Chain reactions with dominoes

· dominoes

· stopwatch

We model a controlled chain reaction where only one neutron goes on to interact with the next fissile nuclei, this can be modelled as a simple linear chain of dominoes.

We model the uncontrolled reaction when two or more neutrons can go on to interact with a fissile nuclei. An example of how to set this up with two neutrons per reaction is below.

There are 15 dominoes in each arrangement. Set them both up and start them off together. Which finishes first?

1. What does a longer time indicate, in terms of energy and power, for a real fission chain reaction?

2. How much space is used up in each reaction. How does this correlate to your understanding of critical mass?