RDS_SPES PROJECT
(RADIATION DAMAGE STUDY FOR SPES)
Aldo Zenoni, Brescia University and INFN, Pavia – CERN, February 4th 2015
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PRESENT PARTNERS OF THE RDS_SPES PROJECT1
1) SPES Exotic Beams Production Group, LNL, Legnaro
2) L.E.N.A. Laboratory, Pavia University
SPES TIS
3) INFN Sezione di Pavia (Department), Pavia University
4) Applied Physics Group and Laboratory of Materials
Science and Technology, Brescia University
Triga Mark II
1
Project mostly supported by INFN and SPES Project at LNL, Legnaro
Aldo Zenoni, CERN, 2015-02-04
2
Partner locations (Northern Italy)
UniBS
LENA UniPV
INFN
Aldo Zenoni, CERN, 2015-02-04
INFN LNL
Legnaro
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SUMMARY
1)
Motivations for the RDS_SPES Project
2) The L.E.N.A. Laboratory at Pavia University (irradiations)
3) The Laboratory of Materials Science and Technology at
Brescia University (analysis of materials/components)
Cherenkov light
4) Possible extensions of the project
5) Conclusions and prospects
Material scientists
Aldo Zenoni, CERN, 2015-02-04
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Target & Ion Source complex (TIS)
(a technological challenge)
HV 40 kV
Ionizer & transfer tube
TIS Heater
2000°C
Thermomechanical
stresses
Complicated
multistep-process for
ion extraction
1013 fissions/s
15 day irradiation
5 year cooling
Radioactive
ion effusion
and diffusion
40 MeV protons
200 mA, 8 kW
Highly radioactive
environment
200 mm
3 graphite dump disks
Aldo Zenoni, CERN, 2015-02-04
7 238UCx
coaxial disks
1.3 mm thickness
Only automatic
handling possible
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Production of neutron rich isotopes by 238U
fission (a nuclear reactor environment)
1013 n/(s MeV)
1013 fission/s
neutrons
Target Activity (Bq)
1.00E+14
gammas
Activity (Bq)
1.00E+13
1.00E+12
1.00E+11
1.00E+10
1.00E+09
1.00E+08
1.00E+07
1.00E-04
1.00E-02
1.00E+00
1.00E+02
Time (hours)
Aldo Zenoni, CERN, 2015-02-04
1.00E+04
15 days
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Radiation biological hazard
TIS bunker at irradiation time (FLUKA)
4 m walls
1 mSv/h
vertical plane
horizontal plane
y (cm)
3 m ceiling
RIB
neutron
dose
z (cm)
y (cm)
proton beam
RIB
vertical plane
proton beam
neutron
dose
103 Sv/h
Aldo Zenoni, CERN, 2015-02-04
x (cm)
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Material properties modifications by
radiation damage
Some critical TIS components
(mainly polymeric materials)
1) Chamber joints (O-rings)
2) Viewport glass and joints
3) Insulators
4) Proton beam joints
5) Chamber handling guides
6) Chamber base insulators
7) Pneumatic motors
8) Electrical motors
9) AC power wire jackets
10) Optical fiber core/cladding
11) Electronic components
Aldo Zenoni, CERN, 2015-02-04
Safe and stable operation performance must be
guaranteed; no manual handling is possible
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The SPES Radioactive Ion Beam (RIB)
front-end line
Steerers and
triplet of
quadrupoles
Diagnostic
box
(FC+BP)
Wien filter
Slits and
Diagnostic box
(BP+FC)
Triplet of
quadrupoles
Emittance meter
Target-ion
source
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Material damage by ionizing radiation
and neutrons
Polymeric materials
Very sensitive to ionizing radiation > 103 Gy
Covalent bonds broken (chain scission)
New chemical bonds formed (cross linking, reticulation)
Free radical formation
Radiation damage affected by temperature, additives,
atmospheric conditions (oxygen)
f. Gas H, He formation
g. Irreversible effects – mechanical, chemical, electrical,
thermal properties affected
h. Molecular weight, solubility, Young’s modulus,
elongation, hardness, embrittlement, viscosity
a.
b.
c.
d.
e.
Ceramics, glasses
a. Mechanical properties unaffected
when irradiation < 107 Gy and
neutron fluences < 1019 n/cm2
b. Darkening and loss of
transparency in glasses
Metals and alloys
a.
b.
c.
d.
e.
f.
