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Neutron Physics at the NCNR
Beam Flux
n cm-2 s-1Peak
WavelengthAvailable Beam
SizeDistance Beam type Monochromator
Polarizer/Analyzer
Filter
NG-6 2.30E+09 0.50 nm 6 cm x 7.5 cm 0.1 m Polychromatic N/A SM, 3He Bi/Be (77 K)NG-6U 4.70E+06 0.89 nm 7 cm (dia.) 2 m Monochromatic PG (I) N/A N/ANG-6M 6.50E+05 0.50 nm 1 cm (dia.) 3m Monochromatic PG SM, 3He Be (77 K)NG-6A 5.00E+05 0.38 nm 2 cm X 3 cm 4m Monochromatic Si (P) SM, 3He N/ANG-7 2.00E+05 0.27 nm 2 cm X 4 cm 8m Monochromatic PG (D) SM, 3He N/ABT-2 3.00E+07 0.18 nm 26 cm (dia.) 5m Polychromatic N/A SM, 3He Bi (77 K)TC- 1, 2,3 1.00E+08 0.18 nm 3 cm (dia.) 2m Polychromatic N/A N/A Be (293 K)
NG-6A
NG-7BT-2
TC-1,2,3
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)
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 (2004 - 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.
NG-6M Experiments
Absolute Neutron Fluence Measurement
Neutron fluence is measured by counting
gamma-rays from the reaction n+10B 4He+7Li + (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 3He 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 3He polarization
and was used in the initial Schwinger scattering
experiment.
NG-6A Experiments
Neutron Schwinger Scattering Experiment
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 3.210-4
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-particle-producing neutron absorption reactions with,3He, 10B, or 6Li, 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 3He proportional tubes, especially the lack of 3He, while preserving their advantages over other techniques. (Patent, R&D 100)
NG -7 Experiments
Neutron Interferometer
Precision Scattering Length Measurement: Silicon
Mass Density of Thin Polymer Films
Search for Quantum Entanglement in Liquid H2O-D2O Mixtures
Demonstration 4π Periodicity of Neutron wave function
Precision Scattering Length Measurement: H and D
Precision Scattering Length Measurement: 3He (spin-independent)
Neutron Charge Radius (Continuing)
Reciprocal Space Neutron Imaging
Vertical Coherence Length in Neutron Interferometry
Precision Scattering Length Measurement: 3He (spin -dependent)
Decoherence Free Neutron Interferometer (QIP)
Precision Scattering Length Measurement: 4He
Magnetic Film characterizations (QIP)
Neutron Interferometeric Study QIP
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Quantum Information
Classical Information
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Bit or Qubit?
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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.
’2 qubit’ quantum computer’
BT-2 Experiments
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
Other Programs
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 Fabrication252Cf Facility
D-T and D-D Neutron Generators
Mn bath neutron Source Calibration Facility
Low Scatter Neutron Dosimeter Calibration Facility
December 31, 2012
Physics
Physics
Physics
NG-C ready
NG-7A Beam-line ready
Second interferometer station
Second cold source at BT-9
NG-7A
NG-C
New Guide Hall Section
December 31, 2014
Physics
Physics
Physics
LD2 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
NG-3
NG-C Guide
Local shutter is located in the middle section of the guide
Total Length: 57.49 m
Radius : 933 m
NG-C becomes operational by the end of 2012
0
2E+10
4E+10
6E+10
8E+10
1E+11
1.2E+11
0 5 10 15 20 25 30
Neu
tro
ns
[n.s
-1.A
-1]
Wavelength [A]
NG-C LD2 Cold Source (2014)
NG-C LH2 Cold Source (2012)
NG-6 LH2 Cold Source
0
1E+11
2E+11
3E+11
4E+11
5E+11
6E+11
0 5 10 15 20 25 30
Inte
gra
ted
Neu
tron
s [n
.s-1
]
Integration Range [A]
NG-C Neutron Counts
0.0E+00
4.0E+09
8.0E+09
1.2E+10
1.6E+10
2.0E+10
0 5 10 15 20 25 30
Inte
gra
ted
Ca
ptu
re F
lux [
n.c
m-2
.s-1
]
Integration Range [A]
0.0E+00
5.0E+08
1.0E+09
1.5E+09
2.0E+09
2.5E+09
3.0E+09
0 5 10 15 20 25 30
Ca
ptu
re F
lux [
n.c
m-2
.s-1
.A-1
]
Wavelength [A]
NGC LD2 Cold Source
(2014)
NGC LH2 Cold Source
(2012)
0
50
100
150
200
250
300
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010
Facility Operating Days
IPNS Lujan HFIR NCNR SNS ILL
A. 3He Neutron Polarizer and Analyzer
Polarized 3He program begun 1993. Spin-off NCNR
program for users begun 2006. 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, 2011. Project completion
June, 2012 (commissioned and as-built drawings
submitted)
Experiment Support Infrastructure
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
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
We are…