Oak Ridge National Laboratory

Physics Division

Physics Division Seminars

Physics Division Seminars bring us speakers on a variety of physics related subjects. Usually these are held in the Building 6008 large Conference Room, at 3:00 pm on the chosen day, but times and locations may vary. For more information, contact our seminar chairman,

Alfredo Galindo-Uribarri
Tel (Office): (865) 574-6124  (FAX): (865) 574-1268


Thu., November 07, 2013, at 3:00 pm - 4 pm, refreshments served at 2:40 pm

Status of the UCNTau Experiment at LANL

Daniel Salvat, LANL and Indiana University
ORNL, Bldg. 6008, Large Conference Room

The free neutron lifetime is the simplest example of nuclear beta decay and is an important experimental input for understanding charged-current weak processes. The neutron lifetime has implications for primordial nucleosynthesis, neutrino detection, and tests of the standard model. In addition, recent determinations of the neutron lifetime are in significant disagreement, and there are several new and on-going experimental efforts to make an improved determination of the neutron lifetime and resolve the current problem with the global data. We present the current status of the UCNTau experiment at LANL. The experiment is designed to measure the neutron lifetime by magnetically and gravitationally confining ultracold neutrons (UCN) in a large-volume permanent magnet trap. The apparatus is installed at the LANSCE UCN source, and we have performed a preliminary test of the storage time of the UCN in the trap. We present the analysis of these data and discuss future improvements and new UCN detection techniques. Potential sources of systematic effects and their characterization will be addressed in the context of developing a next generation neutron lifetime measurement with better than 0.1% precision.

Contact: Alfredo Galindo-Uribarri, 865-574-6124