Neutron Physics at NIST. M. Arif 8 th UCN Workshop St. Petersburg Moscow, Russia June 11-21, 2011

Transcription

1 Neutron Physics at NIST M. Arif 8 th UCN Workshop St. Petersburg Moscow, Russia June 11-21, 2011

2 NCNR Guide Hall 20 MW Reactor

3 Neutron Physics at the NCNR TC-1,2,3 NG-6A BT-2 NG-7 Beam Flux n cm -2 s -1 Peak Wavelength Available Beam Size Distance Beam type Monochromator Polarizer/ Analyzer Filter NG E nm 6 cm x 7.5 cm 0.1 m Polychromatic N/A SM, 3He Bi/Be (77 K) NG-6U 4.70E nm 7 cm (dia.) 2 m Monochromatic PG (I) N/A N/A NG-6M 6.50E nm 1 cm (dia.) 3m Monochromatic PG SM, 3He Be (77 K) NG-6A 5.00E nm 2 cm X 3 cm 4m Monochromatic Si (P) SM, 3He N/A NG E nm 2 cm X 4 cm 8m Monochromatic PG (D) SM, 3He N/A BT E nm 26 cm (dia.) 5m Polychromatic N/A SM, 3He Bi (77 K) TC- 1, 2,3 1.00E nm 3 cm (dia.) 2m Polychromatic N/A N/A Be (293 K)

4 NG-6 Experiments Beam Neutron Lifetime Testing Time Reversal Asymmetry (emit) Testing Parity Violating Spin Roation in Helium I Time Reversal Asymmetry (emit) I Beam Neutron lifetime Time Reversal Asymmetry(emiT) II Radiative Decay of Neutrons (RDK) I Parity Violating Spin Roation in Helium I Radiative Decay of Neutrons (RDK) II Electron- Antineutron Correlation (acorn)

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6 NG-6U Experiments Neutron Lifetime Measurement with UCN Mark I (2000) Demonstrated the technique of 3-D magnetic trapping by confining approximately 480 neutrons per loading cycle. Mark II (2004) Upgraded magnet. Increased the number of trapped neutrons to approximately 1,600 Successful proof-of-principle lifetime measurement. Explored various systematic effects, including marginally trapping. Mark III ( present) Completely rebuilt the apparatus incorporating a new magnetic trap that has allowed us to trap more than 10,000 neutrons per loading cycle.taken initial lifetime data. Initial analysis is underway.

7 NG-6M Experiments Absolute Neutron Fluence Measurement Neutron fluence is measured by counting gamma-rays from the reaction n+ 10 B 4 He+ 7 Li + (478KeV) with a calibrated gamma detector and neutron calorimeter. Polarized 3-He Neutron Spin Analyzers A Spin Exchange Optical Pumping produces dense samples of hyper-polarized 3 He gas that can be used to spin analyze neutron beams. This compact system can be located near an instrument or be mounted in a neutron beam to provide a constant 3 He polarization and was used in the initial Schwinger scattering experiment.

8 Neutron Schwinger Scattering Experiment NG-6A Experiments Schwinger scattering is caused by the interaction between the neutron magnetic dipole moment (MDM) and the atomic electric field in the silicon crystal. The atomic electric field rotates the neutron polarization by a very small angle (about radians). This rotation is magnified by successive (220) Bragg reflections down a narrow slot cut from perfect silicon. Far Ultraviolet Neutron Detector This detector, based charged-particleproducing neutron absorption reactions with, 3 He, 10 B, or 6 Li, measures far ultraviolet light produced by noble gas excimers instead of amplifying and collecting charge. This new technique may be able to circumvent limitations of 3 He proportional tubes, especially the lack of 3 He, while preserving their advantages over other techniques. (Patent, R&D 100)

9 Neutron Interferometer Precision Scattering Length Measurement: Silicon Mass Density of Thin Polymer Films Search for Quantum Entanglement in Liquid H 2 O-D 2 O Mixtures Demonstration 4π Periodicity of Neutron wave function Precision Scattering Length Measurement: H and D Precision Scattering Length Measurement: 3 He (spin-independent) Neutron Charge Radius (Continuing) Reciprocal Space Neutron Imaging Vertical Coherence Length in Neutron Interferometry Precision Scattering Length Measurement: 3 He (spin -dependent) Decoherence Free Neutron Interferometer (QIP) Precision Scattering Length Measurement: 4 He Magnetic Film characterizations (QIP) NG -7 Experiments

10 Neutron Interferometeric Study QIP a y yes a n no Will you marry me? ˆB 1 ˆB ˆB 2 3 I O ˆ Tr P out I H ˆ Tr P out 1 0 in in ˆ e 0 i 0 1 Bit or Qubit? ˆ ˆ ˆ ˆ out B 3B2 B1 inb1 B2 B3 ˆ ˆ ˆ 2 qubit quantum computer ˆ Py 0 Classical Information yes 1 no 0 Pn Quantum Information 2 a y anay * Py C * 2 ayan * an C Pn 0 1 Adding spin to Neutron Interferometer makes it operate like a 2 qubit Quantum Information Processor and may allow study of the all important quantum decoherence phenomena in QIP. In neutron interferometry we can detect individual events and the time scale of the evolution is such that we can modify the experiment between counts. This is different from other method such as NMR where it possible to influence a classical ensemble only.

