Here a fissile uranium-235 nucleus captures a neutron and splits into two highly radioactive fragments.

In the following year he allowed nine nuclear bombs with fissile cores to be transferred into Air Force custody and transported to Okinawa.

He allowed nine nuclear bombs with fissile cores to be transferred into Air Force custody and transported to Okinawa.

These weapons had a fissile core surrounded by a layer of lithium-6 deuteride, in turn surrounded by a layer of depleted uranium.

Consequently, the generation time is essentially equal to the average time elapsing between the release of a neutron and its subsequent capture by a fissionable nucleus.

As a result, the two new fragments are highly radioactive at the moment of their creation, as the excess number of neutrons they inherit from the parent nucleus renders them unstable.

The result can then be a radioactive nucleus that emits a photon or other particle or, in the case of fissionable nuclei such as 235U and 239Pu, the capturing nucleus can fission into two smaller nuclei and more neutrons.

The mean generation time, Λ, is the average time from a neutron emission to a capture that results in fission.

The result can then be a radioactive nucleus that emits a photon or other particle or, in the case of fissionable nuclei such as 235U and 239Pu, the capturing nucleus can fission into two smaller nuclei and more neutrons.