Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Measurement of the differential cross section for the electron impact excitation of the neon 1s/sup 2/2s/sup 2/2p/sup 5/3s metastable states

Thesis/Dissertation ·
OSTI ID:6901094
This thesis is a report of a measurement of the differential cross section of the electron impact excitation of the 1s/sup 2/2s/sup 2/2p/sup 5/3s metastable states of neon. The results are obtained for incident electron energies 0.1-1.0 EV above the 16.6 EV threshold for these states. Electron excitation of the neon atoms is achieved by colliding an electron beam with an atomic neon beam. Both beams are well collimated and collide at 90 degrees. The electron beam is produced by an inline retarding potential type electron gun with an energy width of 0.6 ev full width at half maximum. The data are acquired using a time of flight technique that uses a metastable detector to measure the time of flight of the scattered, long lived J = 0 and J = 2 metastable excited states of neon. Preliminary to extracting the differential cross section, the electron beam energy distribution and neon ground state velocity distribution are measured. The electron beam energy distribution is found to be maxwellian with a characteristic temperature T = 1950 K and a 0.5 v smear, due to the potential drop across the filament producing the electrons. The results obtained for the differential cross section support the existence of a negative ion shape resonance, classified as 1s/sup 2/2s/sup 2/2p/sup 5/3s 3p. This resonance is observed as an onset of S + P wave scattering at an incident electron energy of 17.2 EV.
Research Organization:
Michigan Univ., Ann Arbor (USA)
OSTI ID:
6901094
Country of Publication:
United States
Language:
English