Reasonably unaffected by ionizing radiation
Atom displacement by neutron collisions E> 1 keV
High neutron fluence needed > 1016 n/cm2
Creation of lattice vacancies and interstitials
H and He gas formation, decrease in density
Plastic properties markedly affected: yield strength,
ultimate tensile strength, elongation, fatigue stress,
hardness, impact strength, creep, etc.
g. Damage may be recovered by annealing
h. Thermal neutrons may induce transmutation
Aldo Zenoni, CERN, 2015-02-04
interstitials
vacancies
Displacement dynamics
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Material damage by radiation is a
long-known technological problem
Space science
Nuclear reactor technology
Accelerator technology
CERN Reports on radiation damage tests; the reference
1. Cable insulating materials; CERN 79-04 (1979)
2. Thermosetting and thermoplastic resins; CERN 79-08 (1979)
3. Materials used around high energy accelerators; CERN 82-10 (1982)
4. Selected electrical insulating materials for HP and HV applications; CERN 85-02 (1985)
5. Halogen free cable-insulating materials; CERN 89-12 (1989)
6. Radiation tests at cryogenic temperatures on organic materials for LHC; CERN 96-05 (1996)
7. Thermosetting and thermoplastic resins composite materials; CERN 98-01 (1998)
8. Adhesives; CERN 2001-06 (2001)
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Typical report information CERN 82-10 (1982)
(extensive and systematic work)
Dose limits are specific to the
item tested and to the endpoint criteria applied
General information on materials:
thermoplastic resins
Specific information: cable
insulation by a supplier
Irradiation sources:
a)
b)
c)
d)
Mainly g dose: 95%
switched-off reactor
7 MW Astra reactor, Austria (1012-1014 n/(s cm2); 106 Gy/h)
ASTRA fuel elements or 60Co source (to avoid activation) (104 Gy/h)
CERN accelerators (10-100 Gy/h)
TAPIRO fast reactor at ENEA, Italy (1012 n/(s cm2) )
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Rad-hard study performed on SPES
front-end critical components - I
TEFLON and VITON
are excluded
Front-end MCNPX simulation
Dose rate
Rad dose limit
from CERN reports
15 days operation
are foreseen
Max operating days
before failure
Top view
Side view
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Rad-hard study performed on SPES
front-end critical components - II
PEEK, EPDM, KAPTON, TPE-SBR are
used instead of weaker materials
Open questions with existing data :
a) Are irradiation conditions adopted close to reality?
(Mainly g dose tested)
b) Are end-point criteria adapted to the item use?
c) Are specific material/component included in the
available data?
Aldo Zenoni, CERN, 2015-02-04
SPES
Front-end
Neutron dose
0%
20%
Gamma dose
40%
60%
80% 100%
Chamber insulator 1
Chamber insulator 3
Proton channel insulator
Viewport joint
Guide 2
AC wire cover
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Reasons to propose a program for rad-hard
tests for SPES front-end
a) Radiation hardness of materials and components is a critical item for ISOL
sources in construction or foreseen (SPES, REX-ISOLDE, ALTO, SPIRAL2,
iTHEMBA, EURISOL ….)
b) Data in the literature are somewhat abundant but often not recent
c) New materials, products and suppliers are available and should be tested
d) Specific materials and products utilized in the assembly should be tested in
spite of generic materials
e) Existing data mainly refer to gamma ray damage
f) Reliable tests should reproduce as close as possible real operating
conditions
g) Specific mechanical, electrical, optical requirements of materials and
products should be tested against radiation damage
h) Complex components ad electrical motors or electronic circuits should be
tested.
i) Interest for a systematic campaign of rad-hard tests for ISOL sources and
other applications has been expressed by a number of potential partners
Aldo Zenoni, CERN, 2015-02-04
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The RDS_SPES Project resources
(Radiation Damage Study for SPES)
A. Supported by INFN, Pavia and SPES Project at LNL, Legnaro
B. L.E.N.A. Triga Mark II nuclear research reactor for material
and component irradiations at Pavia University
C. Tests of physical and operational properties of materials and
components at the Laboratory of Materials Science and
Technology at Brescia University
D. Know-how on simulation and transport programs MCNPX,
FLUKA, GEANT4, PHITS, in UniBS, LENA, LNL
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Draft research program of RDS_SPES Project
a) Compilation of materials and products to be rad-hard tested with definitions
of the actual mechanical, electrical, optical, operational requirements to be
guaranteed
b) Simulation of the radiation fields and cumulated dose expected on the
critical SPES Front-end components in the foreseen operational conditions
c) Irradiation campaigns at L.E.N.A. on sample materials and products.
