Partial cross-section measurements for ionization of helium by positron impact

Journal Article · Mon Dec 15 04:00:00 EST 1986 · Phys. Rev. Lett.; (United States)

DOI:https://doi.org/10.1103/PhysRevLett.57.3031· OSTI ID:6750777

Fromme, D; Kruse, G; Raith, W; Sinapius, G

Positrons ionize helium atoms either by impact ionization, resulting in three outgoing particles, or by positronium formation. We determined cross sections for both processes for incident-positron energies ranging from the respective thresholds to 1000 eV. The cross section for impact ionization by positrons (sigma/sub ion//sup +/) exceeds the corresponding electron cross section (sigma/sub ion//sup -/) below 500 eV. On the high-energy side of its maximum, the positronium-formation cross section (sigma/sub Ps/) lies above all theoretical predictions.

• Research Organization: Fakultat fuer Physik, Universitat Bielefeld, D-4800 Bielefeld, Federal Republic of Germany
• OSTI ID: 6750777
• Journal Information: Phys. Rev. Lett.; (United States), Journal Name: Phys. Rev. Lett.; (United States) Vol. 57:24; ISSN PRLTA
• Country of Publication: United States
• Language: English

Related Subjects

640303* -- Atomic
Molecular & Chemical Physics-- Positronium
Muonium
& Muonic & Mesic Atoms & Molecules
74 ATOMIC AND MOLECULAR PHYSICS
ATOM COLLISIONS
COLLISIONS
CROSS SECTIONS
DATA
ELEMENTS
ENERGY RANGE
EV RANGE
EV RANGE 100-1000
EXPERIMENTAL DATA
FLUIDS
GASES
HELIUM
INFORMATION
IONIZATION
NONMETALS
NUMERICAL DATA
POSITRON COLLISIONS
POSITRON-ATOM COLLISIONS
POSITRONIUM
RARE GASES