Thermonuclear ignition criterion in ICF

The Lawson criterion, which determines the onset of thermonuclear ignition in inertial confinement fusion (ICF), is re-derived in terms of physical measurable quantities: the hot spot ion temperature T and the areal density ($\rho R$) of the deuterium-tritium (DT) gas. From this criterion, an ignition curve is generated in the $\rho R -T$ plane. In addition, a minimal required implosion energy for laser-drive and a minimal DT gas mass for a sustainable ignition with respect to the condition are derived.