Narrow Results

About 40 subjects of PIXE have been studied in various research fields at Nishina Memorial Cyclotron Center (NMCC), and many satisfactory results have been obtained and reported. As the results, samples to be analyzed are highly diversified both in form and in elemental composition. Among them, samples most hard to be dealt with by PIXE are ones which contain a great quantity of specific elements. In order to solve this problem, we have developed and tried various absorbers which are specially designed for each kind of sample and are capable of decreasing some distinguished x-ray peak and making x-ray spectra gentle-sloping. It is found that not only the measuring time is fairly shortened but also highly sensitive and highly accurate analysis can be performed for each sample only by selecting absorbers.

A standard-free method developed by ourselves has been applied to bio-medical samples of less than 1 mg or less than 1 μl, to which an ordinary internal standard method can not be accurately applied. As the result, correct values of potassium concentration in NIST-Bovine liver samples of nearly 0.5 mg were obtained. Furthermore, the standard-free method has been applied to small quantity of serum and whole-blood samples, and satisfactory results were obtained. For samples which easily peel off from a backing film, such as serum and whole blood, a carbon tape with an adhesive agent was also used as a backing film, and it is found that this method is also applicable. Moreover, the standard-free method was confirmed to be effective for a case where a specially designed x-ray absorber is used.