EUROPEAN ATOMIC ENERGY COMMUNITY — EURATOM Joint Nuclear Research Center Ispra Establishment — Italy Reactor Physics Department — Experimental Neutron Physics I Reprinted from THE PHYSICAL REVIEW Vol. 138, No. 1A — 1965 lp WÊ felli iiiJUl'W·! ϊψ :nt was prepared under the sponsorship or the Atomic Energy Community (EURATOM). Neither the EURATOM Commission, its contractors nor any person acting on their behalf : ' — Make any warranty or representation, express or implied, with respect to the accuracy, completeness, or usefulness of the information contained in this document, or that the use of any information, apparatus, method, or process disclosed in this document may not infringe privately owned rights; or WW Ce tiréàpart est exclusivement destiné à une diffusion restreinte. Il reprend, avec l'aimable autorisation de l'éditeur, un article publié dans « THE PHYSICAL REVIEW » Vol. 138 1965, No. ΙΑ, uam « xrxis, Í"ÍJJ^^^"JJ»' " " " <"· ^u ¿.sus, i.u. J.*·., A143A147. Tout autre exemplaire de cet article doit être demandé à Street, New York, American institute of Physics, 335 East 45 Ν.Y. 10017 (USA). ^«Íwíía^fiM! Mw iimiïïmmmwWiïm Questoestratto è destinato esclusivamenteaduna diffusione limitata. Essoèstato riprodotto, per gentileconcessione dell'Editore, da «THEPHYSICAL REVIEW» Vol.1381965, No. ΙΑ, A143A147. Ulteriori copie dell'articolo debbonoessere richieste a American Institute of Physics, 335 East 45 Street, New York, NY.