To provide a lid member of a neutron source holder and a mounting method of the lid member, wherein the lid member is constituted of a shutoff plug to be covered on an insertion hole of the neutron source holder, and shutoff plug fixing tools provided on both ends of the shutoff plug, and the lid member is firmly fixed into the insertion hole of the neutron source holder by engaging each tip part of both shutoff plug fixing tools with a circular protrusion of the neutron source holder, to thereby block surely the insertion hole of a neutron source provided on the upper end of the neutron source holder.
This lid member of the neutron source holder for blocking the insertion hole of the neutron source provided on the upper end of the neutron source holder is constituted of the shutoff plug to be covered on the insertion hole of the neutron source holder, and the shutoff plug fixing tools provided on both ends of the shutoff plug, and each tip part of both shutoff plug fixing tools is engaged with the circular protrusion provided on the neutron source holder. Each shutoff plug fixing tool provided on both ends of the shutoff plug is formed to have a rectangular plate piece shape, and has a length projecting from an opening part of the shutoff plug.
SUZUUCHI KOJI
SAKAMOTO HIDEKAZU
