A comprehensive kinetics and extraction model of electron‐beam‐excited xenon chloride lasers is used to examine the feasibility of constructing a megajoule‐class excimer laser. The ratio of small‐signal gain to absorption scales nearly logarithmically with pump rate over the range studied, 10 kW/cm3to 1 MW/cm3, and limits extraction efficiency to 20%–50%. Active volume dimensions are practically constrained to 1–2 m in length and to ∼2 m in width, with efficient extraction possible for pulse lengths of 2 &mgr;s or less. Single modules operating in the technologically conservative, low‐pump‐power (≤100 kW/cm3) regime should be capable of producing pulse energies of 40 kJ.