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 "1m" from "S" and has a speed of `1m/s` .The maximum value of `sigma` if the electron strikes "S" at `t=1s` is `alpha[(m epsilon_(0))/(e)](C)/(m^(2))` ,the value of `alpha` is______________