Hannover 2003 – wissenschaftliches Programm
Q 45.6: Poster
Donnerstag, 27. März 2003, 16:30–18:30, Lichthof
Experimental study of the Ca2 1S+1S Asymptote — •Olivier Allard, Christian Samuelis, Asen Pashov, Horst Knöckel, and Eberhard Tiemann — IQO, University of Hannover, Germany
Recently we reported on a high resolution Fourier transform spectroscopy which allowed us to accurately describe more than 99.8% of the Ca2 X1Σg+ potential well . For the description of the potential energy curve (PEC) at long internuclear distances, information on high vibrational levels was collected using the filtered laser excitation technique. The outer classical turning point of the last observed level is at 20 Å and lies only 0.20 cm−1 below the dissociation limit. For determining the reliability of the PEC for the prediction of cold collision phenomena it is of importance to estimate the uncertainty on the long range model parameters. Analysis based solely on the experimental data set and involving a Monte Carlo simulation permited to determine the uncertainty on the dissociation energy to 1069.868 ± 0.010 cm−1, and on the van der Waals coefficients C6 = 1.003 ± 0.033 ·107 cm−1 Å6. The scattering length a is positive and varies within the interval 250 a0 to 1000 a0 showing that a Bose-Einstein condensate of calcium would be stable .
 O.Allard et al., Phys. Rev. A, 66, 042503 (2002)
 O.Allard et al.,www.arxiv.org/abs/physics/0210029