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Collett B, Bateman F, Bauder WK, Byrne J, Byron WA, Chen W, Darius G, DeAngelis C, Dewey MS, Gentile TR, Hassan MT, Jones GL, Komives A, Laptev A, Mendenhall MP, Nico JS, Noid G, Park H, Stephenson EJ, Stern I, Stockton KJS, Trull C, Wietfeldt FE, Yerozolimsky BG. aCORN: An experiment to measure the electron-antineutrino correlation coefficient in free neutron decay. Rev Sci Instrum 2017; 88:083503. [PMID: 28863637 PMCID: PMC6078102 DOI: 10.1063/1.4996542] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We describe an apparatus used to measure the electron-antineutrino angular correlation coefficient in free neutron decay. The apparatus employs a novel measurement technique in which the angular correlation is converted into a proton time-of-flight asymmetry that is counted directly, avoiding the need for proton spectroscopy. Details of the method, apparatus, detectors, data acquisition, and data reduction scheme are presented, along with a discussion of the important systematic effects.
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Affiliation(s)
- B. Collett
- Physics Department, Hamilton College, Clinton, NY 13323, USA
| | - F. Bateman
- National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - W. K. Bauder
- Physics Department, Hamilton College, Clinton, NY 13323, USA
| | - J. Byrne
- University of Sussex, Brighton, Sussex, BA1 9QH, UK
| | - W. A. Byron
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
| | - W. Chen
- National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
- University of Maryland, College Park, Maryland 20742, USA
| | - G. Darius
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
| | - C. DeAngelis
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
| | - M. S. Dewey
- National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - T. R. Gentile
- National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - M. T. Hassan
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
| | - G. L. Jones
- Physics Department, Hamilton College, Clinton, NY 13323, USA
| | - A. Komives
- Department of Physics and Astronomy, DePauw University, Greencastle, IN 46135, USA
| | - A. Laptev
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
| | - M. P. Mendenhall
- National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - J. S. Nico
- National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - G. Noid
- CEEM, Indiana University, Bloomington, IN 47408, USA
| | - H. Park
- National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | | | - I. Stern
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
| | | | - C. Trull
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
| | - F. E. Wietfeldt
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
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Hassan MT, Bateman F, Collett B, Darius G, DeAngelis C, Dewey MS, Jones GL, Komives A, Laptev A, Mendenhall MP, Nico JS, Noid G, Stephenson EJ, Stern I, Trull C, Wietfeldt FE. The aCORN Backscatter-Suppressed Beta Spectrometer. Nucl Instrum Methods Phys Res A 2017; 867:10.1016/j.nima.2017.05.029. [PMID: 31092963 PMCID: PMC6512858 DOI: 10.1016/j.nima.2017.05.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Backscatter of electrons from a beta spectrometer, with incomplete energy deposition, can lead to undesirable effects in many types of experiments. We present and discuss the design and operation of a backscatter-suppressed beta spectrometer that was developed as part of a program to measure the electronantineutrino correlation coefficient in neutron beta decay (aCORN). An array of backscatter veto detectors surrounds a plastic scintillator beta energy detector. The spectrometer contains an axial magnetic field gradient, so electrons are efficiently admitted but have a low probability for escaping back through the entrance after backscattering. The design, construction, calibration, and performance of the spectrometer are discussed.
