HIGH-RESOLUTION FOURIER-TRANSFORM EMISSION-SPECTROSCOPY OF THE A(1)PI-X(1)SIGMA(ALH)-AL-+

The emission spectrum of the A(1) Pi-X(1) Sigma(+) system of AlH, exci ted in a hollow-cathode discharge lamp, has been observed at high reso lution with a Fourier-transform spectrometer. The rotational lines in the 0-0 and the 1-1 bands have been measured with a precision of +/-0. 001 cm(-1). The present measurements provide a considerable improvemen t over the previous data of Zeeman and Ritter [Can. J. Phys. 32, 555 ( 1954)]. The present data, combined with the previous high-resolution m easurements of the 1-0 vibration-rotation band by White et al. [J. Che m. Phys. 99, 8371 (1993)] and the J = 1-0 pure rotational line of Goto and Saito [Astrophys. J. 452, L147 (1995)] have been used to determin e improved constants for the A(1) Pi state. (C) 1996 Optical Society o f America