Post on 15-Jan-2016
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Preceeding workshops: • 1978: Argonne National Lab, USA• 1979: Abingdon, UK• 1982: Brookhaven National Lab,USA• 1984: Bad Honnef, Germany• 1986: Montana, Switzerland• 1990: Bonn, Germany• 1994: Bad Honnef, Germany• 1996: Vancouver, Canada
Major topics: Advances in: • Target instrumentation
• Material doping methods
• Methods for polarizing HD
• EPR spectroscopy
Polarized Targets for new particle- and nuclear physics experiments
Application of DNP in NMR spectroscopy and MR imaging
Review talks about the milestones of more than 40 years of polarized solid targets
22 22 2
1 1 1 1 1( ) :
( ) ( )( )
A t
A FoM Af P t (f P ) L L
What is a good Polarized Target ?
Most simple case: Experiment measuring the target asymmetry
physAPfNN
NNA
exp# polarizable nucleons
# all nucleonsf
Relation between error A and measuring time t :
22 PfnFoM T
InstrumentationTarget Material
Cryogenic Equipment
• H. Dutz (Bonn): Highlights of PST instrumentation
• Y. Usov (Dubna): Frozen spin solid targets at JINR
4He Evaporation Cryostat
3He/4He Dilution Cryostat
Continuous Mode
Cont. Polarization build-up
Solid ext. magnet needed
Moderate (high) intensities Small solid angle
SLAC, JLAB, COMPASS
The COMPASS Polarized Target
K. Kondo: Polarization measurementJ. Koivuniemi: NMR line shapesY. Kisselev: Local field in polarized LiDN. Doshita: Performance of the cryostatF. Gautheron: Cryogenic control system
max 55 / 50%
/ 3.5 / 1.9 for up/down
P
P P
Cryogenic Equipment
• H. Dutz (Bonn): Highlights of PST instrumentation
• Y. Usov (Dubna): Frozen spin solid targets at JINR
4He Evaporation Cryostat
3He/4He Dilution Cryostat
Continuous Mode
Cont. Polarization build-up
Solid ext. magnet needed
Moderate (high) intensities Small solid angle
SLAC, JLAB, COMPASS
Frozen Spin Mode
Pol. maintained at low B,T
Ext. or thin internal magnet
Low intensities (tagged ) Large (4) solid angle
PSI, Dubna, Mainz, Bonn
heat exchanger
current leads
superconducting coilCopper carrier
reliable operation at Bh = 0.44 T @ 11.5 A, T < 1.2 KNIM A 356 (1995) 111, NIM A 418 (1998) 233
NbTi-wire : 100µm44 mm, l = 120 mm, N = 4000
d = 0.7mm
‘frozen spin polarized target’GDH – frozen spin target (internal superconducting ‘holding coil’)
PT03 Bad Honnef 7
Magnets
• H. Dutz (Bonn): Highlights of PST instrumentation
• C. Djalali et al. (U. South Carol.): Design of an int. superconducting holding magnet for the Jlab Hall B frozen spin target.
Cryogenic Equipment
• H. Dutz (Bonn): Highlights of PST instrumentation
• Y. Usov (Dubna): Frozen spin solid targets at JINR
4Continuous Mode
Cont. Polarization build-up
Thin high field int. magnet
Moderate beam currents Large (4) solid angle
4He Evaporation Cryostat
3He/4He Dilution Cryostat
Continuous Mode
Cont. Polarization build-up
Solid ext. magnet needed
Moderate (high) intensities Small solid angle
SLAC, JLAB, COMPASS
Frozen Spin Mode
Pol. maintained at low B,T
Ext. or thin internal magnet
Low intensities (tagged ) Large (4) solid angle
PSI, Dubna, Mainz, Bonn
minimize and integrate the large polarizing magnet in the d-cryostat
Prinzip : Reduktion des magnetischen Volumen
44 mm, l = 125 mm, N = 2560, 5 Lagen NbTi/CuNi 200µm
Bp = 2.54 Tesla , IN = 100 A , Dicke : 1.5 mm, B/B 10-4
‘4 – continuous mode target’
New concepts
PT03 Bad Honnef 9
Polarization Measurement• G.R. Court (University of Liverpool): Development of NMR techniques for high precision pol. Measurement
• P. Hautle (PSI): Comparison of different NMR concepts
• G. Reicherz (Bochum): Pulsed NMR for pol. measurement
Magnets
• H. Dutz (Bonn): Highlights of PST instrumentation
• C. Djalali et al. (U. South Carol.): Design of an int. superconducting holding magnet for the Jlab Hall B frozen spin target.
