Irène Joliot-Curie
Irène Joliot-Curie was a French chemist and physicist who received the 1935 Nobel Prize in Chemistry with her husband, Frédéric Joliot-Curie, for their discovery of induced radioactivity. They were the second married couple, after her parents, to win the Nobel Prize, adding to the Curie family legacy of five Nobel Prizes. This made the Curies the family with the most Nobel laureates to date.
Her mother Marie Skłodowska-Curie and she also form the only mother–daughter pair to have won Nobel Prizes whilst Pierre and Irène Curie form the only father-daughter pair to have won Nobel Prizes by the same occasion, whilst six father-son pairs have won Nobel Prizes by comparison.
She was also one of the first three women to be a member of a French government, becoming undersecretary for Scientific Research under the Popular Front in 1936. Both children of the Joliot-Curies, Hélène and Pierre, are also scientists.
In 1945, she was one of the six commissioners of the new French Alternative Energies and Atomic Energy Commission created by de Gaulle and the Provisional Government of the French Republic. She died in Paris on 17 March 1956 from an acute leukemia linked to her exposure to polonium and X-rays.
Biography
Early life and education
Irène was born in Paris, France, on 12 September 1897 and was the first of Marie and Pierre's two daughters. Her sister was Ève, born in 1904. They lost their father early on in 1906 due to a horse-drawn wagon incident, and Marie was left to raise them. Education was important to Marie and Irène's education began at a school near the Paris Observatory. This school was chosen because it had a more challenging curriculum than the school nearby the Curie's home. In 1906, it was obvious Irène was talented in mathematics. Her mother chose to focus on that instead of public school. Marie joined forces with a number of eminent French scholars, including the prominent French physicist Paul Langevin, to form "The Cooperative", which included a private gathering of nine students who were children of the most distinguished academics in France. Each contributed to educating these children in their respective homes. The curriculum of The Cooperative was varied and included not only the principles of science and scientific research but also such diverse subjects as Chinese and sculpture, and with great emphasis placed on self-expression and play. Irène studied in this environment for about two years.Irène and her sister Ève were sent to Poland to spend the summer with their Aunt Bronia when Irène was thirteen. Irène's education was so rigorous that she still had a German and trigonometry lesson every day of that break. Irène re-entered a more orthodox learning environment by going back to high school at the Collège Sévigné in central Paris until 1914. She then went onto the Faculty of Science at the Sorbonne to complete her baccalaureate, until 1916 when her studies were interrupted by World War I.
World War I
Irène took a nursing course during college to assist her mother, Marie Curie, in the field as her assistant. She began her work as a nurse radiographer on the battlefield alongside her mother. After a few months she was left to work alone at a radiological facility in Belgium. She taught doctors how to locate shrapnel in bodies using radiology and taught herself how to repair the equipment. She moved throughout facilities and battlegrounds including two bombsites, Furnes and Ypres, and Amiens. She received a military medal for her assistance in X-ray facilities in France and Belgium.After the war, Irène returned to the Sorbonne in Paris to complete her second baccalaureate degree in mathematics and physics in 1918. Irène then went on to work as her mother's assistant, teaching radiology at the Radium Institute, which had been built by her parents. Her doctoral thesis was concerned with the alpha decay of polonium, the element discovered by her parents and named after Marie's country of birth, Poland. Irène became a Doctor of Science in 1925.
Research
As she neared the end of her doctorate in 1924, Irène Curie was asked to teach the precision laboratory techniques required for radiochemical research to the young chemical engineer Frédéric Joliot, whom she would later wed. From 1928, Joliot-Curie and her husband, Frédéric, combined their research efforts on the study of atomic nuclei. In 1932, Joliot-Curie and her husband Frédéric had full access to Marie's polonium. Experiments were done using gamma rays to identify the positron. Though their experiments identified both the positron and the neutron, they failed to interpret the significance of the results and the discoveries were later claimed by Carl David Anderson and James Chadwick respectively. These discoveries would have secured greatness indeed, as together with J. J. Thomson's discovery of the electron in 1897, they finally replaced John Dalton's model of atoms as solid spherical particles.In 1933, Joliot-Curie and her husband were the first to calculate the accurate mass of the neutron. The Joliot-Curies continued trying to get their name into the scientific community; in doing so, they developed a new theory from an interesting experiment they conducted. During an experiment bombarding aluminium with alpha rays, they discovered that only protons were detected. Based on the undetectable electron and positron pair, they proposed that the protons changed into neutrons and positrons. Later in October 1933, this new theory was presented to the Seventh Solvay Conference. The Solvay Conferences consisted of prominent scientists in the physics and chemistry community. Irene and her husband presented their theory and results to their fellow scientists, but they received criticism of their findings from most of the 46 scientists attending. However, they were able to build on the controversial theory later on.
