Accession Number : AD0674750

Title :   ENERGY DISTRIBUTION OF POSITIVE IONS EXTRACTED FROM A HOT-CATHODE GAS DISCHARGE ION SOURCE.

Descriptive Note : Research Communication no. 65,

Corporate Author : DOUGLAS AIRCRAFT CO INC HUNTINGTON BEACH CALIF ADVANCED RESEARCH LABS

Personal Author(s) : Theard,Lowell P.

Report Date : JUN 1968

Pagination or Media Count : 30

Abstract : An electrostatic parallel-plate energy analyzer was used for measuring the energy distribution of Ar(+) ions in a beam extracted from a non-magnetic hot-cathode gas discharge ion source under various conditions of source pressure, anode voltage, and anode current. A large number of energy distribution curves were obtained as X-Y recordings. The curve shape depends upon source conditions, though not strongly when the pressure is greater than 0.003 torr with an anode voltage above 50V (for argon) and an anode current of at least 200 mA. When conditions are optimum, the ion energy distribution curve is a narrow peak with a tail that gradually diminishes towards lower energies over an interval of approximately 30 eV. The actual value of the optimum full-width at half-maximum was found to be 1.1 eV by extrapolation to zero beam energy. The shape of the curve is such that more than 81 percent of the beam ions have energies within a 10-eV interval. The source can be used to increase beam currents greatly in certain types of magnetic deflection mass spectrometers without extreme loss of mass resolution due to ion beam energy spread. (Author)

Descriptors :   (*ION SOURCES, GAS DISCHARGES), (*ARGON, *ION BEAMS), IONS, ENERGY, CATHODES, ANODES, ELECTROSTATICS, MASS SPECTROSCOPY

Subject Categories : Atomic and Molecular Physics and Spectroscopy
      Particle Accelerators
      Nuclear Physics & Elementary Particle Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE