Luminescence ofZCenters in KCl: Sr Crystals

A search has been made for emissions that are characteristic of the $Z_1$ and $Z_2$ centers in additively colored crystals of KCl containing strontium. No emission was found for the $Z_1$ center. The $Z_2$ center was found to emit at 1.14 μ at 77°K. A study of the polarization of the emission of the $Z_2$ center with polarized exciting light leads to the conclusion that this center is of high symmetry.