californium-252
E393260
Californium-252 is a highly radioactive synthetic isotope of californium widely used as a strong neutron source in applications such as nuclear reactor startup, neutron radiography, and cancer therapy.
All labels observed (1)
| Label | Occurrences |
|---|---|
| californium-252 canonical | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T3840685 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: californium-252 Context triple: [High Flux Isotope Reactor, notableProduct, californium-252]
-
A.
X-10 graphite reactor
The X-10 graphite reactor was an early nuclear reactor at Oak Ridge, Tennessee, built during the Manhattan Project as a pilot plant for plutonium production and a key step toward the development of nuclear weapons and nuclear energy.
-
B.
K-West Reactor
K-West Reactor is one of the plutonium production reactors at the Hanford Site in Washington State, historically used to support the U.S. nuclear weapons program.
-
C.
Chicago Pile-2
Chicago Pile-2 was an early research nuclear reactor built at the Argonne site to continue and expand experimental work following the first controlled chain reaction achieved by Chicago Pile-1.
-
D.
S2W nuclear reactor
The S2W nuclear reactor was an early U.S. Navy pressurized water reactor design that powered the world’s first operational nuclear-powered submarine, USS Nautilus.
-
E.
Chicago Pile-1
Chicago Pile-1 was the world’s first artificial nuclear reactor, achieving the first controlled, self-sustaining nuclear chain reaction in 1942 under the leadership of Enrico Fermi.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: californium-252 Target entity description: Californium-252 is a highly radioactive synthetic isotope of californium widely used as a strong neutron source in applications such as nuclear reactor startup, neutron radiography, and cancer therapy.
-
A.
X-10 graphite reactor
The X-10 graphite reactor was an early nuclear reactor at Oak Ridge, Tennessee, built during the Manhattan Project as a pilot plant for plutonium production and a key step toward the development of nuclear weapons and nuclear energy.
-
B.
K-West Reactor
K-West Reactor is one of the plutonium production reactors at the Hanford Site in Washington State, historically used to support the U.S. nuclear weapons program.
-
C.
Chicago Pile-2
Chicago Pile-2 was an early research nuclear reactor built at the Argonne site to continue and expand experimental work following the first controlled chain reaction achieved by Chicago Pile-1.
-
D.
S2W nuclear reactor
The S2W nuclear reactor was an early U.S. Navy pressurized water reactor design that powered the world’s first operational nuclear-powered submarine, USS Nautilus.
-
E.
Chicago Pile-1
Chicago Pile-1 was the world’s first artificial nuclear reactor, achieving the first controlled, self-sustaining nuclear chain reaction in 1942 under the leadership of Enrico Fermi.
- F. None of above. chosen
Statements (49)
| Predicate | Object |
|---|---|
| instanceOf |
californium isotope
ⓘ
neutron source ⓘ radioisotope ⓘ synthetic isotope ⓘ |
| atomicNumber | 98 ⓘ |
| belongsToSeries | actinide series ⓘ |
| chemicalElementCategory | actinide ⓘ |
| decayMode |
alpha decay
ⓘ
spontaneous fission ⓘ |
| discoveredAt | University of California, Berkeley ⓘ |
| discoveredBy |
Albert Ghiorso
ⓘ
Glenn T. Seaborg ⓘ Kenneth Street Jr. ⓘ Stanley G. Thompson ⓘ |
| discoveredInCountry |
United States of America
ⓘ
surface form:
United States
|
| discoveredInYear | 1952 ⓘ |
| elementSymbol | Cf ⓘ |
| halfLife |
2.645 years
ⓘ
about 2.6 years ⓘ |
| isotopeOf | californium ⓘ |
| isSynthetic | true ⓘ |
| massNumber | 252 ⓘ |
| neutronEmissionRate | about 2.3×10^12 neutrons per second per gram ⓘ |
| neutronNumber | 154 ⓘ |
| occursNaturally | false ⓘ |
| primaryDecayMode | alpha decay ⓘ |
| producedBy | neutron irradiation of curium ⓘ |
| producedIn | nuclear reactors ⓘ |
| radiationTypeEmitted |
alpha particles
ⓘ
gamma rays ⓘ neutrons ⓘ |
| requiresShielding | yes ⓘ |
| safetyConcern |
highly radioactive
ⓘ
strong neutron emitter ⓘ |
| significantDecayMode | spontaneous fission ⓘ |
| spontaneousFissionBranchingRatio | about 3.1 percent ⓘ |
| typicalShieldingMaterial |
concrete
ⓘ
polyethylene ⓘ water ⓘ |
| usedFor |
brachytherapy neutron sources
ⓘ
calibration of neutron detectors ⓘ cancer therapy research ⓘ industrial radiography ⓘ moisture gauge calibration ⓘ neutron activation analysis ⓘ neutron flux monitoring ⓘ neutron radiography ⓘ nuclear reactor startup ⓘ well logging ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: californium-252 Description of subject: Californium-252 is a highly radioactive synthetic isotope of californium widely used as a strong neutron source in applications such as nuclear reactor startup, neutron radiography, and cancer therapy.
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.