Radiation fields as close as possible to the expected ones (neutrons vs
gammas). Systematics on adsorbed dose levels.
d) Test of physical and operational properties of irradiated materials and
components for different levels of irradiated dose
e) Analysis of the relation between physical properties changes and structural
modifications due to radiation damage in materials (mainly polymers)
f) One or two year research program
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L.E.N.A. Laboratory at Pavia University
(Laboratorio Energia Nucleare Applicata)
In operation since 1965
Reactor tank:
1.98 m diameter, 6.4 m height
with demineralized water
Biological shield
concrete
1 m thickness
Reactor core:
44.6 cm diameter
64,8 cm height
http://www.unipv-lena.it/it/
TRIGA Mark II pool research reactor
light water and HxZr moderated
250 kW steady-state power
Aldo Zenoni, CERN, 2015-02-04
90 symmetric holes: fuel
elements, control rods, neutron
source, irradiation channels
Graphite reflector
30 cm thickness
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Laboratory of Materials Science and
Technology (LMST) at Brescia University
(Mechanical and Industrial Engineering Department)
Member of:
a. INSTM (Italian National Consortium of
Materials Science and Technology)
b. ESIS (European Structural Integrity
Society),Technical Committee 4
(Polymers, Adhesives and Composites)
sites.google.com/site/materialssciencetechnologylab/
Main research areas:
a. Development of advanced engineering polymeric materials
b. Mechanics of polymers, composites and nanocomposites
c. Rheology of polymers and polymer-based systems
d. Technology and engineering of plastics products
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LMST equipment and available facilities
(Mechanical tests)
Mechanical and rheological tests
Universal dynamometer for mechanical testing - Instron
Instrumented pendulum for impact tests - Ceast
Dynamic dynamometer - Instron
Dynamic Mechanical Thermal Analyzer (DMTA) - Polymer Lab
Dynamic Mechanical Thermal Analyzer (DMTA) - TA Instruments
Instrument for creep tests on polymers
Equipment for specimen preparation - Ceast
Twin-bore capillary rheometer - Ceast
Rotational rheometer - TA Instruments
Melt Flow Indexer - Ceast
Elongational rheometer
Capillary rheometer
Dynamic dynamometer
Universal dynamometer
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LMST equipment and available facilities
(physico-chemical tests and process design)
Physico-chemical and morphologial analyses
Differential Scanning Calorimetry (DSC) - Mettler Toledo
Modulated DSC - TA Instruments
Thermogravimetric Analysis (TGA) - TA Instruments
Infrared Spectrometry (FTIR) - Jasco
UV-vis Spectrophotometry - Perkin-Elmer
Gel Permeation Chromatography (GPC)
Gas Chromatography - Perkin-Elmer
Standard equipment for synthesis and chemical analyses
Travel optical microscope - Leica
Access to Scanning Electron Microscopy (SEM)
Infrared spectrometer (FTIR)
Processing machines
Single-screw extruder - Fuji
Brabender mixer - Brabender
Injection molding machine - Arburg
Compression molding machine -Collin
Access to compounding machine – Coperion
Computer Aided Engineering software analyses
Compression molding machine
Plastic injection molding design software - Moldflow (Autodesk)
Multiphysics modeling and simulation software - COMSOL Multiphysics
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Tests on mechanical and thermal properties of
pre and post-irradiated polymeric samples
1. Tensile tests (mechanical: elastic modulus, tensile
strength and elongation at break)
2. Impact tests (mechanical: impact strength)
3. Bending tests (mechanical: flexural strength )
4. DSC analysis (thermal: glass transition temperature,
melting temperature, degree of crystallinity )
Impact pendulum
5. Rheological tests (molecular weight, molecular
cross-linking, etc.)
6. Infrared analysis (structural analysis)
7. SEM microscopy (structural analysis)
8. Gas chromatography (analysis of evolved gases)
9. Gel permeation chromatography (molecular weight)
10. Swelling test (cross link density)
Aldo Zenoni, CERN, 2015-02-04
Calorimeter DSC
Test will be performed at LMST in Brescia
Polymeric materials should not suffer activation
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Possible extensions of the RDS_SPES
Project (Partners)
ALTO
Possible partners who expressed interest in the project:
Potential partners
first meeting
ESS (European Spallation Source), Lund,
Sweden
Lund, 10-12-2014
ALTO, IPN Orsay, France (radioactive beam
production)
LNL, Legnaro, 15-12-2014
CERN, Sources, Targets & Interactions Group,
Geneva (Switzerland)
CERN, Geneva, 4-2-2015
iTHEMBA Labs, Western Cape, South Africa
(radioactive beam production)
To be fixed
iTHEMBA Labs
The effort could be better aimed and qualified if a larger
Collaboration among interested partners will be established,
sharing experience, know how and resources
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Possible extensions of the RDS_SPES Project
(Metals and alloys, Ceramics, electronic circuits)
Three main questions for inorganic materials:
1) High irradiation neutron fluences needed to test damage in metals
and ceramics; are TRIGA fluxes adequate to needs?
