The [17.0](2)Pi(1/2)<- X-2 Pi(1/2) system of AlCa

Laser-induced fluorescence spectroscopy has been used to study supersonical ly cooled AlCa. This study investigates under higher resolution (0.007 cm(- 1)) a single band previously studied and tentatively assigned as the (0-0) vibrational transition of the [17.0](2)Delta(3/2)(?) <-- (XII1/2)-I-2 syste m of AlCa. The resolution of the rotational structure in the present study enabled a definite assignment as a (II1/2)-I-2 <-- (II1/2)-I-2 transition. Analysis of the spectrum gives B-0' = 0.096685(19) cm(-1), (p + 2q)' = -0.0 13078(370) cm(-1), and B-0(") = 0.105518(20) cm(-1). These convert to groun d and excited state bond lengths of r(0)(") = 3.14942(30) and r(0)(') = 3.2 9014(32) Angstrom, respectively. (C) 2000 Elsevier Science B.V. All rights reserved.