Identification of a new neutron-deficient isotope Am-235

A neutron deficient isotope Am-235 has been produced via the reaction Pu-238(p,4n) Am-235 by 35 MeV proton bombardment of Pu-238. The reaction products were transported by the He-jet recoil-transport apparatus. Radiochemical separations were performed by liquid-liquid extraction to isolate the americium fraction from the mixture of the reaction products. The chemically separated Am fractions were used for the X- and gamma-ray measurements. A new neutron-deficient isotope Am-235 was definitely identified from the growth and decay of its daughter, 25.3.min Pu-235 and X-gamma coincidence measurements. The Am-235 half-life was determined to be 15+/-5 min.