An in-depth analysis of the decay process for β-emitting radionuclides highlights, for some of them, the existence of high-order effects usually not taken into account in literature as considered negligible in terms of energy and yield, and referred to as Internal Bremsstrahlung (IB). This set of β -radionuclides presents, besides their β spectrum, a continuous γ emission due to the Coulomb field braking action on the emitted electron following the decaying nucleus. In this work, we review the theoretical and experimental studies on the IB process focusing on its actual importance for the pure β emitters. It emerges that there is no satisfactory model able to reproduce the experimental IB distribution for most of the investigated beta emitters and the several measurements are sometimes at odds with each other. Moreover, as recently demonstrated, the IB process can give a relevant contribution to the physics of beta emitters thus requiring its inclusion in the physics of the beta decay. A discussion on the importance of considering IB process in both applicative fields such as nuclear medicine, industrial applications, and research or calibration laboratories, and in other relevant fields of particle physics or astrophysics, such as the research on dark matter or neutrino mass, is presented.

中文翻译：

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关于伴随β衰变的内轫致辐射及其在放射源应用中的潜在相关性


对β发射放射性核素衰变过程的深入分析强调了其中一些放射性核素的存在，这些效应在文献中通常没有被考虑，因为在能量和产率方面被认为可以忽略不计，被称为内轫致辐射 （IB）。这组 β 放射性核素除了β谱外，由于衰变原子核后发射的电子受到库仑场制动作用，还表现出连续的γ发射。在这项工作中，我们回顾了 IB 过程的理论和实验研究，重点关注其对纯 β 发射器的实际重要性。事实证明，没有令人满意的模型能够重现大多数研究的 β 发射器的实验 IB 分布，并且几个测量值有时彼此不一致。此外，正如最近所证明的，IB 过程可以对 β 发射器的物理学做出相关贡献，因此需要将其包含在 β 衰变的物理学中。讨论了在核医学、工业应用、研究或校准实验室等应用领域以及粒子物理学或天体物理学的其他相关领域（如暗物质或中微子质量的研究）中考虑 IB 过程的重要性。