sentences:  During his visit to Caltech in 1932–33, together with H. Richard Crane and Charles Christian Lauritsen, he discovered a method for producing neutron beams, by bombarding lithium or beryllium nuclei with accelerated deuterons.He was appointed professor at Warsaw University in 1947, a member of the Polish Academy of Sciences in 1952, and in 1955 he became the first director of the Institute of Nuclear Research in Świerk, Otwock County near Warsaw, now known as the National Centre for Nuclear Research.He served as President of the Polish Physical Society between 1952–1955.