Knowledge Bank

We have used an electron-beam source which is modulated at different radio frequencies for exciting the spectra of $ammonia1(NH3)$ and $ND3$ gases. A 0.5-meter seya-Namioka monochromator is used with an EMI 6256-B photo-Multiplier to record the spectra around 2530 {\AA}. The phase-shift between the input excitation and the emitted radiation is related to the lifetimes of the excited state $d1\Sigma$ of NH and ND. The cascading lifetime parameters are calculated. The individual rotational lifetime for the P, Q, and R branches is measured. The possibility of the predissociation of this state will be $discussed.2$.