Fission of nuclei (into more or less commensurate parts, for example, 235 = 132 + 98 + 4 n) can occur spontaneously, or under the influence of relatively weak influences (fusion with a neutron). Fragmentation can occur in high-energy beams of relativistic particles and heavy ions. Fragmentation is characterized by a multiplicity of fragments of the intermediate mass

There is also Thermal multifragmentation.

it is characterized by a different Time scale of thermal multifragmentation and Two characteristic volumes for thermal multifragmentation.

For fragmentation on proton beams, the formation of He and 12C (spallation) can be expected

phase transitions in hot nuclei are important in Multifragmentation.

Dear Dr Mukhtar Ahmed Rana . See the following useful RG link: Article Nuclear energy release from fragmentation

Kindly see also the following very good link: https://www.sciencedirect.com/topics/engineering/fission-fragment

Check also the following very good RG link: Article Nuclear fragmentation of high-energy heavy-ion beams in water

pls check the following

https://www.eia.gov/energyexplained/nuclear/#:~:text=In%20nuclear%20fission%2C%20atoms%20are,form%20of%20heat%20and%20radiation.

https://www.sciencedirect.com/topics/earth-and-planetary-sciences/nuclear-fission

https://www.sciencedirect.com/topics/chemistry/nuclear-fragmentation

Nuclear fusion and nuclear fission are opposites.

Nuclear fusion is the combination of two lighter atoms into a heavier one. Nuclear fission is a heavier atom split into two lighter ones.