Five multi-hydrogenic optical centers were studied in SrF2:Pr3+ and Ca
F2:Pr3+ crystals. These centers are created by hydrogenic ions replaci
ng those F- ions located between the Pr3+ and its charge compensator i
n the C-4v center. The D-1(2) fluorescence lifetimes of the multi-D- c
enters decrease with increase in the number of D- ions present. The 10
K bleaching rates decrease from H- to T- under identical excitation.
Thermal recovery of bleached centers occurs near 100 K for all three i
sotopes.