Effect of 1.66 GeV argon ions on the creep velocity of the B2O3 glass

The effect of 1.66 GeV Argon ions on the creep velocity (ε) of B2O3 glass fibers has been measured and a viscosity (η) versus temperature plot directly derived by using the relation η = σ/3ε, where σ is the stress applied to the fiber. In this experiment the fiber is only heated by ion beam energy deposition. So, the temperature and the flux of particles are not independent and the temperature range is swept by changing the flux. Up to a threshold temperature, a very drastic decrease of the viscosity, which exhibits a quasi athermal behaviour over a large range of temperatures, is observed under irradiation. Below 1700C it increases again with temperature but this behaviour is clearly shown by only one experimental point because of the limit of sensitivity of the experiment. These effects are discussed within the framework of two models. (author)