Out of curiosity / frustration with matching gain medium with arc lamp spectra, I decided to look at the game files to try to understand why Sodium appears there but other metals don't. It seems that the missing factor is just adding an estimate for the viscosity on most of those metals.
I modded in a "Silver with Viscosity" material that seems to match pretty nicely with Ruby -- better than Xenon.
Is there any reason why we shouldn't be able to use metals as the gas composition, on the proper temperature ranges? Can we get the viscosities of each metal added to the base game so everyone gets to play with more materials, or at least have people with better knowledge than me provide those values for metals of interest?
Metal gas lasers, huh. I think most people want FELs rather than expanding Arc-Lamp laser typology.
Metal gas lasers are a different beast, but it certainly looks like mixing in metal Ions will let us alter the arc lamp emission spectrum and improve pumping efficiency of the laser arc lamps. Then there are new beasts, like the optically pumped alki vapor lasers, which theoretically combine the efficiency of diode lasers with the easy power scaling of gas lasers.
That said, I agree that FELs are probably the best laser for most ships. They're big and bulky, but can have high efficiency and can almost any color of light up to X-rays.
I hope we'll be able some day (again, as part of a laser DLC most likely) to have centralized, spinal laser generation with multiple emitter sites on the ship, though at the cost of some efficiency and requisite cooling need.
I don't think we'll be seeing any sort of DLC for this particular game, since that would divide up the already small user base into "those who have the DLC" and "those who don't," and a DLC would conflict with the ideal of a simulator seeing what space combat would really be like (what's the rationale behind limiting realistic options for base users?). A DLC would also redirect programming time by the tiny one-man team, making the base game not improve in that time.
It's much more likely to eventually (~1-2 years down the road) see a raise in the purchase price of the entire game as features get added to it.
Back on topic:
Is the viscosity value of sodium for its liquid state or gas? I'm pretty sure it's liquid... Which state can the arclamp use? And why is there only one viscosity value in the first place?
I don't think the viscosity is actually used for this simulation; I think it is used as a flag to treat the material as a solid or as a fluid. Which would explain why you can't build anything out of solid sodium in game.
Ideally, we'd be able to use those materials on both solid and liquid / gas phases -- but for now that requires modding new materials.