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TASK #2TASK #2
ProducedProduced and and characterizedcharacterized pelletspelletsuntiluntil summersummer 06 06 forfor SPES DT projectSPES DT projectSPES: A Mid-term Facility based on a 40 MeV proton Driver and on the Multi-Slices Direct Target concept
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Target productionPHILOSOFICAL APPROACH
1) A primary topic in the development of the generation of Radioactive Ion Beams (RIB) is the production of targets characterized by:
high production yield short release times high thermal resistance
2) These capabilities are strongly influenced by many physical and chemical properties of the targets
(e.g. purity degree, grains sizes, grains distributions, grains stoichiometry, porosity etc..)
3) It becomes essential to produce targets with:
a) Strict control of the production method high reproducibility
b) Deep characterization of the samples good knowledge of the produced samples properties
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Target typologies
1) THE “PARTIALLY” COMPLETE PHASES OF SUITABLE ACTINIDE TARGETS PRODUCTION
Strict control of the production process
In-depth characterization of the physical properties of the produced samples
Handling of the produced samples (reactivity troubles)
CALCULATION CODES
TESTING UNDER BEAM
2) THE COMPLETE PHASES OF SUITABLE ACTINIDE TARGETS PRODUCTION
PELLETS PRODUCTION
PELLETS CHARACTERIZATIONLegnaro 19th July - MICHELE TONEZZER
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Target typologies
THE MAIN GOAL OF TASK 2 IS THE PRODUCTION OF ACTINIDE TARGETS (UCx, ThCx..)
1) Phase 1 SiC Pellets No Chemical & Radiologic problems
2) Phase 2 LaC2 Pellets Some Chemical problem of UCx (reactivity with oxygen (pyroforic))
SIMILAR CHALLENGES WITHOUT RADIOACTIVITY
3) Phase 3 UCx Pellets Chemical & Radiologic problems (pyroforic and contamination)
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Phase 1: SiC pellets
1) PELLETS PRODUCTION:
PURCHASED BY THE SAINT GOBAIN(SiC Hexoloy SE)
T= 2000 °CE= 0,7 ± 0,05
Mass before treatment: 800,9 mgMass after treatment: 800,8 mg No weight loss
Emissivity vs. Temperature
0
0.2
0.4
0.6
0.8
1
1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000
Temperature (°C)
Emis
sivi
ty
2) PELLETS CHARACTERIZATION
HIGH TEMPERATURE TESTS
EMISSIVITY TESTS
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Phase 1: SiC pellets
2) PELLETS CHARACTERIZATION
SEM ANALYSIS
XRD ANALYSIS
3) TESTING UNDER BEAM
(planned at ORNL in the first part of 2007 (January-March) )
3 0 3 5 4 0 4 5 5 0 5 5 6 0 6 5 7 0 7 5 8 00
5 0
1 0 0
1 5 0
2 0 0
2 5 0
3 0 0
3 5 0
Cou
nts
(a.u
.)
2 th e ta
S iC H e xo lo y S G a s p u rc h a s e d S iC H e xo lo y S G [1 6 0 0 °C , 2 h , A r] H e xa g o n a l 1 9 -1 1 3 1
4) PROBLEMS
NO PROBLEMS UNTIL NOW Legnaro 19th July - MICHELE TONEZZER
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Phase 2: [LaC2 + C] pellets production
C GRAPHITE
La2O3
1) PELLETS PRODUCTION:
A) PRODUCTION OF STARTING PELLETS:
a) PRODUCTION OF OXIDE PELLETS
THE LaC2 PELLETS PRODUCTION CONSISTS IN TWO PHASES: GREEN PELLETS PRODUCTION + THERMAL TREATMENT
b) PRODUCTION OF OXALATE PELLETS:
NOT MECHANICALLY STABLE
BEFORE AFTER
c) PRODUCTION OF OXIDE PELLETS WITH PEHOLIC MICROSPHERES:
MICROSHERES DO NOT PARTECIPATE IN CARBURIZATION PROCESS
AFTERBEFOREMICROSPHERES
88
Thermal treatments
B) THERMAL TREATMENT OF THE STARTING PELLETS
a) CARBURIZATION OF THE STARTING PELLETS
b) SINTERING OF THE CARBURIZED PELLETS
(INFLUENCE THE MECHANICAL PROPERTIES, THE GRAINS SIZES AND THE POROSITY OF THE FINAL PELLETS)
La2O3 + 11C 2LaC2 + 4C + 3CO ↑(Theoretical mass loss: 18.5%)
0 5 10 15 80 900
200400600800
100012001400160018002000
Tem
pera
ture
(°C
)
T ime (h)
CARBURIZATION (C) SINTERING (S)
The furnacesLNL (vacuum, < 1600 °C) TRENTO (Ar, > 2000 °C) LNL (vacuum, > 2000 °C)
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Phase 2: thermal treatment control
311°C, -6.3 %
479°C, -2.1%
618°C, -1.6%
> 986°C
-H2O
- CO2
Beginning of
Carburization
1) Strict control of the temperature values and temperature ramps (by means of a thermocouple and double frequencies pyrometer);
2) Monitoring of the chamber pressure during the thermal treatment(in order to check the evolution of the reaction product (CO))
3) Monitoring of gaseous species evolved during the thermal treatment by means of a mass spectrometer connected to the furnace vacuum chamber
4) Control of the weight of the pellet during the thermal treatment (in order to have a very accurate control of the occurring reactions)
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Phase 2: characterization of pelletsCommonly used techniques
BEFORE thermaltreatment
AFTER thermaltreatment
BLACK GRAIN (CGRAPHITE)
WHITE GRAIN (La2O3)
LOOK SEM pictures EDS analysis
1111
2 0 2 5 3 0 3 5 4 0 4 5 5 0 5 5 6 00
5 0
1 0 0
1 5 0
2 0 0
2 5 0
3 0 0
3 5 0
4 0 0 L a 2O 3/C g ra p h ite a s d e p o s ite d
L a C 2L a 2O 3
L a 2 O 3 /C g ra p h ite g re e n
Cou
nts
(a.u
.)
