质子韧致辐射的X射线：来自聚变反应堆的证据及其在天体物理学中的意义
X-rays from Proton Bremsstrahlung: Evidence from Fusion Reactors and Its Implication in Astrophysics
摘要：
在聚变反应堆中，在先前的反应中产生的质子和中子可以再次彼此融合。或者它们可以反过来与未反应的氘核融合或被其捕获。在典型的聚变反应堆中，这种反应的平均质心（COM）能量约为10 keV，但也可能低至1 keV。在这个低COM能量下，反应核子在它们的相对角动量方面处于s波状态。因此，由于守恒定律，单伽马辐射过程被强烈抑制。相反，释放的伽马射线很可能伴随着来自核韧致辐射过程的x射线光子。由此产生的X射线具有连续谱，峰值约为几百eV至几keV。用半经典方法计算了这一过程的平均光子能量和光谱性质。结果给出了质子-氘核聚变在1.1 keV附近的一个峰值，并在光谱的高能极限处给出了幂次-负秒定律。一些先前的托卡马克放电数据的分析表明，这种现象可能已经观察到之前，它可能会导致新的等离子体诊断更敏感的离子或核的自由度。这种现象也应该在核天体物理学中发挥作用，作为天体物理学x射线的来源之一。这个过程特别有助于恒星演化的早期阶段，在这个阶段，原恒星或所谓的前主序星（例如金牛座T星）的温度相对较低，只有几百万开氏度。对年轻恒星中的质子-氘核融合率进行了数量级计算。从这个反应的估计X射线光度被发现足够的幅度占实验的。
英文摘要：
In a fusion reactor, a proton and a neutron generated in previous reactions may again fuse with each other. Or they can in turn fuse with or be captured by an un-reacted deuteron. The average center-of-mass (COM) energy for such reaction is around 10 keV in a typical fusion reactor, but could be as low as 1 keV. At this low COM energy, the reacting nucleons are in an s-wave state in terms of their relative angular momentum. The single-gamma radiation process is thus strongly suppressed due to conservation laws. Instead the gamma ray released is likely to be accompanied by x-ray photons from a nuclear bremsstrahlung process. The x-ray thus generated has a continuous spectrum and peaks around a few hundred eV to a few keV. The average photon energy and spectrum properties of such a process are calculated with a semiclassical approach. The results give a peak near 1.1 keV for the proton-deuteron fusion and a power-to-the-minus-second law in the spectrum's high-energy limit. An analysis of some prior tokamak discharge data shows that this phenomenon might have been observed before and it may lead to new plasma diagnostics which are more sensitive to the ionic or nuclear degree of freedom. This phenomenon should also play a role in nuclear astrophysics as one of the sources for astrophysical x-rays. The process contributes particularly to stellar evolution in the early stage, where the temperature of proto-stars or the so called pre-main sequence stars (T Tauri stars, for example), is at a relatively low of several million degrees Kelvin. An order-of-magnitude calculation was made on the proton-deuteron fusion rate in young star objects. The estimated x-ray luminosity from this reaction is found enough in magnitude to account for experimental ones.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
