Ignition timing Ignition timing In a spark ignition internal combustion engine, Ignition timing refers to the timing, relative to the current piston position and crankshaft angle, of the release of a spark in the combustion chamber near the end of the compression stroke. The need for advancing (or retarding) the timing of the spark is because fuel does not completely burn the instant the spark fires, the combustion gases take a period of time to expand and the angular or rotational speed of the engine can lengthen or shorten the time frame in which the burning and expansion should occur. In a
Fusion ignition of deuterium and tritium, which are both isotopes of hydrogen, in order to compress the isotopes to a fraction of their original size, and fuse them into helium atoms (releasing neutrons in the process). In January 2012, National Ignition Facility Director Mike Dunne predicted in a Photonics West 2012 plenary talk that ignition would be achieved at NIF by October 2012. However, , NIF is operating at conditions about 1/10 to 1/3 of breakeven. Confusingly, by LLNL definitions, ignition and breakeven occur at the same point, due to specifics of their experiment. Experts believe that achieving fusion ignition is the