The effects of ionizing radiation on the vacuum-electrolysis of quartz

Electrolysis (electrodiffusion, sweeping) in vacuum has been shown to reduce the sensitivity of quartz resonators to pulsed radiation. Vacuum-sweeping is expected to remove the alkalis associated with the aluminum and the hydrogen associated with the growth-defects and replace them with electronic holes. The process is not very well understood and is often incomplete. It has been suggested that sweeping in the presence of ionizing radiation would speed the release of the trapped ions and hydrogen from the defect sites by enhancing the availability of electronic charge carriers over those generated at the electrodes. Quartz subjected to this process should not show any OH-related infrared absorption. Several blocks of Sawyer Special Premium Q quartz were vacuum-swept while being irradiated. Bremstrahlung (continuous) x-rays produced by colliding 1.5 MeV electrons with a Mo target were used for the irradiation. Low-temperature FTIR profiles showed a complete removal of all of the OH-related absorption bands from two of the three blocks that had been vacuum-swept in the radiation-field. Control blocks were vacuum-swept without the radiation-field. FTIR profiles made on these control blocks showed that the sweeping front had moved only a fraction of the way through the blocks. Low-temperature FTIR measurements showed that the block that was only partially swept in the radiation field was less pure than the other blocks. It was also inhomogenous. The removal of hydrogen by vacuum-sweeping in a radiation-field appears to be permanent; annealing a sample in air at 500/spl deg/C did not reintroduce any OH-related absorption bands.