Document Type
Thesis
Date of Award
1-31-1989
Degree Name
Master of Science in Electrical Engineering - (M.S.)
Department
Electrical Engineering
First Advisor
Roy H. Cornely
Second Advisor
Kenneth Sohn
Third Advisor
Marek Sosnowski
Abstract
A microwave discharge system for producing atomic nitrogen at low flow rate and low pressure has been investigated. The molecular nitrogen passes through a microwave cavity in a quartz tube and is dissociated by the microwave energy. Subsequent recombination of nitrogen atoms produces a characteristic yellow glow due to the relaxation of excited molecular nitrogen to its ground state. The titration of nitric oxide with atomic nitrogen was used to measure the atomic nitrogen yield. At a 2 sccm nitrogen flow rate the atomic nitrogen yield was 8.75*1015 atom/sec, which corresponds to a nitrogen generation efficiency of about 1%. A 200 ml spherical reactor with a 1.3 mm diameter nozzle was used for more complete gas reaction and for minimization of nitric oxide back diffusion towards the microwave cavity. Relations between the afterglow light intensity, atomic nitrogen yield, gas traveling length and gas flow rates were studied. Surface recombination and gas phase recombination are also discussed. It was found that coating the quartz discharge tube with phosphoric acid inside the cavity was essential for obtaining high atomic nitrogen yield. Coating of the tube downstream from the microwave cavity reduces the losses of atomic nitrogen due to surface recombination. The reduction of losses by a factor of 5.7 was estimated for a quartz tube of 10 mm diameter and the length of 1 meter.
Recommended Citation
Shieh, Jong-Shun, "Generation of atomic nitrogen by gas discharge in microwave cavity" (1989). Theses. 2896.
https://digitalcommons.njit.edu/theses/2896
