The demon core was a subcritical mass of plutonium that was involved in two criticality accidents in 1945 and 1946. The core was involved in the deaths of two scientists, Harry K. Daghlian Jr. and Louis Slotin, who were conducting experiments with the core when they received lethal doses of radiation. After the accidents, the core was recovered and later became part of a larger plutonium stockpile that was used for nuclear weapons testing.
As for whether the demon core still exists, the answer is no. The demon core was never a standalone entity but rather a piece of plutonium that was used for various experiments and then integrated into the US nuclear arsenal. The core was eventually melted down and reprocessed into other plutonium components for use in nuclear weapons.
To understand what happened to the demon core, we need to go back to its origins. The core was originally part of the first atomic bomb, which was detonated at the Trinity site in New Mexico on July 16, 1945. After the test, the plutonium used in the bomb was recovered and sent to Los Alamos National Laboratory for further study.
At Los Alamos, the plutonium was used in a series of experiments to better understand how the material behaved under different conditions. One of these experiments involved the construction of a subcritical mass of plutonium that was surrounded by neutron-reflective material. The idea was to study how the plutonium would respond to the introduction of additional neutrons.
On August 21, 1945, the first criticality accident involving the demon core occurred. Harry K. Daghlian Jr. was performing an experiment that involved adding tungsten carbide bricks to the core to see how it would affect the neutron flux. While moving one of the bricks, Daghlian accidentally dropped it onto the core, causing a sudden increase in the neutron flux and a release of radiation. Despite his best efforts to remove the brick and minimize his exposure, Daghlian received a lethal dose of radiation and died 25 days later.
After the accident, the demon core was recovered and the neutron-reflective material was removed. The core was then used in a series of experiments led by Louis Slotin, who was attempting to measure the critical mass of the core by slowly lowering a neutron-reflective tamper around it. On May 21, 1946, Slotin slipped and the tamper fell, causing a burst of radiation. Slotin was exposed to a lethal dose of radiation and died nine days later.
After Slotin’s death, the demon core was recovered and placed into a larger plutonium stockpile. The core was used in a number of weapons tests, including the Operation Crossroads tests at Bikini Atoll in 1946 and the Operation Sandstone tests at Eniwetok Atoll in 1948. The core was eventually melted down and reprocessed into other plutonium components for use in nuclear weapons.
So, in summary, the demon core no longer exists as a separate entity. The plutonium used in the core was melted down and incorporated into other nuclear weapons components. The legacy of the demon core lives on, however, as a cautionary tale about the dangers of working with radioactive materials and the importance of strict safety protocols. The accidents involving the demon core were among the first criticality accidents ever recorded, and they helped to establish many of the safety guidelines that are still in use today.