*reorganizes micro-catalysts and loads synth-material into vaoprization capsule*
Well tachyons are particles that travel faster than the speed of light. Because of this fact, they have unusual physical properties, they don't have normal mass and instead of slowing down over time, they speed up over time. As a result, we can keep draining the kinetic energy from tachyons as long we don't drain them below the speed of light. Once they drop below the speed of light, you can continue to drain them for large amounts of energy, but it is impossible to return them to tachyons.
The total number of tachyons determines max energy capacity and energy regen rate as a result. They are hard to contain though, so the total number of of tachyons able to be contained is limited. The generator also automatically drains energy from time to time and uses them to fill capacitors. Any additional energy beyond the capacitor's max capacity is converted to various forms of matter, essentially giving you healing capability when not draining. I'm currently trying to push the limits of how many tachyons I can fit, but current trap technology can only get me to 4.