MULTISTAGE ZEEMAN DECELERATION: STOPPING AND REFLECTING COLD BEAMS OF HYDROGEN
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Date
2008
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Journal ISSN
Volume Title
Publisher
Ohio State University
Abstract
With the goals of: (i) performing ultra-high resolution spectroscopy with long interaction times between a cloud of cold atoms or molecules and a narrow bandwidth radiation field, and (ii) studying cold reactive collisions in which the kinetic energies and quantum states of the colliding particles may be controlled to a high degree, a multistage Zeeman decelerator for neutral radicals has recently been developed in our laboratory}, \emph{Phys. Rev. A}, {\bf 75} 031402 (2007). {\sc S. D. Hogan, D. Sprecher, M. Andrist, N. Vanhaecke, and F. Merkt}, \emph{Phys. Rev. A}, {\bf 76}, 023412 (2007).}. This instrument relies on the same concept of phase stability as employed in charged particle accelerators}, \emph{J. Phys. (USSR)}, {\bf 9}, 153 (1945). {\sc E. M. McMillan}, \emph{Phys. Rev.}, {\bf 68}, 143 (1945).} and multistage Stark decelerators}, \emph{Phys. Rev. Lett.}, {\bf 83}, 1558 (1999).} and can be used to decelerate cold samples of radicals in supersonic beams.\\ The results of a recent series of experiments in which we have decelerated ground state H and D atoms will be presented. In these experiments magnetic fields of 1-2~T were pulsed in each coil for tens of microseconds, with rise and fall times shorter than 5~$\mu$s. We have studied the influence Majorana spin-flip transitions on the deceleration process and made systematic studies of the deceleration behavior as a function of the phase angle, the magnitude of the pulsed magnetic fields and the initial velocity of the beam. Finally we have shown that a supersonic beam of H atoms initially moving at 435~m/s can be stopped and reflected at the end of a 12-stage decelerator. \\
Description
N. Vanhaecke, U. Meier, M. Andrist, B.H. Meier, and F. Merkt V. Veksler H. L. Bethlem, G. Berden, and G. Meijer
Author Institution: Laboratorium fur Physikalische Chemie, ETH Zurich, 8093 Zurich, Switzerland
Author Institution: Laboratorium fur Physikalische Chemie, ETH Zurich, 8093 Zurich, Switzerland