レーザーコンプトン散乱ガンマ線源の中性子応用
Application of Neutron by Laser Compton
Scattering Gamma-ray Source
NewSUBARU Synchrotron Light Facility
in Harima Science Garden City

SPring-8
SACLA

NewSUBARU
S. MIYAMOTO, K. SUGITA, Y. Morimoto, S. HASHIMOTO, S. AMANO(LASTI, University of Hyogo)
Y.Arikawa (ILE Osaka University), T.Hayakawa (QST)
14th Particle Accelerator Society of Japan, Hokkaido University, Sapporo

OUTLINE
1. レーザー・コンプトン散乱ガンマ線ビームを用いた中性子源(1) ガンマ線ビーム
Eγ= 1 MeV〜76 MeV, 106 γ/s

光核反応中性子(GDR)
En= 2 MeV〜10 MeV, 104 γ/s(2) TOF計測のための蓄積リングの疑似単バンチ運転
2. 中性子計測と画像検出器開発のための試験(1) 高速中性子発生分布の偏光依存計測
ターゲット：Au, I, Cu + Ag, Y
GDR
ターゲット：BeCDR(低エネルギー中性子発生の試験)(2) 熱化中性子による放射化計測試験
2

NewSUBARU

circumference
119 melectron energy 0.5-1.5 GeV
Lorentz factor
γ=1000-3000
electron current 300-500 mA

LCS γ-ray beamline
NewSUBARU Synchrotron Light Facility, University of Hyogo
Laboratory of Advanced Science and Technology for Industry

NewSUBARU電子蓄積リングでのガンマ線ビーム源の特徴
γ-beamθelectronbeam

EeEγlaser
EL beam

24 E LγEγ =2 21+ γ θγ-ray intensity

電子ビーム
0.5〜1.5GeV / 300 mA
レーザービーム
0.5µm 〜10µm / 30W1) Eγ = 1MeV - 76 MeV
Flux = 106 photon/s

λ=1064nm
collimated 3mmφ€2) 偏光ガンマ線 ビーム

1GeV- 低発散角

102030γ-ray Energy (MeV)θ〜1/γ3) 中性子発生, 陽電子発生

1.5GeV
0Laser Compton Scattering404相互作用断面積で見たガンマ線の利用(/ 581,

NewSUBARU

BL01
3 5- CC
2 7- CC 2 77275

1(77151 8E7)

11,E7511.

0 45中性子検出器
Plastic scintillator
TOF measurement

Liquid scintillator
pulse shapediscrimination
Li-6 scintillator
nuclear reaction

He-3 detector
Space integration
He-3proportionalcounter x 40

moderator

Bubble detector
Time integration

NewSUBARU 電子蓄積リングのフィリングパターン2.5

2016/6/30 10:00(mA)

2.070+70 oner
FullFill 3:1

1.5
1.0300mA TopUp

0.50.00100200ns(mA)

30

400

I=30mA20

TOF計測(夜間)30mA TopUp

100

300

0100200

ns

300

400

疑似単バンチモデル

10I=2mA(mA)

300mA TopUp
10100

I=20mA
200300ns

400

2016/10/3 12:07

10(mA)

300mA TopUp

I=2.04011mA

0100200

ns300

TOF計測(昼間)
疑似単バンチ

I=19.742mA

1単バンチ運転

400

-ray beams used for the study of the 1/2+ state% - 3.5%.
光核反応スペクトル断面積計測時のB

A 99% 9 Be rod of 20
ガンマ線スペクトル(2mmφコリメーター)was used as a target. A
3000
7000
dimension was also used
Ee=962 MeV
fect of the LCS -ray b
6000
2500
E =562foundMeV compared with be'EJ=31 keV(99.9%)
in an aluminum
5000
1.4%〜2.2%'E=1.4%(FWHM)(1.8% FWHM)(1.8%〜3.5%FWHM)
2000
Jwindows(FWHM) of 25.4µm-thic
4000
target of 14mm diamete
1500
integration of deuterium
3000
Ge detector
3LaBr (Ce) detector
beam energy 1460 MeV
1000
2000absolute cross section mrun confirmed a negligi
500
1000
photoneutron emission.
00500

1000

EJ [keV]

1500

2000

001234567

EJ [MeV]C.
A response function and the energy distribution of an LCS γ-ray beam.
FIG. 4: (Color
A theresponse
H. Utsunomiy et al, “ Photodisintegrationof 9online)
Be through1/2+ statefunction
and clusterof the La(Color online) A response function of the Ge detector
and theenergy
distributionof12”an NaI(Tl)
LCS -radipole resonance”, Phys. detector
Rev. C 92, 064323(2015).
A8”⇥
energy distribution of the LCS -ray beam.

ficiency was used as aOUTLINE
1. レーザー・コンプトン散乱ガンマ線ビームを用いた中性子源(1) ガンマ線ビーム
Eγ= 1 MeV〜76 MeV, 106 γ/s

