Displacement damage in optocouplers induced by high energy neutrons at back-n in China Spallation Neutron Source

Neutron radiation experiments of optocouplers at back-streaming white neutrons (back-n) in China Spallation Neutron Source (CSNS) are presented. The displacement damages induced by neutron radiation are analyzed. The performance degradations of two types of optocouplers are compared. The degradations of current transfer ratio (CTR) are analyzed, and the mechanisms induced by radiation are also demonstrated. With the increase of the accumulated fluence, the CTR is degrading linearly with neutron fluence. The radiation hardening of optocouplers can be improved when the forward current is increased. Other parameters related to CTR degradation of optocouplers are also analyzed.