Spectroscopy of correlated electron pairs was employed to investigate the energy dissipation process, as well as the transport and the emission of low-energy electrons on a polymethylmethacrylate surface, providing secondary electron spectra causally related to the energy loss of the primary. Two groups are identified in the cascade of slow electrons, corresponding to different stages in the energy dissipation process. The characteristic lengths for attenuation due to collective excitations and momentum relaxation are quantified for both groups and are found to be distinctly different: ${\lambda }_1=(12\pm 2)\AA$ and ${\lambda }_2=(62\pm 11)\AA$. The results strongly contradict the commonly employed model of exponential attenuation with the electron inelastic mean free path as characteristic length, but they essentially agree with a theory used for decades in astrophysics and neutron transport, albeit with characteristic lengths expressed in units of angstroms rather than light-years.

中文翻译：

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聚甲基丙烯酸甲酯中快电子的能量耗散：走向~0 eV 和相对论能量之间固体中电子束衰减的通用曲线

采用相关电子对的光谱来研究能量耗散过程，以及低能电子在聚甲基丙烯酸甲酯表面上的传输和发射，提供与初级能量损失因果相关的二次电子光谱。在慢电子级联中识别出两组，对应于能量耗散过程的不同阶段。对两组由于集体激励和动量弛豫而导致的衰减特征长度进行了量化，发现明显不同：${\lambda }_1=（12\pm 2）A$和${\lambda }_2=（62\pm 11）A$。结果与常用的以电子非弹性平均自由程作为特征长度的指数衰减模型强烈矛盾，但它们基本上与天体物理学和中子输运几十年来使用的理论一致，尽管特征长度以埃而不是光为单位表示-年。