THE ABSOLUTE DETERMINATION OF CUMULATIVE YIELD OF SEVERAL NUCLIDES FROM INDUCED FISSION OF 238U BY 5 MeV NEUTRONS

The cumulative yields of 95Zr, 97Zr, 99Mo, 103Ru, 106Ru, 140Ba,143Ce and 147Nd in 238U fission induced with 5.00 MeV neutrons are measured absolutely by radiochemical technique. The neutrons of 5.00±0.17 MeV are produced by reaction D (d, n) 3He on a Van de Graaff accelerator. The neutron fluxes range from 4×108 n/s to 1×109 n/s.The sample target is made of depleted uranium. The standard targets are prepared by molecular plating and the sample targets consist of about 3-4 uranium metal disks each weighing 2 to 3 gramms. The absolute fission rate of the sample target is measured by double fission ionization chamber.By means of modified standard radiochemical procedures the nuclides mentioned above are separated, purified and counted.The cumulative yields determined for the nuclides are listed in the table below.The errors given in the table are total errors including both statistic and systematic ones.