R&D on graphite based oxidation resistant materials and - - PowerPoint PPT Presentation
The High Power Targetry R&D Roadmap for High Energy Physics Workshop @Fermilab, USA 31st May, 2017 R&D on graphite based oxidation resistant materials and radiation resistant tungsten J PARC Center, High Energy Accelerator Research
The High Power Targetry R&D Roadmap for High Energy Physics Workshop @Fermilab, USA 31st May, 2017
Many thanks to everyone, (^_^)/ Muon Section, J‐PARC: S Makimura, S Matoba, N Kawamura , K Shimomura
T Ishida, T. Nakadaira, E. Wakai, M. Teshi J‐PARC, T2K, JAEA P. G. Hurh, K. Ammigan, D.Senor, A. Casella, N.Simos, and RaDIATE (FNAL, BNL, PNNL,,,) M. Calviani, A. P. Marcone, C.L.T. Martin, E. Fornasiere and CERN
supported by RaDIATE & US‐JP collaboration Ductile Tungsten alloy, supported by Industry and Nuclear Fusion Field H. Kurishita, KEK Kinzoku Giken (Metal Technology Co., LTD) Collaborative research Ito Seisakujyo Co., LTD H. Noto, National Institute for Fusion Science Collaborative research
Muon Rotating target at MLF 3 GeV, 1 MW, thickness 20 mm Thermal radiation in vac. 950 Kelvins @ 1MW
Graphite target IG‐430U 26mmf x ~900mm Outer tube / beam window (Ti‐6Al‐4V) Inner tube (graphite)
Neutrino target at J‐PARC 30 GeV, 750 kW, thickness 900 mm He‐cooling: 1010 Kelvins @ 750 kW
Pion Production Target Pion Capture Solenoid
MuSIC target
MuSIC target at RCNP 400 MeV, 400 W, thickness 200 mm Thermal rad. In vac. 600 K COMET target P1 at J‐PARC 8 GeV, 4 kW, thickness 400 mm Thermal rad. In vac. 500 K E target (PSI) 600 MeV, 1.2 MW, thickness 60 mm Thermal rad. In vac. 1700 K NUMI, MSU, ISIS, GSI,,,
PROS
High thermal resistance (1600 degC @Vac.) Mech. properties (Low Young’s modulus, Low thermal expansion, High
resistance to thermal shock)
Experience as irradiation material (Nuclear fission reactor)
CONS
Easy oxidation at high temperature
For use in vacuum, Unexpected air introduction
For use in He‐cooling, Loss of target material through O2, impurity during normal beam operation
Low density (Volume of muon/pion source should be small for efficient
transport.)
Toyo‐tanso Co., LTD Ibiden Co., LTD
1.E-05 1.E-04 1.E-03 1.E-02 1.E-01 1.E+ 00 1.E+ 01 1.E+ 02 1.E+ 03 1.E+ 04 1.E+ 05 1.E+ 06 1.E+ 07 800 1000 1200 1400 1600 1800 2000 Temperature [C] Oxygen partial pressure [Pa] Klaus G. Nickel, "Corrosion of Non -Oxide Ceramics," Ceramic International, 23, 127 -133, (1997) Balat (Sintered SiC) CO2 (g) = CO (g) + ½ O2 (g) Balat calculated Schneider Balat CVD-SiC Schneider Active to passive transition region
Active oxidation Active oxidation (ACTIVE I) (ACTIVE I) HOT HOT PASSIVE PASSIVE Expansion of Expansion of ACTIVE II ACTIVE II ACTIVE II ACTIVE II
Active-to-Passive Transition in the Oxidation of Silicon Carbide, ” J. Mater. Sci., 33, 535–47 (1998)
Microw ave-Excited Air,” J. Eur. Ceram. Soc., 16, 55–62 (1996)
Accidental Loss of Vacuum during beam operation Loss of target material through O2, impurity during normal beam operation Research of CVD‐SiC for fusion nuclear reactor
NU normal
Scope J‐PARC/MLF/Muon 700 degC in vacuum Accidental loss of Vac. J‐PARC/Neutrino 800 degC in He Loss of target material by oxidation during normal operation
By Dr. Park MLF Vac. Loss MLF normal Our scope is here! Oxidation tests
Oxidation behavior depends on temperature and partial oxygen pressure. Passive vs Active
CVD‐SiC
SiC‐coated graphite (IG‐610U, IG‐110U) Graphite (IG‐430U) Diameter: 10 mm, thickness: 1mm Thickness of Coating: 0.1 mm 800 deg C Dried air (N2 + O2 21 %): 200 cc/min.
