Interaction rate of polystyrene fiber optics with pseudocumene-based liquid scintillator

To quantify the risk of using wavelength shifting fiber immersed in pseudocumene-based liquid scintillator, we have measured the rate of reaction of the polystyrene core of this fiber with solutions of pseudocumene dissolved in mineral oil. The rate of reaction drops rapidly with concentration. For samples below 17% pseudocumene by volume, the amount of core that reacted in 18 months was less than our measurement limit of 6μm.