{{short description|1945–1946 sphere of plutonium}} {{Good article}} {{Use American English|date=October 2023}} [[File:Partially-reflected-plutonium-sphere.jpeg|thumb|alt=A square base of metal blocks, with a smaller square of metal on the top in the center, a Cooper block (the "core") contained in its center. A ruler along one side of the base shows roughly {{convert|10.5|in|sp=us}} square.|A re-creation of the experiment involved in the 1945 incident. The sphere of plutonium is surrounded by tungsten carbide blocks acting as neutron reflectors.]]
The '''demon core''' was a sphere of plutonium–gallium alloy that was involved in two fatal radiation accidents when scientists tested it as a fissile core of an early atomic bomb. It was manufactured in 1945 by the Manhattan Project, the U.S. nuclear weapon development effort during World War II. It was a subcritical mass that weighed {{convert|6.2|kg|lb}} and was {{convert|89|mm|in|sp=us}} in diameter. The core was prepared for shipment to the Pacific Theater as part of the third nuclear weapon to be dropped on Japan, but when Japan surrendered, the core was retained for testing and potential later use in the case of another conflict.
The two criticality accidents occurred at the Los Alamos Laboratory in New Mexico on August 21, 1945, and May 21, 1946. In both cases, an experiment was intended to demonstrate how close the core was to criticality, using a neutron-reflective tamper (layer of dense material surrounding the fissile material). In both accidents, the core was accidentally put into a critical configuration. Physicists Harry Daghlian (in the first accident) and Louis Slotin (in the second accident) both suffered acute radiation syndrome and died shortly afterward. Others present in the laboratory were also exposed to radiation during the accidents. The core was melted down during the summer of 1946, and the material was recycled for use in other cores.
==Manufacturing and early history== The demon core was a solid {{convert|6.2|kg|lb|0|adj=on}} softball-sized sphere measuring {{convert|89|mm|in|sp=us}} in diameter; it was similar to the core used in the bombing of Nagasaki. It consisted of three parts made of plutonium–gallium: two hemispheres and an anti-jet ring, designed to keep neutron flux from "jetting" out of the joined surface between the hemispheres during implosion. The core of the device used in the Trinity Test at the Alamogordo Bombing and Gunnery Range in July did not have such a ring.<ref>{{cite web |publisher=Restricted data blog |last=Wellerstein |first=Alex |title=You don't know ''Fat Man'' |url=http://blog.nuclearsecrecy.com/2011/11/28/you-dont-know-fat-man/ |access-date=April 4, 2014 |url-status=live |archive-url=https://web.archive.org/web/20140407081651/http://blog.nuclearsecrecy.com/2011/11/28/you-dont-know-fat-man/ |archive-date=April 7, 2014}}</ref><ref>{{cite book |last=Coster-Mullen |first=John |chapter=Core Differences |title=Atom Bombs: The Top Secret Inside Story of ''Little Boy'' and ''Fat Man'' |year=2010}}</ref>
[[File:Louis Slotin & Harry K. Daghlian Jr.jpg|thumb|The two physicists Harry Daghlian (center left) and Louis Slotin (center right) during the Trinity Test. Both died following supercritical accidents involving the "demon core".]]
