# Is order of reaction defined for nuclear reactions?

Order of reaction is defined for chemical reaction. But wikipedia says about spontaneous nuclear decay:

Another class of first-order reactions is radioactive decay processes which are all first order. These are, however, nuclear reactions rather than chemical reactions.

Spontaneous nuclear decay is governed by nuclear forces for which it follows an exponential form. There can be deviations from the exponential law at very short time and at very time. But, that's under nuclear physics.

But, has anyone tried to extend the concept of order of reaction to other nuclear reactions eg. transmutation, spallation,fission,fusion etc.

Ben Crowell's comment on my previous phy.stack post:

If you want to make an analogy with chemical reactions, then you should probably be considering nuclear reactions, rather than spontaneous nuclear decay. For example, you could consider the cross-section for neutron or proton transfer reactions as a function of the number of nucleons (mass number) in the target and projectile.