This has a far higher spontaneous fission rate than plutonium-239.

In May 1940 they assumed that spontaneous fission was discovered.

The high spontaneous fission rate of californium-252 was observed in these samples.

They repeated their experiment in 1970 looking for spontaneous fission.

A fourth decay by direct spontaneous fission was also proposed.

Another possibility is spontaneous fission into two or more nuclides.

Most of the discussion about alpha particles will also apply to spontaneous fission.

All these isotopes are characterized by high rates of spontaneous fission.

One possible neutron source is californium-252 which undergoes spontaneous fission.

Pu-240 has a high rate of spontaneous fission, which can cause a nuclear weapon to predetonate.

Spontaneous fission of Db was not confirmed in recent experiments.

The first study produced evidence for a spontaneous fission with a 0.3 second half-life and another one at 8 seconds.

They also detected a 10 s spontaneous fission activity tentatively assigned to 102.

The most commonly used spontaneous fission source is the radioactive isotope californium-252.

This further underwent spontaneous fission with a half-life of about 1.3 h.

Spontaneous fission is a type of radioactive decay that some heavy elements undergo.

Spontaneous fission, which occurs without assistance of the neutron, is usually not considered a nuclear reaction.

Cluster decay was shown to be a superasymmetric spontaneous fission process.

's high rate of spontaneous fission events makes it an undesirable contaminant.

Pu-240 undergoes spontaneous fission as a secondary decay mode at a small but significant rate.

All of these decay through alpha decay or spontaneous fission.

Within days the group observed five times the rate of spontaneous fission as with the cyclotron-produced plutonium.

However, small amounts do exist as spontaneous fission products in uranium ores.

Neutrons can also be produced in spontaneous fission and by neutron emission.

Due to spontaneous fission of Pu-240, only a very low level of it is tolerable in material for making weapons.