Applications in Heavy Ion Radiolysis
Jay A. LaVerne
Radiation Laboratory and Department of Physics
University of Notre Dame
Funded by:
Division of Chemical Sciences, Geosciences, and Biosciences
Office of Basic Energy Sciences
U. 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.
50 MeV C6+ ions in air
physics  chemistry  medicine / engineering / environment
Notre Dame Radiation Laboratory
Elucidate fundamental radiolytic decomposition of
molecules and the kinetics of the transients
Examine problems relevant to nuclear energy
Gamma source
Notre Dame Radiation Laboratory
3 electron accelerators (2-8 MeV)
3 gamma sources (0.3-24 kCi)
Electron linac
Radiation Effects in Nuclear Power Industry
Waste Storage
Power Plant Chemistry
Radiation effects are
found throughout the
nuclear energy
complex.
Fuel Processing
Wide variation in type
of radiation.
Waste Transport
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
Communication
Solar Flares
Exploration
Space travel
Applications in space exploration and origin of life.
Health / Therapy Effects due to Track Structure
DNA damage
Cancer therapy
Energy Deposition
Precise dose delivery with heavy ions
FN Tandem
Stopping Power in Water (eV/nm)
Ion Characteristics
10
5
10
4
238
10
U
3
58
Ni
10
2
10
1
12
C
MeV/amu = 5
10
10
10
0
20
4
He
50
electron
1
100
H
-1
10
-1
10
0
1
2
10
10
10
Ion Energy (MeV)
3
10
4
10
Radiolysis cell
Notre Dame has a core set of ion accelerators.
Each ion has a different track structure, physics and chemistry.
5
Differences in 10 keV Track Segments at 1 ps
 eaq H+
 OH
H
 H2
 OH H2O2
Z Axis (nm)
150
100
50
0
150
150
-50
-100
50
0
XA
x is
(n m
0
50
)
100
-50
x is
YA
(nm
)
Z Axis (nm)
100
-50
100
50
0
10 MeV 1H
150
-50
-100
100
-50
50
0
XA
5 MeV 4He
x is
(nm
0
50
)
100 -50
Y
Ax
i
nm
s(
)
Notre Dame Heavy Ion Beamline
Gamma Radiolysis
Water and Aqueous Solutions
H2O  eaq-, H3O+, OH, H, H2, H2O2
Measure the products of
water radiolysis under
realistic conditions.
eaq- : dissolution, H2
formation
H2 : explosive, flammable
OH : biological
H2O2 : corrosive
Water radiolysis cell
Water Decomposition
H2O
ionization
ethermalization
solvation
(250-300 fs)
eaq-
+
H2O+
(H2O)*
H2 + O
H + OH
radical reactions
(0.1 ns - 1s)
proton transfer
hydration
(100 fs)
OH + H3O+
Radiation effects are
generally over within
a microsecond.
OH Radical Yields
H2O  eaq-, H3O+, OH, H, H2, H2O2
-rays
1
H
Gi(OH) (molecules/100 eV)
4
He
12
C
1
7.7 ns
77 ns
770 ns
0.1
1
10
100
1000
Stopping Power in Water (eV/nm)
Track structure determines radiation chemistry
Yields and models used for medical therapy
Motivation for Radiolysis of Organic Compounds
Basic Science: elucidate fundamental radiation
decomposition mechanisms in nonaqueous media
Applications:
Hydrocarbons: tissue, oils,
lubricants
Polymers: lithography, masks,
reactor components,
space environment,
waste storage
Resins: separations, reactors
Benzene/iodine radiolysis
H2 Yields in Monomers and Polymers
Chang, LaVerne and Araos Radiat. Phys. Chem. 2001, 60, 253.
polyethylene
10
1
-ray
H
4
He
12
C
G(H2) (molecules/100 eV)
hexane
polyethylene
H
H
C
C
H
H
1
0.1
0.01
0
10
polystyrene
benzene
polystyrene
1
10
2
10
3
10
Track Average LET (eV/nm)
Many studies on simple liquids and polymers
H
H
C
C
H
Radiolysis of Ion Exchange Resins
Nuclear Reactors
Separations
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?
10 kGy
50 kGy
Resins
100 kGy
Can we make them
functional but radiation
robust?
H2 Yields with Amberlite Resins
Amberlite IRA400
CH
G(H2) (molecules/100 eV)
Amberlite IRA400
CH2
n
12
C
1
4
He
CH2
-rays
0.1
1
H
-
OH
-
Cl
NO-
3
0.01
1
10
100
H3C
N+
Cl-
CH3
CH3
OH- > Cl- > NO3-
1000
Track Average LET (eV/nm)
Resin radiolysis is vital in the nuclear
power industry, but can be deadly.
Interfacial Radiolysis
H2O + SiO2 , ZrO2, CeO2, TiO2, UO2
Radiation effects at water – solid
interfaces are responsible for corrosion.
H2 initiative
Waste transport / storage
Fuel rod integrity
Reactor engineering
H2
4He
ion radiolysis of CeO2
oxide

oxide
water
water – ceramic oxides – radiation
Summary
University based accelerators are important for
examination of radiation effects.
Studies evolve as problems arise.
Applications:
nuclear power industry
medical therapy
space study and exploration
homeland security
Simplified Radiation Chemistry of Water
H 2O

H + OH
OH + OH

H 2O2
H + H

H2
OH + S

Product
H + S

Product
S
OH
H
H
OH