2 th e ta
Not commonly used techniques: the XRD patterns
1) THE SAMPLE SHOWS THE PRESENCE OF LA2O3 (SEVERAL LANTHANUM OXIDE PEAKS ARE MANIFEST)
2) THE SAMPLE SHOWS ANY PRESENCE OF LAC2 (NO LANTHANUM CARBIDE PEAKS ARE VISIBLE)
3) THE SAMPLE SHOWS THE PRESENCE OF IMPURITIES LIKE BINDER (PRESENCE OF EXTRANEOUS PEAKS)
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2 0 2 5 3 0 3 5 4 0 4 5 5 0 5 5 6 00
5 01 0 01 5 02 0 02 5 03 0 03 5 04 0 04 5 05 0 0
L a 2O 3/C g ra p h ite 1 2 0 0 ° C ,v a c u u m ,2 4 h L a C 2 L a 2O 3
L a 2 O 3 /C g ra p h ite t r e a te d [1 2 0 0 ° C , v a c u u m , 2 4 h ]C
ount
s (a
.u.)
2 th e ta
Not commonly used techniques: the XRD patterns
2) THE SAMPLE SHOWS YET ANY PRESENCE OF LaC2 (NO LaC2 PEAKS ARE VISIBLE)
1) THE SAMPLE IS YET MADE UP OF La2O3 (HEXANOGAL STRUCTURES)
CRYSTALLINE GRAINS ARE GROWN (La2O3 PEAKS BECOME MORE NARROW AND HIGH)
3) IT IS POSSIBLE TO NOTE THE DECREASE OF THE IMPURITIES QUANTITY (DECREASE OF EXTRANEOUS PEAKS)
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2 0 2 5 3 0 3 5 4 0 4 5 5 0 5 5 6 00
5 0
1 0 0
1 5 0
2 0 0
2 5 0 L a 2O 3/C g ra p h ite 1 8 0 0 ° C ,v a c u u m ,2 4 h
L a C 2 L a 2O 3
L a 2 O 3 /C g ra p h ite t r e a te d [1 8 0 0 ° C , v a c u u m , 2 4 h ]C
ount
s (a
.u.)
2 th e ta
Not commonly used techniques: the XRD patterns
1) THE SAMPLE SHOWS NOW ANY PRESENCE OF La2O3 (NO La2O3 PEAKS ARE VISIBLE)
2) THE SAMPLE IS MADE UP OF LaC2 (LARGE GRAINS, NARROW AND HIGH PEAKS)
3) THE SAMPLE SHOWS ANY PRESENCE OF IMPURITIES (NO PRESENCE OF EXTRANEOUS PEAKS)
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Phase 2: [LaC2 + C] pellets
3) PELLETS TESTING UNDER BEAM
(to be planned)
4) RESULTS
OBTAINED RESULTS
a) COMPLETE CARBURIZED PELLETS HAVE BEEN OBTAINED
b) KNOWLEDGE OF THE CARBURIZATION TEMPERATURE AND DISCRIMINATION BETWEEN CARBURIZATION AND SINTERING PROCESS TEMPERATURE HAS BEEN ACHIEVED
c) VARIOUS SINTERING GRADES OF THE CARBURIZED PELLETS HAVE BEEN OBTAINED
NOT YET OBTAINED IMPORTANT RESULTS
a) MECHANICAL STABILITY OF THE FINAL PELLETS
b) KNOWLEDGE ABOUT HANDLING OF THE FINAL CARBURIZED PELLETS (CHEMICAL REACTIVITY)
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Phase 3: UCx pellets
1) PELLETS PRODUCTION:
A PELLET OF URANIUM AND THORIUM OXIDE HAS BEEN PRODUCED
ANY THERMAL TREATMENT HAS BEEN YET PERFORMED (not yet available furnace)
3) PELLETS TESTING UNDER BEAM
(to be planned)
2) PELLETS CHARACTERIZATION
NO CHARACTERIZATION ANALYSES ARE DISPOSABLE AT OUR FACILTIES
IT BECOMES NECESSARY TO RELY ON DEDICATED REASEARCH CENTRES
( IT IS PLANNED FOR TOMORROW A VISIT AT I.T.U. OF KARLSRUHE)
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TASK #2TASK #2
ProducedProduced and and characterizedcharacterized pelletspelletsuntiluntil summersummer 06 06 forfor SPES DT projectSPES DT projectSPES: A Mid-term Facility based on a 40 MeV proton Driver and on the Multi-Slices Direct Target concept
Legnaro 19th July - MICHELE TONEZZER