Experimental determination of L subshell fluorescence yields of Ba, La and Pr using synchrotron radiation N.M. Badiger a , Edgardo V. Bonzi b, * a Department of Physics, Karnatak University, Dharwad 580 003, Karnataka, India b Facultad de Matema ´ tica, Astronomı ´a y Fı ´sica, Universidad Nacional de Co ´ rdoba, Ciudad Universitaria, 5010 Co ´ rdoba, Argentina Received 9 June 2005; received in revised form 8 August 2005 Available online 21 September 2005 Abstract L subshell fluorescence yields x 1 , x 2 and x 3 have been measured for Ba, La and Pr elemental targets. The characteristic L X-ray pho- tons, induced in the targets by synchrotron radiation, were measured with a Si(Li) detector coupled to multichannel analyzer. Measured L subshell fluorescence yields have been compared with theoretical values, compilation data and other experimental data. Ó 2005 Elsevier B.V. All rights reserved. PACS: 32.50.+d; 32.80.Fb; 32.80.Hd; 33.50.j Keywords: L shells fluorescence; L fluorescence yield; Synchrotron radiations; Photon induced X-ray 1. Introduction Study of X-ray fluorescence has been a subject of exper- imental as well as theoretical interest in recent years [1] in view of their applications for non-destructive elemental analysis in medical physics, environmental science and industry. Precise values of these parameters are needed to check atomic physics theory and the existing models used in predicting theoretical fluorescence parameters. A vacancy produced by the primary radiation in the inner shell of an atom is filled by the radiative and non- radiative transitions. In the case of radiative transition, the inner shell vacancy is filled by the electrons from the higher shells by emitting X-ray photons. The Auger and Coster–Kronig transitions are the non-radiative transi- tions. In Auger transitions, because of the mutual repulsion of two electrons in higher shells, the vacancy can shift from one shell to another shell, whereas in the Coster–Kronig transition, the vacancy is transferred from tightly bound subshell to less tightly bound subshells of the same shell. K shell fluorescence yields have been predicted accurately as the radiative and Auger transition probabilities are known accurately [1]. However, study of L shell fluores- cence yields is interesting because the vacancies produced by the primary photons in the subshells may be redistrib- uted among the higher subshells through Coster–Krong transitions. Campbell [2] has recently presented a critical review on L subshell fluorescence yields x 1 , x 2 and x 3 and Coster–Kronig transitions f ij . Some researchers have calculated L subshell fluorescence yields using different models [3–5]. Krause [3] has carried out a semi-empirical compilation of atomic L i subshell X-ray fluorescence yields x i (i = 1, 2, 3), Auger transition yields a i and Coster–Kronig transition yields f ij for the ele- ments with Z = 12–110. Chen et al. [4] tabulated values of x i for elements with 18 6 Z 6 100 based on the relativistic Dirac–Hartree–Slater (DHS) model. Puri et al. [5] presented theoretical values of x i subshell fluorescence yields calcu- lated using radiative emission rates of Scofield [6] and non-radiative emission rates computed by Chen et al. [7]. L subshell fluorescence yields have been measured by inducing L X-rays in the target by electron beam, proton 0168-583X/$ - see front matter Ó 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.nimb.2005.08.125 * Corresponding author. Tel.: +54 351 4334050; fax: +54 351 4334054. E-mail address: bonzi@famaf.unc.edu.ar (E.V. Bonzi). www.elsevier.com/locate/nimb Nuclear Instruments and Methods in Physics Research B 243 (2006) 34–37 NIM B Beam Interactions with Materials & Atoms