Scaling of positive-column Hg—Ar discharges towards display cells

Measurements are presented of the ultraviolet output and the electric field of Hg-Ar positive-column discharges with diameters
2R
ranging from 0.5 to 5 mm. The UV exitance and efficiency remain constant (and equal to that of the standard fluorescent tube), provided the pressures are scaled in proportion to
1/R
. From the existing models of the Hg-Ar column a parametric description is obtained. When full account is given of collisional line broadening in the transport of resonance radiation, comparison of measurements and model leads to the conclusion that they are not in agreement. The UV measurements suggest that the electron temperature remains constant at constant
pR
, which is also in disagreement with the models.