1. n_TOF Target HiRadMat Experiment Proposal (1704)
R. Esposito, M. Butcher, M. Calviani, J. Canhoto, A. Perillo‑Marcone (EN-STI); L. Gentini, E. Urrutia (EN-MME); D. Lee (HSE-RP)
HiRadMat Scientific Board (15/09/2017)

2. Outline Introduction Objectives Experiment design n_TOF facility
Current target (Target #2)
New target (Target #3)
R&D activity carried out until now
Objectives
Experiment design
Samples
Beam parameters
Residual dose
Instrumentation
Tank
Post-Irradiation-Examinations (PIE)
15/09/2017
n_TOF Target HiRadMat Experiment Proposal (1704)
HiRadMat Scientific Board

3. n_TOF facility Applications Neutron spallation source
Pulsed proton beam from PS interacts with lead target to generate neutrons
Neutron spectra measured by time of flight
Neutrons detected in two experimental areas: EAR1 and EAR2
Applications
Basic nuclear physics
Nuclear astrophysics
Nuclear technology
Neutron imaging
Medical research
15/09/2017
n_TOF Target HiRadMat Experiment Proposal (1704)
HiRadMat Scientific Board

4. Current target (Target #2)
Water cooled pure Pb cylinder
Contact water-Pb
Pb corrosion-erosion
Water contaminated with spallation products
Beam intensity limited to 5 kW
400 mm
600 mm
15/09/2017
n_TOF Target HiRadMat Experiment Proposal (1704)
HiRadMat Scientific Board

5. New target (Target #3) Details: EDMS 1822240 TOF-TAR-ES-0002 Vertical
moderator
Stainless steel
tank
Details:
EDMS
TOF-TAR-ES-0002
Water cooling
system
Horizontal
moderator
SS or Al
vessel
Ti-Pb core
Beam
Be stiffeners
External Pb block
Anticreep
structure
Gas cooling
system
15/09/2017
n_TOF Target HiRadMat Experiment Proposal (1704)
HiRadMat Scientific Board

6. New target backup solutions
Water cooling system
Moderators
Water cooling system
Beam
Ta-W core
Beam
Ti-Pb core
Pb external block
Air cooling system
SS vessel
SS vessel
Target cores (Ti-contained Pb and Ta-cladded W) are the most stressed parts and the object of the experiment.
Protective layers (Ti64 and Ta) must be limited in thickness due to physics requirements
15/09/2017
n_TOF Target HiRadMat Experiment Proposal (1704)
HiRadMat Scientific Board

7. Target behaviour studies
n_TOF new target design beam parameters:
Beam size (1 along x and y): 15 mm
Pulse intensity: 1013 p+
Pulse length (4): 25 ns
Pulse period: 1.2 s
Supercycle period: 36 s
Pulses per supercycle to n_TOF: 14 out of 30
Physics optimization studies
Thermo-mechanical studies
Material
Ti-6Al-4V Pb Ta W
Tmax 44
217 54 94
max
260
16.3 32 81
Fluid dynamic studies
15/09/2017
n_TOF Target HiRadMat Experiment Proposal (1704)
HiRadMat Scientific Board

8. R&D activities
This HiRadMat experiment will be an important checkpoint of a wide R&D activity performed for the new target in collaboration with EN-MME
Electrochemical studies (Cetim-Cermat)
6 materials (Al, Al 5083, SS316L, Ti64, Inconel, Ta)
Demineralised water
With and without oxygen
2 temperatures
EDMS : Electrochemical study by CETIM-CERMAT on corrosion behaviour of different materials in demineralized water
Ta-cladded W studies to find best process and supplier
3 processes: coating, sleeving, hot isostatic pressing
Different suppliers tested
EDMS : Microscope observation of tantalum coating on tungsten rod
EDMS : Scanning electron microscope (SEM) observation of tantalum (Ta) sleeved tungsten (W) rod
EDMS : Quality study of tungsten (W) rods and tantalum (Ta)-cladded W material
EDMS : Inspection procedure on potential material target for n_TOF
EDMS : Quality inspection of potential material target for n_TOF
15/09/2017
n_TOF Target HiRadMat Experiment Proposal (1704)
HiRadMat Scientific Board

9. R&D activities Details: EDMS 1822240 TOF-TAR-ES-0002 90% 91%
EDMS : Microstructural characterization of a pure lead (Pb) specimen
Pb high temperature and strain-rate tensile tests
90%
91%
EDMS : Ultrasonic testing of a titanium (Ti) - lead (Pb) prototype
Ti-Pb prototypes: 2 processes tested (cryogenic fitting and casting)
Details:
EDMS
TOF-TAR-ES-0002
X-ray radiographies (ESRF)
Ti-Pb prototype 3 with Be inserts
15/09/2017
n_TOF Target HiRadMat Experiment Proposal (1704)
HiRadMat Scientific Board

10. (review panel report: EDMS 1837722)
Objectives
Ti-contained Pb core
Ability of Ti-6Al-4V container to keep its structural function during the entire target lifetime
Effects on thermal contact between Ti and Pb
Effects on the beryllium plates
Numerical-experimental correlation
Beam-induced effects on lead core
Entity of stress waves damping through Pb and Ti-Pb interface
Ta-cladded W core
Ability of tantalum cladding to keep its structural function during the entire target lifetime
Effects on diffusion bonding between Ta and W
Beam-induced effects of tungsten core
Review panel of the n_TOF Target #3 Preliminary Design review held in June 2017 encouraged the beam irradiation experiment to validate the proposed solutions
(review panel report: EDMS )
15/09/2017
n_TOF Target HiRadMat Experiment Proposal (1704)
HiRadMat Scientific Board