The refined plutonium was shipped from the Hanford Site in Washington to the Los Alamos Laboratory; an inventory document dated August 30 shows Los Alamos had expended "HS-1, 2, 3, 4; R-1" (the components of the Trinity and Nagasaki bombs) and had in its possession "HS-5, 6; R-2", finished and in the hands of quality control. Material for "HS-7, R-3" was in the Los Alamos metallurgy section and would also be ready by September 5 (it is not certain whether this date allowed for the unmentioned "HS-8{{"'}}s fabrication to complete the fourth core).<ref name=third>{{cite web |title=The Third Core's Revenge |publisher=Restricted data blog |last=Wellerstein |first=Alex |url=http://blog.nuclearsecrecy.com/2013/08/16/the-third-cores-revenge/ |access-date=April 4, 2014 |url-status=live |archive-url=https://web.archive.org/web/20140407081649/http://blog.nuclearsecrecy.com/2013/08/16/the-third-cores-revenge/ |archive-date=April 7, 2014}}</ref> The metallurgists used a plutonium–gallium alloy, which stabilized the delta ({{lang|el|δ}}) phase allotrope of plutonium so it could be hot pressed into the desired spherical shape. As plutonium was found to corrode readily, the sphere was then coated with nickel.<ref>{{cite journal |last1=Baker |first1=Richard D. |last2=Hecker |first2=Siegfried S. |last3=Harbur |first3=Delbert R. |title=Plutonium: A Wartime Nightmare but a Metallurgist's Dream |url=http://library.lanl.gov/cgi-bin/getfile?07-16.pdf |journal=Los Alamos Science |issue=Winter/Spring |year=1983 |publisher=Los Alamos National Laboratory |pages=142–151 |access-date=22 November 2010 |url-status=live |archive-url=https://web.archive.org/web/20111017034523/http://library.lanl.gov/cgi-bin/getfile?07-16.pdf |archive-date=17 October 2011}}</ref>
On August 10, Major General Leslie R. Groves Jr., wrote to General of the Army George C. Marshall, the Chief of Staff of the United States Army, to inform him that: {{Blockquote|The next bomb of the implosion type had been scheduled to be ready for delivery on the target on the first good weather after August 24th, 1945. We have gained 4 days in manufacture and expect to ship the final components from New Mexico on August 12th or 13th. Providing there are no unforeseen difficulties in manufacture, in transportation to the theatre or after arrival in the theatre, the bomb should be ready for delivery on the first suitable weather after August 17th or 18th.<ref name=third/>}}
Marshall added an annotation, "It is not to be released on Japan without express authority from the President", on President Harry S. Truman's orders.<ref name=third/> On August 13, the third bomb was scheduled. It was anticipated that it would be ready by August 16 to be dropped on August 19.<ref name=third/> This was pre-empted by Japan's surrender on August 15, 1945, while preparations were still being made for it to be couriered to Kirtland Field. The third core remained at Los Alamos.<ref>{{cite web |first1=Raemer |last1=Shreiber |author-link=Raemer Schreiber |first2=Richard |last2=Rhodes |author-link2=Richard Rhodes |title=Raemer Schreiber's Interview |year=1993 |url=https://manhattanprojectvoices.org/oral-histories/raemer-schreibers-interview-1993 |access-date=May 28, 2015 |url-status=live |archive-url=https://web.archive.org/web/20150429100225/http://www.manhattanprojectvoices.org/oral-histories/raemer-schreibers-interview-1993 |archive-date=April 29, 2015}} Raemer Schreiber being interviewed by Richard Rhodes</ref>
==First incident== The core, once assembled, was designed to be at "−5 cents".<ref name="McLaughlin">{{cite report |url=https://www.orau.org/PTP/Library/accidents/la-13638.pdf |access-date=May 18, 2014 |title=A review of criticality incidents, 2000 Revision (LA-13638) |pages=70–78 |first1=Thomas P. |last1=McLaughlin |first2=Shean P. |last2=Monahan |first3=Norman L. |last3=Pruvost |first4=Vladimir V. |last4=Frolov |first5=Boris G. |last5=Ryazanov |first6=Victor I. |last6=Sviridov |date=May 2000 |url-status=live |archive-url=https://web.archive.org/web/20140722230204/http://www.orau.org/ptp/Library/accidents/la-13638.pdf |archive-date=July 22, 2014}}</ref> In this state, there is only a small safety margin against extraneous factors that might increase reactivity, causing the core to become supercritical, and then prompt critical, a brief state of rapid energy increase.<ref>{{cite web |url=http://www.pipeline.com/~rstater/nuke1tttt.html |title=Prompt Criticality: A Concept with False Credentials |date=December 13, 2012 |access-date=September 27, 2015 |first=Robert G. |last=Stater |publisher=Nuke Facts |url-status=dead |archive-url=https://web.archive.org/web/20160304073037/http://www.pipeline.com/~rstater/nuke1tttt.html |archive-date=March 4, 2016}}</ref> These factors are not common in the environment; they are only likely to occur under conditions such as the compression of the solid metallic core (which would eventually be the method used to explode the bomb), the addition of more nuclear material, or provision of an external reflector which would reflect outbound neutrons back into the core. The experiments conducted at Los Alamos leading to the two fatal accidents were designed to see how much neutron reflection was required to approach supercriticality, and included arranging such reflectors in a way that would guarantee that the core was indeed close to the critical point.<ref name="McLaughlin"/>
