# Fission fragments

I was reading a bit about nuclear/particle physics when I came up to Cours et problèmes corrigés de physique nucléaire et de physique des particules by Philippe Miné in 2016 ISBN 2340011566, which is a french book about Nuclear & Particle Physics.

In this book, in a chapter dedicated to the nuclear energy, it is said that:

La fission d'un noyau lourd libère une énergie élevée, de l'ordre de 200 MeV. Elle se manifeste sous différentes formes : la plus grande partie part sous forme d'énergie cinétique communiquée aux fragments de fission à cause de la répulsion coulombienne. Le reste se répartit entre les énergies cinétiques des neutrons, photons, électrons et antineutrinos. Seule l'énergie des antineutrinos est perdue car ils sont capables de traverser une grande quantité de matière sans interagir. Les produits de fission ne parcourent que quelques micromètres dans l'uranium métallique...

Which roughly translates as:

The fission of a heavy core frees high amount of energy, near 200 MeV. It happens in different ways: most of it goes as kinetic energy given to the "fission fragments" because of the Coulomb repulsion. The rest is split between the kinetic energies of neutrons, photons, electrons and antineutrinos. Only the energy of antineutrinos is lost because they are able to go through a high amount of matter without interacting. The fission products can only go through micrometers

My questions are:

• What did the author mean as 'fission fragments'? Did he mean the products of fission? Did he mean Quarks?

• What is called 'product of fission' are just the photon of the desintegration of U238, the electrons and antineutrinos of the desintegration of U239 and Np239. Am I correct to assume this? I've read a bit further about effective areas $$\sigma$$ and it seems to fit the understanding I have of this word.