A wide-aperture copper vapour laser was demonstrated at $\sim 10$ kHz rep-rate with hydrogen additive in its buffer gas. Maximum power in excess of $\sim 50$ W (at 10 kHz) was achieved by adding 1.96% hydrogen to the neon buffer gas at 20 mbar total gas pressure. This increase in output power was about 70% as compared to $\sim 30$ W achieved with pure neon at 5.5 kHz rep-rate. The 70% enhancement achieved was significantly higher than the maximum reported value of 50% so far in the literature. The enhancement was much higher (about 150%) as compared to its 20 W power at 10 kHz rep-rate using pure neon as the standard CVL operation.