Theory of atomic hydrogen in a high uniform magnetic field and excitation and detachment of the hydrogen negative ion in fast collisions

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:5835680

Liu, Chih-Ray

In this dissertation, the author investigates two problems. First, atomic hydrogen in a uniform magnetic field using an adiabatic approximation in cylindrical coordinates. Second, fast H{sup {minus}} collisions with He (treated in Born approximation) involving both detachment and excitation of the H atom to an excited state. The first study concerns the wave functions, energies, and binding energies for the first Landau level in uniform magnetic fields B>10{sup 9} G. Using only a single configuration wave function and no parameters, the author presents cylindrical adiabatic upper and lower bounds on the binding energies thus providing in one place stringent tests of past (and future) calculations. The second study concerns the electron detachment cross sections for collisions of 0.5 MeV H{sup {minus}} projectiles on He targets. The first Born-approximation and the closure approximation are employed assuming that the H atom is left in either the 2s or 2p state. The calculations are carried out in the projectile frame and then transformed to the laboratory frame. The H{sup {minus}} wave functions are represented by adiabatic approximation hyperspherical wave functions, which include a significant portion of the most important electron correlations. The first three partial wave components (i.e., s, p, and d) of the detached electron are included. Five H{sup {minus}} excited channels, i.e., {sup 1}S{plus minus}, {sup 1}P{plus minus} and {sup 1}D{plus}, for involving the H atom in n=2 excited states, are used in the calculations. The calculated doubly differential cross section using an average He excitation energy 35 eV, agree well with experimental data for {theta}=0{degree} involving the H atom excited to the 2p state.

• Research Organization: Nebraska Univ., Lincoln, NE (USA)
• OSTI ID: 5835680
• Country of Publication: United States
• Language: English

Related Subjects

640302 -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ADIABATIC PROCESSES
ANIONS
ATOM COLLISIONS
BINDING ENERGY
BORN APPROXIMATION
CHARGED PARTICLES
COLLISIONS
CROSS SECTIONS
DIFFERENTIAL CROSS SECTIONS
ELECTRON DETACHMENT
ELEMENTS
ENERGY
ENERGY-LEVEL TRANSITIONS
EXCITATION
FLUIDS
FUNCTIONS
GASES
HELIUM
HYDROGEN
HYDROGEN IONS
HYDROGEN IONS 1 MINUS
ION COLLISIONS
ION-ATOM COLLISIONS
IONS
MAGNETIC FIELDS
NONMETALS
RARE GASES
WAVE FUNCTIONS