Berlin 2005 – scientific programme
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Q: Quantenoptik und Photonik
Q 74: Teilchenoptik
Q 74.5: Talk
Wednesday, March 9, 2005, 15:00–15:15, HU 2014a
Determination of the 4He3 Size by Diffraction from an Inclined Transmission Grating. — •J. Peter Toennies1, Rüdiger Brühl1, Gerhard C. Hegerfeldt2, Anton Kalinin1, Oleg Kornilov1, and Martin Stoll2 — 1Max-Planck-Institut für Strömungsforschung, Bunsenstr. 10, 37073 Göttingen, Germany — 2Institut für Theoretische Physik, Friedrich-Hund-Platz 1, Universität Göttingen, 37077 Göttingen, Germany
The size of helium trimer is determined by diffracting a 4He beam from a 100 nm grating inclined by 21∘. Compared to normal incidence, due to the bar thickness the projected slit width is roughly halved to 27 nm, increasing sensitivity to the trimer size. The peak intensities measured out to the 8th order are evaluated via few-body scattering theory. The trimer pair distance is found to be <r>=1.1+0.4/−0.5 nm in agreement with predictions for the ground state. The concentration of Efimov trimers in the beam is estimated to be less than 6%.