Abstract
In previous papers, we have shown that the least radiation sensitive fibers are drawn from Fluosil and Diasil preforms and that the specific radiation response of these pure-silice core fibers is unequivocally determined by the test conditions. Here we demonstrate that the actual sensitivity levels of such fibers may differ by factors of up to 3-5 from charge to charge. Furthermore, we tested a pure silica core fiber drawn from a new PICVD preform developed by Schott. This plasma impulse chemical vapor deposition process (PICVD) allows the production of preforms for pure-silica core fibers as well as for arbitrarily shaped graded index fibers doped with Ge or F. The new fiber compares favorably with Fluosil SW and Diasil type Fibers, not only as regards the sensitivity levels but also the recovery characteristics.