Abstract
A positive column cell, which radiates the vacuum-ultraviolet light from the positive column region, has high luminous efficiency. To investigate the relation between the exited atoms density and luminous efficiency, we measured the spatial density distribution of excited Xe atoms in the positive column region by laser spectroscopy absorption. Though the density of excited Xe atoms increased according to the increase in discharge current, the positive column region contracted toward the anode side. Next, we investigated the density of excited Xe atoms of the narrowed cell, which varies the cell width from 0.12 to 0.36 mm under the same discharge current. The density of excited Xe atoms increased according to the decrease in cell width. It is clearly that the higher density of exited Xe particles near the wall serves to excite the phosphor of the inner cell wall.
