\[\boxed{\mathbf{1513}\mathbf{.}}\]
\[x\ - сторона\ основания;\ \]
\[y - высота\ призмы.\]
\[Диагональ\ призмы = 2\sqrt{3}:\]
\[d = \sqrt{x^{2} + h^{2}} = 2\sqrt{3}\]
\[\sqrt{x^{2} + h^{2}} = \sqrt{12}\]
\[x^{2} + h^{2} = 12\]
\[x^{2} = 12 - h^{2}.\]
\[V(h) = S \bullet h = x^{2} \bullet h =\]
\[= \left( 12 - h^{2} \right) \bullet h = 12h - h^{3};\]
\[V^{'}(h) = (12h)^{'} - \left( h^{3} \right)^{'} =\]
\[= 12 - 3h^{2}.\]
\[Промежуток\ возрастания:\]
\[12 - 3h^{2} > 0\]
\[4 - h^{2} > 0\]
\[h^{2} < 4\]
\[- 2 < h < 2.\]
\[h = 2 - точка\ максимума.\]
\[Ответ:\ \ 2.\]