A computer program for background and multiple peak fitting

Summarization: A computer program is described for the analysis of complex X-ray spectra. The program uses specific functions for the background and peak shapes, which can be easily changed in order to analyse similar spectra of gamma rays and particles. A gradient expansion algorithm is used for the chi-square fitting, adopted for fast and efficient analysis with a small computer, such as a PDP-15 with 24k memory. The regions for the background fitting, as well as an average width and the approximate positions of the peaks, are given once to the computer, then the program can automatically analyse a series of similar spectra.Presented on: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atom

Elemental analysis of water and sediments by external beam PIXE part 4. Aliakmon River, Greece

Summarization: The Aliakmon River originates in the North Western part of Greece, traverses the Western part of Macedonia, and discharges into the Thermaikos Bay in the North Aegean Sea. Proton induced X-ray emission (PIXE) method with external beam was used for the determination of the metallic elements in the waters and sediments of the Aliakmon River. the pH, dissolved oxygen, conductivity, and total phosphate and nitrate concentrations were also monitored in the water samples. Data collected for a 20-month period indicate that the Aliakmon River can be still considered as an unpolluted river.Presented on: Chemistry and Ecolog

Elemental analysis of water and sediments by external beam PIXE part 3: Axios (Vardar) River, Greece

Summarization: The Axios (Vardar) River originates from the south west part of Yugoslavia, transverses Greece, and discharges into the Thermaikos bay in the north Aegean Sea. The proton induced X-ray emission (PIXE) method with external beam was used for the elemental analysis of water and sediment samples, while measurements of water temperature, dissolved oxygen content, conductivity, pH, and the water flow were made in situ. Water samples were also analysed for total phosphates, nitrates, chlorophyll, and BOD. The data collected for a 16-month period indicate that the Axios River is polluted as far as the metal content is concerned; its primary productivity is low and it is slightly enriched during its course into the Greek territory.Presented on: Chemistry and Ecolog

The X-ray continua from proton bombardment of thick targets in He

Δημοσίευση σε επιστημονικό περιοδικόSummarization: Continuous X-ray spectra were obtained from the proton bombardment in helium atmosphere of thick targets of light elements. A computer program was designed for fitting the spectra to any arbitrary function, using a PDP-15 computer with 24k memory. An attempt is made at the description of the X-ray continua by a semiempirical formula, with parameters depending on the atomic number of the matrix elements of the target.Presented on: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atom