Investigation of the abnormally-high annihilation rate of ortho-positronium in iodomethane gas

虽然邻正电子素在碘甲烷气体中异常高的湮没率的机理尚未得到揭示，但通过研究发现，对于所有已报道的气体原子和分子，拾取猝灭截面与由粘度导出的几何截面之间存在基本的比例关系。在此基础上，提出了一个实用的理论，它把正电子偶素的寿命与正电子偶素被俘获的自由空间的平均尺寸联系起来。

Although the mechanism of the abnormally high annihilation rate of ortho-positronium in iodomethane gas has not been revealed, a fundamental proportional relationship between the pick-off quenching cross-section and the geometrical cross section derived from the viscosity has been found for all the gaseous atoms and molecules previously reported through the study. Based on this result, a practical theory, which relates the positronium lifetime to the average size of free spaces in which positronium trapped, has been proposed.