Formation of H(2p) and H(2s) atoms in collisions of 2 to 26 keV protons with hydrogen atoms
A modulated crossed-beam technique was used to determine cross sections for the four reactions: H/sup +/ + H(1s) yields H(2s or 2p) + H/sup +/ (electron capture) and H/sup +/ + H(1s) yields H/sup +/ + H(2s or 2p) (exc itation) within the energy range 2.3 to 26 keV. Results were based on measurements, using a Doppler-shift identification technique, of the Lyman alpha radiation emitted from the beam intersection region both in the absence and in the presence of an electric field. While cross sections for excitation of the 2s state have not been reported previously, cross sections for capture into the 2s state agree well with those measured by Bayfield (Phys. Rev.; 185: 105-12 (1969)) using a furnace target technique. The H(2p) formation cross sections are also shown to be in reasonable accord with values based on the crossed-beam measurements of Stebbings et al (Phys. Rev.; 138A: 1312-16 (1965)). The cross sections for all four reactions are in good general agreement over the entire energy range with the coupled-state calculations of Cheshire et al (J. Phys. B. Atom. Molec. Phys.; 3: 813-32 (1970)) incorporating a pseudo-state expansion. Below 7 keV the data are well represented by a molecular treatment of the collision. As part of a check on the experimental procedure, measurements were also carried out using H/sub 2/ and Ar targets including, in the latter case, studies of the polarization of the Lyman alpha radiation. (auth)
- Research Organization:
- Queen's Univ., Belfast
- NSA Number:
- NSA-29-008673
- OSTI ID:
- 4377867
- Journal Information:
- J. Phys., B (London), v. 6, no. 10, pp. 2118-2138, Journal Name: J. Phys., B (London), v. 6, no. 10, pp. 2118-2138; ISSN JPBAB
- Country of Publication:
- United Kingdom
- Language:
- English
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*HYDROGEN-- ION-ATOM COLLISIONS
ARGON
ATOMS
CATIONS
COLLIDING BEAMS
COLLISIONS
COMPARATIVE EVALUATIONS
COUPLING
CROSS SECTIONS
ELECTRON CAPTURE
EXCITATION
HYDROGEN IONS
KEV RANGE 01-10
KEV RANGE 10-100
LYMAN LINES
MOLECULES
N60400* --Physics (Atomic & Molecular)--Collision Phenomena
P STATES
PROTONS
S STATES
TARGETS