Discovery of neutron by James Chadwick (1891-1974)

Born in 1891 near Macclesfield, not far from Liverpool, of middle class parents, Chadwick spent his boyhood in that region.

He received his secondary school education in Manchester where a special aptitude for mathematics and science soon became apparent.

Chadwick received a First Class Horns Degree in 1911 from Victoria University of Manchester and his external examiner being J.J Thomson, discoverer of the electron.

Chadwick earned his Master of Science degree in 1913 and PhD from Cambridge in 1921. In 1921 he became a fellow of Gonville and Caius College, Cambridge and two years later was appointed assistant director of radioactive research at the Cavendish Laboratory.

The discovery of the neutron was made in 1932. Chadwick knew that when α-particles from polonium hit beryllium foil, very penetrating radiation was emitted. He took three years for Chadwick to find a way to detect the presence of any neutrons he created in this way. He used a strong electrical field to deflect α-particles.

Chadwick proved that the radiation consisted of uncharged particles, each of mass about the same as a proton. In other words, Chadwick showed that the radiation was composed of high-speed neutron.

The existence of neutron was predicted by Rutherford in a 1920 lecture, and by mid 1920s, Chadwick was obsessed with the search for Rutherford’s uncharged proton-electron.

Chadwick’s discovery of the neutron not only explained the hitherto unresolved problem of just what particles composed the nuclei of atoms but also gave a powerful tool to explore the nature of these nuclei.
Discovery of neutron by James Chadwick (1891-1974)

History of Cavendish laboratory

The Cavendish Laboratory is probably one of the most famous scientific institutions in the world.

The Royal Commission on the University having in 1850 published evidence of the needs of science.

Established in 1871, at a time when Cambridge University was being reformed by Parliament, the Cavendish Laboratory initially met with stiff resistance from those who sought to maintain the prestige and reputation of the Mathematical Tripos.

Construction work began soon after and Cavendish Laboratory was formally opened on June 16, 1874. The laboratory became the site of the natural sciences practical examinations and starting with the Lent term of 1877, also became the site of the Elementary Experimental Lectures.

The Laboratory cost about £ 6,300 and the family name of Cavendish had been linked with science in the person of the great Henry Cavendish came forward and offered to bear the cost of the building.

The professorship was established in 1871.

The Cavendish Laboratory officially became a graduate school in 1895. Ernest Rutherford was among the first advanced students to arrive at the lab, soon to be followed by other of great talent, including a few guests from the United States.
History of Cavendish laboratory