Also, to tune that new-found laser enthusiasm to a proper linewidth, these may be beneficial:
https://www.thorlabs.com/tutorials.cfm?tabID=f7dfa931-5afa-441b-8176-292d8735b143https://www.rp-photonics.com/external_cavity_diode_lasers.htmlEspecially Thorlabs has pretty good overall information IMO.
Before you jump down the laser rabbit hole, I've been told that laser rabbit holes can be very deep indeed. Something to keep in mind while working out your hobby time & money budget.
If the hypothetical effect you want to verify grows linearly with voltage difference, then instrumentation step 1 is a no-brainer. Get a vandergraafgenerator that
juuuuust gets through the door. Clear room of furniture & cats. Off you go! As you have found, beyond a certain point the cost & difficulty of precision timing goes up. The incremental cost of upgrading voltage at this point would seem far lower than the timing part. I hesitate to bring it up, but the even lower cost part to upgrade would be theory & thought experiments. Consider working out your idea to the max. If the effect whatever-it-is exists, planet earth is not the only place. What are other places you can look? Can you take previous discoveries and steal ideas there? We live on a planet with pretty cool lightning. Those water molecules in that cloud up there live at a pretty large potential difference compared to the planet below. What would be the effect of that? Same question for planets.
Gah, I was going to google a reasonable site/paper with the kind of info I was thinking of.
This just in! Our solar system could be destroyed by lightning!
http://www.systovi.com/en/faq/can-solar-system-be-destroyed-by-lightning/Yeah well, okay, that's a solar system too I suppose. But not the one I was looking for.
Anyways, thinking some more about it, due to proximity lighting on our planet is the most practical. So given the potential difference, is there any difference that would be caused by the hypothetical effect? I dunno, marginal difference in ozone percentage? Difference in nitrogen oxides? Why go to the trouble of building stuff when you have a free lab all around you for the basic sanity checks?
Another one that comes up during the
"What if?". Suppose that voltage difference is
consistent with time dilation. (Nope, not going any stronger than consistent with). Then looking for parallels you can take general relativity. Dump a clock down the cliff into the gravity well, tada time dilation. And if I understood your hypothetical situation correctly then the hypothesis would be: put clock in Faraday cage, crank up the voltage, tada time dilation. Right? If so, what happens during the ramping up and down of the voltage? Does the time taken for ramping up/down make any difference? What happens when you put
another Faraday cage next to it? What happens when you now also ramp up the voltage on the neighboring Faraday cage? Any predictions there? Basically you can take everything you already know from general relativity and work out the parallel case. It would be silly to ignore relativity just because it's inconvenient and forces you to think a little more. Because general relativity gives you some hints that you will now have to be prepared for inconvenient things. If you have a model that actually has an answer for that, and predicts new verifiable behavior, then I say gogogo. It has low probability, but worth a shot. If not, well ...
IMO: Biggest wins at this stage are thought experiments + inspired star gazing. After that working out the model beyond the "if voltage, then time dilation" stage. If it survives that, then up the voltage. And only then fiddle with the timing side. Possibly less fun, but more practicable. Or
"stick it in at an oblique angle" again, and hope for the best. Oh well, if nothing else you end up with more cool toys to play with, that's always a plus.