The proton–proton chain, also commonly referred to as the p–p chain, is one of two known sets of nuclear fusion reactions by which stars convert hydrogen to helium. It dominates in stars with masses less than or equal to that of the Sun , [ 2 ] whereas the CNO cycle , the other known reaction, is suggested by theoretical models to dominate ...

一、质子质子链(proton–proton chain reaction，简称PP链，pp chain)质子-质子链是亚瑟·爱丁顿（Arthur Eddington）在1920年代提出的。 当时，太阳核心的温度被认为太低而无法克服库仑势垒。

質子﹣質子鏈反應（英語： proton-proton chain ，簡寫為p-p chain）是恆星內部將氫融合成氦的幾種核融合反應中的一種，另一種主要的反應是碳氮氧循環。 質子﹣質子鏈反應 在 太陽 或更小的恆星上佔有主導的地位。

Proton-proton chain, chain of thermonuclear reactions that is the chief source of energy radiated by the Sun and other cool main-sequence stars. Four hydrogen nuclei are combined to form one helium nucleus; 0.7 percent of the original mass is lost mainly by conversion into energy.

In this reaction there are a sequence of intermediate steps that we’re now going to examine in detail. The simplest sequence, known as the proton-proton (pp) chain, be-gins with the interaction of a proton with another proton.

How do we turn hydrogen into helium and make energy? The process is called the Proton-Proton (PP) Chain, and it operates inside the Sun and stars of similar mass. Step 1: Smash two protons together to make deuterium. Do Steps 1 and 2 again, so that we have two helium-3 nuclei. Then (69% of the time):

质子-质子链（PP Chain），碳氮氧循环(CNO Cycle)和三氦过程(Triple α)在不同温度（T）下的相对能量输出（ε）的对数。 在太阳核心温度下PP链更占优势，太阳核聚变能量99%来自PP链，1%来自CNO循环。

2018年10月24日 · We measure the neutrino–electron elastic-scattering rates for neutrinos produced by four reactions of the chain: the initial proton–proton fusion, the electron-capture decay of beryllium-7, the...

With only hydrogen available (for example, a first generation star) the ppI chain (see previous slide) is the only possible sequence of reactions. (other reaction chains require catalyst nuclei). The ppI chain proceeds as follows: This does not work because the d abundance is too low. d + p leads to rapid destruction of d.

pp链所代表的氢核聚变是指质量M＜=2M☉,中心温度的主序星，核心处发生的一系列反应。