Knowledge Bank

The inversion spectrum of $ND3$ has been previously observed by Nuckols, Rueger and $Lyons1$ in the region 1500 - 2500 Mc/sec. In the present work some of the hyperfine structure effects were investigated. Satellites due to the nuclear quadrupole moment of nitrogen were observed in several lines. The displacement of these satellites from the corresponding main lines is in agreement with theory and confirms the identification of the lines as given by Nuckols, Rueger, and Lyons. A value $eqQ=4090\pm 20$kc/sec was obtained for the quadrupole coupling constant of nitrogen, which is in good agreement with latest values obtained for $NH3$.$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$ In this work a Stark-Modulated L-band spectrograph was used, employing a cell of dimensions $10\prime \times 6-1/2\prime \prime \times 3-1/2\prime \prime$ in a TEM mode. Half line widths as low as 15 kc/sec were observed.