The alpha process, also known as the alpha ladder, is one of two classes of nuclear fusion reactions by which stars convert helium into heavier elements, the other being the triple-alpha process. The triple-alpha process consumes only helium, and produces carbon. After enough carbon has accumulated, further reactions below take place, listed below. Each step only consumes helium and the product of the previous reaction. The energy produced each the reaction, E , is primarily in the gamma ray (γ), with a small amount taken by the byproduct element, as added momentum.