View of the High-Voltage transformer and Thyratron. The transformer to the right side of the photo is the thyratron filament transformer.

The main high-voltage transformer (the big black unit which looks like a small refrigerator compressor) develops around 11,000 Volts. This voltage is then used to charge up the high-voltage capacitors. The high-voltage is then very quickly discharged into the laser tube with the thyratron. The power supply runs at 16khz. 

At this high frequency, you don't need to double discharge the tube as the power supply is generating pulses quicker than required to maintain free Copper atoms.

Here is another view of the business end of the laser tube. Note the cover / shield over the tube as a safety feature. Here the laser tube is just on lasing threshold. The initial Neon glow has given way to the characteristic Copper green glow. As the Copper Vapour pressure continually increases, the tube will begin to lase, and the output power dramatically increase.

This photo of the high reflector, the laser tube is just starting to lase. The large coil above the laser tube is connected across the laser tube / supply in parallel - this is used to present a closed circuit to charge the capacitors, but present as an open circuit to the pulses (this is the same function as in nitrogen lasers).

The output of the laser is coupled into a fibre optic cable. The photo shows the focal point of the collimating lens used to focus the light into the fibre.