Contents lists available at ScienceDirect Nuclear Inst. and Methods in Physics Research B journal homepage: www.elsevier.com/locate/nimb KMMRAE structure and Sawada lines of Co, Ni, Cu, Zn and Ga B. Seetharami Reddy a, ⁎ , K. Ram Narayana b , S. Abdul Sattar c , V. Koteswara Rao a a Nuclear Physics Department, Andhra University, Visakhapatnam 530 003, India b B.G.B.S. Women’s College, Narsapur 534 275, India c Nitte Meenakshi Institute of Technology, Bangalore 560 064, India ARTICLE INFO Keywords: KMMRAE Sawada lines WDXRF ABSTRACT Kβ spectrum of Co, Ni, Cu, Zn and Ga generated by photoexcitation is studied using a WDXRF spectrometer. KMM RAE structure is de-convoluted into six components. The energy shift of the peaks of these components relative to the diagram line is determined and compared with various theoretical estimates available. The in- tegrated relative intensity of KMM structure is measured. The energy and relative intensity of Sawada lines and Kβ 5 peaks are also measured. 1. Introduction The diagram line Kβ 1,3 arises out of 3p-1s transition. On either side of this, weaker lines called satellites appear. Those on the higher energy side are called the high-energy satellites and the ones on the lower side, the low energy satellites. High energy satellites are interpreted as arising out of M−K transitions in the presence of spectator L holes which are designated as KβL n where n stands for the number of L holes. As per Åberg [1], a widely accepted interpretation of these satellites occurring on the low energy side of the Kβ 1,3 diagram line, is that they are KMM RAE (Radiative Augur Emission) peaks. In this RAE phe- nomenon, a hole in the inner shell is flled by a transition of an electron from an outer shell, while simultaneously another outer shell electron is excited and either flls an unoccupied atomic bound state or ejected to the continuum, the former being called a shake-up process and the later a shake of process. Obviously, RAE competes with the emission of the corresponding diagram line. If it occurs through flling of a K-hole by an M j electron with an M k electron, flling an unflled atomic bound state or getting ejected to the continuum, the transition is termed as KM j M k RAE. Thus, these lines are designated by a similar nomenclature followed in the case of non-radiative Auger emission. The RAE X-ray emitted shares its energy with the excited Auger electron. KMM RAE lines were studied by Budnar et al. [2] by proton excitation in Ca, Ti and Cr compounds. Utrianien et al. [3] measured KMM RAE relative intensities for elements in the Z range 15 to 22 by electron excitation and K, Ca, Sc, Ti, V, Cr and Mn by Raju et al. [4] and Ca, Ti, Fe, Zn and Ge by Verma [5] by photon excitation. Sermova et al. [6] and Keski- Rahkonen et al. [7] measured the relative yields of these lines for the elements in the Z range 23–30. But their intensities are lower than theoretical values by factor of more than two. Nigam and Soni [8] computed KMM RAE edge energies for the elements in the Z range 13–44. Similar to KMM RAE, satellites that are observed on the low energy side of Kα diagram line are interpreted as KLLRAE lines. These were studied for silica, phosphate and sulfate by Abrahams et al. [9], for F, Na, Mg, Al, Si, P, S, Cl, K and Ca by Takahashi et al. [10] and for Fe, Co, Ni and Cu by Koo [11]. Kawai et al. [12–14] noted that RAE and X-ray absorption fne structure (XAFS) are similar. They demonstrated this for Na [15], Mg [16–18], Al [13, 14, 19, and 20] and Si [21–25]. Owing to this, Kawai et al. [26] coined the term extended X-ray emission fne structure (EXEFS) for RAE satellites. A theoretical basis was also provided for the similarity between EXEFS and XAFS [27–29]. This EXEFS was used to study some semi-conductor wafers [20] and to analyze some environ- mental samples [30]. Despite XAFS being a very useful analytical techniques for structural analysis, it is rather prohibitive cost wise as it requires usually a synchrotron facility, while as EXEFS can be harnessed for this purpose using a conventional WDXRF spectrometer [31]. As there is considerable potential for employing EXEFS as an analytical tool, more data need to be generated on RAE. Moreover as pointed by Török et al. [32] since the integrated intensity of KMM RAE lines is generally a few percent of the intensity of Kβ diagram line, some im- provement in the accuracy of ftting K X-ray lines in the X-ray spectra of elements in the range 22 < Z < 37, measured by Si(Li) detector, as for example in the case of PIXE analysis, can be achieved if the intensity of these lines is also included in the ftting model, though they are not detected by the Si(Li) detector. https://doi.org/10.1016/j.nimb.2019.04.005 Received 19 February 2019; Received in revised form 1 April 2019; Accepted 2 April 2019 ⁎ Corresponding author. E-mail address: seetharam.byreddy@gmail.com (B. Seetharami Reddy). URL: https://orcid.org/0000-0002-9849-4517 (B. Seetharami Reddy). Nuclear Inst. and Methods in Physics Research B 448 (2019) 43–51 Available online 09 April 2019 0168-583X/ © 2019 Elsevier B.V. All rights reserved. T