Joseph M. Proud

Bound‐free emission in HgBr

We report the first experimental observation of bound‐continuum fluorescence in the mercuric bromide system. HgBr (B2Σ+) population is created in ultraviolet photodissociative excitation of the dihalide. The resulting bound‐free fluorescence (B2Σ+→A2Π) is detected over a bandwidth of ≂120 nm centered at 685 nm. The associated and well known bound‐bound fluorescence (B2Σ+→X 2Σ+) is also seen. A semiclassical computer code has been developed to predict the transition probability density for the observed bound‐free features.

Enhanced HgBr(B2Σ+→X 2Σ+) emission at low pressures

Additives of N2 and I2 vapor in diffuse HgBr2 discharges have been observed to produce a large enhancement of radiated power due to B2Σ+→X2Σ+ transitions at low pressures. The integrated power in the spectral range between 374 and 543 nm was recorded by means of an optical multichannel analyzer system. Optimization of the B→X radiation was investigated, and absolute efficiency was determined over a range of ‖E‖/N.