1. Neutrons: from fundamental physics to probing condensed matter
Tsukuba, March 25, 2010
Neutrons: from fundamental physics to probing condensed matter
F. Mezei
Ordinary Member, Hungarian Academy of Sciences
Member of Academia Europaea
European Spallation Source Preparatory Phase Project (EU, FP7)
ASEPS

2. The founding of neutron research
The founding of neutron research
J. Chadwick discovers the neutron
particle physics, nuclear physics
1938 O. Hahn and F. Strassmann discovers nuclear fission
nuclear industry, neutron sources for research
1950 C. Shull et al. observe antiferromagnetism by neutron diffraction
condensed matter research
neutron magnetic moment  magnetism
Two curves
3 pages
2 Nobel prizes
ASEPS
Halle, , F. Mezei

3. The founding of neutron research
The founding of neutron research
J. Chadwick discovers the neutron
particle physics, nuclear physics
1938 O. Hahn and F. Strassmann discovers nuclear fission
nuclear industry, neutron sources for research
1950 C. Shull et al. observe antiferromagnetism by neutron diffraction
condensed matter research
neutron magnetic moment  magnetism
2010: Multiferroics, e.g. LuFe2O4
ASEPS
Halle, , F. Mezei

4. Neutrons in particle and nuclear physics
E.g. Neutron Electric Dipole Moment: symmetry violations if  0
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5. Neutrons in particle and nuclear physics
E.g. Neutron cross sections: not predictable, partially known
Well known:
slow neutrons (eV)
 condensed matter res.
Sporadically known:
fast neutrons (keV, MeV)
 astrophysics
 transmutation (nuclear
waste)
 single event upsets
ASEPS

6. Neutrons in particle and nuclear physics
E.g. Neutron cross sections: not predictable, partially known
Well known:
slow neutrons (eV)
 condensed matter res.
Sporadically known:
fast neutrons (keV, MeV)
 astrophysics
 transmutation (nuclear
waste)
 single event upsets
ASEPS

7. Neutrons in particle and nuclear physics
E.g. Neutron cross sections: not predictable, partially known
Well known:
slow neutrons (eV)
 condensed matter res.
Sporadically known:
fast neutrons (keV, MeV)
 astrophysics
 transmutation (nuclear
waste)
 single event upsets ??
ASEPS

8. Neutrons in particle and nuclear physics
E.g. Neutron cross sections: not predictable, partially known
Well known:
slow neutrons (eV)
 condensed matter res.
Sporadically known:
fast neutrons (keV, MeV)
 astrophysics
 transmutation (nuclear
waste)
 single event upsets
Huge related issues:
materials for fast neutron
radiation (fusion, 4th gene-
ration fission reactors,…)
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9. Slow neutron cross sections offer unique features
Neutron see:
Light elements next to heavy ones
Deep inside most materials (mm - dm) : weak interaction
 theory exact
 negligible radiation damage
Differences between isotopes,
including activation
Magnetic field B inside matter
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10. Inelastic Neutron Scattering X-ray correlation spectroscopy
Slow neutron cross sections offer unique features
Neutrons see:
Light elements next to heavy ones
Deep inside most materials (mm - dm) : weak interaction
 theory exact
 negligible radiation damage
Differences between isotopes,
including activation
Magnetic field B inside matter
Space and time on micro- and nanoscale
10-8
10-6
10-4
10-2
100
102
104
10-3
10-1
101
energy E = h [meV]
scattering vector Q [Å-1]
108
106
103
length d = 2/Q [Å]
time t [ps]
Spin Echo
Backscattering
Chopper
Inelastic x-ray
Multi-Chopper
Inelastic Neutron Scattering
UT3
Brillouin scattering
Raman scattering
Photon correlation
VUV- FEL
µSR
NMR
Infra- red
Dielectric spectroscopy
X-ray correlation spectroscopy
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11. Neutrons see hydrogen atoms
Life sciences: hydration, H-bonds, ….
Materials for hydrogen economy
Catalysis …..
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12. Neutrons see deep inside engineering parts
Neutrons see (tensile) stress inside bulky metal parts that caused wheel failure (M. Grosse et al. J. Neutr. Res. 2001)
ICE accident, Eschede
Standard engineering theory of plastic deformation stress was wrong end of XX. century!
Knowledge based society???
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13. Neutrons activation: destruction free chemical analysis
Neutron activation radiography
X-ray radiography
Tiziano Vecellio
Mädchen mit Fruchtschale (ca. 1555)
Gemäldegalerie zu Berlin
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F. Mezei, ESS WR-Audit Juelich, Dec. 2001