Cryogenic Equipment
• H. Dutz (Bonn): Highlights of PST instrumentation
• Y. Usov (Dubna): Frozen spin solid targets at JINR
4Continuous Mode
Cont. Polarization build-up
Thin high field int. magnet
Moderate beam currents Large (4) solid angle
4He Evaporation Cryostat
3He/4He Dilution Cryostat
Continuous Mode
Cont. Polarization build-up
Solid ext. magnet needed
Moderate (high) intensities Small solid angle
SLAC, JLAB, COMPASS
Frozen Spin Mode
Pol. maintained at low B,T
Ext. or thin internal magnet
Low intensities (tagged ) Large (4) solid angle
PSI, Dubna, Mainz, Bonn
Target Material
Doping Method Material Properties
• Dilution factor• Radiation hardness
• Polarized background• Handling
Organic Materials
Experiments in hadron physicswith low to moderate currentsPSI, Dubna, GDH@Bonn/Mainz
Alcohols Diols Plastics
S. Mango (PSI)
Chemical Doping
• Chemical reaction• Dissolution of free radicals
E.I. Bunyatova(Dubna)
Radiation Doping
• Point Defects by ionizing radiation
Inorganic Materials
Experiments at high energies with moderate to high intensitiesCOMPASS, SLAC, JLAB
Ammonia Lithium Hydrides HD
W. Meyer (Bochum)
J. Ball (Saclay)
LDZ
e
SS
LDZ
e
SS
TDT
TDT
1
)/(2
1
1
)/(
1
min
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Static and Dynamic Nuclear Polarization
B[T] T[mK] P(p)[%] P(d)[%]
2.5 1000 0.25 0.05
15 17 70 18
15 12 90 30
2.5 ~ 1 ~ 100 ~ 50
2 2I I
TE I dyn IL SS
B BP P
kT kT
B B
Doping with unpaired electrons
Off-resonance wave saturation
2 2 2hom inhomD D D Minimize to minimize
the spin temperatureS. Goertz et al., Bochum
DNP
Magnetic Field [T]
0 1 2 3 4 5
|Pola
riza
tion| [%
]
0
10
20
30
40
50
60
70
Sample 1Sample 2
-55.1 %
-70.8 %
+45.5 %
-34.8 %
-50.3 %
S.Goertz et al., Bochum
Novel doping methods for organic deuterated materials
Radiation doping of d-butanoland deuterated polyethylene
Chemical doping of d-butanol andd-propanediol with the trityl-radical
D.G.Crabb et al., Virginia
S.Goertz et al.,Bochum
• New standard tool:
Low and high field EPR measurements
J. Heckmann et al. (Bochum): EPR spectroscopy at DNP conditions
Highest deuteron polarization in a polarization experiment
nGDH @ MAMI 2003
0 50 100 150 200 250 300 350 4000
10
20
30
40
50
60
70
80
90
100
D-butanol (trityl-complex) D-butanol (porphyrexide)
d-p
ola
riza
tio
n [
%]
Time [h]
d-run 2003
• BF polarization of H (D) • Forb. AFP to polarize D + • Aging of H2 (6d), D2 (18d)
2I
TE I
BP
kT
B
Polarized Hydrogen Deuterium (HD), f =1 !
