Setting up of PIGE facility at FOTIA, BARC and its application to Borosilicate Glass Samples for Determination of Fluorine by an Internal Standard Method

Particle Induced Gamma-ray Emission (PIGE) [1] is an important nuclear analytical technique used for determination of light elements like Li, Be, B, F, Na, Mg, Al and Si in diverse matrices. In this technique, beam of charged particles fall on sample surface and nuclear reactions like (p, p’), (p, ) and (p, ). Gamma rays emitted in this process are the signature of a particular nucleus and the numbers of counts are proportional to the concentration of the element in the sample. PIGE is advantageous over PIXE, since it uses gamma-rays, thus experiences less matrix effect. This property helps in applying PIGE for thick samples. It is non-destructive, simultaneous capable and high sensitive some of the light elements like Li, B and F. Determination of F in complex matrix like borosilicate glass is difficult by many chemical methods, involving dissolution and quantitative separation, and also by NAA since it contains B and Na. Fluorine is determined by on-line measurement of prompt  rays of 110 and 197 keV from F(p, p)F as well as 6.1 MeV from F(p, )O by high resolution -ray spectrometry [2]. In beam experiments current normalization is an important aspect. This can be done in two ways: either by taking count rate normalized to the backscattered protons from a thin target like gold kept before the sample or by counting them relative to one of the components (external / internal) which is not an element of interest in the sample to be investigated. The limitation of the first method is the inhomogenities of the gold foils used for samples and standards which in turn reflect in the inaccuracy of F concentration. The second method of internal standard (IS) is advantageous over the first method as it is an in-situ monitor of current variation and does not depend on the sample-todetector geometry. The sensitivity (cps / ppm) of IS is used for the normalized count rate of gamma-ray peak of interest. In the present work, we have standardized an internal standard particle induced gamma-ray emission (IS-PIGE) method to determine fluorine in glass matrix. The element Li, which is almost equal sensitive like F was used as an internal standard. The work was carried out using 4 MeV proton beam obtained from Folded Tandem Ion Accelerator (FOTIA), BARC, Mumbai.