Stark spectroscopy of high-lying odd parity levels in atomic samarium

We have performed a series of experiments to observe 11 Stark-induced E1 transitions from the 15650.55 cm^-1 level to higher levels with odd parity in samarium (Sm) with optical double-resonance technique. Five Stark-induced E1 transition to the 28233.08, 28613.22, 28913.97, 29041.31 and 29130.03 cm^-1 levels have been observed. In order to investigate the contributors to the Stark-induced E1 transition, we have measured scalar and tensor polarizabilities for the observed Stark-induced E1 transitions. Clear Stark splittings were observed for the levels 28233.08 and 28613.22 cm^-1, and their tensor polarizabilities were determined for each isotope. Scalar polarizabilities were determined for the 28233.08, 28613.22, 28913.97 and 29130.03 cm^-1 levels for the first time. Among them, scalar polarizability for the 28233.08 cm^-1 level was the largest in magnitude and was 3.60(10) x 10³ kHz/(kV/cm)² for Sm. We noticed that both scalar and tensor polarizabilities of the 28233.08 cm^-1 level depend on the isotope; the difference of magnitude of the scalar and tensor polarizabilities between Sm and Sm were remarkably large and were about 10 and 6 percent, respectively.Received: 10 February 2003, Published online: 30 July 2003PACS: 32.60.+i Zeeman and Stark effects - 32.10.Dk Electric and magnetic moments, polarizabilityD. Angom: Present address: Physical Research Laboratory, Navarangpura, Ahmedabad 380 009, India.