The present work puts forward the design concepts of two types of gas cooling arrangements for solid state laser cavities those operate at high repetition rates, these are, the transverse cooling and the axial cooling arrangement. The proposed designs are based on introducing one of commercially available gases (He, H2, Ar, or N2) to the laser cavity through multiple ports, taking intq, consideration the principal thermal parameters of the cavity and the gas, and the cooling requirements of gas flow and pressure. The thermal effects on the laser crystal, such as temperature gradient, thermal stresses and lensing have been theoretically studied and modeled. The work also .includes the designmdjdonstruction of a 20 Hzjmlsed power supply for an existing Nd:YAG laser cavity which is equipped with a passive Q-switching dye foil that facilitates 20 ns pulse duration. Laser output energy of 130 mJ per pulse has been obtained, which is in good agreement with the calculated value.The theoretical analysis and calculations revealed the feasibility of gas cooling techniques for ^prolonged operations. Besides, the simplicity of their application promotes their viability for mobile and airborne equipment.