Density-Sensitive Dielectronic Satellite Lines in Microballon Neon Spectra

It is suggested that the 12.3-Å feature in the spectra from compressed neon-filled microballoons, previously identified as the second-order silicon Lyman-$\alpha$ line, is actually a blend of neon dielectronic satellite lines. The relative intensities of these satellite lines, some of which are strong functions of electron density, agree with a numerical model of collisional mixing of the Ne ix $2l2l^{\prime }$ doubly excited levels.