Deceleration and trapping of cold free radicals by pulsed magnetic fields

Momose, Takamasa

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https://hdl.handle.net/2142/59149 Copy

Description

Title

Deceleration and trapping of cold free radicals by pulsed magnetic fields

Author(s)

Momose, Takamasa

Issue Date

2014-06-18

Keyword(s)

Plenary

Abstract

The study of cold and ultracold molecules is a rapidly growing interdisciplinary research field. The application of translationally cold molecules includes ultra-high resolution spectroscopy, tests of fundamental symmetry, coherent control, and investigation of cold and ultra cold chemistry. However, producing and trapping translationally cold molecules is still challenging. Cold free radicals are of great interest in relation to interstellar chemistry. In our laboratory, we have constructed a Zeeman decelerator for the deceleration of supersonic molecular beams of free radicals. Every paramagnetic molecule has a magnetic dipole moment, and therefore manipulation of the translational motion of free radicals is possible using inhomogeneous magnetic fields. Our decelerator consists of a series of solenoid coils, which provides periodic inhomogeneous magnetic fields of up to 7 T along the molecular beam axis. Rapid modulation of the field intensity removes the kinetic energy of paramagnetic species via the Zeeman effect. With this Zeeman decelerator, we have successfully decelerated supersonic beams of free radicals such as CH$_3$. The temperature of molecules thus created is low enough to trap them in an anti-Helmholtz type magnetic trap. Resonance-enhanced multiphoton ionization spectroscopy is used to confirm that radicals with specific rotational states are confined in the magnetic trap for more than several hundred micro seconds. One of the advantages of the Zeeman decelerator is it can decelerate and trap the rotational ground state of any paramagnetic molecule. We will discuss details of our Zeeman molecular decelerator, and possible applications including the study of high resolution spectroscopy and cold reactive collisions of free radicals below sub Kelvin temperatures. The work is supported by CFI funds for the Canadian Centre for Research on Ultra-Cold Systems (CRUCS) at UBC.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/59149

DOI

https://doi.org/10.15278/isms.2014.WA02

Copyright and License Information

Copyright 2014 by the authors. Licensed under a Creative Commons Attribution 4.0 International License. http://creativecommons.org/licenses/by/4.0/

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