Hello.

Our lab has significant portion of job associated with the single-shot HV (High Voltage) gas discharge. Peak current is several hundreds amperes and rising time to peak is about ~ 100 ns. HV is up to 35 kV and considered to be further increase.

We're going to move new lab which is 3rd floor. I mostly worry about weakening of the lab ground due to such a height with respect to soil. Current lab is in 2nd floor and has additional ground connections directly to the soil with 25 mm^2 wires, but our experience tells that this ground is not good enough for transient discharge time. Every conductors inside the lab are fluctuated with huge degree over such a short time so some of sensitive instruments becomes malfunctioned, although we've tried our best to ground all metals as much as possible.

I guess future ground setup in new lab has to be more reliable and I am thinking that ground wires can be replaced to some sort of copper bar or plane. Could you provide me any suggestions to this new ground construction like recommended physical dimensions of ground conductor to the soil from lab?