In 1961, a group of scientists, constituted by A. Ghiorso, T. Sikkeland, A. E. Larsh and R. M. Latimer, of the Laboratory of Radiation, at the University of California, announced the discovery of the element 103, suggesting the name lawrencium in honor of Ernest O. Lawrence. The irradiation of several isotope of californium with boron ions (B 10 and B 11) and the consequent analysis, using solid state detectors, of the irradiation products revealed a source of alpha particles of 8.6 MeV. They attributed it to the isotope of element 103, with number of mass 257.