11 Quantum Gates In Neutron Interferometry

12 Neutron Imaging Fuel Cell Hydrogen Storage Devices Li-Ion Batteries Membranes Geology and Archeology Very high resolution detector development Additional Cold Neutron Phase Imaging Facility (2013) Large user base from government, industry, and academia BT-2 Experiments

13 Neutron Instrument Calibrations Neutron Source Calibrations Neutron Detector Developments Neutron Standards Development Homeland Security Related Research Neutron Cross-sections Standards Fast Neutron Measurement for DUSEL Additional Facilities Laser Labs for He-3 Cell Fabrication 252 Cf Facility D-T and D-D Neutron Generators Mn bath neutron Source Calibration Facility Low Scatter Neutron Dosimeter Calibration Facility Other Programs

14 December 31, 2012 NG-C ready NG-7A Beam-line ready Second interferometer station Second cold source at BT-9 New Guide Hall Section NG-C Physics Physics Physics NG-7A

15 December 31, 2014 LD 2 cold source installation complete Neutron Physics on NG-6 completes move to NG-3. NG-3 has optical filter. Upgrade NG-3 guide? NG-C Experiment should be in progress NG-C Physics NG-3 Physics Physics

16 Liquid D 2 Cold Source (2014) 2015? New cold Source becomes operational at the end of 2014

17 NG-C Guide Total Length: m Radius : 933 m NG-C becomes operational by the end of 2012 Local shutter is located in the middle section of the guide

18 Neutrons [n.s -1.A -1 ] Capture Flux [n.cm -2.s -1.A -1 ] Integrated Neutrons [n.s -1 ] Integrated Capture Flux [n.cm -2.s -1 ] 6E+11 NG-C Neutron Counts 2.0E+10 5E+11 4E+11 3E+11 2E+11 1E E E E E Integration Range [A] 0.0E Integration Range [A] 1.2E E+09 1E+11 NG-C LD2 Cold Source (2014) NG-C LH2 Cold Source (2012) 2.5E+09 NGC LD2 Cold Source (2014) 8E+10 NG-6 LH2 Cold Source 2.0E+09 NGC LH2 Cold Source (2012) 6E E+09 4E E+09 2E E Wavelength [A] 0.0E Wavelength [A]

19 300 Facility Operating Days IPNS Lujan HFIR NCNR SNS ILL

20 Experiment Support Infrastructure A. 3 He Neutron Polarizer and Analyzer Polarized 3 He program begun Spin-off NCNR program for users begun Neutron physics applications include NPDg, interferometry, polarimetry, and axion limits. Recent work is relevant to operation in high flux beams. B. Super Mirror Neutron Polarizer and Analyzers C. Helium Recovery and Re-liquefaction System Will supply all of NIST's liquid helium needs. Initially hooked up to recover 60% of NIST use by recovering from two buildings (235, 223) Will produce 150,000 liters of LHe annually. Can be expanded to 250,000 liters/yr production easily Primary reason for system is to insulate NIST program from helium supply interruptions Groundbreaking May, Project completion June, 2012 (commissioned and as-built drawings submitted)

21 New Guide Hall With Instruments

22 New Guide Hall Photos

23 We are Typically about a total of thirty five (35) permanent staff, resident guest researchers, post docs, and students at any given time Responsible for 9 neutron beam-lines (3 more after the upgrade) Extensive outside collaborations Ph.D. Students (40) Jonathan Richardson Harvard University T.E. Chupp 1993 Eric Wasserman Harvard University T.E. Chupp 1994 Klaus Raum University of Innsbruck, Austria A. Zeilinger 1995 Diane Markoff University of Washington B. Heckel 1997 Shenq-Rong Hwang University of Michigan T.E. Chupp 1998 Peter Fischer Munich Technical University, Germany F. Mezei 1998 Laura Lising University of California Berkeley S.J. Freedman 1999 Annette LaCroix University of Innsbruck, Austria A. Zeilinger 1999 Clinton Brome Harvard University J.M. Doyle 1999 Zema Chowdhuri Indiana University W.M. Snow 2000 Ken Litrell University of Missouri S.A.Werner 2000 Daniel McKinsey Harvard University J.M. Doyle 2002 Carlo Mattoni Harvard University J.M. Doyle 2002 Pieter Mumm University of Washington J.F. Wilkerson 2003 Hartmut Lemmel Atom Institute, Austria H. Rauch 2003 Sergei Dzhosyuk Harvard University J.M. Doyle 2004 Keary Schoen University of Missouri S.A. Werner 2004 Greg Hansen Indiana University W.M. Snow 2004 Liang Yang Harvard University J.M. Doyle 2006 Dmitry Pushin Massachusetts Institute of Technology D. Cory 2006 Chris Bass Indiana University W.M. Snow 2008 Robert Cooper University of Michigan T.E. Chupp 2008 Bob Trull Tulane University F.E. Wietfeldt 2008 Venera Zhumabekova Kazakh National N. Takibayev 2008 Mike Huber Tulane University F.E. Wietfeldt 2009 Da Luo Indiana University W.M. Snow 2009 George Noid Indiana University E. Stephenson 2010 Chris O'Shaughnessy North Carolina State University P. Huffman 2010 Kangfei Gan George Washington University A. Opper 2011 Carl Schelhammer North Carolina State University P. Huffman Current Andrew Yue University of Tennessee G. Greene Current Ben O Neill Arizona State R. Alarcon Current Tom Langford University of Maryland E. Beise Current Matt Bales University of Michigan T. E. Chupp Current Mohamed AbuTaleb Massachusetts Institute of Technology David Cory Current Taufique Hassan Tulane F. Wietfeltd Current Chandra Shahi Tulane F. Wietfeldt Current

24 There goes the bell My time is up! THANK YOU