In 1934, the Joliot-Curies finally made the discovery that sealed their place in scientific history. Building on the work of Marie and Pierre Curie, who had isolated naturally occurring radioactive elements, the Joliot-Curies realised the alchemist's dream of turning one element into another: creating radioactive nitrogen from boron, radioactive isotopes of phosphorus from aluminium, and silicon from magnesium. Irradiating the natural stable isotope of aluminium with alpha particles resulted in an unstable isotope of phosphorus: 27Al + 4He → 30P + 1n. This phosphorus isotope is not found in nature and decays emitting a positron. This discovery is formally known as positron emission or beta decay, where a proton in the radioactive nucleus changes to a neutron and releases a positron and an electron neutrino. By then, the application of radioactive materials for use in medicine was growing, and this discovery allowed radioactive materials to be created quickly, cheaply, and plentifully. The Nobel Prize for chemistry in 1935 brought with it fame and recognition from the scientific community and Joliot-Curie was awarded a professorship at the Faculty of Science.
The work that Irène's laboratory pioneered, research into radium nuclei, would also help another group of physicists within Germany. Otto Hahn and Fritz Strassman on 19 December 1938 bombarded uranium with neutrons, but misinterpreted their findings. Lise Meitner and Otto Frisch would theoretically correct Hahn and Strassmann's findings, and after replicating their experiment based on Hungarian physicist Leo Szilard's theory that he had confided to Meitner back in 1933, confirmed on 13 January 1939 that Hahn and Strassmann had indeed observed nuclear fission: the splitting of the nucleus itself, emitting vast amounts of energy. Lise Meitner's now-famous calculations actually disproved Irène's results and proved that nuclear fission was possible and replicable.
In 1948, using work on nuclear fission, the Joliot-Curies, along with other scientists, created the first French nuclear reactor. The Joliot-Curies were a part of the organization in charge of the project, the Atomic Energy Commission, Commissariat à l'énergie atomique. Irène was the commissioner of the CEA, and Irène's husband, Frédéric, was the director of the CEA. The reactor, Zoé used nuclear fission to generate five kilowatts of power. This was the beginning of nuclear energy as a source of power for France.
Years of working so closely with radioactive materials finally caught up with Joliot-Curie, and she was diagnosed with leukemia. She had been accidentally exposed to polonium when a sealed capsule of the element exploded on her laboratory bench in 1946. Treatment with antibiotics and a series of operations relieved her suffering temporarily, but her condition continued to deteriorate. Despite this, Joliot-Curie continued to work and in 1955 drew up plans for new physics laboratories at the Orsay Faculty of Sciences, which is now a part of the Paris-Saclay University, south of Paris.
Political views
The Joliot-Curies had become increasingly aware of the growth of the fascist movement. They opposed its ideals and joined the Socialist Party in 1934, the Comité de vigilance des intellectuels antifascistes a year later, and in 1936 they actively supported the Republican faction in the Spanish Civil War. In the same year, Joliot-Curie was appointed Undersecretary of State for Scientific Research by the French government, in which capacity she helped in founding the Centre National de la Recherche Scientifique.Frédéric and Irène visited Moscow for the two hundred and twentieth anniversary of the Russian Academy of Science and returned sympathizing with Russian colleagues. Frédéric's close connection with the Communist Party caused Irène to later be detained on Ellis Island during her third trip to the US, coming to speak in support of Spanish refugees, at the Joint Antifascist Refugee Committee's invitation.
The Joliot-Curies had continued Pierre and Marie's policy of publishing all of their work for the benefit of the global scientific community, but afraid of the danger that might result should it be developed for military use, they stopped: on 30 October 1939, they placed all of their documentation on nuclear fission in the vaults of the French Academy of Sciences, where it remained until 1949.
Joliot-Curie's political career continued after the war and she became a commissioner in the Commissariat à l'énergie atomique. However, she still found time for scientific work and in 1946 became director of her mother's Institut Curie.
Joliot-Curie became actively involved in promoting women's education, serving on the National Committee of the Union of French Women and the World Peace Council. The Joliot-Curies were given memberships to the French Légion d'honneur; Irène as an officer and Frédéric as a commander, recognising his earlier work for the resistance.