酸素燃焼過程

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: この項目では、核融合過程での酸素燃焼過程について説明しています。工業用燃焼技術の「酸素燃焼」については「酸素燃焼」をご覧ください。
酸素燃焼過程（さんそねんしょうかてい、英: oxygen burning process）は大質量星で起きる核融合過程である。酸素の燃焼は1.5×109 K の温度と4×1010 kg/m3 の圧力下で起こる。
以下に主な反応を示す：
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | 71 | 72 | 73 | 74 | 75 | 76 | 77 | 78 | 79 | 80 | 81 | 82 | 83 | 84 | 85 | 86 | 87 | 88 | 89 | 90 | 91 | 92 | 93 | 94 | 95 | 96 | 97 | 98 |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |

|  {\ce {^{16}O}}  |  {\ce {+}} |  {\ce {^{16}O}} |  {\ce {->}} |  {\ce {^{28}Si}} |  {\ce {+}} |  {\ce {^{4}He}} |  {\ce {+}} | 9.594 MeV |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|   |   |   |  {\ce {->}} |  {\ce {^{31}P}} |  {\ce {+}} |  {\ce {^{1}H}} |  {\ce {+}} | 7.678 MeV |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|   |   |   |  {\ce {->}} |  {\ce {^{31}S}} |  {\ce {+}} |  {\ce {\mathit {n}}} |  {\ce {+}} | 1.500 MeV |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|   |   |   |  {\ce {->}} |  {\ce {^{30}Si}} |  {\ce {+}} |  {\ce {2^{1}H}} |  {\ce {+}} | 0.381 MeV |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|   |   |   |  {\ce {->}} |  {\ce {^{30}P}} |  {\ce {+}} |  {\ce {^{2}H}} | -  | 2.409 MeV |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
または:
|   |   |   |  {\ce {->}} |  {\ce {^{32}S}} |  {\ce {+}} |  {\ce {\gamma}} |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
|   |   |   |  {\ce {->}} |  {\ce {^{24}Mg}} |  {\ce {+}} |  {\ce {2^{4}He}} |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
ネオン燃焼過程は恒星のコアに酸素とマグネシウムの不活性なコアを形成する。ネオン燃焼が終了するとコアの温度は低下し、コアは重力により圧縮される。その結果、コアの密度と温度が上昇し、酸素の燃焼が始まる。酸素の燃焼はおよそ半年から1年の間続き、ケイ素が豊富なコアを形成する。この時点ではケイ素燃焼過程が始まる温度に達していないのでケイ素のコアは不活性である。酸素が全て消費されると、コアは再び冷却されて圧縮される。コアの温度が上昇し、ケイ素燃焼過程が始まる。このとき、コアの外側には順番に、酸素燃焼が続いている殻、ネオンの殻、炭素の殻、ヘリウムの殻、水素の殻が存在している。