1. Polarization via `Brute Force Method´ using the `Switching Mechanism´
HYDILE target for the GRAAL facility at ESRF
Pmax (p) = 60%, Pmax (D) = 14%, > 1 week
J.P. Didelez et al. (IN2P3, INFN):
X. Wei et al. (BNL, Athens, Virginia S.U., Madison U.):
Pmax (p) = 70%, Pmax (D) = 18% Pmax (p) = 30%, Pmax (D) = 6% after transfer to IBC
SPHICE target at BNL‘s LEGS facility
2. Dynamic polarization via radiation induced creation of atomic hydrogen
E. Radtke (Bochum): Efforts towards a dynamically polarized HD-target
Further new achievements in polarized target material research
B. Van den Brandt et al. (PSI): DNP with the free radicals deuterated TEMPO and deteurated oxo-TEMPO
New record polarization in d-polystyrene doped with 2x1019 spins/cm3 TEMPO-d18
Pmax = +34% / -40 % (+10%) at 2.5T / 100mK
EXP. Lab Year Proton Deuteron
E 143 SLAC 1993/94 15NH315ND3
E 155 SLAC 1997 15NH36LiD
Gen98 JLab 1998 - 15ND3
E155x SLAC 1999 15NH36LiD
Gen01 JLab 2001 - 15ND3
RSS JLab 2002 15NH315ND3
NH3 ND3
P.M. McKee (Virginia): Observation of radiation damage and recovery in ammonia
• NH3 is still THE polarized proton material for intense particle beams !• ND3 shares the leading role with 6LiD depending on physics demands.
Essentially no un-anneable radiation damage in ND3 NH3
M. Iio et al. (Miyazaki, Osaka, Nagoya, Chubu, Tsukuba, Yamagata, Tokyo): Development of a polarized target for nuclear fusion experiments
Measurement of D(d,p)T using the 20 MeV beam of the UTTAC tandem accelerator
T. Wakui et al. (Tokyo, Osaka):
Optimization of laser parameters for polarizing protons in naphtalene crystals
T. Uesaka et al. (CNS Tokyo, RCNP Osaka):
The CNS polarized proton target for radioactive isotope beam experiments
First succesful application of the CNS PT at the RI beam at RIKEN: Vector analysing power for the proton-6He elastic scattering
Polarized Targets for new particle- and nuclear physics experiments
O. Zimmer et al. (München, PSI, Saclay):
The spin-dependent nd scattering length – a proposed high accuracy measurement
• Measurement of the `incoherent´ nd scattering length bi,d (ai,d)• High accuracy (10-3) relative to the well known bi,p of the proton
Equipment: Cold neutron beam at PSI Ramsay apparatus for pseudomagnetic precession Proton and deuteron polarized target
Allows extraction of important parameters for effective field theories
J.H. Ardenkjaer-Larsen et al. (Amersham Health, Malmö, Sweden): Generating highly polarized nuclear spins in solution using dynamic nuclear polarization
• NMR spectroscopy, analytical technique
• MRI, non-invasive clin. imaging method
Low senisitivity at room temperature
Is it possible to generate dynamically polarized nuclei in a solvent at room temperature ? YES !
1 min…
in glycerol + OX063
13C-urea
13C coronal projection image of a rat 1s 3s
Heart
Vascular treeof the lung
Aorta
Kidneys
48 participants from 10 countries and 23 universities and instutions all over the world :
Amersham Health R&D, Malamö, Sweden Laboratoire Saturne LNS/SAP, Gif-sur-Yvette, FranceCEA Sackay, Gif-sur-Yvette, FranceUnisersity of Bielefeld, GermanyJoint Institute of Nuclear Research, Moscow, RussiaUniversity of Liverpool, UKUniversity of Virginia, Charlottes, USAInstitut de Physique Nucleaire, Orsay, FranceUniversity of South Carolina, Columbia, USACERN, SwitzerlandUniversity of Bonn, GermanyCharles University Prague, Czech Republic
Ruhr-University Bochum, GermanyPaul Scherrer Insitut, Villigen, SwitzerlandMiyazaki University, JapanUniversity of Michigan, Ann Arbor, USAUniversity of Mainz, GermanyCzech Technical University, Prag, Czech Rep.Institut de Biologie, Grenoble, FranceUniversity of Tokyo, JapanRIKEN, JapanBrookhaven National Lab, New York, USATechnical University München, Germany
The Process of Dynamic Nuclear Polarization
The Microscopic Picture
Degrees of freedom of the electron and nuclear spin system
? The Macroscopic Picture
Observation of spin diffusion by SANSat PSI, at ILL Grenoble and at Saclay
P. Hautle / J. Kohlbrecher et al. (PSI)
2
Idyn I I I I
SS
BP
kT
B B