Measurement of the neutron lifetime by counting trapped protons in a cold neutron beam
Creators
- Nico, J.S.1, 2, 3, 4, 5, 6
- Dewey, M.S.1, 2, 3, 4, 5, 6
- Gilliam, D.M.1, 2, 3, 4, 5, 6
- Wietfeldt, F.E.1, 2, 3, 4, 5, 6
- Fei, X.1, 2, 3, 4, 5, 6
- Snow, W.M.1, 2, 3, 4, 5, 6
- Greene, G.L.1, 2, 3, 4, 5, 6
- Pauwels, J.1, 2, 3, 4, 5, 6
- Eykens, R.1, 2, 3, 4, 5, 6
- Lamberty, A.1, 2, 3, 4, 5, 6
- Van Gestel, J.1, 2, 3, 4, 5, 6
- Scott, R.D.1, 2, 3, 4, 5, 6
- 1. Scottish Universities Research and Reactor Centre, East Kilbride G75 0QU (United Kingdom)
- 2. European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, B-2440 Geel (Belgium)
- 3. University of Tennessee/Oak Ridge National Laboratory, Knoxville, Tennessee 37996 (United States)
- 4. Indiana University and Indiana University Cyclotron Facility, Bloomington, Indiana 47408 (United States)
- 5. Tulane University, New Orleans, Louisiana 70118 (United States)
- 6. National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)
Description
A measurement of the neutron lifetime τn performed by the absolute counting of in-beam neutrons and their decay protons has been completed. Protons confined in a quasi-Penning trap were accelerated onto a silicon detector held at a high potential and counted with nearly unit efficiency. The neutrons were counted by a device with an efficiency inversely proportional to neutron velocity, which cancels the dwell time of the neutron beam in the trap. The result is τn=(886.3±1.2[stat]±3.2[sys]) s, which is the most precise measurement of the lifetime using an in-beam method. The systematic uncertainty is dominated by neutron counting, in particular, the mass of the deposit and the 6Li(n,t) cross section. The measurement technique and apparatus, data analysis, and investigation of systematic uncertainties are discussed in detail
Additional details
Identifiers
- DOI
- 10.1103/PhysRevC.71.055502;
- arXiv
- arXiv:nucl-ex/0411041v1;
Publishing Information
- Journal Title
- Physical Review. C, Nuclear Physics
- Journal Volume
- 71
- Journal Issue
- 5
- Journal Page Range
- p. 055502-055502.27
- ISSN
- 0556-2813
- CODEN
- PRVCAN
INIS
- Country of Publication
- United States
- Country of Input or Organization
- International Atomic Energy Agency (IAEA)
- INIS RN
- 37014703
- Subject category
- S73: NUCLEAR PHYSICS AND RADIATION PHYSICS; S72: PHYSICS OF ELEMENTARY PARTICLES AND FIELDS;
- Descriptors DEI
- ABSOLUTE COUNTING; BETA DECAY; COLD NEUTRONS; CROSS SECTIONS; DATA ANALYSIS; EFFICIENCY; ENERGY LEVELS; LIFETIME; LITHIUM 6 TARGET; NEUTRON BEAMS; NEUTRON REACTIONS; SI SEMICONDUCTOR DETECTORS; TRAPPED PROTONS; TRAPS
- Descriptors DEC
- BARYON REACTIONS; BARYONS; BEAMS; COUNTING TECHNIQUES; DECAY; ELEMENTARY PARTICLES; FERMIONS; HADRON REACTIONS; HADRONS; MEASURING INSTRUMENTS; NEUTRONS; NUCLEAR DECAY; NUCLEAR REACTIONS; NUCLEON BEAMS; NUCLEON REACTIONS; NUCLEONS; PARTICLE BEAMS; PROTONS; RADIATION DETECTORS; SEMICONDUCTOR DETECTORS; TARGETS
Optional Information
- Notes
- (c) 2005 The American Physical Society