dry' the lead anode is 45mm away from the terbium chips in the stainless cup at the bottom, suggesting that a closer spacing might give a much higher voltage
Wow! 45 mm! It is an enormous distance! I would love to see fraction of mA flowing in that 45 mm of air under an external small voltage! I think this will astonish a lot of people...
Can you confirm that after flushing the air inside the cell with fresh air, it will take some time to rebuild-up the voltage? This would be an interesting measure of the ionization flux and ionization dynamics.