Neutron cross section measurement of MA Hideo Harada Nuclear - - PowerPoint PPT Presentation

▶
neutron cross section measurement of ma
SMART_READER_LITE
LIVE PREVIEW

Neutron cross section measurement of MA Hideo Harada Nuclear - - PowerPoint PPT Presentation

Mar 22, 2024 137 likes •359 views

Neutron cross section measurement of MA Hideo Harada Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency 2007 Symposium on Nuclear Data Nov. 30, 2007, RICOTTI Convention Center 2007 Symposium on Nuclear Data 1 Neutron

slide-1
SLIDE 1

2007 Symposium on Nuclear Data 1

Neutron cross section measurement of MA

Hideo Harada

Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency 2007 Symposium on Nuclear Data

  • Nov. 30, 2007, RICOTTI Convention Center
slide-2
SLIDE 2

2007 Symposium on Nuclear Data 2

① Activities in the World ② Activities in Japan for thermal neutrons ③ Activities in Japan for keV neutrons ④ Possibilities in Japan for MeV neutrons ⑤ Summary: Toward improvement in the MA data

Neutron cross section measurement of MA

slide-3
SLIDE 3

2007 Symposium on Nuclear Data 3

① Activities in the World

LANL (USA)

DANCE

Ref.

研究者数、化学部門との連携、人材育成、大形予算

slide-4
SLIDE 4

2007 Symposium on Nuclear Data 4

① Activities in the World

n-TOF (CERN, EU) ILL (CEA, France) Karlsruhe (Germany) IRMM (EU)

High flux reactor activation @ thermal neutrons keV neutron capture （FP） Activation @ keV neutrons TOF: 4πBaF2 Van de Graff, Electron L. A.: Fission, Capture, Total, (n,2n) TOF: Ge, C6D6 TOF: 4πBaF2, C6D6

TOF method

Pulse height weighting technique: C6D6 , NaI etc low neutron sensitivity Total absorption detector: 4πNaI, BGO, BaF2 etc high efficiency Gamma-spectroscopic method: Ge high energy resolution

slide-5
SLIDE 5

2007 Symposium on Nuclear Data 5

① Activities in the World

IRMM (EU) Gamma-spectroscopic method: Ge

PR C56, 1266 (1996) 1200h beam time 694g U-238 F.P.=12.85 m 70% Ge

slide-6
SLIDE 6

2007 Symposium on Nuclear Data 6

2003 2004 2005 2006 2002

Fundamental R&D on Neutron Cross Sections for Innovative Reactors Using Advanced Radiation Measurement Technology Project Leader: M. Igashira (T.I.T.)

Activities in Japan

500 1000

  • 80
  • 60
  • 40
  • 20

20 40 60 80 100 120

信号波形 ノイズの代表波形 Voltage [ch] Time [ch]

En=1- 100 keV！ 4πGe spectrometer

KURRI lead slowing down spectrometer KUR KUR 5MW 5MW JRR JRR-

  • 3M

3M 20MW 20MW

KURRI electron linac

Tohoku: Fission JAEA: Capture, Decay heat Kyoto: Capture & Fission TIT: Capture , γ-spectra

YAYOI 2kW YAYOI 2kW

slide-7
SLIDE 7

2007 Symposium on Nuclear Data 7

② Activities in Japan for thermal neutrons No.1

Neutron Energy (eV)

0.01 0.1 1 10

Capture cross section (barn)

1 10 100 1000 10000

JENDL-3.3, T = 3000K ENDF/B-VI, T = 3000K 180.97 b 161.73 b 0.0253 eV

237Np

Cd cut-off

When there are resonance peaks below 0.5 eV, can we measure σ０ and resonance integral correctly ?

slide-8
SLIDE 8

2007 Symposium on Nuclear Data 8

σ0 639.4 b σ0g

0g =628±22 b 241Am(n, γ)242gAm

(150 b) σ =174.5±5.3 b

243Am(n, γ)244Am

161.7 b σ0 =169±4 b

237Np(n, γ)238Np

JENDL-3 Present Reaction

References: Harada et al. JNST 43 (2006) 1289. Ohta et al. JNST 43 (2006) 1441. Nakamura et al. JNST 44 (2007) Dec.

σ0g

0g 533±13 b

σ0 587±12 b 620.84 b (150 b) 175.9±2.9 b 162.2 b

Mughabghab Atlas 5th ed.

ENDF/B- VII

② Activities in Japan for thermal neutrons

slide-9
SLIDE 9

2007 Symposium on Nuclear Data 9

Ohta et al. JNST 43 (2006) 1441.

