|Berkeley—Glenn T. Seaborg, Arthur Wahl, Joseph W. Kennedy, Edwin McMillan elements|
- In December 1940, Glenn Seaborg and his team
- made neptunium-238 in their cyclotron
- by bombarding uranium-238 with deuterons.
- Neptunium-238 decays, with a half-life
- of two and a half days, by negative beta emission
- leaving plutonium-238, which has a longer half-life—
- eighty-seven years and two-hundred seventy days—
- and is fissile—it easily breaks apart
- when hit by a slow-moving neutron, resulting
- in a nuclear chain-reaction
- as its neutrons hit other nearby plutonium atoms,
- releasing a huge amount of energy and radiation.
Atomic number 94
- All isotopes of plutonium
- are radioactive.
- Plutonium-244 has a half-life
- of 80.8 million years.
- Plutonium-228 has a half-life
- of a little over a second.
- Plutonium-238 with its high decay heat
- powered spacecraft and landers.
- The discovery of plutonium
- was kept secret until 1948.
- In December 1940,
- World War II had already begun.
- Franklin D. Roosevelt approved
- production of nuclear bombs in October 1941.
- Production of plutonium and uranium
- for nuclear bombs proceded concurrently.
- The X-10 Graphite Reactor at Oak Ridge
- irradiated uranium to produce plutonium.
- Facilities at Hanford
- separated plutonium from the uranium.
- B Reactor at Hanford produced
- plutonium for weapons used during the war.
- Glenn Seaborg said that their little joke—choosing
- the abbreviation Pu instead of Pl—was hardly noticed.