Born with the Curie curiosity
James Williams charts the achievements of Irne and Frederic Joliot-Curie, who were awarded a Nobel Prize for their work.
The names of Pierre and Marie Curie are beacons in science and the story of the discovery of both polonium (named after Marie's home country, Poland) and the much more famous radium is well known. Marie Curie is often hailed as the single most famous and important woman in the history of science. Her achievements, along with those of her husband Pierre are well documented; Marie's coining of the term radioactivity heralded a new age in physics and chemistry and their work led to a greater understanding of the structure of the atom. After the discovery of radium, the Radium Institute, established in Berlin, even encouraged patients to breathe in the radioactive emissions from radium, oblivious for some time of its harmful effects.
Less well known is the story of the Curie's daughter Irne and the work that she and her husband Frederic carried out on radioactive isotopes. Irene Joliot-Curie was born in 1897 to Pierre and Marie Curie and became a research assistant to them. Frederic Joliot, born in l900, studied engineering and chemistry and, after graduating, also took a position as a research assistant to the Curies. Here he met and finally married Irne in 1926, adopting the Curie name.
The Joliot-Curies' work concentrated on the effects of alpha radiation on different substances, principally metals. Almost by accident they discovered the first artificially created radioisotope by bombarding aluminium with alpha particles. They discovered that after bombardment, the metal became radioactive. To their astonishment they also discovered that a second element, not present in the aluminium at the start, had also been created - phosphorous. The phosphorous was not, however, of the ordinary type as its nucleus had more neutrons than normal, thereby making it radioactive, heavy and unstable. They experimented with other metals and achieved surprising results creating radioactive examples of many common elements, such as radioactive nitrogen and silicon. Their work earned them a Nobel Prize for Chemistry in 1935.
In the late 1930s the threat of a second world war was becoming clear. At this time the Joliot-Curies had started work on nuclear fission with uranium. The prospect of the German army controlling technology such as this concerned them greatly. A key advance in nuclear technology was the production of heavy water - water in which the hydrogen atom is replaced with the heavier deuterium atom. The principal producer of heavy water was Norway. Just a few months before the Germans invaded Norway, the Joliot-Curies persuaded the French government to buy up all the stocks of heavy water.
A further problem arose when the Germans invaded France. The heavy water then had to be smuggled out of the country and across the Channel to England. They became active members of the French Resistance and successfully thwarted any attempts to use existing French installations for the creation of nuclear bombs. Ironically, the bomb that was dropped on Nagasaki, the "fat man", used the radioactive isotope plutonium-239.
After the war Irne and Frederic joined the French Communist Party and thereby alienated themselves from the mainstream scientific community because of their supposedly extreme-Left political views. It was their membership of the party that led to their removal from work on the first European nuclear reactor in 1948. From that point, until their deaths, Frederic in 1958 and Irne in 1956, they were ignored by the community that had only 20 years earlier awarded them the highest of scientific honours, the Nobel Prize.
James Williams is head of the science faculty at The Beacon School, Banstead, Surrey.