RESEARCH ARTICLE Effect of pressure on pressed pellets in XRS Demet Yılmaz 1 | Zeynep Uzuno glu 2 1 Department of Physics, Faculty of Sciences, Atatürk University, Erzurum, Turkey 2 Department of Medical Services and Techniques, Opticianry Programme, Patnos Vocation School, A grı _ Ibrahim Çeçen University, A grı, Turkey Correspondence Demet Yılmaz, Department of Physics, Faculty of Sciences, Atatürk University, Erzurum, Turkey. Email: ddemir@atauni.edu.tr In this study, the absorption experiments which are an application area in XRS are discussed. The effect on the absorption parameters of the pressure applied to make pellet powder samples was investigated. The mass attenuation coeffi- cients (μ m ), mean free paths and half-value layers of samples prepared at dif- ferent pressures were experimentally determined. C 6 H 10 O 5 , VF 4 , CaO and Y 2 O 3 samples were pressed at 1.91, 3.82, 5.72 and 7.63 tons/cm 2 . A variable energy x-ray source from Amersham (AMC.2084) was used in order to irradi- ate the samples at energies 13.39, 19.63, 24.90, 32.06, 36.39, 44.48, 51.70 and 59.54 keV. The photon intensities were measured by using an HPGe detector with a resolution of 182 eV at 5.9 keV. The theoretical radiation absorption parameters were calculated by WinXCOM program. The calculated values were compared with the experimental values. Good agreement has been observed within experimental uncertainties for low pellet pressure. The obtained results show that the radiation absorption parameters change with the amount of pressure applied to the sample. 1 | INTRODUCTION Sample preparation is now by far the most significant source of error in absorption experiments and the ele- mental analysis of materials by XRF. Viewed from this perspective, it is clear that high quality sample prepara- tion techniques and practices are the key to achieving consistent and reliable analytical results. One of the methods sample preparation is to pellet the sample. In the process of making pressed pellets for XRF anal- ysis should be considered as follows: particle size, the choice of binder, the dilution ratio, the amount of pres- sure applied to the sample, thickness and contamination. It is known that X-ray intensity changes depending on pellet pressure. The particle size can directly influence the intensity of the element. The pressure applied to sam- ple can mitigate this effect. X-ray fluorescence intensity increases with applied pressure due to higher sample density. Also, above a certain pressure the X-ray intensity saturates. [1,2] Errors due to this effect can be minimized by keeping sample amount and pressure constant for each pellet that is prepared. With the rapid increase in the use and applications of ionizing radiation in several scientific and industrial areas in the last few decades, providing adequate protec- tion from radiation has become an important concern. Different radiation protection materials were developed in order to reduce the harm of radiation to the human body and environment. The shielding properties of these materials are important research topics in recent years. The pressure effect should be considered in radiation absorption experiments. The pressure affecting sample density can indirectly affect radiation shielding parame- ters. Effective pressure amount should be known in the preparation of shielding materials. Li et al investigated high-pressure pressed powder pellet technique for the analysis of coal by wavelength dispersive X-ray fluorescence (WDXRF) spectroscopy. [3] The authors are observed that the sensitivity, precision and limit of detection for most components in XRF results were improved when the coal sample was pressed at 1600 kN compared with preparation at 400 kN. Zhang et al investigated on high pressure sample preparation method for pressed powder pellet and its application in Received: 31 December 2019 Revised: 11 February 2020 Accepted: 19 March 2020 DOI: 10.1002/xrs.3153 X-Ray Spectrom. 2020;1–7. wileyonlinelibrary.com/journal/xrs © 2020 John Wiley & Sons Ltd 1