The magnetic force experienced by the neutron,
$F=M \frac{\delta B}{\delta r}=\frac{m v^2}{r}$
$\Delta B=\frac{m v^2}{r}$
$\Delta B=\frac{m v^2}{M r} \Delta r$
$=\frac{1.67 \times 10^{-27} \times 54^2 \times 0.01}{9.67 \times 10^{-27} \times 1}=5.04\; T$




