Since N_(A) establishes the link between the atomic and the macroscopic mass scales, its value should be determined to the highest possible accuracy. The interest in N_(A) determination was renewed by the combination of x-ray and optical interferometry, which reduced significantly the uncertainty of the N_(A) value. This achievement stimulated continuous uncertainty reductions and the target of the 10~(-8) level is considered the first step towards a new definition of the mass unit. Consequently, the Istituto di Metrologia "G. Colonnetti" (IMGC) and the Dipartimento di Fisica Generale "A. Avogadro" (DFGAA) are giving special attention to the improvement of the measurements of the silicon (220) lattice spacing and Si density.
展开▼
机译：由于N_（a）建立原子和宏观质量尺度之间的链路，因此应确定其值最高的精度。通过X射线和光学干涉法的组合更新N_（a）测定的兴趣，这显着降低了N_（a）值的不确定性。这一成就刺激了持续的不确定性减少，10〜（-8）水平的目标被认为是迈向质量单位的新定义的第一步。因此，Istituto di Metolologia“G. Colonnetti”（IMGC）和Dipartimemo di Fisica Generale“A. Avogadro”（DFGAA）特别注意改善硅（220）晶格间距和Si密度的测量。
展开▼
