Electron Paramagnetic Resonance in Irradiated CsCl

Two paramagnetic species have been observed in CsCl after irradiation at low temperatures with 2-Mev electrons. One of these, an anisotropic, "hole"-type center, has not yet been positively identified. The resonance signal from the other center has all the properties expected of the CsCl $F$ center. The $F$-center parameters are $g=1.984\mathrm{}\pm 0.001$, $A=49.5\mathrm{}\pm 1.0$ gauss, and the envelope width at half maximum is approximately 800 gauss. The partially resolved hyperfine lines due to the nearest-neighbor Cs nuclei have an estimated width at half maximum of 17±5 gauss. Due to the low signal-to-noise ratio only 38 of the expected 57 lines have been observed.