Excitation functions of longer lived radionuclides formed by deuteron irradiation of germanium

Abstract

The cross sections of nuclear reactions induced by deuteron particles on natural germanium were investigated by using the stacked target technique, activation method and standard high resolution gamma spectrometry. Targets were natural germanium, vacuum evaporated onto 25micron thick polyimide (kapton) foils with nominal thickness of about 2μm. The stack was composed of 26 kapton–Ge–Ge–kapton sandwich targets foils and 24 aluminum and 25 titanium foils with nominal thickness of 50 and 11μm respectively. The Al foils served as monitors and at the same time as energy degraders in the high energy part of the stack. Ti foils were included in the stack to monitor the beam parameters in the low energy region. The irradiation was done with 50MeV deuteron particles with a beam current of about 50nA for about 1h. Activation cross sections were determined for production of the 70,71,72,73,74,76As, 69,75,77Ge and 66,67,73Ga radionuclides. The deduced experimental cross sections were compared to the results of theoretical calculations taken from the TENDL-2013 data library based on the TALYS computer code. A comparison was made with available experimental data measured earlier. Thick target yields were deduced from the experimental cross sections and were compared with the data published before. The possible production routes of arsenic radioisotopes are discussed.