Activity of Fusion Neutronics Sub-task from October 2000 to September 2001

Presented by Takeo NishitaniLeader of the Fusion Neutronics Sub-task

ExCo of IEA Fusion Reactor Nucl. Technology

Baden-Baden, Germany, 19th October, 2001

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.

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

A schematic view of FNS blanket experiments

FNS 80deg. D-T target

A blanket assembly

Detectors (NE213)

Shielding (Li2CO3)

Breeding Blanket ExperimentsTo verify the nuclear performances of resent designed thermal blankets.

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

Shutdown dose measurements

Cross sectional view of the assembly Comparison of shutdown dose rates

Shutdown dose rates can be evaluated by the new one step method within experimental error (~10%)

D-T source Test region

Shield(SS316/H20)

Source Reflector(SS316)

120

0φ

300

20080

0φ

356#A#B #C

#a #b #c

Reflector(SS316)

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

1.0E+05 3.0E+05 5.0E+05 7.0E+05 9.0E+05 1.1E+06 1.3E+06 1.5E+060.5

1.0

1.5

2.0

2.5

3.0

3.5

1.0

Cooling time (x 105sec)

Shut

dow

n do

se ra

te（

Sv

/hr）

9.0

8.0

7.0

6.0

5.0

4.0

3.0

2.0

1.0

0.0

3.5

3.0

2.5

2.0

1.5

1.0

0.53.0 7.0 9.0 11.0 13.0 15.05.0

FENDL/2AFENDL/2

#A

#a

Double bent duct streaming experiment

Typical streaming effects can be reproduced by MCNP & FENDL/2 (~30%)

Cross sectional view of the assembly Comparison of neutron spectrum

Iron Rack

Auxiliary Shield

Streaming Assembly

Auxiliary Shield

1800200

800

1000 900 Duct Opening

(300 x 300)

DT Source

1700

1200

550750

765

335

565

150

#1 #2 #3

#4 #5

#6

1.0E-12

1.0E-11

1.0E-10

1.0E-09

1.0E-08

1.0E-07

1.0E-06

1.0E-05

1.0E-04

1.0E+00 1.0E+01 1.0E+02

Energy (MeV)

Ne

utr

on

flu

x (n

/cm

2 /so

urc

e/le

tha

rgy)

Calculation

Experiment #3

#4

#5

#6

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 5.486 MeV particles, which gives us a good prospect to the 14 MeV neutron spectrometer using a single crystalline CVD diamond.

1.0 mm(a) 1.0 mm(b)

0

100

200

300

400

500

750 775 800 825 850Channel number

5.486 MeV particles

0.4 %

CVD diamond

Single crystallinePolycrystalline

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

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

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 The DDX and EDX data for 1919F(n,xp) reactionF(n,xp) reaction

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 ext

racted 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.

(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.

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 JENDLs16O: 6 MeV peak is not reproduced by JENDLs.

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 co

ndition (the plug is just above the source and on the ceiling) at 140 m from the facility.