Demon Core

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About

Demon Core is a nickname given to a spherical core that was experimented on as a part of the Manhattan Project. The core was involved in two fatal incidents in 1945 and 1946, with one of the incidents caused by severe safety protocol violations as a physicist let a screwdriver, with which a beryllium hemisphere was held, slip. Starting in 2018, the incident gained popularity as a historic reference, particularly among Japanese artists, inspiring memes and fan art of anime girls experimenting with the core.

Origin

Fatal Incidents

The demon core, known as "Rufus" before the incidents, was a spherical 6.2-kilogram subcritical mass of plutonium 3.5 inches (89 millimeters) in diameter that was used in experiments at Los Alamos Laboratory as a part of the Manhattan Project in 1945 and 1946 and originally intended to be used in nuclear tests in 1946.^[1] In 1946, the core was melted down, with the material used to create other cores.

On August 21st, 1945, the core produced a burst of neutron radiation after physicist Harry Daghlian dropped a tungsten carbide brick into it, causing it to go supercritical. Daghlian quickly removed the brick, but received a fatal dose of radiation, dying 25 days later.

On May 21st, 1946, physicist Louis Slotin and seven others conducted an experiment to verify the closeness of the core to criticality. During the experiment, Slotin, as he had done a number of times before, violated the safety measures by using a screwdriver instead of shims to prevent beryllium hemispheres placed around the core from closing together, which would result in the core going critical. At one point during the experiment, the screwdriver slipped outward from the core, with the hemispheres closing and the core becoming supercritical. An intense burst of neutron radiation was emitted for about a half-second before Slotin manually knocked the top hemisphere to the floor, stopping the accident. A flash of blue light was observed by the experimenters when the accident occurred. Slotin, who received a lethal 1,000 rad dose of radiation, died nine days after the accident.

Photographs from a re-creation of the 1946 experiment

Spread

In Popular Culture

In the 1989 war film Fat Man and the Little Boy,^[2] events of the second incident are depicted, with actor John Cusack portraying Louis Slotin (scene shown below).

YouTube Videos

On YouTube, a number of documentaries and popular science videos about the incident were posted starting in 2017. On October 13th, 2017, the YouTube^[3] channel Qxir posted the first such video to go viral, with the upload gaining over 920,000 views in four years (shown below, left). On November 27th, 2020, YouTuber^[4] Kyle Hill posted a video that as of May 2021 was the most-viewed video on the topic with over 6 million views (shown below, right).

Anime Girls Experimenting With the Demon Core

On April 4th, 2018, artist nibi tweeted^[5] a fan art of Touhou character Aunn Komano using a screwdriver to experiment with the core that gained over 300 retweets and 570 likes (shown below, left).

On April 18th, 2018, artist shirosato tweeted^[6] a similar fan art of Touhou character Koakuma that received over 220 retweets and 400 likes, with a Pixiv^[7] post gaining over 540 smiles and 460 likes.

Following the posts, drawing fan art in which various characters used a screwdriver to experiment with the Demon Core became popular among Japanese artists on Twitter,^[8] Pixiv^[9] and niconico^[10] (examples shown below).

On December 17th, 2018, Twitter^[15] user @wellestrein highlighted the popularity of Demon Core fan art among Japanese users, with their tweet gaining over 1,300 retweets and 1,600 likes in two years.

On March 13th, 2019, YouTuber^[11] Karameru (からめる) posted a humorous video titled "Demon Core-kun" that gained over 3.2 million views in two years (shown below).

In May 2021, following a fan art posted by Twitter^[12] user @HellOnEarthIII on May 6th (shown below, left) and a tweet^[13] posted by user @drab_makyo on May 10th (shown below, right; based on a 2020 artwork by Tumblr^[14] user bepisode), the Japanese trend gained recognition among the Western social media users.

Elephant's Foot

The Elephant's Foot is the nickname given to a large radioactive mass of corium and other materials that formed underneath the Chernobyl Nuclear Power Plant during the Chernobyl Disaster of April 1986. Following the rise of general awareness of the Chernobyl Disaster assisted by the Chernobyl television series, the foot has been referenced in various memes.