A Priori Method of Using Photon Activation Analysis to Determine Unknown Trace Element Concentrations in NIST Standards
Photon activation analysis detected elements in two NIST standards that did not have reported concentration values. A method is currently being developed to infer these concentrations by using scaling parameters and the appropriate known quantities within the NIST standard itself. Scaling parameters include: threshold, peak and endpoint energies; photo nuclear cross sections for specific isotopes; Bremstrahlung spectrum; target thickness; and photon flux. Photo nuclear cross sections and energies from the unknown elements must also be known. With these quantities, the same integral was performed for both the known and unknown elements resulting in an inference of the concentration of the un reported element based on the reported value. Since Rb and Mn were elements that were reported in the standards, and because they had well identified peaks, they were used as the standards of inference to determine concentrations of the unreported elements of As, I, Nb, Y, and Zr. This method was tested by choosing oth.