Level lifetimes in NII and NIII: Apparatus and results

Abstract

The construction of a beamfoil target chamber for level lifetime determinations is described. Results obtained for NII and N III levels are compared to values obtained by other authors, as well as theoretical values resulting from Coulomb approximation and previous Hartree-Fock-Slater approximation calculations. Possible explanations of discrepancies in recorded lifetimes are tendered.

Radiative liferimes in O II obtained from beam-foil experiments

“…The target chamber assembly, spectrometer system, and electronics used, were the same as described by Brink et al [3] and Coetzer et al [4] to cover the wavelength range 200 nm-500 nm. The spectra were recorded at accelerating voltages of I, 0.7 and 0.5 MV and beam currents of 2 gA.…”

Beam-foil level lifetimes in Krypton III

“…The experimental system was the same as that described elsewhere [3,4]. The experimental system was the same as that described elsewhere [3,4].…”

Beam-foil mean lifetimes in Kr II obtained from ANDC analysis

“…CN) accelerator of the CSIR (Council for Scientific and Industrial Research, PO Box 72, Faure 7131, South Africa). The experimental lay-out has been described in detail elsewhere [3] and only a brief account of the data acquisition procedure is presented here. During lifetime measurements the spectrometer (a McPherson model 218 scanning monochromator) was set manually on the peak of the identified wavelength associated with the transition from the upper to the lower level.…”