If the distance between the source & absorber is halved, then intensity of radiant energy will be

Let us say source is a point source emitting radiation of power P.

Intensity of radiation at a distance d is $\mathrm{I}=\frac{\mathrm{P}}{4{\mathrm{\pi d}}^2}\propto \frac{1}{d^2}$

When distance between the source & absorber is halved, then Intensity of radiant energy will become four times.