RaDIATe/BLIP Status of irradiation campaign of Ir, TZM, Si and Graphite-SiC coated samples Claudio Torregrosa, Elvis Fornasiere, David Horvath, Antonio Perillo-Marcone, Marco Calviani

Outline 4th May Geometry of the targets 2.Monte Carlo simulations of deposited energy and proton attenuation at the targets 3.Thermal and structural analysis of targets 4.Residual dose estimations 5.Discussion on specimens geometry and post-irradiation tests 6.Status of the production 7.Conclusions and next steps

Geometry of the Targets 3 Ir + TZM Samples Thickness: 0.5 mm Ir + 1 mm TZM Si + Graph-SiC Samples* 2 mm Si + 1 mm Graph-SiC coated Beam 1) Stainless steel Capsule 2) Graphite Matrix 3) Samples: Two Capsules Configurations 40 mm Total thickness of the Capsule: mm Total thickness of the Capsule: mm Steel walls thickness: mm / inch 4th May 2016 *Geometry of these samples will be updated Preliminary

Ratio of protons received by the targets 4 the 40 x 40 mm square targets receiving the 90.74% of the protons, while the graphite sees 9.09% 4th May 2016

Deposited energy in the targets 5 Ir+TZM Capsule Si + Graph-SiC coated Capsule Longitudinal profile 4th May 2016

Thermal Analysis: Assumptions 6 HTC = 6000 W/m2K at external surfaces Radial heat flux = 0 W/m2 Contact Conductance between layers of materials estimated by Mikic correlation for elastic contacts: ContactPRESSURE [MPa]Contact Conductance [W/m2K] Ir_SS5900 TZM_SS1 (due to bending of the container) 230 Ir_TZM55000 Ir_Graph SS_Graph TZM_Graph Si_SS SiC_SS Si_Graph SiC_Graph SS_Graph SiC_Si Assumed Roughness Ra = 1.6 µm *Contact Pressure estimated through Structural-Thermal iterations Water Flow Heat flux 4th May 2016

Temperatures: Ir+TZM Capsule 7 Max Temp Ir = 600 °C Max Temp TZM = 620 °C Max Temp Graphite = 330 °C Max Temperature at the external Stainless Steel wall = 115 °C *Same as conservatively considering perfect thermal contact between layers Max HF = 500kW/m2 (boiling point at 2 bars=120 ° C) 4th May 2016

8 Temperatures: Si+ SiC-coated grahpite Max Temp Si = 750 °C Max Temp Graph sample = 720 °C Max Temp Graphite matrix = 330 °C Max Temperature at the external Stainless Steel wall = 53 °C *Conservatively considering perfect thermal contact between layers = 70 C 4th May 2016

Structural Analysis: External capsules 9 Max Stress in SS capsule= 160 MPa Yield strength SS304 at 150 °C = 200 Mpa At 70 °C = 240 MPa Ir+TZM Capsule Si + Graph-SiC coated Capsule *Assuming frictionless contact between layer of materials Max Stress in SS capsule= 50 MPa 4th May 2016

Deformation of external capsules 17 March 2016C. Torregrosa10 Max radial Deformation = mm Max Longitudinal Deformation = +0.1 mm To be taken into account in the design of the sample holder to avoid thermal stresses at the capsules *These deformations, however, will be probably affected by the specific geometry of the samples and minor gaps between them (reduced)

Ir+TZM capsule – Residual dose After two weeks of Irradiation + 6 hours of cooling 4th May 2016

Ir+TZM capsule – Residual dose at the extraction hot cell After two weeks of irradiation and 6 hours of cooling time the capsule could be safely extracted inside the hot cell 4th May 2016 Hot cell wall thickness assumed: 18 cm

4P bend testing: open questions 13 Materials to be tested: Silicon, TZM and Iridium 3 brittle 4-points bend testing preferred to tensile tests Dimensions: 0.5x0.5x40 mm 3 samples for Ir and Silicon and 1x1x40 mm 3 for TZM Confirmation of the possibility of doing 4P-bend testing? Cross-section very small (0.5x0.5)  Some experience with testing of this geometry? Long specimen for small cross section  Stick to this dimension of possibility of cutting by half the specimen and put two in a row in order to obtain 40 mm (double statistics)? Change of temperature during testing? Range? 4th May 2016

Small punch test: open questions I 14 Schematic view of SP operation ((a), with the courtesy of [1]), comparison between the rigid plastic model calculation and experimental load deflection curve of a Ø3 mm and 0.25 mm thickness HT-60 material in SP test ((b), with the courtesy of [2]), example of all measured data of temperature dependence of SP fracture energy estimate based on the data partitioning method for small specimens of HT-9 steel tempered for 2 h at 973 K: the lower-bound curve in the figure is defined as a 5% failure probability and the upper-bound curve corresponds to 95% failure probability, respectively ((c),. with the courtesy of [3]). 4th May 2016

Small punch test: open questions II 15 In parallel to 4P-bend testing, small-punch or shear- punch testing on order to crosscheck obtained properties and have additional information (change of DBTT, etc.) Experience with these tests? Recommendation? Change of temperature during testing? Range? Ball-punch test vs Shear-punch test? Shear punch test  extract plastic flow properties Ball punch test  fracture properties Dimension of the sample Usually discs of 3 mm (SEM). Investigation of use of square sample (easier to insert in the capsule) 4th May 2016

Status of the production 16 Some of the samples materials already received: Ir ( mm) and TZM ( mm) Ir 0.5 mmTZM 1.0 mm 4th May 2016

Conclusions 17 Two capsules configurations are proposed, Ir+TZM and Si+Graph-SiC coated. Estimated temperatures at capsules surfaces are 115°C and 53 °C. Boiling of cooling water is not expected. Stresses at the external capsule checked. Residual dose after two weeks of irradiation allows the safe extraction of the samples. 4th May 2016

Open Points and next steps 18 Detailed geometry and configuration of the specimens inside the capsule still to be decided depending on mechanical testing requirements. Small gaps between the specimens would be desirable to allow thermal expansion. (maximum gap?) Feedback and comments are more than welcome! 4th May 2016

Bibliography 19 [1] D. Finarelli, F. Carsughi and P. Jung, “The small ball punch test at FZJ,” Journal of Nuclear Materials, vol. 377, no. 1, pp , [2] X. Mao and H. Takahashi, “Development of a further-miniaturized specimen of 3 mm diameter for TEM disk (Ø3 mm) small punch tests,” Journal of Nuclear Materials, vol. 150, pp , [3] T. Misawa, T. Adachi, M. Saito and Y. Hamaguchi, “Small punch tests for evaluating ductile-brittle transition behavior of irradiated ferritic steels,” Journal of Nuclear Materials, vol. 150, no. 2, pp , th May 2016