Proposal of a new Zeeman slower for fabrication of nano-scale length standards

To meet the requirement of Nano-scale dimensional metrology, length standards with features below 100 nanometers are indispensible instruments. Our group has successfully fabricated length standards with periodic length of 213±0.1nm using the laser focused atomic deposition method, which is related to the atomic transition frequency and thus retraceable to a constant measured with high accuracy. For further improvement of the quality of these standards, we propose the use of Zeeman slower, which consists of an array of symmetrically positioned small discrete NdFeB magnets. Ideal magnetic field distribution is obtained employing Zeeman-tuned Doppler cooling theory. A simple and effective point-like magnetic dipoles model (MD) is used to represent the magnets during simulation. Two kinds of different oriented MDs are compared and only one is selected. By introducing local field contribution approximation, periodic array assumption and a new relative field deviation parameter, MDs array's configuration are calculated and optimized. The overall RMS of the difference between the ideal and calculated field in the whole length is reduced to 3.08E-3 T, and an optimal MDs array configuration is found and presented.