An electron is moving under the influence of the electric field of a uniformly charged infinite plane sheet $\mathrm{S}$ having surface charge density $+\sigma$. The electron at $t=0$ is at a distance of $1 \mathrm{~m}$ from $S$ and has a speed of $1 \mathrm{~m} / \mathrm{s}$. The maximum value of $\sigma$ if the electron strikes $S$ at $t=1 \mathrm{~s}$ is $\alpha\left[\frac{m \epsilon_0}{e}\right] \frac{C}{m^2}$, the value of $\alpha$ is ___________.