Berlin 2001 – scientific programme

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A: Atomphysik

A 17: Posters Friday (Spectroscopy)

A 17.20: Poster

Friday, April 6, 2001, 12:30–15:00, AT3

An ANDC Analysis of Decay Curves Obtained by Delayed Coincidence Method — •K. Blagoev, V. Pentchev, and G. Bobcheva — Institute of Solid State Physics, 72 Tz. Chaussee, 1784 Sofia, BULGARIA

The measurement of radiative lifetimes of the excited states nonselective excitation meet the cascading problem, which in beam-foil experiments has been solved employing ANDC analysis [1]. In delayed coincidence method experiments the problem has been settled by decreasing the energy of the electrons and using the multiexponential analysis of the decay curves. In this case the contribution of the cascading is reduced and at threshold measurements one exponential curves could be obtained. This is the reason why ANDC procedure has not been employed in the DC experiments up to now. We apply the ANDC procedure to 7p states of HgII. These states were investigated using B-F method and ANDC analysis [2]. The results differ with data obtained by DC method [3]. For ANDC analysis we use the transitions from upper nd excited states, which have considerable contribution in the cascade repopulation of the 7p states.

[1] L. J. Curtis, R. M. Schectman, J. L. Kohl, D. A. Chojnacki and D. R. Shoffstall, NIM, 90, (1970)207.

[2] S. T. Maniak, J. L. Curtis, R. E. Irving, I. Martinson and R. Hellborg, Phys. Lett. A182(1993)114.

[3] K. Blagoev, P. Bogdanovich, N. Dimitrov and A. Momkauskaite, Phys. Rev A37(1988)4679.