Francis William Aston
Born 1st September 1877 in Harborne, Birmingham,
Died 20th November 1945 at Trinity College, Cambridge.
During its long history Birmingham has played host to many famous scientists such as Matthew Boulton and James Watt (Steam engines) and John Roebuck (Lead chamber process for making sulphuric acid) among others, but Francis William Aston is one of the lesser known members of the scientific community in Birmingham.Although Francis William Aston is best known for his work in the area of Physics, he initially began his university career studying Chemistry and Physics at Birmingham University where he studied the optical properties of organic acids; he wrote a paper on this subject which was published in 1901.
After a short break from the academic world during which he worked as a chemist for a brewer, he returned to academia, being awarded a scholarship to study at Birmingham University where he began building vacuum pumps to investigate the properties of gases in evacuated tubes.
In 1908 he moved to Cambridge under the tutelage of J.J Thompson at the Cavendish Laboratory.
Whilst he was working at the Cavendish Laboratory he obtained definite evidence of the existence of two Isotopes(1) of the noble(2) gas Neon.
(1) The six noble gases are found in group 18 of the periodic table. These elements were considered to be inert gases until the 1960s when it was found that Xenon formed a Fluoride; since then chemical compounds have been formed with most of the noble gases with the possible exception of Helium.
(2) An Isotope is any of two or more forms of a chemical element, having the same number of protons in the nucleus, or the same atomic number, but having different numbers of neutrons in the nucleus or different atomic weights. There are 275 isotopes of the 81 stable elements in addition to over 800 radioactive isotopes and every element has known isotopic forms. Isotopes of a single element possess almost identical properties.
His research into isotopes was interrupted by World War One when he worked at Farnborough investigating new aircraft designs
After the end of the war he returned to Cambridge In 1919 and restarted his work on separation of the isotopes of Neon using electromagnetism, this apparatus would become known as a Mass Spectrograph.
A total of 212 naturally occurring isotopes were found. Aston published many papers and wrote his book ‘Isotopes’ in 1922, later reprinted as ‘Mass Spectra and Isotopes’. He won the Nobel Prize for Chemistry in 1922.
Outside of work he was an enthusiastic sportsman; skiing, rock climbing, tennis and swimming were among the sports in which he excelled. He was also a keen musician playing the piano, violin and the cello.
Francis Aston’s invention of the Mass Spectrograph has paved the way to modern forensic science which can tell where someone was born by the differing Oxygen isotopes in the body, tracing explosives by their Carbon 12/13 ratios, medical applications such as Iodine 131 for thyroid investigations, P.E.T* Scanners using Oxygen 15 and Fluorine 18, the separation of Uranium 235 and 238 and Plutonium 239 for Nuclear Weapons/Nuclear fuel for power stations(depending on the amount of enrichment) and Americium 241 for Ionisation Smoke detectors.
*Positron emission tomography (PET) scan is an imaging test that allows your doctor to check for diseases in your body. The scan uses a special dye that has radioactive tracers.