In the summer of 1949, she traveled to Oak Ridge National Laboratory (ORNL), sponsored by the Rockefeller Foundation, to participate in a training course on the use of radioisotopes for research in nuclear physics, medicine, and agriculture. At UPR she was member of the Cosmic Rays Laboratory and the director in 1953-1954. In this period, her research focused on cosmic radiation measurements. With funding from the Research Corporation and the Office of Naval Research, she and physicist Jesús Dávila Aponte investigated the range distribution of μ-mesons at sea level. Later they conducted a study to measure underground cosmic radiation. She also collaborated in a study, led by Amador Cobas, to measure the variation of cosmic rays at higher altitudes. The experiments were conducted using globes that contained photographic plates sensitive to protons and beta rays.