11. 1) Ti-contained Pb sample
Samples
1) Ti-contained Pb sample
with Be inserts
2) Ta-cladded W sample
by HIP process Pb Be
Ti64 (2mm)
330mm
150mm
Ta (2mm) W
254mm
100mm
Ti64 (0.5mm)
Ta (2mm)
Ti64 (0.5mm)
Ta (2mm) Be
15/09/2017
n_TOF Target HiRadMat Experiment Proposal (1704)
HiRadMat Scientific Board

12. Diluter needed to obtain similar temperature distribution!
Experiment design
n_TOF: 15 mm
HRMT: 2 mm
Diluter needed to obtain similar temperature distribution!
Sample
BTV
to be
removed
Diluter
Possible configuration: sample on Table C, diluter on Table A
If diluter not feasible or convenient, pulse intensity must be lower to avoid excessive peak temperature in Pb
Same stress level in Ti possible, but different stress and temperature cycles in Pb
15/09/2017
n_TOF Target HiRadMat Experiment Proposal (1704)
HiRadMat Scientific Board

13. Experiment design Ti-Pb sample Ti-6Al-4V Fatigue Strength vs.
Number of Cycles
Value for HiRadMat experiment
360 MPa
340 MPa
Value for n_TOF operation
280 MPa
2000 cycles
107 cycles
260 MPa
15/09/2017
n_TOF Target HiRadMat Experiment Proposal (1704)
HiRadMat Scientific Board

14. Experiment design Ta-W sample Tantalum Fatigue Strength vs.
Number of Cycles
Value for HiRadMat experiment
71 MPa
57 MPa
Value for n_TOF operation
40 MPa
500 cycles
107 cycles
32 MPa
15/09/2017
n_TOF Target HiRadMat Experiment Proposal (1704)
HiRadMat Scientific Board

15. Beam parameters Ti64-contained Pb Ta-cladded W No diluter No diluter
Ti64 (2mm)
330mm
150mm
Ta (2mm) W
254mm
100mm
Ti64 (0.5mm)
Ta (2mm)
Ti64 (0.5mm)
Ta (2mm) Be
Ti64-contained Pb
No diluter
< 21011 p+  2000 pulses = 41014 p+
Diluter
< 51012 p+  2000 pulses = 1016 p+
Ta-cladded W
No diluter
< 21011 p+  500 pulses = 11014 p+
Diluter
< 51012 p+  500 pulses = 2.51015 p+
1 pulse every 24.6 s (possible as discussed with HiRadMat team)
No diluter total protons: 51014 p+
With diluter total protons: 1.251016 p+
15/09/2017
n_TOF Target HiRadMat Experiment Proposal (1704)
HiRadMat Scientific Board

16. Residual dose Values in mSv/h Ti-Pb Ta-W 41014 p+ 1016 p+ 1014 p+
Contact
1 week
9.920
248.0
27.40
685.0
1 month
1.164
29.10
6.600
165.0
6 months
0.097
2.420
2.260
56.50
1 year
0.030
0.761
0.809
20.23
10 cm
1.260
31.50
1.150
28.75
0.147
3.680
0.329
8.225
0.012
0.305
0.117
2.925
0.004
0.093
0.042
1.040
40 cm
0.138
3.450
2.433
0.016
0.397
0.027
0.678
0.001
0.035
0.010
0.242
0.011
0.086
Ti-Pb 40 cm
1 month
6 months
1 year
Ta-W 40 cm
1 month
6 months
1 year
15/09/2017
n_TOF Target HiRadMat Experiment Proposal (1704)
HiRadMat Scientific Board

17. Instrumentation BTV (beam profile, size and position)
PT100 (temperature)
Strain gauges, rosette layout (strain)
Laser Doppler Vibrometer (radial surface velocity)
Interferometer (radial surface displacement)
Rad-hard camera
max: < 4000 m/m
Tmax: < 250 C
Max. displacement: < 1.5 mm
Max. velocity: < 1m/s
15/09/2017
n_TOF Target HiRadMat Experiment Proposal (1704)
HiRadMat Scientific Board

18. Tank Same tank as in PROTAD experiment (proposal by C. Torregrosa)
Multi-purpose tank designed to be re-used for future experiments (shorter setup between experiments, more time, cost and waste effective)
If solution with diluter adopted,
water cooling vessel needed (already designed)
15/09/2017
n_TOF Target HiRadMat Experiment Proposal (1704)
HiRadMat Scientific Board

19. Post-Irradiation-Examinations (PIE)
Inspections to be performed to evaluate status of samples
Non-destructive
Visual inspection
High energy X-ray radiography at ESRF
Neutron diffraction for strain measurement (ISIS/RAL)
Neutron tomography (PSI/NEUTRA)
Neutron radiography (n_TOF)
Destructive
Ultrasonic inspection
Dye penetrant
Optical microscopy
Scanning electron microscopy
Experiment to be performed ideally in May 2018
Neutron radiography (n_TOF) and neutron tomography (PSI) AD target
15/09/2017
n_TOF Target HiRadMat Experiment Proposal (1704)
HiRadMat Scientific Board

20. Thank you for your attention