This paper deals with the mechanism of bypass channel and mainly discusses the theory, technics and interpretation method of using neutron Lifetime Log(NLL)to evaluate channeling.

A method of measuring positron lifetime is used to investigate temperature dependence of positron trapping at defects in neutron-irradiated silicon crystals.

This article introduces the new logging method which uses Gadolinium-injecting instead of Boron-injecting and uses Neutron-Gamma Logging instead of Neutron Lifetime Logging.