1. Activity of Fusion Neutronics Sub-task from October 2000 to September 2001
Presented by Takeo Nishitani
Leader of the Fusion Neutronics Sub-task
ExCo of IEA Fusion Reactor Nucl. Technology
Baden-Baden, Germany, 19th October, 2001

2. Major contribute in this sub-task
European Community
FZK, TU Dresden, UP Madrid, ENEA frascati
Japan
JAERI and Osaka University
USA
UCLA, et al.
Russia
Kurchatov, et al.

3. Fusion Neutronics Activity at JAERI from October 2000 to September 2001
Breeding Blanket Experiments
Shielding benchmark experiments
Shutdown dose measurements
Double bent duct streaming experiment
Decay heat measurements
Activation Experiments for Sequential Charged Particle Reactions
Development of Neutron Measurement Technique
Development of Artificial Diamond Detector
Development of Micro Fission Chamber for ITER

4. A schematic view of FNS blanket experiments
Breeding Blanket Experiments To verify the nuclear performances of resent designed thermal blankets.
Detectors (NE213)
FNS 80deg. D-T target
A blanket assembly
Shielding (Li2CO3)
A schematic view of FNS blanket experiments

5. The profiles of reaction rates
Preliminary Result
We have obtained the profile of reaction rates of the iron, chromium and tungsten in F82H and tritium production in 95-% Li2TiO3.
C/E of the 95-% Li2TiO3 tritium production is closed to 1 with the error of plus and minas 10%.
However, since experimental result of activities of Au foil in Be is significantly underestimated, The investigation of the cause is in progress.
The profiles of reaction rates
at the assembly

6. Shutdown dose measurements
Shutdown dose rates can be evaluated by the new one step method within experimental error (~10%)
1.0
Cooling time (x 105sec)
Shutdown dose rate（mSv/hr）
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
0.0
3.5
2.5
1.5
0.5
11.0
13.0
15.0
D-T source
Test region
Shield
(SS316/H20)
Source Reflector
(SS316)
1200φ
300
200
800φ
356 #A #B #C #a #b #c
Reflector
FENDL/2A
FENDL/2 #A #a
Cross sectional view of the assembly
Comparison of shutdown dose rates

7. Double bent duct streaming experiment
Typical streaming effects can be reproduced by MCNP & FENDL/2 (~30%)
Iron Rack
Auxiliary Shield
Streaming Assembly
1800
200
800
1000
900
Duct Opening
(300 x 300)
DT Source
1700
1200
550
750
765
335
565
150 #1 #2 #3 #4 #5 #6
Calculation
Experiment #3 #4
Neutron flux (n/cm2/source/lethargy) #6 #5
Energy (MeV)
Cross sectional view of the assembly
Comparison of neutron spectrum

8. Development of Artificial Diamond Detector
Recently, we tried to use a chemical vapor deposition (CVD) diamond with single crystal.
The detector has an energy resolution of 0.4 % for MeV  particles, which gives us a good prospect to the 14 MeV neutron spectrometer using a single crystalline CVD diamond.
CVD diamond
5.486 MeV  particles
0.4 %
Polycrystalline
Single crystalline

9. Future Plan in Fusion Neutronic at FNS/JAERI
Extend of Breeding Blanket Experiments
Breeder and Beryllium pebbles
Activation Experiments for Sequential Charged Particle Reactions
Development of Neutron Measurement Technique
Development of Neutron Detector using Optical Fiber
Development of Artificial Diamond Detector

10. Fusion Neutronics Activity at Osaka Universityin 1999-2000
Differential experiments:
Charged particle emission DDX
Gamma-ray production cross section
(n,2n) reaction cross section with a beam source
Integral experiments:
Leakage gamma-ray spectra from slabs
Secondary gamma-ray skyshine

11. Measurements of double differential cross sections for charged particle emission reactions by 14 MeV neutrons.
Samples:natSi and 19F
Facility:OKTAVIAN, pulsed neutrons
Method:2-dimensional analysis of energy
and time-of-flight (E-TOF)
Compound samples were successfully
employed for light element measurements
Agreement is not good with the
evaluated nuclear data for both elements.
The DDX and EDX data for 19F(n,xp) reaction

12. Measurements of secondary gamma-ray production cross sections with Hp-Ge detector induced by 14 MeV Neutrons.
Samples:natSn
Facility: OKTAVIAN, pulsed neutrons
Method: TOF-gated PHS analysis
Discrete and continuum components were successfully extracted from the measured pulse height spectrum (PHS) with Hp-Ge (the results were still preliminary).
The present data are the first measured discrete gamma-ray production cross sections for natSn.

13. (n,2n) reaction cross section measurement with a beam DT neutron source
For 55Mn, the measured (n,2n) cross section was in good agreement with the experimental value obtained by the activation method.
Samples:55Mn (to check the system)
Facility:FNS, pencil beam neutrons
The method to directly measure
the spectra of two neutrons emitted
from (n,2n) reaction has been
established.

14. Fusion neutronics benchmark experiment - leakage gamma-ray spectrum measurement -
Samples:LiAlO2, Li2TiO3, Li2ZrO3 12C, 51V, natFe, natCu, natPb, natW,
Facility:FNS, pulsed neutrons
Result:
natV: Underestimation of all the
nuclear data files.
natFe: Overestimation of JENDL
-3.2.
natPb: Reproduction is not good
for JENDLs
16O: 6 MeV peak is not
reproduced by JENDLs.

15. Secondary gamma-ray skyshine from 14 MeV neutron source facility
Facility: FNS, DC neutrons (～1x1011)
Detector: NaI(5”x5”,8”x8”), Hp-Ge(40%)
Clean skyshine benchmark data can be obtained up to 1000 m from the neutron source.
Preliminary experiment has been done under the plug-in condition (the plug is just above the source and on the ceiling) at 140 m from the facility.