On August 21, 1945, the plutonium core produced a burst of neutron radiation that resulted in physicist Harry Daghlian's death. Daghlian made a mistake while performing neutron reflector experiments on the core. He was working alone; a security guard, Private Robert J. Hemmerly, was seated at a desk {{convert|10|to|12|ft|m|0|sp=us}} away.<ref name="hempelman"/> The core was placed within a stack of neutron-reflective tungsten carbide bricks, and the addition of each brick made the assembly closer to criticality. While attempting to stack another brick around the assembly, Daghlian accidentally dropped it onto the core and thereby caused the core to go well into supercriticality, a self-sustaining critical chain reaction. He quickly moved the brick off the assembly, but he received a fatal dose of radiation. He died 25 days later from acute radiation poisoning.<ref name="Millerp68">{{cite book |last=Miller |first=Richard L. |title=Under the Cloud: The Decades of Nuclear Testing |publisher=Two Sixty Press |location=The Woodlands, Texas |year=1991 |isbn=0-02-921620-6 |pages=[https://archive.org/details/underclouddec00mill/page/68 68, 77] |url=https://archive.org/details/underclouddec00mill/page/68}}</ref>
{| class="wikitable" |- ! scope=col | Name ! scope=col | Age at accident ! scope=col | Profession ! scope=col | Dose<ref name=hempelman>{{cite conference |last1=Hempelman |first1=Louis Henry |last2=Lushbaugh |first2=Clarence C. |last3=Voelz |first3=George L. |title=What Has Happened to the Survivors of the Early Los Alamos Nuclear Accidents? |conference=Conference for Radiation Accident Preparedness |date=October 19, 1979 |url=http://www.orau.org/ptp/pdf/accidentsurvivorslanl.pdf |access-date=January 5, 2013 |publisher=Los Alamos Scientific Laboratory |location=Oak Ridge |id=LA-UR-79-2802 |url-status=live |archive-url=https://web.archive.org/web/20140912141857/http://www.orau.org/ptp/pdf/accidentsurvivorslanl.pdf |archive-date=September 12, 2014}} Patient numbers in this document have been identified as: 1 – Daghlian, 2 – Hemmerly, 3 – Slotin, 4 – Graves, 5 – Kline, 6 – Young, 7 – Cleary, 8 – Cieleski, 9 – Schreiber, 10 – Perlman</ref>{{Rp|page=20}} ! scope=col | Aftermath |- ! scope=row | Haroutune "Harry" Krikor Daghlian Jr. | style="text-align:center;" | 24 || Physicist || {{convert|200|rad|abbr=on|lk=on}} neutron<br/>{{convert|110|rad|abbr=on}} gamma || Died 25 days after the accident of acute radiation syndrome, hematopoietic focus<ref name="hempelman"/>{{Rp|page=22}} |- ! scope=row | Private Robert J. Hemmerly | style="text-align:center;" | 29 || Special Engineer Detachment guard || {{convert|8|rad|abbr=on}} neutron<br/>{{convert|0.1|rad|abbr=on}} gamma || Died in 1978 (33 years after accident) of acute myelogenous leukemia at age 62<ref name="hempelman"/>{{Rp|pages=9–11,22}} |}
==Second incident== {{Multiple image | direction = vertical | width = 220 | footer = A re-creation of the 1946 experiment. The spherical beryllium shell is seen, but the core inside is not. A screwdriver holds up the top half of the shell. | image1 = Tickling the Dragons Tail.jpg | image2 = The demon core.jpg }} thumb|right|300px|A sketch used by doctors to determine the amount of radiation to which each person in the room had been exposed during the excursion thumb|right|300px|A drawing based on the above sketch
=== Background === On May 21, 1946,<ref name=accidents>{{cite web |url=http://library.lanl.gov/cgi-bin/getfile?00314607.pdf |title=A Review of Criticality Accidents |date=September 26, 1967 |publisher=Los Alamos Scientific Laboratory |access-date=August 12, 2015 |url-status=live |archive-url=https://web.archive.org/web/20170118111722/http://library.lanl.gov/cgi-bin/getfile?00314607.pdf |archive-date=January 18, 2017}}</ref> physicist Louis Slotin and seven other personnel were in a Los Alamos laboratory conducting another experiment to verify the closeness of the core to criticality by the positioning of neutron reflectors. Slotin, who was leaving Los Alamos, was showing the technique to Alvin C. Graves, who would use it in a final test before the Operation Crossroads