Effects of 14-MeV Neutron Irradiation on Optical Components for Fusion Diagnostics

Abstract

Various kinds of optical fibers and related optical components for fusion diagnostics were irradiated with 14-MeV neutrons from OKTAVIAN or RTNS-II. This report shows typical fusion neutron irradiation effects on them and their hardness levels to mean 14-MeV neutron fluences at which their important performance degrades 10%. Also experimental formulas for fusion neutron induced backgrounds of scintillators and a photomultiplier tube are given by fitting their pulse height distributions for 14-MeV neutrons with a summation of exponential functions. These data and formulas are useful for the estimation of lifetimes and background levels of optical fusion diagnostic systems which may be located in the 14-MeV neutron environment of a fusion reactor.

KEYWORDS:

• fusion diagnostic detectors
• fusion neutron damage
• physical radiation effects
• neutron beams
• MeV range 14
• irradiation
• neutron-induced back-ground
• optical components
• optical fibers