② Activities in Japan for thermal neutrons

slide-10
SLIDE 10

2007 Symposium on Nuclear Data 10

③ Activities in Japan for keV neutrons

T1/2= 2.144×106 yr

+ n

237Np 93

10-9 10-7 10-5 10-3 10-1 10-10 10-8 10-6 10-4 10-2 100 102

Relative neutron flux(/MeV) Neutron Energy (MeV) > 1 eV

e--Ta reaction H2O moderator

KURRI Linac Neutron flux ! 22m 10m JAEA, TIT, Kyoto

slide-11
SLIDE 11

2007 Symposium on Nuclear Data 11

Electron beam Neutron producing target Water moderator Lead shadow bar BF3-counter neutron monitor Neutron beam filters Linac shielding wall Evacuated flight tubes Lead Concrete H2BO3

10.0 m MA sample 4 4π πGe Ge spectrometer spectrometer

Np-237 Am-241 Am-243

③Activities in Japan for keV neutrons: Capture JAEA, Tokyo Tech., Kyoto

slide-12
SLIDE 12

2007 Symposium on Nuclear Data 12

Electron beam：Energy 30 MeV, Ave. Current 31μA

  • Rep. Rate

100 Hz, Pulse Width 100 ns 4 4π πGe spectrometer Ge spectrometer

Cluster 2 (14 Ge crystals) Clover 4 (16 Ge crystals) BGO anti-coincidence shields

Experiments for Capture Experiments for Capture

KUR Electron Linear Accelerator Facility

slide-13
SLIDE 13

2007 Symposium on Nuclear Data 13

  • J. Nucl. Sci. Technol. 42, 135 (2005)
  • Nucl. Instru. Meth. A 562, 767 (2006)

水本等、原子力学会2007年秋の大会

The data were successfully obtained, but needs more statistics for high energy region.

③ Activities in Japan for keV neutrons

slide-14
SLIDE 14

2007 Symposium on Nuclear Data 14

Deduced capture cross section of 237Np (5MBq sample)

slide-15
SLIDE 15

2007 Symposium on Nuclear Data 15

Needs more statistics for En>100eV

Comparisons of data for keV neutrons

Energy [eV]

slide-16
SLIDE 16

2007 Symposium on Nuclear Data 16

237Np, 241Am, 242mAm, 243Am En=1- 100 keV Kyoto University Lead Slowing Down Spectrometer (KULS)* driven by a 46 MeV electron linear accelerator *Kobayashi et al; measurements for minor actinide, En< 20 keV

In the present study

  • Back-to-back fission chamber (BTB,

Ratio measurement)

235U 99.9 %, as a standard

  • For extension of energy range to high energy side,
  • Digital signal processing (DSP) technique to eliminate “γ-flash”
  • Heavy electrical shielding of BTB, cable, PA
  • Quantitative assay of samples: low geometry α-counting

Tohoku, Kyoto Fission ③ Activities in Japan for keV neutrons

slide-17
SLIDE 17

2007 Symposium on Nuclear Data 17

  • Wave form analysis for each slowing down time
  • Subtraction of “γ-flash” noise from raw signal (noise + signal)

DSP DSP

500 1000

  • 80
  • 60
  • 40
  • 20

20 40 60 80 100 120

信号波形 ノイズの代表波形 Voltage [ch] Time [ch]

Noise Signal

Fission

Ar + CO2 Ar + CO2 Connector Electrode (anode) Sample deposit (U-235) Sample deposit (MA) Chamber (aluminum) 43 mm 49 mm Ar + CO2 Ar + CO2 Connector Electrode (anode) Sample deposit (U-235) Sample deposit (MA) Chamber (aluminum) Ar + CO2 Ar + CO2 Connector Electrode (anode) Sample deposit (U-235) Sample deposit (MA) Chamber (aluminum) 43 mm 49 mm

slide-18
SLIDE 18

2007 Symposium on Nuclear Data 18

The data is very limited especially for MeV neutrons.

④ Problems in measurement for MeV neutrons

103 104 105 106 107 10-2 10-1 100 101 Neutron Energy (eV) Cross Section (b)

D.C.Stupegia+ ('67) M.Lindner+ ('76) L.W.Weston+ ('81) Ju.N.Trofimov+ ('83) N.N.Buleeva+ ('88) N.N.Buleeva+ ('88) N.N.Buleeva+ ('88) Katsuhei Kobayashi+ ('02) Katsuhei Kobayashi+ ('02) E.I.Esch+ ('05)

237Np capture

present (=CCONE) JENDL-3.3 ENDF/B-VII.0

Nakagawa 2007

slide-19
SLIDE 19

2007 Symposium on Nuclear Data 19

④ Possibilities in Japan for MeV neutrons Activation by fast neutrons at Yayoi

slide-20
SLIDE 20

2007 Symposium on Nuclear Data 20

④ Possibilities in Japan for MeV neutrons TOF by fast neutrons at JAEA Tokai

http://www3.tokai-sc.jaea.go.jp/rphpwww/senryo/index2.htm

放射線標準施設

slide-21
SLIDE 21

2007 Symposium on Nuclear Data 21

⑤ Toward improvement in the MA data

Neutron Energy thermal eV keV MeV JRR3 J-PARC

放射線 標準施設 KUR Yayoi KURRI linac

LANL, IRMM, n-TOF

CEA ILL differential Integral

JAEA Japan Abroad

T.I.T.

Several facilities covering a wide energy range are or will be soon available for the measurements of MA cross section in Japan. High flux field will contribute to deduce statistical uncertainties. Efforts to deduce the experimental uncertainties including systematic uncertainties are

  • important. The comparisons of independent measurements will help to

notice the unexpected systematic uncertainties.