時間依存密度関数理論 ^{238}U{n,f), ^{240,242}Pu{n,f), ^{237}Np{n,f) の反応の記述
Aurel Bulgac1, Ibrahim Abdurrahman2, Matthew Kafker1
1University of Washington, Department of Physics,, Seattle, Washington 98195-1560, USA.
Physical review letters
|August 27, 2025
まとめ
奇数核では,ペア化されていない核からの擬磁場が,誘導分裂中にクーパーペアに影響を与える. この研究は,自発的な対称性破裂とパウリブロックの破綻を明らかにしています.
科学分野:
- 核物理学
- 量子力学
- 計算物理
背景:
- 奇数の核子を持つ核は,消滅しないスピン密度を持ち,擬磁場を形成する.
- このフィールドは,特に奇数核のダイナミックな進化の間に,ヌクレオン・クーパー・ペアの分裂を高める.
研究 の 目的:
- 特定の奇数中性子 (U,Pu) と奇数奇数 (Np) 化合物核における誘導分裂の最初の顕微鏡研究を行う.
- 核分裂のダイナミクスにおけるペアレスな核と自発的な時間逆転対称性破裂の役割を調査する.
主な方法:
- 超流動フェルミオン系に拡張された時間依存密度関数理論を用いて.
- 仮定を簡素化せず,制御された数値近似で,多くの初期条件で計算を行う.
主要な成果:
- 時相反対称性の自発的な破裂が観察され,これはしばしば無視される側面である.
- 核分裂断片の性質は,隣接する偶数核と類似していることが判明した.
- から分裂までの時間は,奇数の質量を持つ原子核では,刺激が増加し,複雑な潜在エネルギー面があるため,より長かった.
- パウリ阻害近似は 核分裂ダイナミクスで 驚くほど強く 破られた.
結論:
- この研究は奇数核における誘導分裂に関する 顕微鏡による包括的な理解を提供している.
- ペアリングされていない核は,分裂ダイナミクスを著しく影響し,自発的な対称性破裂と分裂時間の変化につながります.
- この発見は,これらのシステムにおける核分裂過程を記述する際に,パウリブロックなどの既存の近似値に異議を唱えている.
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