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Curium is a synthetic chemical element; ... Curium-244 alpha decays to 240 Pu, but it also absorbs neutrons, hence a small amount of heavier curium isotopes.
Curium (96 Cm) is an artificial element with an atomic number of 96. Because it is an artificial element, a standard atomic weight cannot be given, and it has no stable isotopes. The first isotope synthesized was 242 Cm in 1944, which has 146 neutrons. There are 19 known radioisotopes ranging from 233 Cm to 251 Cm.
A common source of alpha particles is curium-244. It emits particles with an energy of 5.8 MeV. X-rays of 14 and 18 keV are emitted in the decay of plutonium-240. The Mars Exploration Rovers' Athena payload uses curium-244 with a source strength of approximately 30 millicuries (1.1 GBq). [10]
After removal of fuel from reactor, decay will predominate for shorter-lived isotopes such as 238 Pu, 241 Pu, 242–244 Cm; but 245–248 Cm are all long-lived. Fertile material is a material that, although not fissile itself, can be converted into a fissile material by neutron absorption .
That same year, curium-244 was produced as a heat source for space exploration. This was the first full scale conversion of an SRP reactor load to non-weapons materials. R-Reactor and HWCTR were shut down in 1964. In 1965, californium-252, the heaviest isotope produced at SRP, was separated as a byproduct of the curium program. Beginning in ...
Prolonged irradiation of americium, curium, and plutonium with neutrons produces milligram amounts of 252 Cf and microgram amounts of 249 Cf. [55] As of 2006, curium isotopes 244 to 248 are irradiated by neutrons in special reactors to produce mainly californium-252 with lesser amounts of isotopes 249 to 255. [56]
The reactor core is cylindrical, about 2 ft (0.61 m) high and 15 inches (380 mm) in diameter. A 5-in. (12.70-cm)-diameter hole, the "flux trap," forms the center of the core. The target is typically loaded with curium-244 and other transplutonic isotopes and is positioned on the reactor vertical axis within the flux trap. The fuel region is ...
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