14. Neutrons see motion in space and time
intensity
time
Time [ns]
NSE signal
de Gennes "reptation" in polymers
-1.2
Atomic/ molecular mobility is key to functionality in soft and nanostructured matter:
polymers, proteins, glasses,…
Protein activity  extra fluctuation spectrum
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15. Development of neutron sources for research
 Parasitic use of energy research reactors (1949…)
 Dedicated beam reactors (Chalk River, 15 MW, 1958, ….. )
 ILL (Grenoble, 58 MW, 1972): limit of power at reasonable costs
 Pulsed sources (1960’s, Dubna): more efficient use of fewer neutrons produced
16.67 Hz pulsed source
continuous source Hz pulsed source
Efficiency gain by pulsing:  / ~8-1000
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16. Development of neutron sources for research
 Parasitic use of energy research reactors (1949…)
 Dedicated beam reactors (Chalk River, 15 MW, 1958, ….. )
 ILL (Grenoble, 58 MW, 1972): limit of power at reasonable costs
 Pulsed sources (1960’s, Dubna): more efficient use of fewer neutrons produced
 Spallation sources (1970’s, Russian patent; IPNS, Argonne, USA) less heat / energy = costs per neutron produced
Fission reactors: ~ 109 fast neutron / joule
Spallation: ~ (> 400 MeV protons on heavy metal target)
Fusion: ~1.5x1010
(but neutron slowing down efficiency reduced by ~20 times)
Photo neutrons: ~ (hard  radiation on light nuclei)
Nuclear reaction (p, Be): ~ 108 (< 14 MeV protons on Be) Small, cheap!
ASEPS

17. Development of neutron sources for research
 Parasitic use of energy research reactors (1949…)
 Dedicated beam reactors (Chalk River, 15 MW, 1958, ….. )
 ILL (Grenoble, 58 MW, 1972): limit of power at reasonable costs
 Pulsed sources (1960’s, Dubna): more efficient use of fewer neutrons produced
 Spallation sources (1970’s, Russian patent; IPNS, Argonne, USA) less heat / energy per neutron produced
 MW class pulsed spallation sources: 3 facilities world wide recommended by OECD Megascience Forum (1991)
 SNS (Oak Ridge, USA, 2006) & J-PARC (Tokai, Japan, 2008) Leap in source performance to surpass ILL: fewer neutrons more efficiently produced and used
ASEPS

18. Development of neutron sources for research
 Parasitic use of energy research reactors (1949…)
 Dedicated beam reactors (Chalk River, 15 MW, 1958, ….. )
 ILL (Grenoble, 58 MW, 1972): limit of power at reasonable costs
 Pulsed sources (1960’s, Dubna): more efficient use of fewer neutrons produced
 Spallation sources (1970’s, Russian patent; IPNS, Argonne, USA) less heat / energy per neutron produced
 MW class pulsed spallation sources: 3 facilities world wide recommended by OECD Megascience Forum (1991)
 SNS (Oak Ridge, USA, 2006) & J-PARC (Tokai, Japan, 2008) Leap in source performance to surpass ILL: fewer neutrons more efficiently produced and used
But: reach approx. limits of traditional short pulse spallation source technology: shock waves in target, space charge in accelerator ring,…
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19. Next generation of spallation neutron sources
Next generation of spallation neutron sources
simplify
Linear accelerators alone can produce the same cold beam neutron pulses by ~100 s proton pulses
ASEPS
Halle, , F. Mezei

20. Next generation of spallation neutron sources
Next generation of spallation neutron sources
simplify
Linear accelerators alone can produce the same cold beam neutron pulses by ~100 s proton pulses
 Make the pulses shorter if needed by innovative mechanical neutron chopper systems ( 15 M€)
 Leave the linac switched on for more neutron per pulse: Long Pulse (LP) concept
 Spend the 150 M€ saved on the ring for more power for the linac: ESS (cf. poster)
 One LP source neutron costs 5 – 40 times less than a SP source neutron
ASEPS
Halle, , F. Mezei

21. Next generation of spallation neutron sources
Next generation of spallation neutron sources
Neutron research in Europe:
~4000 scientists, 11 facilities (and decreasing): ~ 330 M€/a
simplify
Linear accelerators alone can produce the same beam cold neutron pulses by ~100 s proton pulses
 Make the pulses shorter if needed by innovative mechanical neutron chopper systems ( 15 M€)
 Leave the linac switched on for more neutron per pulse: Long Pulse (LP) concept
 Spend the 150 M€ saved on the ring for more power for the linac: e.g. ESS
 One LP source neutron costs 5 – 40 times less than a SP source neutron
ASEPS
Halle, , F. Mezei

22. Industrial /commercial use of neutron research facilities
Some uses (e.g. neutron radiography) by industrial / military facilities
Others need the higher source brilliance:
 High quality doping of Si for IT industry
 Production of blue topaz from colorless
( 6 t/year)
 Radioactive (medical) isotope production
 Neutron tomography:
3d reconstruction of interior
 Material testing for engineering applications (structure, stress, wear & tear…)
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23. European Roadmap Need for “top tier” neutron source for Europe
EU funded Preparatory Phase Projects: promote realization of ESFRI roadmap
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24. European business prevision for neutron research
ESS extra amount over level spending: ~ 1000 M€ (2007 value)
ESS scientific output
a) New resources to be identified 2009 – 2019
for ESS investment
b) Level spending beyond 2018 compatible with ESS operations and return on investment

25. Excellent collaboration opportuties
Within Europe: EU FP7 Preparatory Phase Project for European Spallation Source (ESS):
EU grant to facilitate realization of ESFRI Roadmap
2 years, 5 M€ funding (March 2008 – March 2010)
11 institutions from 9 countries (France, Germany, Hungary, Italy, Latvia, Spain, Sweden, Switzerland, United Kingdom)
Between Asia and Europe:
Extensive exchange of information
Coordinated development of components and techniques
Sharing of information, software tools
Standardizing user interfaces
…..
……much is already ongoing
Global Design Effort:
To implement OECD 1991 recommendation: opportunity missed
Future: could be of great benefit
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