Total Neutron Cross Sections Of Compounds With Different Crystalline Structures

The total neutron cross sections of polycrystalline compounds, such as closed packed hexagonal ZnO, body centered cubic TiBr, and face centered cubic CaO and TiC were determined with the Argonne neutron velocity selector and neutron crystal spectrometer in the energy region of 0.001 to 1.0 electron volt. From the size of the cross section peaks which are due to coherent scattering of neutrons the following scattering amplitudes were determined: Ca, +0.46 x 10-l2 cm; Ti, -0.25 x 10-12 cm; T1, +0.75 x 10-12 cm. The previously reported value of +0.58 x 10-12 cm for Zn was confirmed. The free atom scattering cross section of Ca is 2.5 barns.

Neutron Cross Sections presents the principles of cross-section measurement and use, as well as sufficient theory so that the general behavior of cross sections is made understandable. This compilation is a direct result of experiences connected with the collection and evaluation of cross-section data during the past eight years at ""Sigma Centre"", Brookhaven National Laboratory. Here, experimental results received from laboratories throughout the world are carefully evaluated and compiled in the curves and tables of the large volume Neutron Cross Sections, The most recent version of the compilation, known as BNL 325, appeared 1 July 1955, and Supplement 1 to BNL 325 was published on 1 January 1957. The compilation itself consists almost completely of cross sections at specific energies, shown in the form of curves or tables, with only brief explanatory texts. The text opens with discussions of the general properties of cross sections and principles of nuclear structure that are important to the understanding of cross-section behavior. Separate chapters follow that describe specific techniques for measuring cross sections along with experimental results involving fast neutrons, resonance neutrons, resonances in fissionable materials, and thermal neutrons.

Neutron Cross Sections, Volume 2: Neutron Cross Section Curves presents data for total reaction cross sections and related fission parameters as a function of incident-neutron energy. This book covers energy range from 0.01 eV to 200 MeV to exclude crystalline and magnetic effects for slow neutrons and relativistic effects for high energy neutrons. The data in this volume are grouped into sections corresponding to the element of the target nucleus in the neutron-induced reaction. These sections are ordered in increasing atomic number. Within a section, graphical data are presented for the natural element followed by the isotopes of that element in order of increasing atomic mass. A list of the reaction types is provided at the end of each section. This book also provides graphical section, wherein each graphical page is annotated on the outer edge with a symbol for an element or isotope followed by the list of the cross section data for that element or isotope. The data plotted in the graphical section are tagged by a mnemonic consisting of year, laboratory, and author's last name. This tag can be used to find the corresponding reference on the bibliographic pages.

This book provides a comprehensive and up-to-date introduction to the fundamental theory and applications of slow-neutron scattering.