OICC Press Journal of Theoretical and Applied Physics 2251-7235 19 1 2025 02 10 Achieving High-Pressure Pulsed Avalanche Homogeneous Discharges through Surface Plasma Pre-ionization: A Study of Optimization and Characterization to improve CO2 laser performance 1 8 10.57647/j.jtap.2025.1901.10 EN Behrooz Hajilooei Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, Iran Pourya Seyfi Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, Iran https://orcid.org/0009-0005-0767-8935 Hamid Ghomi Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, Iran https://orcid.org/0000-0003-2203-5194 Journal Article 2025 02 10 In this paper the necessary requirements on surface plasma pre-ionization for the creation of high-pressure pulsed avalanche homogeneous discharges are analyzed. In this study, three factors were optimized to achieve a glow discharge in the laser gap. Initially, the upper electrode of the laser was developed according to the coding provided by Ernst Profile. Subsequently, the most efficient laser electrode was constructed through simulation. Secondly, a novel pre-ionization technique is employed on the lower electrode of the laser in order to establish a uniform distribution of surface plasma pre-ionization.   During this phase, five distinct electrode types underwent testing, and it was found that the electrode featuring islands with external and internal diameters of 3 and 1 mm was the most optimal electrode, respectively, given a maximum laser output energy of 394 mj. And finally, the maximum laser output energy for each pulse was measured as 394 mj in the 3-1-1 helium-carbon dioxide-nitrogen gas combination.   This particular method of pre ionization using surface plasma is ideal for situations with large volumes and high pressures, where traditional pre-ionization methods such as spark arrays or corona discharge do not work effectively.