The Demon Core Claims Slotin: Nuclear Dangers Exposed
Physicist Louis Slotin received a lethal dose of radiation on May 21, 1946, while performing a criticality experiment on the same plutonium core that had killed Harry Daghlian eight months earlier. The core was nicknamed the "demon core." Slotin was holding two beryllium half-spheres around the core using only a screwdriver as a spacer when the screwdriver slipped, allowing the spheres to close and the assembly to go supercritical. Slotin reflexively pulled the top hemisphere off, ending the chain reaction in less than a second but absorbing an estimated 1,000 rad of radiation. He walked out of the lab, told his colleagues their dosages, and died nine days later of acute radiation syndrome. The accident prompted Los Alamos to ban all hands-on criticality experiments.
May 21, 1946
80 years ago
Key Figures & Places
Los Alamos National Laboratory
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Louis Slotin
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criticality incident
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demon core
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Louis Slotin
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Criticality accident
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Demon core
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Los Alamos National Laboratory
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May 30
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August 21
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Plutonium
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Acute radiation syndrome
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