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arXiv 2408.07567nucl-ex
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极低能量下DD反应新通道的实验特征

Experimental signatures of a new channel of the DD reaction at very-low energy

R. Dubey, K. Czerski, Gokul Das H, A. Kowalska, N. Targosz-Sleczka, M. Kaczmarski, M. Valat

AI总结:

实验证实极低能量氘-氘聚变存在新通道,通过高能正电子探测和干涉理论计算,揭示$e^+e^-$对产生分支比显著增强,为未来清洁能源提供新可能。

摘要:

氘-氘聚变在极低能量下存在一个新的强反应通道,这一发现可能对未来构建清洁高效能源具有重大意义。继关于$^4$He核中氘-氘阈值共振及其通过内部$e^+e^-$对产生主导衰变的首个理论和实验迹象之后,我们在此呈现一项广泛的实验研究,证实了高能电子和正电子的发射。通过同时使用不同厚度的硅带电粒子探测器和大型NaI(Tl)与HPGe探测器,我们首次能够确定在氘核能量低至5 keV时发射质子、中子和$e^+e^-$对之间的分支比。高能正电子可通过其轫致辐射谱和湮灭辐射被明确探测,并辅以蒙特卡洛Geant4模拟支持。基于阈值共振与$^4$He中已知宽共振之间的相消干涉的理论计算,与实验观察到的随入射粒子能量降低而分支比增加的现象非常吻合。阈值共振对$e^+e^-$对产生的分宽度应至少是质子通道的10倍。

英文摘要:

The discovery of a new, strong reaction channel of the deuteron-deuteron fusion at very low energies might have major consequences for the construction of a future clean and efficient energy source. Following the first theoretical and experimental indications for the existence of the deuteron-deuteron threshold resonance in the $^4$He nucleus and its dominant decay by the internal $e^+e^-$ pair creation, we present here an extensive experimental study confirming emission of high-energy electrons and positrons. A simultaneous use of Si charged particle detectors of different thicknesses and large volume NaI(Tl) and HPGe detectors has allowed for the first time to determine the branching ratio between emitted protons, neutrons and $e^+e^-$ pairs for deuteron energies down to 5 keV. The high-energy positrons could be unambiguously detected by their bremsstrahlung spectra and annihilation radiation, supported by the Monte Carlo Geant4 simulations. The theoretical calculations, based on a destructive interference between the threshold resonance and the known broad resonance in $^4$He, agree very well with experimentally observed increase of branching ratios for lowering projectile energies. The partial width of the threshold resonance for the $e^+e^-$ pair creation should be at least 10 times larger than that of the proton channel.

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