Evidence for resonant formation of Ca[sup [minus]] in collisions of Rydberg and ground-state Ca atoms

Journal Article · Sun Feb 20 23:00:00 EST 1994 · Physical Review Letters; (United States)

DOI:https://doi.org/10.1103/PhysRevLett.72.1176· OSTI ID:5008636

McLaughlin, K W; Duquette, D W ^[1]

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1. Behlen Laboratory of Physics, University of Nebraska, Lincoln, Nebraska 68588-0111 (United States)

Relative yields of Ca[sup +] and Ca[sup [minus]] ions from thermal-energy collisions between highly excited Ca[sup *] 4[ital snd] [sup 1][ital D] Rydberg atoms and Ca ground-state atoms are measured as a function of [ital n]. The collisions take place within an effusive Ca atomic beam. The cross section for a collision resulting in a bound Ca[sup [minus]] and a ground-state Ca[sup +] is expected to be large when the binding energy of the excited Rydberg state nearly matches the electron affinity of Ca. We observe a large increase in positive and negative ions for [ital n]=25 only. This result strongly suggests that the binding energy of Ca[sup [minus]] is 24[plus minus]1.4 meV.

• OSTI ID: 5008636
• Journal Information: Physical Review Letters; (United States), Journal Name: Physical Review Letters; (United States) Vol. 72:8; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

664300* -- Atomic & Molecular Physics-- Collision Phenomena-- (1992-)
74 ATOMIC AND MOLECULAR PHYSICS
AFFINITY
ALKALINE EARTH METALS
ANIONS
ATOM COLLISIONS
ATOM-ATOM COLLISIONS
ATOMIC BEAMS
BEAMS
CALCIUM
CALCIUM IONS
CATIONS
CHARGED PARTICLES
COLLISIONS
ELEMENTS
ENERGY LEVELS
EXCITED STATES
GROUND STATES
IONS
METALS
RESONANCE
RYDBERG STATES
YIELDS