1. Accelerator-driven p+Be Fast Neutron Source at NPI Rez
Workshop LEA NuAG – SPIRAL2-CZ – CANAM , Prague
Accelerator-driven p+Be Fast Neutron Source at NPI Rez
Milan Stefanik*,¶)
Pavel Bem, Mitja Majerle, Jaromir Mrazek, Jan Novak, Eva Simeckova, Jan Stursa, and Vaclav Zach
*) Department of Nuclear Reactions
Nuclear Physics Institute in Rez near Prague
The Academy of Sciences of the Czech Republic

2. Accelerator-driven p+Be Fast Neutron Source at NPI Rez
Content
The experimental study of the p(35) + Be reaction by using upgraded neutron source at NPI Řež
Isochronous cyclotron U-120M at the NPI
Accelerator driven fast neutron generator – Be-target station
Activation technique
Neutron field investigation by the multi-foil activation technique
New TR-24 cyclotron and development of high-power p(24)+Be fast neutron generator
The research programs realized at the neutron generators of the NPI Rez
4 May 2017
Accelerator-driven p+Be Fast Neutron Source at NPI Rez

3. Accelerator-driven p+Be Fast Neutron Source at NPI Rez
NPI Cyclotron U-120M
Cyclotron U-120M (1975)
Isochronous regime – 1990s
Alternative operation in +/- mode
NG-1 target station
Positive ion mode (H, D, He)
Protons: MeV (3 μA)
Deuterons: MeV (3 μA)
3He-ions: MeV (1 μA)
Small dimensions of hall
NG-2 target station
Negative ion mode (H, D)
Good beam-current stability
Protons: MeV (15 μA)
Deuterons: MeV (10 μA)
Fig. 2: Isochronous cyclotron U-120M
Fig. 1: Schematic of cyclotron halls
4 May 2017
Accelerator-driven p+Be Fast Neutron Source at NPI Rez

4. Neutron generator at NPI
Accelerator driven fast neutron source
Neutron source reactions: p(37)+D2O, p(35)+Be, p+Li(C)
Quasi-monoenergetic and broad (white) neutron spectra up to 34 MeV
Nuclear data measurements, fusion related research program (IFMIF)
CANAM Infrastructure (Open-access mode)
Fig. 3: High-power p+D2O neutron white-spectrum Source
Fig. 4: Variable energy p+7Li(C) quasimonoenergetic neutron source
Fig. 5: Variable energy p+9Be neutron white-spectrum source
4 May 2017
Accelerator-driven p+Be Fast Neutron Source at NPI Rez

5. Beryllium target station
Standardly used source reaction
p + 9Be, Ep = 18–35 MeV
Target station set-up
9Be target (thickness of 8 mm)
Alcohol coolant (5 °C)
Beam-power of 500 W
Pressure and temperature of alcohol
White neutron spectrum
Broad neutron spectrum up to 34 MeV from p(35)+Be source reaction
Spectral flux up to 1011 cm–2s–1 at the irradiation position of 15 mm
Multi-foil activation method + MCNPX calc. + SAND-II unfolding
Fig. 6: Variable energy p+9Be white-spectrum neutron source
Target station upgrade
Reduction of construction materials
Smaller source-to-sample distance
4 May 2017
Accelerator-driven p+Be Fast Neutron Source at NPI Rez

6. Neutron field spectrometry
Multi-foil activation technique and gamma-ray spectrometry were used for neutron spectrum determination
Set of activation materials was irradiated in activation experiments – Al, Au, In, Ti, Fe, Y, Lu, Co, Ni, Nb, and Bi
Induced radioactivity of foils repeatedly measured by two semiconductor HPGe detectors
Modified version of SAND-II used for neutron spectrum unfolding
Set of reactions with thresholds up to 23 MeV
Cross-section data from the EAF-2010 library
Initial guess spectrum calculated in the MCNPX code
Neutron spectrum at several positions
Fig. 7: MCNPX model of Be target, aluminum holder, and samples
4 May 2017
Accelerator-driven p+Be Fast Neutron Source at NPI Rez

7. The p(35)-Be neutron field
Fig. 8 Neutron field of NG-2 generator with source reaction of p(35)+Be at 0° – in lin-log scale and log-log scale
Fast neutron flux: 1.2 x 1011 cm-2s-1 at position P0
2.8 x 1010 cm-2s-1 at position P2
1.9 x 109 cm-2s at position P14
Positions: P0=14 mm, P2=34 mm, and P14=154 mm
4 May 2017
Accelerator-driven p+Be Fast Neutron Source at NPI Rez

