Kreuz, M., Nesvizhevsky, V. V., Schmidt-Wellenburg, P., Soldner, T., Thomas, M., Boerner, H. G., ...
We present a method to measure the resonance transitions between the gravitationally bound quantum states of neutrons in the GRANIT spectrometer. The purpose of GRANIT is to improve the accuracy of...
UCN production by multiphonon processes in superfluid Helium under pressure (2008)
Schmidt-Wellenburg, P., Andersen, K. H., Zimmer, O.
Cold neutrons are converted to ultra-cold neutrons (UCN) by the excitation of a single phonon or multiphonons in superfluid helium. The dynamic scattering function S(q, omega) of the superfluid...
Ultracold-neutron infrastructure for the gravitational spectrometer GRANIT (2008)
Schmidt-Wellenburg, P., Andersen, K. H., Courtois, P., Kreuz, M., Mironov, S., Nesvizhevsky, V. V., ...
The gravitational spectrometer GRANIT will be set up at the Institut Laue Langevin. It will profit from the high ultracold neutron density produced by a dedicated source. A monochromator made of...
Zimmer, O., Schmidt-Wellenburg, P., Assmann, M., Fertl, M., Klenke, J., Mironov, S., ...
We report experiments on the production of ultracold neutrons (UCN) in a converter of superfluid helium coated with fluorinated grease. We employed our technique of window-free extraction of...
GRANIT project: a trap for gravitational quantum states of UCN (2007)
Pignol, G., Protasov, K. V., Rebreyend, D., Vezzu, F., Nesvizhevsky, V. V., Petukhov, A. K., ...
Previous studies of gravitationally bound states of ultracold neutrons showed the quantization of energy levels, and confirmed quantum mechanical predictions for the average size of the two lowest...
A source of ultra-cold neutrons for the gravitational spectrometer GRANIT (2007)
Schmidt-Wellenburg, P., Geltenbort, P., Nesvizhevsky, V. V., Plonka, C., Soldner, T., Vezzu, F., ...
We present the status of the development of a dedicated high density ultra-cold neutron (UCN) source dedicated to the gravitational spectrometer GRANIT. The source employs superthermal conversion of...
A superfluid helium converter for accumulation and extraction of ultracold neutrons (2007)
Zimmer, O., Baumann, K., Fertl, M., Franke, B., Mironov, S., Plonka, C., ...
We report the first successful extraction of accumulated ultracold neutrons (UCN) from a converter of superfluid helium, in which they were produced by downscattering neutrons of a cold beam from the...
Efficient extraction of a collimated ultra-cold neutron beam using diffusive channels (2007)
Schmidt-Wellenburg, P., Barnard, J., Geltenbort, P., Nesvizhevsky, V. V., Plonka, C., Soldner, T., ...
We present a first experimental demonstration of a new method to extract a well-collimated beam of ultra-cold neutrons (UCN) from a storage vessel. Neutrons with too large divergence are not removed...