The experiment was performed by using Tube furnace at the CROSS‐Tokai user laboratories. IG‐430U SiC‐coated graphite Volume loss was observed on graphite and not observed SiC coated graphite.. Fresh Fresh 20 min 60 min
METTLERTOLEDO (MS205DU) Accuracy: 0.01 mg Reliability of measurements: 0.1mg (Effect of humidity)
Weight loss of Graphite is large. Oxidation resistance of SiC‐coating is very high.
Weight variation of SiC coating without damage is less than measuring range (< 0.1 mg).
Loss (mg) 0‐5 (min) 5‐10 (min) 10‐20 (min) IG430 18.2 24.2 60.8
Radiation Damage In Accelerator Target Environments
Radiation Damage In Accelerator Target Environments
radiate.fnal.gov
Purpose: Investigation of irradiation effects Irradiation at BLIP facility at BNL is on- going.
MoU planning (2016〜)
SiC coated graphite is included at CERN capsule. Confirmation through Microstructural analyses at PNNL whether exfoliation will be conducted. Comparison of three kinds of graphite
13 13
Remaining gap Graph/SiC –Filler: 94 um Max T Si samples: 216 ºC Max T Graph/SiC: 220-240 ºC Max T Sigraflex: 193 ºC Max T SS window: 71 ºC
Temperatures
SS Flexible graphite
Thermal Expansions:
Initial lateral gaps Samples-Fillers = 0.1 mm Initial lateral gap Fillers-SS capsule = 0.2 mm
*Assumed TCC in Back-up slides Remaining gap Si samples – Si Filler: 80 um Remaining Fillers– SS Capsule: 200 um (remains the same) Max HF SS window-Water: 28 W/cm2 Si samples SS
Graph/SiC samples
T profile at the center of the capsule
By Claudio. L.T. Martin at CERN
Specimens were assembled in Si capsule of CERN. BLIP irradiation has been conducted at BNL. Microstructural analysis will be conducted at PNNL. Thickness measurement, Optical Microscopy, SEM, EDX, TEM to make sure the effect of gas production.
BNL, Feb.27, 2017 PNNL, Feb.24, 2017
High melting point, Low coefficient of thermal expansion, Low vapor pressure, High thermal conductivity High density, Large mass number, Low solubility of hydrogen isotopes
Tungsten rotating target at European spallation source, He cooling Spallation Neutron Source, 2nd target station at ORNL, Water cooling Mu2e target at FNAL, COMET phase 2 target at J‐PARC, thermal radiation Candidates of MLF 2nd target station at J‐PARC, ??
Limitation against design and lifetime Enhanced by p‐irradiation or under high temperature
load
J.Reiser et al. JNM, 423 (2012) 1.
tough brittle
Pure W foil : ductile load
Recrystallized grain structure by heating at and above Tr Fiber grain structure by heavy plastic working GB fracture :
Current structure modification to mitigate GB fracture Equiaxed, especially after recrystallization
The use of W and Mo is limited below Tr (Tr : ~0.4Tm for stress relieved pure W)
(Tm : ~ 3700K)
PLANSEE
Radiation embrittlement : caused by radiation induced lattice defects which impede the movement of dislocations (radiation hardening) Suppression of accumulation of radiation induced point defects by introducing sinks : Dispersoids (precipitates) and GBs
Stress (MPa)
1500 500 1000 2000 2500
1320 1230
Strain
840 870 250 320 Z 10 mm t X Y
Number is fracture strength
W-1.1TiC/H2
1000 2000 3000 4000 5000 0.005 0.01 0.015 0.02 0.025
Strain Stress (M Pa)
y
1920 K GSMM Fracture strength: 3200 MPa
TFGR~W-1.1％TiC
5 m 2150
1.5 mm t
1100
Y
Ductility is improved by heavy plastic working with orientation. But, Brittle after anneal. As-received
1240˚C x 1 hr anneal
Z
X
W plate (hot rolling)
Y
MA-HIPed W-0.5TiC/H-170ppmO TFGR W-1.1TiC/H-160ppmO
No damage
DBTT = 235K DBTT = 830K
0.17 mm 4 mm 4 mm
During heating
Compressive stresses
During cooling
Repeated dynamic heating and cooling
Tensile stresses Cracking occurs during cooling (T < DBTT) cut
Stress relieved pure W TFGR W-1.1TiC/H
Tokunaga et al. JNM 442(2013) S297.
Significant surface roughening and GB cracking
No appreciable roughening and cracking
・ Grain size strengthening ・ Dispersion strengthening
・ Reinforcement of recrystallized GBs
Glove box Powder handling Mechanical Alloying
with high energy ball milling
The powder with hard balls in a vessel (TZM)
Purified H2 or Ar W- X wt%TMC
W TMC
GB Sliding based Microstructural Modification at ~1700˚C
TFGR sample Funding was approved and fabrication will be completed this December. Small specimens can be made by an
Collaborative research with National Institute for Fusion Science Applying for funding to manufacture large specimens