Zeeman deceleration beyond periodic phase space stability

Research output: Contribution to journalArticlepeer-review

Authors

  • Jutta Toscano
  • Atreju Tauschinsky
  • Katrin Dulitz
  • Christopher J. Rennick
  • Brianna R. Heazlewood

External organisations

  • University of Freiburg
  • National Physical Laboratory
  • Oxford University

Abstract

In Zeeman deceleration, time-varying spatially inhomogeneous magnetic fields are used to create packets of translationally cold, quantum-state-selected paramagnetic particles with a tuneable forward velocity, which are ideal for cold reaction dynamics studies. Here, the covariance matrix adaptation evolutionary strategy is adopted in order to optimise deceleration switching sequences for the operation of a Zeeman decelerator. Using the optimised sequences, a 40% increase in the number of decelerated particles is observed compared to standard sequences for the same final velocity, imposing the same experimental boundary conditions. Furthermore, we demonstrate that it is possible to remove up to 98% of the initial kinetic energy of particles in the incoming beam, compared to the removal of a maximum of 83% of kinetic energy with standard sequences. Three-dimensional particle trajectory simulations are employed to reproduce the experimental results and to investigate differences in the deceleration mechanism adopted by standard and optimised sequences. It is experimentally verified that the optimal solution uncovered by the evolutionary algorithm is not merely a local optimisation of the experimental parameters - it is a novel mode of operation that goes beyond the standard periodic phase stability approach typically adopted.

Details

Original languageEnglish
Article number083016
JournalNew Journal of Physics
Volume19
Issue number8
Early online date11 Jul 2017
Publication statusPublished - 16 Aug 2017

Keywords

  • decelerator sequence optimisation, evolutionary strategy, Zeeman deceleration

ASJC Scopus subject areas