Conveners
Th - 2
- Session Chair: Nathal Severijns (Katholieke Univ. Leuven)
Prof.
Oliver Zimmer
(Institut Laue Langevin)
12/09/2013, 10:50
Oral
Conversion of cold to ultracold neutrons (UCN) via single-phonon emission in superfluid helium provides a viable mechanism to achieve high densities of UCN at the end of a neutron guide. In a current development at the ILL new sources based on this mechanism have been implemented at two monochromatic neutron beam lines. The first beam feeds an upgraded prototype source with characterized...
Dr
Peter Geltenbort
(Institut Laue-Langevin)
12/09/2013, 11:15
Oral
We present estimations and experimental studies of systematic effects in the neutron lifetime experiment carried out in 2008-2010 at ILL. Taking into account these corrections, we reduce the data of three independent measurements carried out with different energy spectra of ultracold neutrons at different temperatures to the averaged neutron lifetime value equal to xxx(1.1) s.
Dr
Alexey Fomin
(Petersburg Nuclear Physics Institute)
12/09/2013, 11:35
Oral
Improvement of accuracy of neutron lifetime measurements is of great importance for physics of elementary particles and cosmology. At present the best accuracy of measurements is reached in PNPI experiment with a gravitational trap of ultracold neutrons (UCN) [Phys. Lett. B 605, 72 (2005)]. Now at PNPI a new installation with a big UCN gravitational trap is made. The planned accuracy of...
Alexander Saunders
(Los Alamos National Lab)
12/09/2013, 11:55
Oral
In this talk, we present an overview of the science program at the Los Alamos spallation-driven solid-deuterium ultra-cold neutron (UCN) source and describe the performance of the source. Experiments in operation or development include the UCNA beta correlation measurements, the UCNTau neutron lifetime experiment, nEDM storage cell performance tests, and detector development for UCN and cold...
Dr
Steven Clayton
(Los Alamos National Laboratory)
12/09/2013, 12:20
Oral
We report a new experiment to measure the beta decay rate of the free neutron. The apparatus is based on the asymmetric magneto-gravitational trap for ultracold neutrons (UCNs) proposed by Walstrom et al. [NIMA 599 (2008) pp. 82-92]. A permanent-magnet Halbach array creates the levitating field for "low-field-seeking" UCNs, while external holding field coils eliminate field zeros inside the...
Dr
Maynard Dewey
(NIST)
12/09/2013, 12:40
Oral
The most precise determination of the neutron lifetime using the beam method reported a result of $\tau_{n} = \left(886.3 \pm 1.2\left[\textrm{stat}\right] \pm 3.2\left[\textrm{sys}\right]\right)$ s. The dominant uncertainties were attributed to the absolute determination of the fluence of the neutron beam (2.7 s). The neutron beam fluence was determined with a monitor that counted the...
