[en] This document lists numerical data on activation detector materials, on detection reactions involved, and on radionuclides produced. The data are mainly taken from existing evaluations. Where evaluations were missing, unknown or obsolete, data were taken from recent literature. The detection reactions considered were selected on the basis of available information of its use for reactor neutron measurements. To the opinion of the Euratom Working Group on Reactor Dosimetry this document may contribute to the creation of a common data set for all laboratories working in the field of reactor neutron metrology. It is expected that after one or two years an updated and revised guide will be issued. A second part will give numerical data for fission reactions. The present document supersedes the previous report ECN-37