Applications in Heavy Ion Radiolysis
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Transcript of Applications in Heavy Ion Radiolysis
Applications in Heavy Ion Radiolysis
Jay A. LaVerneRadiation Laboratory and Department of Physics
University of Notre Dame
Funded by: Division of Chemical Sciences, Geosciences, and BiosciencesOffice of Basic Energy SciencesU. S. Department of Energy
Fundamental Basis to Applications
Examine energy loss, charge and other properties of ionizing radiation.
Elucidate fundamental radiolytic decomposition of molecules and the kinetics of the transients.
physics chemistry medicine / engineering / environment
50 MeV C6+ ions in air
Notre Dame Radiation Laboratory
Elucidate fundamental radiolytic decomposition of molecules and the kinetics of the transients
Examine problems relevant to nuclear energy
3 electron accelerators (2-8 MeV)3 gamma sources (0.3-24 kCi)
Gamma source
Electron linac
Notre Dame Radiation Laboratory
Radiation Effects in Nuclear Power Industry
Waste Storage Power Plant Chemistry
Fuel ProcessingWaste Transport
Radiation effects are found throughout the nuclear energy complex.
Wide variation in type of radiation.
How will materials decompose due to radiation?
Can we design materials more radiation robust?
Heavy Ion Radiolysis in Space
solar/cosmic radiation: H, He, etc.planetary particles
Applications in space exploration and origin of life.
Exploration
Communication
Space travel
Solar Flares
Health / Therapy Effects due to Track Structure
Precise dose delivery with heavy ions
Cancer therapyDNA damage
Energy Deposition
Ion Characteristics
Notre Dame has a core set of ion accelerators.Each ion has a different track structure, physics and chemistry.
10-1 100 101 102 103 104 10510-1
100
101
102
103
104
105
electron
58Ni
238U
12C
4He1H100
5020
10MeV/amu = 5
Sto
ppin
g P
ower
in W
ater
(eV
/nm
)
Ion Energy (MeV)
FN Tandem
Radiolysis cell
-100-50
050
100
-50
0
50
100
150
-50
0
50100
150
Z A
xis
(nm
)
Y Axis (nm)X Axis (nm)
-100-50
050
100
-50
0
50
100
150
-50
050
100150
Z A
xis
(nm
)
Differences in 10 keV Track Segments at 1 ps
10 MeV 1H
5 MeV 4He
eaq-
H+
OH H H2
OH-
H2O2
Notre Dame Heavy Ion Beamline
Gamma Radiolysis
Water and Aqueous Solutions
H2O eaq-, H3O+, OH, H, H2, H2O2
Water radiolysis cell
Measure the products of water radiolysis under realistic conditions.
eaq- : dissolution, H2 formation
H2 : explosive, flammable
OH : biological
H2O2 : corrosive
Water Decomposition
Radiation effects are generally over within a microsecond.
e-
eaq- H2 + O
H2O
H2O++
proton transfer hydration (100 fs)
OH + H3O+
(H2O)* thermalization solvation (250-300 fs)
ionization
radical reactions (0.1 ns - 1s)
H + OH
OH Radical Yields
H2O eaq-, H3O+, OH, H, H2, H2O2
Track structure determines radiation chemistryYields and models used for medical therapy
1 10 100 1000
0.1
1
770 ns77 ns
7.7 ns
-rays
12C
4He
1HG
i(OH
) (m
olec
ules
/100
eV
)
Stopping Power in Water (eV/nm)
Motivation for Radiolysis of Organic Compounds
Applications:
Hydrocarbons: tissue, oils, lubricants
Polymers: lithography, masks, reactor components, space environment, waste storage
Resins: separations, reactors
Basic Science: elucidate fundamental radiation decomposition mechanisms in nonaqueous media
Benzene/iodine radiolysis
H2 Yields in Monomers and Polymers
100 101 102 1030.01
0.1
1
10
polystyrene
polyethylene
hexane
benzene
-ray 12C4He1H
G(H
2) (m
olec
ules
/100
eV
)
Track Average LET (eV/nm)
Chang, LaVerne and Araos Radiat. Phys. Chem. 2001, 60, 253.
polyethylene
polystyrene
C
H
C
H
H
H
C
H
C
H
H
Many studies on simple liquids and polymers
Radiolysis of Ion Exchange Resins
Nuclear ReactorsSeparations
Resins are important in separation waste streams and in reactor water purification.
Exactly how do they decompose with radiation?
How do they hold up under radiation stress?
Can we make them functional but radiation robust?
Resins
10 kGy 50 kGy 100 kGy
H2 Yields with Amberlite Resins
OH- > Cl- > NO3-
1 10 100 10000.01
0.1
1
12C
4He
1H-rays
Amberlite IRA400
NO-3
Cl-OH-
G(H
2) (m
olec
ules
/100
eV
)
Track Average LET (eV/nm)
CH CH2
CH2
N+
Cl-
H3C
CH3
CH3
n
Amberlite IRA400
Resin radiolysis is vital in the nuclear power industry, but can be deadly.
Interfacial Radiolysis
H2O + SiO2 , ZrO2, CeO2, TiO2, UO2
water – ceramic oxides – radiation
H2
oxide
oxide
water
4He ion radiolysis of CeO2
Radiation effects at water – solid interfaces are responsible for corrosion.
H2 initiativeWaste transport / storageFuel rod integrityReactor engineering
Summary
University based accelerators are important for examination of radiation effects.
Studies evolve as problems arise.
Applications:
nuclear power industrymedical therapyspace study and explorationhomeland security
Simplified Radiation Chemistry of Water
H2O H + OH
OH + OH H2O2
H + H H2
OH + S Product
H + S Product
OH
OH
H
H
S