OSCILLATOR-STRENGTHS FOR N-II LINES, INCLUDING INTERSYSTEM LINES, ANDTESTS OF THE SPECTROSCOPIC COUPLING SCHEME

We have measured the relative line strengths for a fairly large number of lines of the 3s-3p and 3p-3d transition arrays of N II with a wall -stabilized are source in order to test the quality of recent advanced atomic structure calculations. We have observed significant deviation s from LS coupling for weaker 3p-3d lines and have found that our meas urements agree much better with recent intermediate coupling results. Also, fairly strong intersystem, or spin-forbidden, lines occur for th e N II ion due to a near coincidence of the 3s P-1(0) and 3s P-3(0) le vels. We provide experimental comparison data for two recent calculati ons that differ by a factor of 2 for these intersystem lines.