OUTPUT

For this problem we are asked to plot neutron density using Neumann boundary conditions to show it is supercritical always (chain-reaction occurs).

To do this, I modified the neuron program, and ran it for a number of L, starting from 2

To 5. In each plot the system is supercritical.

Notice that for L=2 for example, the system us supercritical, in the book, figure 6.9 shows the system to be subcritical, with the only difference is that this problem uses Neumann boundary conditions, while the example in the book used Dirichlet boundary conditions.

» nma_problem_6_12_b

solves neutron desity equation

for Neumman bounday conditions using FTCS

method. Problem 6.12 part b

Nasser Abbasi

Enter time step:5e-4

Enter number of space grid points:61

Enter system length L:2

Enter number of time steps:12000

Solution is expected to be stable

» nma_problem_6_12_b

solves neutron desity equation

for Neumman bounday conditions using FTCS

method. Problem 6.12 part b

Nasser Abbasi

Enter time step:5e-4

Enter number of space grid points:61

Enter system length L:3

Enter number of time steps:12000

Solution is expected to be stable

» nma_problem_6_12_b

solves neutron desity equation

for Neumman bounday conditions using FTCS

method. Problem 6.12 part b

Nasser Abbasi

Enter time step:5e-4

Enter number of space grid points:61

Enter system length L:4

Enter number of time steps:12000

Solution is expected to be stable

» nma_problem_6_12_b

solves neutron desity equation

for Neumman bounday conditions using FTCS

method. Problem 6.12 part b

Nasser Abbasi

Enter time step:5e-4

Enter number of space grid points:61

Enter system length L:5

Enter number of time steps:12000

Solution is expected to be stable