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Affiliation(s)
- M T Hassan
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
| | - F Bateman
- National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - B Collett
- Physics Department, Hamilton College, Clinton, NY 13323, USA
| | - G Darius
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
| | - C DeAngelis
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
| | - M S Dewey
- National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - G L Jones
- Physics Department, Hamilton College, Clinton, NY 13323, USA
| | - A Komives
- Department of Physics and Astronomy, DePauw University, Greencastle, IN 46135, USA
| | - A Laptev
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
| | - M P Mendenhall
- National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - J S Nico
- National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - G Noid
- CEEM, Indiana University, Bloomington, IN 47408, USA
| | | | - I Stern
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
| | - C Trull
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
| | - F E Wietfeldt
- Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA
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Collett B, Anderman R, Balashov S, Bateman FB, Byrne J, Dewey MS, Fisher BM, Goldin L, Jones G, Komives A, Konopka T, Leuschner M, Mostovoy Y, Nico JS, Thompson AK, Trull C, Wietfeldt FE, Wilson R, Yerozolimsky BG. Proposed Measurement of the Beta-Neutrino Correlation in Neutron Decay. J Res Natl Inst Stand Technol 2005; 110:401-405. [PMID: 27308157 PMCID: PMC4852822 DOI: 10.6028/jres.110.060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 08/11/2004] [Indexed: 06/06/2023]
Abstract
Currently, the beta-neutrino asymmetry has the largest uncertainty (4 %) of the neutron decay angular correlations. Without requiring polarimetry this decay parameter can be used to measure λ (ga/gv ), test Cabibbo-Kobayashi-Maskawa (CKM) unitarity limit scalar and tensor currents, and search for Charged Vector Current (CVC) violation. We propose to measure the beta-neutrino asymmetry coeffcient, a, using time-of-flight for the recoil protons. We hope to achieve a systematic uncertainty of σa / a ≈ 1.0 %. After tests at Indiana University's Low Energy Neutron Source (LENS), the apparatus will be moved to the National Institute of Standards and Technology (NIST) where the measurement can achieve a statistical uncertainty of 1 % to 2 % in about 200 beam days.
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Affiliation(s)
- B Collett
- Physics Department, Hamilton College, Clinton, NY 13323
| | - R Anderman
- Physics Department, Hamilton College, Clinton, NY 13323
| | | | - F B Bateman
- National Institute of Standards and Technology, Gaithersburg, MD 20899
| | - J Byrne
- University of Sussex, United Kingdom
| | - M S Dewey
- National Institute of Standards and Technology, Gaithersburg, MD 20899
| | - B M Fisher
- Department of Physics, Tulane University, New Orleans, LA 70118
| | - L Goldin
- Physics Department, Harvard University, Cambridge, MA 02139
| | - G Jones
- Physics Department, Hamilton College, Clinton, NY 13323
| | - A Komives
- Physics Department, DePauw University, Greencastle, IN 46135
| | - T Konopka
- Physics Department, Hamilton College, Clinton, NY 13323
| | - M Leuschner
- Indiana University Cyclotron Facility, Bloomington, IN 47408
| | | | - J S Nico
- National Institute of Standards and Technology, Gaithersburg, MD 20899
| | - A K Thompson
- National Institute of Standards and Technology, Gaithersburg, MD 20899
| | - C Trull
- Department of Physics, Tulane University, New Orleans, LA 70118
| | - F E Wietfeldt
- Department of Physics, Tulane University, New Orleans, LA 70118
| | - R Wilson
- Physics Department, Harvard University, Cambridge, MA 02139
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Komives A, Wietfeldt FE, Trull C, Bateman FB, Dewey MS, Thompson AK, Anderman R, Balashov S, Mostovoy Y. A Backscatter Suppressed Electron Detector for the Measurement of "a". J Res Natl Inst Stand Technol 2005; 110:431-436. [PMID: 27308163 PMCID: PMC4852833 DOI: 10.6028/jres.110.066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 08/11/2004] [Indexed: 06/06/2023]
Abstract
A new method of measuring the electron-antineutrino angular correlation coefficient, little "a", from neutron decay-to be performed at the National Institute of Standards and Technology-will require an electron spectrometer that strongly suppresses backscattered electrons. A prototype consisting of six trapezoidal veto detectors arranged around a plastic scintillator has been tested with an electron beam produced by a Van de Graaff accelerator. The results of this test and its implications for the little "a" measurement are discussed.
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Affiliation(s)
- A Komives
- DePauw University, Greencastle, IN 46135
| | | | - C Trull
- Tulane University, New Orleans, LA 70118
| | - F B Bateman
- National Institute of Standards and Technology, Gaithersburg, MD 20899
| | - M S Dewey
- National Institute of Standards and Technology, Gaithersburg, MD 20899
| | - A K Thompson
- National Institute of Standards and Technology, Gaithersburg, MD 20899
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