Two-electron,one-photon transitions in nickel

The two emission lines, Kα₁α₃^h and Kα₂α₃^h resulting from the two-electron transitions $\text{1s}{}^{\mathrm{?2}}\text{→ 2s}{}^{\mathrm{?1}}\text{2p}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}{}^{\mathrm{?1}}$ and $\text{1s}{}^{\mathrm{?2}}\text{→ 2s}{}^{\mathrm{?1}}\text{2p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}{}^{\mathrm{?1}}$ were resolved for elemental nickel. Their measured energies agree well with calculations. Their relative intensity $\text{I(Kα}{}_1\text{α}{}_3{}^{\mathrm{h}}\text{)/I(Kα}{}_2\text{α}{}_3{}^{\mathrm{h}}\text{) ≈}\text{3}\text{4}$ and their intensity relative to that of the Kα diagram lines is about 10^?4. This is some 10⁴ times larger than both theoretical results and the results of ion-atom collision experiments.     

Determination of electron density in an atomic plasma by least-squares fit to the Stark profile

The measurement of electron density by a unique, one-parameter least-squares fit to the Stark-broadened hydrogen emission line is presented. The curve-fit approach utilizes approximately 60–80 points, and provides improved precision in the measurement.A comparison of data obtained by measurement of the width at half-height and by least-squares analysis indicates that the half-width method exhibits substantial systematic errors, generally over-estimating electron density by a factor of 2–3.     

Shock formation distance in real air

A simple derivation of the shock formation distance in spherically symmetric, unsteady, non-equilibrium flow is presented. The one-dimensional unsteady flow and the ideal gas flows emerge as special cases. The results are applied to atmospheric air and the ambiguity and limitations of the shock formation concept are discussed.     

ESR of exchange coupled Cr3+ pairs in the dimer Di-μ-Diphenylphosphinatoacetyl-Acetonatochromium(III) (DPACr)

DPACr is a dimeric phosphinate in which the pairs of Cr³⁺ ions are superexchange coupled via -OPO- bridges. The consequences of site anisotropy and inequivalence are demonstrated in the ESR spectra and can be derived using a perturbation scheme on the appropriate Hamiltonian. First and second order fine structure, multiplet shifts, g-shifts and g-anisotropies are discussed. This dimeric system is the simplest member of a class of poly(chromium phosphinates).     

Observation of pure quadrupole resonance in zinc metal

We report the first observation of nuclear quadrupole resonance (NQR) in Zn metal. A resonance line, which under the assumption of axial symmetry (η=0) corresponds to the $\text{|M| =}\text{3}\text{2}\text{?}\text{5}\text{2}$ transition in the $\text{I =}\text{5}\text{2}$ ground state of ⁶⁷Zn, has been found at v = 4.086(2) MHz at 4.2K. This yields (for η=0) a quadrupole coupling constant of $\text{e}{}^2\text{qQ}\text{h}\text{= 13.620(8)}$MHz, which is the most accurate value currently available.     

Energy dependence of multinucleon transfer reactions induced by 20Ne on 12C

The energy dependence of up to five nucleon transfer reactions induced by ²⁰Ne on ¹²C has been measured in the energy range 150 to 294 MeV. Good agreement is found between the experiment and both DWBA and semiclassical calculations.