Another important parameter for fusion based power plant is Q, the ratio of fusion power to input auxiliary heating power. While fusion power plant generating electricity would need Q≥10, an ignited power plant would correspond to Q=∞ , since there is no externally injected heating power in such a device. Present day fusion experiments have brought the triple product to within a factor of  3-5 of its final required value and have already exceeded conditions equivalent to a Q=1 operating power plant.