Characteristics of PIGE Setup with the Dhaka Van de Graaff and its use for Light Element Analysis in Environmental Related Samples

Author
Dr. Engr. A. K. M. Fazlul Hoque
Professor
Natural Sciences
Daffodil Internation University

Abstract

The need for elemental analysis especially related to environment has increased in recent years to a great extent. The analytical need has created a worldwide spurt to develop rapid, sensitive and accurate methods for the determination of trace as well as major elements in various environmental related samples. Proton Induced X-ray Emission (PIXEl has been extensively applied for Air pollution related analysis and multi-element analysis of Environmental, Medical, Biological, Agricultural samples, etc. However this method has limitations in detecting elements with Z<ll using internal beam technique. The limits of detection of elements such as Na, AI and Si are rather poor because of the self-absorption corrections, which strongly depends on the sample matrix, experimental chamber window thickness and also detector window thickness. External beam method that is used extensively for environmental samples is practically limited to elements with Z> 18 due to presence of Argon in air. Moreover, very light elements are not detectable at all in practice.

The Proton Induced Gamma Emission (PIGE) technique, based on the detection of gammarays following (p, y), (p, p’ y) and (p, a ) reactions leading to the emission of gamma-rays, offer a great potential for elemental analysis, especially for the light elements. To complement PIXE for the analysis of light elements, development of PIGE methodology has been in progress in the Van de Graafflaboratory for some years. Sensitivity ofPIGE systems are installation dependent due to background signals which are different for different setups. Over the years the sensitivity of the developed methodology (PIGE) has improved considerably and has now reached a level that can be used for practical applications. In this report the current status of the PIGE setup ¬† capabilities have been discussed. Comparative assessments of the present and previous¬† capabilities of the system have been made to illustrate the progress achieved. At present the Dhaka Van de Graaff laboratory has the capability for the analysis of light elements like F, Na, B, Mg, Si, etc. using the PIGE methodology.