8. Accelerator-driven p+Be Fast Neutron Source at NPI Rez
Reaction
Position 0
Position 2
Position 14
27Al(n,α)24Na
0.99
1.06
natTi(n,x)46Sc
0.90
0.86
0.82
natTi(n,x)47Sc
1.20
1.16
1.14
natTi(n,x)48Sc
1.00
1.05
1.09
natTi(n,x)47Ca
0.85
0.83
natFe(n,x)51Cr
0.92
0.94
natFe(n,x)54Mn
1.04
0.98
natFe(n,x)56Mn
1.08
1.12
1.11
59Co(n,γ)60Co
1.02
59Co(n,2n)58Co
0.96
59Co(n,3n)57Co
0.95
59Co(n,p)59Fe
59Co(n,α)56Mn
0.91
1.01
natNi(n,x)60Co
0.75 –
natNi(n,x)58Co
natNi(n,x)57Co
0.97
natNi(n,x)57Ni
89Y(n,γ)90mY
89Y(n,2n)88Y
93Nb(n,x)90mY
0.84
93Nb(n,2n)92mNb
1.17
115In(n,n')115mIn
1.03
natLu(n,x)176mLu
0.87
natLu(n,x)173Lu
0.93
197Au(n,γ)198Au
197Au(n,2n)196Au
197Au(n,3n)195Au
197Au(n,4n)194Au
209Bi(n,3n)207Bi
0.88
Fig. 9: Calculated over experimental reaction rates ratio
Fig. 10: Reaction rate and spectral flux ratios for P0 and P14
4 May 2017
Accelerator-driven p+Be Fast Neutron Source at NPI Rez

9. Accelerator-driven p+Be Fast Neutron Source at NPI Rez
Cyclotron TR-24
Cyclotron TR-24 – Advanced Cyclotron System Inc. (Canada)
High-power neutron generator at TR-24 Cyclotron
Parameters
Proton energy range
18-24 MeV
Proton beam current
300 µA
Beam spot on target
  30 mm
Acceleration mode H-
Simultaneous beams 2
Weight
25 t
Dimensions
1.8 x 1.8 x 2.5 m
Fig. 11: Cyclotron TR-24 in accelerator hall
4 May 2017
Accelerator-driven p+Be Fast Neutron Source at NPI Rez

10. High-power p+Be neutron generator at TR-24 Cyclotron
High-power neutron facility
p+Be source reaction
Proton beam 24 MeV/0.3 mA
White neutron spectrum up to 22 MeV
Neutron fluency up to 3 x 1012 cm-2s-1
MCNPX calculations, later multi-foil activation technique
Target station
Static Be-target (thickness 4 mm, diameter 60 mm) – thick target
Proton beam power 7.2 kW
Water cooling based on submerged jet
Fig. 12: Calculated p+Be neutron field of high-power neutron generator at TR-24 cyclotron
4 May 2017
Accelerator-driven p+Be Fast Neutron Source at NPI Rez

11. Accelerator-driven p+Be Fast Neutron Source at NPI Rez
IFMIF
International Fusion Material Irradiation Facility
Accelerator driven neutron source, d(40) + Li
Spectrum mean energy of 14 MeV
Testing of materials for fusion reactors
Neutron spectrum can be experimentally simulated by neutron source NG-2
Deuteron beam
Neutron
beam
Liquid Li
Fig. 13: Schematic of the IFMIF target
Chamber with samples
4 May 2017
Accelerator-driven p+Be Fast Neutron Source at NPI Rez

12. Accelerator-driven p+Be Fast Neutron Source at NPI Rez
Conclusion
Neutron field of p(35)+Be source reaction at NPI Rez
Fast spectral flux of p(35)-Be generator up to 1.2x1011 neut./cm2s
Useful tool for integral benchmarks, cross-section data validation, tests of radiation hardness, neutron activation analysis experiments, etc.
Fast neutron source NG-2 focused to fusion related research programs (IFMIF)
Mean energy agree with ITER (14 MeV, d-T reaction) Energy range is compatible with the main energy range of the IFMIF facility (reaction of d(40)-Li with mean energy of 14 MeV)
New TR-24 Cyclotron
Development stage of high-power accelerator driven neutron source with Be-target
4 May 2017
Accelerator-driven p+Be Fast Neutron Source at NPI Rez

13. Accelerator-driven p+Be Fast Neutron Source at NPI Rez
Conclusion
Research programs realized in the neutron fields of accelerator- driven fast neutron source at the NPI:
The integral benchmarks
Cross-section data validation
Testing the hardness of micro-electronics against the fast neutron fields
Irradiation of RADMONs and MEDIPIX detectors developed for CERN
Material hardness study
4 May 2017
Accelerator-driven p+Be Fast Neutron Source at NPI Rez

14. Accelerator-driven p+Be Fast Neutron Source at NPI Rez
CANAM
Center for Accelerators and Nuclear Analytical Methods
4 May 2017
Accelerator-driven p+Be Fast Neutron Source at NPI Rez

15. Thank you for your attention.
Workshop LEA NuAG – SPIRAL2-CZ – CANAM , Prague
Thank you for your attention.
Milan Stefanik*) *)