nuclear tests scheduled a month later at Bikini Atoll. It required the operator to place two half-spherical shells of beryllium (a neutron reflector) around the core to be tested and manually lower the top reflector over the core using a thumb hole at the polar point. As the reflectors were manually moved closer and farther away from each other, neutron detectors indicated the core's neutron multiplication rate. The experimenter needed to maintain a slight separation between the reflector halves to allow enough neutrons to escape from the core in order to stay below criticality. The standard protocol was to use shims between the halves, as allowing them to close completely could result in the instantaneous formation of a critical mass and a lethal power excursion.<ref name=accidents/>
Using his own unapproved protocol, Slotin did not place any shims. The top half of the reflector was resting directly on the bottom half at one point, while 180 degrees from this point a gap was maintained by the blade of a flat-tipped screwdriver in Slotin's hand. The size of the gap between the reflectors was changed by twisting the screwdriver. Slotin became the local expert, performing the test on almost a dozen occasions, often in his trademark blue jeans and cowboy boots in front of a roomful of observers. Enrico Fermi reportedly told Slotin and others they would be "dead within a year" if they continued performing the test in that manner.<ref>{{cite book |title=The Plutonium Files |last=Welsome |first=Eileen |page=[https://archive.org/details/plutoniumfiles00wels_0/page/184 184] |year=1999 |isbn=978-0-385-31402-2 |location=New York |publisher=Dial Press |url=https://archive.org/details/plutoniumfiles00wels_0/page/184 |access-date=November 18, 2012}}</ref> Scientists referred to this flirtation with a nuclear chain reaction as "tickling the dragon's tail", based on a remark by physicist Richard Feynman.<ref name="NYT">{{cite news |last=Weber |first=Bruce |title=Theater Review; A Scientist's Tragic Hubris Attains Critical Mass Onstage |url=https://www.nytimes.com/2001/04/10/theater/theater-review-a-scientist-s-tragic-hubris-attains-critical-mass-onstage.html |work=The New York Times |date=10 April 2001 |access-date=12 November 2007 |archive-date=3 November 2012 |archive-url=https://web.archive.org/web/20121103135846/http://www.nytimes.com/2001/04/10/theater/theater-review-a-scientist-s-tragic-hubris-attains-critical-mass-onstage.html |url-status=live}}</ref><ref>{{cite journal |date=November–December 2002 |title=Science as Theater: The Slip of the Screwdriver |journal=American Scientist |publisher=Sigma Xi |volume=90 |issue=6 |pages=550–555 |bibcode=2002AmSci..90..550S |doi=10.1511/2002.6.550 |last1=Shepherd-Barr |first1=Kirsten |last2=Lustig |first2=Harry |s2cid=208868168 |url=http://www.americanscientist.org/issues/feature/2002/6/science-as-theater/99999 |archive-url=https://web.archive.org/web/20170520181417/http://www.americanscientist.org/issues/feature/2002/6/science-as-theater/99999 |archive-date=May 20, 2017 |url-status=dead |url-access=subscription}}</ref>
On the day of the accident, Slotin's screwdriver slipped outward a fraction of an inch while he was lowering the top reflector, allowing the reflector to fall into place around the core. Instantly, there was a flash of light; the core had become supercritical, releasing an intense burst of neutron radiation. Slotin quickly twisted his wrist, flipping the top shell to the floor.<ref name="schreiber" /> There was an estimated half-second between when the sphere closed to when Slotin removed the top reflector.<ref name="McLaughlin" /> The reaction in the room was one of immediate, somber realization. Slotin received a lethal dose of 1,000 rad (10 Gy) neutron and 114 rad (1.14 Gy) gamma radiation in less than a second. While the position of his body over the apparatus shielded the others from much of the neutron radiation, his own exposure was irreversible. Slotin reportedly turned to his colleagues in the hushed room and famously uttered the remark, "Well, that does it."<ref>{{Cite web |last=Dockrill |first=Peter |date=2018-04-26 |title=The Chilling Story of The 'Demon Core' And The Scientists Who Became Its Victims |url=https://www.sciencealert.com/the-chilling-story-of-the-demon-core-and-the-scientists-who-became-its-victims-plutonium-bomb-radiation-wwii |access-date=2026-05-07 |website=ScienceAlert |language=en-US}}</ref> As an expert in criticality, Slotin knew he had received a lethal dose. He immediately began drawing a sketch of the room’s layout to assist medical teams in calculating the specific dosages received by each survivor, even as his own health began its rapid decline. He died nine days later from acute radiation poisoning.
