As early as the 1960’s, an ion source based on reflex‐type discharge was established which was expected to be highly effective in producing negative ions [1,2]. From the first, considerable discrepancies were observed between the source emissive abilities and numerical estimates of the latter; however, in obtaining such estimates, nothing but the reaction of electron dissociative attachment to non‐excited H2molecules was taken into consideration. A further attempt to explain the discrepancy assumed that all of the H−ions generated in the discharge column are collected towards the emission slit [2].In this paper, we present the theoretical and experimental results concerning the source, and discuss the processes of H−production and loss in the light of our most up‐to‐data knowledge [3,4,5].