Impact of the target material surface layer on neutron yield and target lifetime of the neutron tube

Abstract

The neutron yield and target lifetime of a neutron tube are affected by the target materials, the oxide layer and the overcoat layer on the target film. Target lifetime can be improved by adopting alloy instead of pure titanium. The neutron yields of pure titanium target and 200 nm oxide titanium target are simulated by SRIM, which are in good agreement with the experimental results. The neutron yield and target lifetime are calculated at different deuterium energy and alloy targets with variable surface layers. The protective overcoat layers include Pd, Ni and Al. The simulated results show that oxide layer reduces the neutron yield, and the thicker the oxide layer is, the less the neutron yield is. The target lifetime is increased by using the alloy targets, in which the scandium-titanium alloys has a higher lifetime. Meanwhile, depositing a protective overcoat on the target film surface can increase the neutron yield and extend the target lifetime of the neutron tube. In order to meet the requirements of long lifetime and high yield neutron tubes in different applications, the target was optimized theoretically.