Francis William Aston (Aston Francis William)

(1877-1945)
Awarded the 1922 Nobel Prize in Chemistry for his discovery of stable isotopes and the rules of integer atomic masses. Born September 1, 1877 in Harborne, near Birmingham. From 1889 to 1891 he studied at Harbornskoy parochial school, from 1891 to 1903 - at Malvern College, in 1893 went to Mason College, Birmingham (later the University of Birmingham). In 1898, Foster received a scholarship, but the means to study science is not enough, therefore, studied the chemistry of fermentation, Aston from 1900 to 1903 he worked in a brewery. At the same time he created in his father's laboratory, where he studied electrical discharge in vacuum tubes. For this work, Aston was awarded a scholarship at Birmingham University and since 1903 has continued in its walls, together with research Poynting (studying 'dark space Crookes' in the glow discharge, . found another, . precathode 'dark space', . now called the space of Aston),
. In 1909 Aston became assistant to JJ Thomson at the Cavendish Laboratory at Cambridge University, . where he focused on determining the ratio between the charge and mass of ions in the beam of positively charged particles, . began studying stable isotopes of neon (1913) (this work interrupted by World War I),
. During the war, Aston worked at the Royal Aircraft Center in Farnborough, which investigated the effects of atmospheric conditions on the plating of aircraft.
Returning to Cambridge shortly before the end of the war, he continued his study of isotopes of neon. From 1920 Aston - Member of the Board of Trinity College, Cambridge, in 1921 was elected a Fellow of the Royal Society Londoskogo. In 1919 created a new device - the mass spectrograph that could separate the particles with different mass to charge ratio. With the help of Aston found that the mass of the atoms are integer and that almost all elements have isotopes; discovered 213 stable isotopes of chemical elements, determined their relative prevalence. In 1925 constructed a mass spectrometer with high resolving power, which held a high-precision measurements of the mass elements and discovered a so-called. mass defect, which consists in the fact that the mass of the system of coupled particles (the nucleus of an atom) is not equal to the sum of the masses of particles in the free state. This effect Aston explained the loss of mass by converting it into energy coupling between the particles. Measuring the mass number of isotopes, built the first curve of packing coefficients, characterizing the energy of the nuclei (1927). He opened the isotope uranium-238.

Aston died in Cambridge on Nov. 20, 1945.