Neutral uncharged molecules are affected by the electromagnetic field of a charged particle beam if they carry either an electric or a magnetic dipole moment. The residual gas in an accelerator beam pipe consists of such molecules. In this paper we study their dynamics. Under a few approximations, whose validity we explore and justify, we derive the equations of motion of neutral molecules and their invariants, determine the conditions for these neutral molecules to become trapped in the field of the beams as a function of beam-pipe temperature, and compute the resulting enhancement of molecule density in the vicinity of the beam. We demonstrate that large agglomerates of molecules, “flakes,” are much more likely to be pulled into the beam than single molecules, and suggest that this phenomenon might help explain some beam observations at the Large Hadron Collider.

中文翻译：

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束电磁场俘获中性分子

如果中性不带电分子带有电或磁偶极矩，则它们会受到带电粒子束的电磁场的影响。加速器束管中的残留气体由此类分子组成。在本文中，我们研究了它们的动力学。在几个近似的基础上，我们探索并证明了它们的有效性，得出了中性分子及其不变量的运动方程，确定了这些中性分子作为束管温度的函数而被束缚在束流场中的条件，并计算光束附近分子密度的增强结果。我们证明，大的分子团块（“薄片”）比单个分子更有可能被拉入光束中，