Triple Alpha Process三α过程
If the central temperature of a star exceeds 100 million Kelvins, as may happen in the later phase of red giants and red supergiants, then helium can fuse to form beryllium and then carbon. 如果恒星的中心温度超过1亿开尔文，如在红巨星或红超巨星的后期相中可能发生，那么氦可以融合形成铍，然后形成碳。
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Index Nuclear fusion in stars 恒星中的核融合索引 | ||
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The Hoyle Resonance霍伊尔共振
Around 1950, astronomer Fred Hoyle was working on the modeling of stellar nucleosynthesis and considered carbon synthesis in the light of the observed carbon abundance in the stars. Carbon could be formed by the fusion of three alpha particles, but the probability is relatively so low that this would be too slow to explain the observed carbon abundance. The formation of 8Be from two alpha particles is energetically favorable since they have almost the same energy, and the subsequent fusion with another alpha particle would create a 12C nucleus.
84Be + 42He -> 126C + 2γ (+7.367 MeV) 8 4 Be + 4 2 He → 12 6 C + 2γ (+7.367 MeV) 大约在1950年，天文学家弗雷德·霍伊尔正在研究恒星核合成的建模，并考虑了恒星中碳的合成情况，基于观测到的恒星中碳的丰度。碳可以通过三个α粒子的融合形成，但这种概率相对较低，因此这种过程太慢，无法解释观测到的碳的丰度。由两个α粒子形成8 Be的过程在能量上是有利的，因为它们几乎具有相同能量，随后与另一个α粒子融合将形成12 C核。 4 2 He + 4 2 He -> 8 4 Be -0.092 MeV When the production of carbon by this process was modeled, it still seemed to be too slow to account for the observed carbon abundance, and this led Hoyle to propose that carbon had a nuclear resonance in the neighborhood of 7.7 MeV, even though none had been observed at that time. Hoyle, et al. did discover a resonance at 7.65 MeV which brought the modeled production rate into agreement with carbon observations.  当用这一过程来模拟碳的产生时，它仍然显得太慢，无法解释观测到的碳丰度，这促使霍伊尔提出碳在7.7 MeV附近存在核共振，尽管当时尚未有观测到这种共振。霍伊尔等人后来确实发现了7.65 MeV处的共振，使模拟的产生速率与碳的观测结果相符。 F. Hoyle, D. N. F. Dunbar, W. A. Wensel, W. Whaling, Phys. Rev. 92, 649 (1953). F. Hoyle, D. N. F. Dunbar, W. A. Wensel, W. Whaling, Phys. Rev. 92, 649 (1953).（专名或术语） The dramatic implications of the Hoyle resonance in the modeling of the triple-alpha process are highlighted in a statement from Stephen Hawking and Leonard Mlodinow: "Such calculations show that a change of as little as 0.5% in the strength of the strong nuclear force, or 4 percent in the electric force, would destroy either nearly all carbon or all oxygen in every star, and hence the possibility of life as we know it. " 霍利共振在三α过程建模中的重大意义在史蒂芬·霍金和伦纳德·莫洛dinow的声明中得到了强调：'这些计算表明，强核力的强度仅改变0.5%，或电力的强度改变4%，就会摧毁恒星中几乎所有的碳或所有的氧，从而摧毁我们所知的生命的可能性。 |
Index Nuclear fusion in stars Reference Barrow & Tipler Ch 4 Hawking & Mlodinow Ch 7, p159 索引 核融合在恒星中的参考 Barrow & Tipler 第4章 Hawking & Mlodinow 第7章，第159页 | ||
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