2) A metallurgy test laboratory is needed to perform pre and post
irradiation tests on metallic samples
3) Metals may be activated by neutron irradiation, transmutation effects
4) Just an observation: a lot of interest, but lack of background and
expertise in the present collaboration
Electronic circuits and components:
No particular problems; integrated
electronics is very sensitive to radiation
damage
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Possible answers to questions concerning
investigation on inorganic materials: 1), 2)
1) Are TRIGA fluxes adequate to needs?
a) This has to be verified. Possibly a factor 10 lower than the highest reactor fluxes
b) Consider also that radiation damage and damage evolution can be predicted by
computational models to a certain extent.
c) Reliable radiation damage correlation requires integration of theoretical,
computational end experimental tools.
2) A metallurgical laboratory is needed to perform the tests
a) The Group of Metallurgy of the Brescia University is interested in a possible
collaboration; pre e post irradiation mechanical test on (non activated) metallic
samples may be performed in Brescia
b) The same interest has been manifested by the Groups of Metallurgy and
Machine Design of the Padua University
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The Laboratory of Metallurgy at the
Brescia University
Tests at the Brescia Metallurgy Laboratory
1. All metal plastic properties can be tested: yield
strength, ultimate tensile strength, elongation to
fracture, fatigue stress, hardness, impact
strength, creep, ductility, brittleness, etc.
2. Microindentation and nanoindentation testing
equipments are available for non destructive
tests
Vickers microindenter
http://dimgruppi.ing.unibs.it/metallurgia/
diecasting plant
optical microscopy
Aldo Zenoni, CERN, 2015-02-04
strain machine
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The Laboratories of Metallurgy and
Machine Design at the Padua University
Metallurgy studies performed
1. Neutron damage on microstructure:
2. Tests on mechanical properties: hardness,
tensile strength, fatigue, etc
3. Steels and alloys for nuclear reactor use:
valve bodies, cooling systems, canisters
4. Optical, SEM, TEM microscopy
5. Hardness measurement instrumentation
6. X ray diffractrometer
7. Corrosion laboratory
8. High temperature fatigue tests
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Possible answers to questions concerning
investigation on inorganic materials: 3)
3) Metals may be activated by neutron irradiation
a) If metallic samples are activated by neutron irradiation, some testing
equipment may be installed in the mechanical workshop inside the
LENA building
b) If needed and justified, automated “hot cells” may be installed too
c) Rad-waste creation and disposal must be carefully evaluated
d) A list of possible “hot” analysis may be considered and studied on a
case by case basis
LENA mechanical workshop
Aldo Zenoni, CERN, 2015-02-04
LENA mechanical workshop
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Conclusions and prospects
1) We are convinced that the RDS_SPES Project on radiation damage may
be a timely and useful initiative for many European (and worldwide)
facilities presently in construction in the field of nuclear physics and
applications
2) The atouts of the Project are the availability of the LENA Laboratory for
irradiations and Materials Science Laboratories to perform pre and post
irradiation tests on materials and components
3) Possible collaborations and sharing of experience, knowhow and
resources could be strategic to aim the project effort at best.
4) ESS Lund and ALTO Orsay have already expressed their interest in
joining the collaboration
5) In next weeks we will start the first campaign of radiation damage study on
vacuum O-rings
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SPARE SLIDES
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Materials employed for the simulations
name
composition
EPDM
Etylene-Propylene Diene Monomer
rubber
PEEK
Polyether ether ketone
organic thermoplastic polymer
PMMA
polymethilacrilate
Plexiglass, lucite
SBR
Styrene-butadiene
rubber
TPE
Thermoplastic elastomer
rubber
VITON
Fluoropolymer elastomer
rubber
TEFLON
Politetrafluoretene
KAPTON
poly-oxydiphenylene-pyromellitimide
FPE
Fluorinate ethylene propylene
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Materials employed
for the simulations
Aldo Zenoni, CERN, 2015-02-04
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