Color Centers in CsBr Single Crystals Irradiated at Liquid-Helium Temperature.

Abstract

The principal absorption bands induced by irradiation at liquid-helium temperature with x rays in CsBr crystals are the complex F band and two overlapping V bands at 435 and 497 m/*. In view of the dichroic properties of these V bands, the most obvious model seems to be a Br 2~ molecule -ion lying in the (100) directions. The two observed absorption bands would be due to two transitions in the same center. Regarding the bleaching properties, the F center cannot be the only color center responsible for the structure of the complex absorption band. Hypotheses are proposed about the interactions between the V and F centers.

Release of stored energy of X‐irradiated KCl and CsBr

“…To identify the annealing reactions responsible for the energy release, our results were compared with the results of experiments on thermal bleaching of the optical absorption bands reported by van de Wiele and Jacobs [14]. The threefold F-band with absorptions at 605,638,655 nm, and the H-band at 435 nm show a sharp decrease a t 15 K, while the a-band (205 nm) is found to anneal a t 26 K. Similar results were found by optical measurements performed on the crystals used for the energy release measurements.…”

Structure and properties of electronic and hole centers in CsBr from theoretical calculations

“…The calculated versus. experimentally observed optical absorption peaks [47,[50][51][52] for all the primary defects are given in table 3.…”