10 th International Conference on Particle Induced X-ray Emission and its Analytical Applications PIXE 2004, Portorož, Slovenia, June 4-8, 2004 http://pixe2004.ijs.si/ 404.1 The IAEA PIXE/RBS Facility: developments and applications S. Bamford, A.Markowicz, E. Chinea-Cano, and D. Wegrzynek Instrumentation Unit, Agency's Laboratories Seibersdorf, IAEA, A-1400 Vienna, Austria. M. Jakšić, I. Bogdanović Radović, and M. Bogovac Ruđer Bošković Institute, Zagreb, Croatia ABSTRACT A dedicated PIXE/RBS beam line at the Tandem Van de Graaff accelerator of the Ruder Boskovic Institute in Zagreb, Croatia, has been equipped by the International Atomic Energy (IAEA) in order to provide both training and analytical support services to Agency laboratories in Seibersdorf and to some member countries of the IAEA. The development of new data acquisition software SPECTOR and study of the influence of the proton elastic scattering data on the accuracy of RBS analysis as an input to quantitative PIXE analysis are the two main activities described here. Some examples of PIXE analysis on different sample types are presented as well.. Keywords: data acquisition system/software, PIXE/RBS optimization and analysis. Correspondence to: S. Bamford, Instrumentation Unit, IAEA Seibersdorf Laboratories, A-2444 Seibersdorf, Austria, E- mail: S.A.Bamford@iaea.org , Tel: +43 1 2600 28244, Fax: +43 1 2600 28222: 1. INTRODUCTION The IAEA beam line at the Tandem Van de Graaff accelerator of the Ruder Boskovic Institute in Zagreb, Croatia, has been equipped recently with a scattering chamber for the performance of routine measurements using conventional broad ion beam analysis techniques. The chamber is equipped with sample changer, Si(Li) detector for PIXE, Ge detector for PIGE and particle detector for RBS. A new user-friendly data acquisition system SPECTOR [1] has been adopted for routine PIXE analysis, enabling also control of sample changer and fine sample positioning. This system also has possibility for use in other multi-parameter experiments, such as ion beam and x-ray microprobe, nuclear physics experiments, IEE and TOF ERDA, high resolution PIXE, etc. In order to increase reliability of PIXE analysis, particular attention has been given to RBS quantification as an important input to PIXE quantification. The RBS results were also provided as an input (after an one time a priori determination) to conventional tube-excited x-ray fluorescence spectrometry in extending and improving quantitative XRF analysis performed in IAEA Seibersdorf Laboratories. Results of recently performed analysis of aerosol-loaded filters from an industrial area, and samples from different species of tropical timber are also presented here. 2. EXPERIMENTAL The experimental set-up of the IAEA beam line at the Ruder Boskovic Institute in Zagreb, Croatia, consists of a universal scattering chamber of octagonal shape, a 16-position sample changer, and an electron suppression electrode placed in front of the sample holder in order to increase reliability of the charge measurement. Since the preferable ion beams used for PIXE are 3 MeV protons, RBS measurements were also done using the same conditions. Beam current was in most cases kept typically low at about 1 nA with the 5 mm diameter collimated beam. A silicon particle detector for RBS was positioned at the 165º in respect to the beam direction, while the Si(Li) detector for PIXE was at the 135º. Solid angles of both detectors were adjusted in a way to maintain similar count rates of both x-rays and backscattered particles. Figure 1 below shows the schematics of the data acquisition system.