Graves, the next nearest person to the core, was watching over Slotin's shoulder and was thus partially shielded by him. He received a high but non-lethal radiation dose, and was hospitalized for several weeks with severe radiation poisoning.<ref name="hempelman"/> He died 19 years later, at age 55, of heart failure. While Graves's heart failure may have been caused by exposure to radiation, it may have been caused by a hereditary condition, as his father also died of heart failure.<ref name="Alsop54">{{cite news |last=Alsop |first=Stewart |author2=Robert E. Lapp |title=The Strange Death of Louis Slotin |newspaper=Saturday Evening Post |volume=226 |issue=36 |pages=25ff |date=March 6, 1954 |url=http://dspace.wbpublibnet.gov.in:8080/jspui/bitstream/10689/11989/3/Chapter1_65-135p.pdf |access-date=April 3, 2014 |archive-url=https://web.archive.org/web/20141017051919/http://dspace.wbpublibnet.gov.in:8080/jspui/bitstream/10689/11989/3/Chapter1_65-135p.pdf |archive-date=October 17, 2014}}</ref><ref name="NYT20110423">{{cite news |url=https://www.nytimes.com/1989/11/19/magazine/america-s-radiation-victims-the-hidden-files.html |title=America's Radiation Victims: The Hidden Files |author=Clifford T. Honicker |newspaper=The New York Times |date=November 19, 1989 |access-date=April 23, 2011 |url-status=live |archive-url=https://web.archive.org/web/20120217095609/http://www.nytimes.com/1989/11/19/magazine/america-s-radiation-victims-the-hidden-files.html |archive-date=February 17, 2012}}</ref>
The second accident was reported by the Associated Press on May 26, 1946: "Four men injured through accidental exposure to radiation in the government's atomic laboratory here [Los Alamos] have been discharged from the hospital and 'immediate condition' of four others is satisfactory, the Army reported today. Dr. Norris E. Bradbury, project director, said the men were injured last Tuesday in what he described as an experiment with fissionable material."<ref>Associated Press, "Several at Atomic Bomb Laboratory Injured", ''The San Bernardino Daily Sun'', San Bernardino, California, Monday 27 May 1946, Volume 52, page 1.</ref>
===Medical studies=== Later research was performed concerning the health of the men. An early report was published in 1951. A later report was compiled for the U.S. government and submitted in 1979.<ref name="hempelman"/> A summary of its findings:
{| class="wikitable" |- ! scope=col | Name ! scope=col | Origin ! scope=col | Age at accident ! scope=col | Profession ! scope=col | Dose<ref name="hempelman"/> ! scope=col | Aftermath |- ! scope=row | Louis Alexander Slotin | Winnipeg, Manitoba, Canada || style="text-align:center;" | 35 || Physicist || {{convert|1000|rad|abbr=on|lk=on}} neutron <br/> {{convert|114|rad|abbr=on}} gamma || Died 9 days after the accident of acute radiation syndrome, gastrointestinal focus.<ref name=accidents/> |- ! scope=row | Alvin C. Graves | Austin, Texas || style="text-align:center;" | 36 || Physicist || {{convert|166|rad|abbr=on}} neutron <br/> {{convert|26|rad|abbr=on}} gamma || Died in 1965 (19 years after the accident) of myocardial infarction, with aggravating "compensated myxedema and cataracts", while skiing.<ref name="hempelman"/> |- ! scope=row | Samuel Allan Kline | Chicago, Illinois || style="text-align:center;" | 26 || Physics student, later patent attorney || || Died in 2001 (55 years after the accident) at age 81; refused to participate with studies and was prevented from obtaining his own medical records from the incident.<ref name="hempelman"/> |- ! scope=row | Marion Edward Cieslicki | Mt. Lebanon, Pennsylvania|| style="text-align:center;" | 23 || Physicist || {{convert|12|rad|abbr=on}} neutron <br/> {{convert|4|rad|abbr=on}} gamma || Died of acute myelocytic leukemia in 1965 (19 years after the accident).