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GRUPPENLEITUNG:

Univ. Prof. Dr. Hartmut Abele

Tel.: +43-1-58801-141202 
Fax: +43-1-58801-14199

TU Wien - Atominstitut
Stadionallee 2
1020 Wien
Austria

  

KOLLABORATIONEN




DIE PROJEKTE WERDEN GEFÖRDERT VON:




FWF project I 530-N20 „Gravitational induced phases in neutron interferometry"

Large crystal neutron interferometer measurements

New interferometer:

The largest perfect crystal neutron interferometer (30x12 cm) has been fabricated with our co-operation partner at the Physikalisch Technische Bundesanstalt (PTB). The 15 mm thick sample blades can be used for a high angular resolution measurement.

New IFM together with the first Si perfect crystal interferometer

Publication:

M. Zawisky, J. Springer, H. Lemmel: 
“High angular resolution neutron interferometry” 
Nucl. Instr. Methods A634 (2011) p.46-49
   

Chameleon experiment:

We search for phase shifts associated with a coupling to scalar fields. We set stringent limits for a scalar chameleon field, a prominent quintessence dark energy candidate, and we found that the the coupling constant ß is less than 1.9 ×10^7 (for Ratra-Peebles index n = 1) at 95% confidence level.

Neutron interferometer with a vacuum chamber. The chameleon phase profile between the chamber walls is shown as well

Publication:

H. Lemmel, Ph. Brax, A. N. Ivanov, T. Jenke, G. Pignol, M. Pitschmann, T. Potocar, M. Wellenzohn, M. Zawisky, H. Abele, 
Neutron interferometry constrains dark energy chameleon fields, 
Physics Letters B (2015)
  

Laue phase:

In this study, we investigate the phase shift induced by Laue transmission in a perfect Si crystal blade in detail. This 'Laue phase' was measured at two wavelengths in the vicinity of the Bragg condition within a neutron interferometer. A fascinating steep phase slope of 5.5° ((220) Bragg peak) and 11.5° ((440) Bragg peak) per 0.001 arcsec deviation from the Bragg angle has been achieved. 

Laue phase for the (220) case

Publication:

T. Potocar, M. Zawisky, H. Lemmel, J. Springer and M. Suda,
Neutron interferometric measurement and calculations of a phase shift induced by Laue transmission, 
Acta Cryst. A71 (2015)


We thank the Austrian Science Fund (FWF, Proj. No. I530-N20) and CENI, Central European Neutron Initiative, as well as the Collaboration Agreement between ILL and TU-Wien (ILL-1132.1-3) for financial support.