Louis Slotin
Who was Louis Slotin?
Canadian physicist and chemist (1910-1946)
Biographical data adapted from Wikipedia’s article on Louis Slotin (CC BY-SA 4.0).
Biography
Louis Alexander Slotin was born on December 1, 1910, in the North End of Winnipeg, Manitoba, Canada, an immigrant neighborhood that strongly influenced his early life. He went to St. John's High School in Winnipeg and then attended the University of Manitoba, where he earned his Bachelor of Science and Master of Science degrees. In 1936, he went to England to complete his doctorate in physical chemistry at King's College London, becoming a skilled scientist at a young age.
After his doctoral studies, Slotin joined the University of Chicago as a research associate, where he helped design a cyclotron. His skills in experimental physics caught the attention of those involved in the Manhattan Project. In 1942, he was invited to join this effort at Los Alamos, New Mexico, where he played a key role in figuring out the critical mass of materials like uranium and plutonium. This vital work put him in daily contact with great physical risks.
Slotin became very skilled and confident in nuclear experiments, earning a reputation as one of the most knowledgeable in criticality testing at Los Alamos. He used a technique that involved manually bringing two halves of a beryllium reflector close to a plutonium core, then separating them before a chain reaction could sustain itself. While his colleagues recognized his skill, many saw this method as risky, often referring to it as "tickling the dragon's tail."
On May 21, 1946, during an experiment, Slotin's screwdriver slipped, causing the beryllium hemispheres to close fully around the plutonium core. This set off a brief but intense nuclear chain reaction, marked by a blue flash and a burst of hard radiation. Slotin quickly pulled the assembly apart with his bare hands, stopping the reaction and likely saving the lives of the other seven people in the room. However, he absorbed a massive radiation dose and was rushed to the hospital.
Slotin died nine days later on May 30, 1946, becoming the second person to die from a criticality accident. He was 35 years old. The plutonium core involved in his accident was the same one that had caused the death of Harry Daghlian the previous year and was known as the "demon core" at Los Alamos. The U.S. government honored Slotin as a hero for his quick action, although later reviews showed he had ignored safety protocols and that the accident could have been avoided. His death led to major changes in the procedures for criticality testing.
Before Fame
Louis Slotin grew up in Winnipeg's North End, a neighborhood mostly filled with Eastern European Jewish immigrants, just like his family. His surroundings were modest but filled with intellectual energy, and he showed an early talent for science and mechanics. He finished secondary school at St. John's High School before attending the University of Manitoba. There, he stood out in the sciences and earned both a bachelor's and a master's degree.
When he chose to pursue a doctorate at King's College London, he was joining one of the top centers for physical chemistry at a time when atomic and nuclear science were rapidly advancing. After getting his PhD in 1936, he came back to North America and joined the University of Chicago, where groundbreaking work on particle accelerators was happening. These years of learning and experimenting led him straight to the most impactful scientific project of the twentieth century.
Key Achievements
- Earned a doctorate in physical chemistry from King's College London in 1936
- Contributed to the Manhattan Project by conducting critical mass experiments on uranium and plutonium cores
- Participated in the assembly and testing of nuclear devices at Los Alamos, including work connected to the Trinity test
- Prevented the deaths of seven colleagues by immediately terminating a runaway nuclear chain reaction at the cost of his own life
- Assisted in the design of a cyclotron at the University of Chicago as a postdoctoral research associate
Did You Know?
- 01.The plutonium core involved in Slotin's fatal accident had already killed another scientist, Harry Daghlian, in a separate criticality incident in 1945, leading researchers to nickname it the 'demon core.'
- 02.Slotin used a flathead screwdriver to keep two beryllium reflector hemispheres apart during criticality experiments, a technique widely criticized by colleagues as unnecessarily dangerous.
- 03.After the accident, Slotin drew a diagram from memory showing exactly where each person in the room had been standing, which allowed doctors to estimate the radiation dose received by each individual.
- 04.Slotin is believed to have received a radiation dose of approximately 1,000 rads, roughly ten times the dose considered lethal for fifty percent of exposed individuals.
- 05.Despite having no formal training as a weapons designer, Slotin became one of the primary assemblers of nuclear cores at Los Alamos and was present at the Trinity test in 1945.