<ref name="hempelman"/> |- ! scope=row | Dwight Smith Young | Chicago, Illinois || style="text-align:center;" | 54 || Photographer || {{convert|51|rad|abbr=on}} neutron <br/> {{convert|11|rad|abbr=on}} gamma || Died of aplastic anemia and bacterial endocarditis in 1975 (29 years after the accident) at age 83.<ref name="hempelman"/> |- ! scope=row | Raemer Edgar Schreiber | McMinnville, Oregon|| style="text-align:center;" | 36 || Physicist || {{convert|9|rad|abbr=on}} neutron <br/> {{convert|3|rad|abbr=on}} gamma || Died of natural causes in 1998 (52 years after the accident), at age 88.<ref name="hempelman"/><ref name="schreiber">{{cite news |title=Nuclear Naiveté |first=Larry |last=Calloway |newspaper=Albuquerque Journal |url=http://www.abqjournal.com/trinity/trinity2.pdf |access-date=August 12, 2015 |date=July 1995 |url-status=dead |archive-url=https://web.archive.org/web/20150816161934/http://www.abqjournal.com/trinity/trinity2.pdf |archive-date=August 16, 2015}}</ref> |- ! scope=row| Theodore Perlman | New Orleans, Louisiana<ref>{{cite web |url=https://www.ancestry.com/1940-census/usa/Louisiana/Theodore-Perlman_4b7wwk |title=Theodore Perlman in the 1940 Census | Ancestry® |website=Ancestry.com}}</ref> || style="text-align:center;" | 23 || Engineer || {{convert|7|rad|abbr=on}} neutron <br/> {{convert|2|rad|abbr=on}} gamma || "Alive and in good health and spirits" as of 1978; most likely died in June 1988 (42 years after the accident), in Livermore, California.<ref name="hempelman"/> |- ! scope=row| Private Patrick Joseph Cleary | New York City, New York || style="text-align:center;" | 21 || Security guard || {{convert|33|rad|abbr=on}} neutron <br/> {{convert|9|rad|abbr=on}} gamma || Sergeant 1st Class Cleary was killed in action on September 3, 1950 (4 years after the accident), while serving with the 8th Cavalry Regiment, US Army in the Korean War.<ref name="hempelman"/><ref>{{cite web |title=Korean War Veterans Memorial Honor Roll |url=https://www.abmc.gov/honor-roll-database-search-results?field_first_name=Patrick+Joseph&field_last_name=Cleary&service_number=&field_abmc_burial_unit=8th+Cavalry+Regiment+%2867492%29&field_place_of_entry=All&field_cemetery=All&field_cemetery2=All&field_branch_of_service=All&search_api_fulltext=&field_dod_day=All&field_dod_month=All&field_dod_year=&items_per_page=10&sort_bef_combine=field_last_name_ASC |website=American Battle Monuments Commission |publisher=|access-date=18 December 2024 |language=en}}</ref> |}
Two machinists, Paul Long and another, unidentified, in another part of the building, {{convert|20-25|ft|m|round=0.5|abbr=on|sp=us}} away, were not treated.<ref>{{cite web |url=http://www.mphpa.org/classic/NPO/Slotin%20Accident.doc |title=Louis Slotin |publisher=The Atomic Heritage Foundation |access-date=April 4, 2014 |archive-url=https://web.archive.org/web/20140407070650/http://www.mphpa.org/classic/NPO/Slotin%20Accident.doc |archive-date=April 7, 2014}}</ref>
After these incidents, the core, originally known as "Rufus", was referred to as the "demon core".<ref name=third/><ref name="New Yorker"/> Hands-on criticality experiments were stopped, and remote-control machines and TV cameras were designed by Schreiber, one of the survivors, to perform such experiments with all personnel at a quarter-mile distance.<ref name="schreiber"/>
