SAMPLE PREPARATION OF ARCHAEOLOGICAL MATERIALS FOR PIXE ANALYSIS

A method to prepare thin samples of archeological materials such as po tteries and bones for PIXE analysis is presented. In this method fine powder of the matter under analysis is suspended and deposited on poly carbonate filters. The process takes place in a chamber where clean ai r and the powder are mixed and forced to pass through the filter. Thin samples with typical mass density of about 50 mug cm-2 are obtained. The uniformity of the mass deposit has been optically tested with a He -Ne laser showing fluctuations of the order of one percent. Samples of clay standards from NIST were prepared with this method and analyzed by PIXE. The agreement between our results and NIST values is very goo d, with linear correlation factors close to unity. The method was appl ied to study the elemental composition of clay from different fragment s of a Chilean pre-Hispanic pottery piece. These results are very cons istent showing that the analysis of samples from a small fragment can represent the whole piece.