Nuclear fusion is the process by which two or more atomic nuclei join together, or "fuse", to form a single heavier nucleus. During this process, matter is not conserved because some of the mass of the fusing nuclei is converted to energy which is released. The binding energy of the resulting nucleus is greater than the binding energy of each of the nuclei that fused to produce it. Fusion is the process that powers active stars. Creating the required conditions for fusion on Earth is very difficult, to the point that it has not been accomplished at any scale for protium, the common light isotope of hydrogen that undergoes natural fusion in stars. In nuclear weapons, some of the energy released by an atomic bomb (fission bomb) is used for compressing and heating a fusion fuel containing heavier isotopes of hydrogen, and also sometimes lithium, to the point of "ignition". At this point, the energy released in the fusion reactions is enough to briefly maintain the reaction. Fusion-based nuclear power experiments attempt to create similar conditions using far lesser means, although to date these experiments have failed to maintain conditions needed for ignition long enough for fusion to be a viable commercial power source. There are many experiments examining the possibility of fusion power for electrical generation. Nuclear fusion has great potential as a sustainable energy source. This is due to the abundance of hydrogen on the planet and the inert nature of helium (the nucleus which would result from the nuclear fusion of hydrogen atoms). Unfortunately, a controlled nuclear fusion reaction has not yet been achieved, due to the temperatures required to sustain one. In hot fusion it need a temperature of 4000 million degrees. Without a minimum of 3000 million degrees we can't make the hot fusion reaction, to obtain the nuclear power. Today we have just 150 million degrees made. To replace the lack of necessary temperature, it uses various tricks. Because obtaining the necessary huge temperature for hot fusion is still difficult, it is time to focus us on cold nuclear fusion. We need to bomb the fuel with accelerated deuterium nuclei. The fuel will be made from heavy water and lithium. The optimal proportion of lithium will be tested. It would be preferable to keep fuel in the plasma state. Research into developing controlled thermonuclear fusion for civil purposes also began in earnest in the 1950s, and it continues to this day. Two projects, the National Ignition Facility and ITER are in the process of reaching breakeven after 60 years of design improvements developed from previous experiments. The best results were obtained with the Tokamak-type installations