An electron is moving under the influence of the electric field of a uniformly charged infinite plane sheet $$S$$ having surface charge density $$+\sigma$$. The electron at $$t = 0$$ is at a distance of $$1$$ m from $$S$$ and has a speed of $$1$$ m s$$^{-1}$$. The maximum value of $$\sigma$$, if the electron strikes $$S$$ at $$t = 1$$ s is $$\alpha \left[\frac{m\varepsilon_0}{e}\right] \frac{C}{m^2}$$. The value of $$\alpha$$ is _______.