==Planned uses and fate of the core== The demon core was intended for use in the Operation Crossroads nuclear tests, but after the second criticality accident, time was needed for its radioactivity to decrease and for it to be re-evaluated for the effects of the fission products it held, some of which were very neutron poisonous to the desired level of fission. The next two cores were shipped for use in ''Able'' and ''Baker'', and the demon core was scheduled to be shipped later for the third test of the series, provisionally named ''Charlie'', but that test was canceled because of the unexpected level of radioactivity resulting from the underwater ''Baker'' test and the inability to decontaminate the target warships. The core was melted down during the summer of 1946, and the material was recycled for use in other cores.<ref name="New Yorker">{{cite news |newspaper=The New Yorker |last=Wellerstein |first=Alex |title=The Demon Core and the Strange Death of Louis Slotin |url=http://www.newyorker.com/tech/elements/demon-core-the-strange-death-of-louis-slotin?intcid=mod-latest |date=May 21, 2016 |access-date=May 22, 2016 |url-status=live |archive-url=https://web.archive.org/web/20160524022150/http://www.newyorker.com/tech/elements/demon-core-the-strange-death-of-louis-slotin?intcid=mod-latest |archive-date=May 24, 2016}}</ref>
== In popular culture == The "demon core" is often portrayed in popular culture as an example of a scientific cautionary tale.<ref>{{Cite web |last=Mitton |first=Clarissa |date=April 3, 2024 |title=The Demon Core: A Tale of Atomic Ambition and Tragic Fate |url=https://science.howstuffworks.com/demon-core.htm |website=How Stuff Works}}</ref><ref>{{Cite web |last=Dockrill |first=Peter |date=April 26, 2018 |title=The Chilling Story of The 'Demon Core' And The Scientists Who Became Its Victims |url=https://www.sciencealert.com/the-chilling-story-of-the-demon-core-and-the-scientists-who-became-its-victims-plutonium-bomb-radiation-wwii |website=Science Alert}}</ref><ref>{{Cite web |date=2024 |title=The Demon Core: A Cautionary Tale from the Atomic Age |url=https://vocal.media/history/the-demon-core |website=Vocal Media}}</ref>
While not explicitly featured in the 2023 Christopher Nolan film ''Oppenheimer'', the story of the core and Slotin is frequently cited in popular discussions surrounding the film.<ref>{{Cite web |last=Bernhardt |first=Darren |date=July 29, 2023 |title=Louis Slotin and the demon core: Winnipeg's Oppenheimer connection |url=https://www.cbc.ca/news/canada/manitoba/louis-slotin-oppenheimer-atomic-bomb-winnipeg-1.6915932 |website=Canadian Broadcasting Corporation}}</ref>
In 2023, the post-punk band Unborn Ghost released a song titled "The Worm at The Demon Core," alluding to the "demon core" and William James' phrase "the worm at the core," from The Varieties of Religious Experience.<ref>{{Cite book |last=Solomon |first=Sheldon |title=The Worm at the Core: On the Role of Death of Life |last2=Greenberg |first2=Jeff |last3=Pyszczynski |first3=Tom |date=May 12, 2015 |publisher=Random House |isbn=9780679604884 |pages=passim |language=En}}</ref>{{quote needed|date=May 2026}}
Numerous online science communication channels and documentaries discuss the core, often focusing on the dramatic "blue glow" and the reckless nature of the "tickling the dragon's tail" experiments. Starting around 2018, the "demon core" has often been the subject of online memes.<ref>{{Cite web |last=Kirk |first=Benny |date=August 16, 2023 |title=Demon Core: The Catastrophic Nuclear Experiment That Became a Viral Meme 80 Years Later |url=https://www.autoevolution.com/news/demon-core-the-catastrophic-nuclear-experiment-that-became-a-viral-meme-80-years-later-219570.html |website=autoevolution}}</ref>
==See also== * Cecil Kelley criticality accident
==References== {{Reflist}}
==External links== * {{Commons category-inline|Demon core}}
{{Manhattan Project}} {{Portal bar|History of Science|Nuclear technology|Physics}}
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