelectron angular distributions {beta}{sub N}(E{sub {gamma}}) were measured for the final ionic states He{sup +}(N>4) in the region between the N=8 and N=13 thresholds (E{sub {gamma}}>78.155 eV) using the cold target recoil ion momentum spectroscopy technique (COLTRIMS). Comparison of the experimental data with two independent sets of theoretical predictions reveals disagreement for the branching ratios to the various He{sub N}{sup +} states. The angular distributions just below the double ionization threshold suggest an excitation process for highly excited N states similar to the Wannier mechanism for double ionization.

• OSTI ID: 20699671
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 24 Vol. 95; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ANGULAR DISTRIBUTION
BRANCHING RATIO
CATIONS
COMPARATIVE EVALUATIONS
CROSS SECTIONS
EV RANGE 10-100
EXCITATION
EXCITED STATES
EXPERIMENTAL DATA
HELIUM
HELIUM IONS
PHOTOELECTRON SPECTROSCOPY
PHOTOIONIZATION
PHOTON-ATOM COLLISIONS
RECOILS