摘要:

Tabulations are presented of the atomic form factor,F(&agr;,Z), and the incoherent scattering function,S(x,Z), for values ofx(=sin &Vthgr;/2)/&lgr;) from 0.005 A˚−1to 109A˚−1, for all elementsA=1 to 100. These tables are constructed from available state‐of‐the‐art theoretical data, including the Pirenne formulas forZ=1, configuration‐into action results by Brown using Brown‐Fontana and Weiss correlated wavefunctions forZ=2 to 6 non‐relativistic Hartree‐Fock results by Cromer forZ=7 to 100 and a relativisticK‐shell analytic expression forF(x,Z) by Bethe Levinger forx≳10 A˚−1for all elementsZ=2 to 100. These tabulated values are graphically compared with available photon scattering angular distribution measurements. Tables of coherent (Rayleigh) and incoherent (Compton) total scattering cross sections obtained by numerical integration over combinations ofF2(x,Z) with the Thomson formula andS(x,Z) with the Klum‐Nishina Formual, respectively, are presented for all elementsZ=1 to 100, for photon energies 100 eV (&lgr;=124 A˚) to 100 MeV (0.000124 A˚). The incoherent scattering cross sections also include the radiative and double‐Compton corrections as given by Mork. Similar tables are presented for the special cases of terminally‐bonded hydrogen and for the H2molecule, interpolated and extrapolated from values calculated by Stewart et al., and by Bentley and Stewart using Kolos‐Roothaan wavefunctions.

ISSN:0047-2689    

DOI:10.1063/1.555523

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

A survey of the electron affinity determinations for the elements up toZ=85 is presented, and based upon these data, a set of recommended electron affinities is established. Recent calculations of atomic electron affinities and the major semiempirical methods are discussed and compared with experiment. The experimental methods which yield quantitative electron binding energy data are described and intercompared Based primarily upon extrapolation techniques, fine structure splittings for these ions and excited state term energies are given.

ISSN:0047-2689    

DOI:10.1063/1.555524

出版商:AIP    

年代:1975

数据来源: AIP

摘要:

An electron swarm consists of a small number densitynof electrons in a gas of much higher number densityN. The mean energy and energy distribution of such a swarm are determined by the value ofE/NwhereEis the electric field. At any given valueE/Nthe swarm may be characterized by the values of eight parameters, viz; drift velocity, diffusion coefficient. (diffusion coefficient/mobility, excitation coefficient, electron attachment coefficient, electron detachment coefficient, ionization coefficient, recombination coefficient. In this survey, data on these parameters obtained by a variety of experimental techniques are collected, discussed, and compared graphically. Also included on the graphs are computed values of the parameters obtained in many cases from cross sections and energy distributions chosen to give the best fit with the swarm data. Selected tabulations of the data are also given except in cases for which the accuracy of the data is not sufficient to warrant numerical presentation. The mean energy of the electron swarms ranges from thermal to several electron volts and the gases for which data are given are the rare gases, the common molecular gases (H2, N2, O2, CO, NO, CO2, NO2) and air. The survey also contains an extensive bibliography which includes references (i) to publications on electron swarms in a much wider range of gases than those for which data are given and (ii) to papers concerned with energy distributions, conductivity and ionization coefficients in crossed electric and magnetic fields in addition to those relating to the eight parameters listed above.

ISSN:0047-2689    

DOI:10.1063/1.555525

出版商:AIP    

年代:1975

数据来源: AIP