https://doi.org/10.1140/epjd/e2004-00160-9
Decelerated molecular beams for high-resolution spectroscopy
The hyperfine structure of 15ND3
1
Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6,
14195 Berlin, Germany
2
FOM-Institute for Plasmaphysics “Rijnhuizen”, Edisonbaan 14,
3439 MN Nieuwegein, The Netherlands
3
General Physics Institute RAS, Vavilov str. 38, 119991 Moscow, Russia
4
Department of Molecular and Laser Physics, University of Nijmegen,
Toernooiveld 1, 6525 ED Nijmegen, The Netherlands
Corresponding author: a meijer@fhi-berlin.mpg.de
Received:
25
June
2004
Revised:
7
September
2004
Published online:
23
November
2004
Ultimately, the resolution of any spectroscopic experiment is limited by the
interaction time between the particles that are to be examined and the
measuring device. The obtainable spectroscopic resolution in a molecular beam
experiment can be considerably improved using samples of slow molecules, as
produced, for example, in a Stark-decelerator. This is demonstrated here by
measuring the inversion tunneling spectrum of 
using a pulsed
molecular beam that has been decelerated to about 52 m/s. Hyperfine resolved
inversion transitions in in the 
state (around 1.43 GHz)
are induced in a microwave region, and molecules that have
undergone the transition are subsequently detected using a UV-laser based
ionization detection scheme. To increase the signal intensity, the
decelerated molecular beam is both transversally and longitudinally focused
into the laser detection region. The observed spectral width of individual
hyperfine transitions in the fully resolved spectrum is about 1 kHz, and the
standard deviation of the best fit is 62 Hz.
PACS: 33.15.Pw – Fine and hyperfine structure / 33.20.Bx – Radio-frequency and microwave spectra / 33.40.+f – Multiple resonances / 33.70.Jg – Line and band widths, shapes, and shifts / 39.10.+j – Atomic and molecular beam sources and techniques
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2004
