Abstract
Preliminary experiments has been carried out in order to produce Xe128, Kr80, Kr82 and Ar38 tracers from the samples of potassium iodide, ammonium bromide and sodium chloride by the neutron irradiation in the reactor(JRR-2). 0.1-5.0 grams of the samples were irradiated under the thermal neutron flux of 4.3×1012/cm2.sec during 20 minutes.Gamma-rays from irradiated samples were analysed and the existences of Br82, I128 and Na24 were confirmed. After two months from the irradiation procedures, 0.1 grams of the samples were heated at about 1000°C in the vacuum to extract the rare gas products. The extracted gas samples were analysed with a mass spectrometer and the quantities of Xe128, Kr80, Kr82 and Ar38 were roughly estimated to be 6×10-7, 4×10-7, 1×10-7 and 8×10-7 cc STP respectively. Using Xe128 gas, produced in this way, the spikes of 10-9 cc STP were prepared in order to measure the micro amount of Xe130 (double β decay product). The method for the preparation of the spikes was described.