I would like to create an experiment where I would hold ionized air molecules. Most likely negative O2-1 ions. I am looking for the most appropriate enclosure so that the ions do lose as little of charge to the surroundings as possible. I couldn't find any suggestions... Any help would be greatly appreciated.
The chamber should be made from a dielectric material so it doesn't interact with your ions. Use plastic, for example. PVC or methacrylate if the pressure is high. The enclosure should be tight, so melt down the plastic sheet borders and join them properly.