光核反応中性子(GDR)
En= 2 MeV〜10 MeV, 104 γ/s(2) TOF計測のための蓄積リングの疑似単バンチ運転
2. 中性子計測と画像検出器開発のための試験(1) 高速中性子発生分布の偏光依存計測
ターゲット：Au, I, Cu + Ag, YGDR
ターゲット：BeCDR(低エネルギー中性子発生の試験)(2) 熱化中性子による放射化計測試験
9NewSUBARU単バンチ運転による中性子飛行時間法計測システム
Synthesizer
Klystron

Neutrondetector

Singlebunch
electronSinglebunch

2.5MHzDiscriminatorγStartn(γ,n)

TAC500MHzStopTargetLaser
pulseCounter

25 kHzMCA
Laser: λ=1064 nm
pulse (8 ns, 25 kHz)
Delay中性子信号と散乱ガンマ線信号(TOF信号例)
410310PlasticND
Au Target 10mmøx40mm
17 MeV gamma-beam, 30 min

scattered γ-ray

210neutron
1

100

10560

600

Low energy
Limit 〜２MeV

ns

640
8MeV680

中性子放出分布の偏光依存性計測
neutron detector
꜆ $Photo nuclear reactionἈneutron꜆

neutron꜆8/θ=90°қ Đ б Ж˃
angle
φ″F꜆ ʵқ

sampleᴎ ᷆γ-raypolarized
plane̳⁄ ё ⁄ ю͏ ̏

LCS gamma-rayЌ͏ ₐч ͏̣ч ͏̣γ-rayF꜆ ʵnuclei
қ ʵnucleiτ Ģ

偏光依存発生分布
In= a + b·cos(2φ)
Ref. A. Agodi, Nuovo Cimento 5 (1) (1957) 21.

NeutroNeutron Intensity

16.7 MeV γ-rayGold 197Au-90090180

Iodine 127I
270-90090180

Copper 63,65Cu
270-90090180270Angle [Degrees]

The solid lines show a function in form of In= a + b·cos(2φ)*.

K.Horikawa, et al., Physics Letters B, 737,FIG.
pp.109-113(2014). of neutrons of (∞, n) reactions on (a) Au, (b) NaI,
3: Angular distributions
4tatgets. The solid lines show a function in form of a + b·sin2 ¡ obtained by ¬2 -fit

-6-5

2.0x102.0x104

neutron counts normalized[a.u.]
Neutronintensity

Signal counts normalized[a.u.]
Neutronintensity

Neutron Intensity

中性子放出分布の偏光依存性計測

1.5

31.02

係数値 標準偏差

0.5

189Y

ab=1.3727e-06=4.5371e-07

2.23e-08
2.88e-0800

ab

11=1.1782e-05 1.54e-07=3.607e-06 2.02e-07

21.0
10.5

Angle [Degrees]

107Ag, 109Ag

00.00.0031.5

係数値 標準偏差50
100150 of (∞, n) reactions on 0(a) Au, (b) NaI,
50 and (c) natural
100 CuFIG. 3:50
Angular distributionsof neutrons
050100100150180
polarization axis vs neutron
detector[degree]

150150to thetatgets.Angle
The solidlinespolarization
show a function in form of a + b·sin2 ¡ obtained by ¬2Angle-fitting.to the polarization
polarization axis VS NeutronDetector[degree]11180

MiniPIXによるターゲットアライメント
50100

150200250

NaI detector(12”x8”)00150

10050collimator=6mmφγ-ray beam
17 MeV6mmφ

250

200

30分積算
50100

150200250

100150250

金10mmφMiniPIXUSBAu target
40x10mmφ200nocollimator

5000Acquisition time [s]=1800

MiniPIV(ADVACAM)

55µm pixel
256x256

9Be クラスター共鳴からの中性子発生偏光依存
PHYSICAL REVIEW C 92, 064323 (2015)

TEGRATION OF 9 Be THROUGH THE 1/2 . . .

5GDR

9Be( ,n)Kneissl (1975) et al., Phys.Present
H.Utsunomiya
Rev. C,
Goryachev (1992)
92, pp.
064323-1-8 (2015).

3NEXT

neutrondetectors

Utsunomiya (2001)
Arnold (2012)

2 1/2+

30° 30°5/2+

1γ-ray02-5

3.0x10594Pr

68 1030

γ-ray Energy[MeV]

E [MeV]

No.4̲1st-5

3.0x1058I(θ)=a+b*cos2θ

2.54

No.4̲2ndeliminary

In= a + b·cos(2φ)

No.1
No.2MeV[46–49]. The strength integrated over 4–16

tribution from the2.0
tail of the GDR is3low-energy
V. Thus, the resonancestrength is 11.3–14.2 mb

χ square = 28.8592

degree of freedom : 18V. CONCLUSIONS
下側累積確率0.950
上側累積確率0.050
9neutron signal normalized[a.u.]

Neutron intensity(Color online) The Be(γ ,n) cross section in the energy region from the n + Be threshold to GDR (see text for details).2.5
neutron signal normalized[a.u.]

1m1m

CDR

Neutron intensity

cross section[mb/atom]

[mb]

4

9Be target(7.3mmφ✕104mm）

42.0

Pr

No.4̲1stIn= a + b·cos(2φ)+ c·cos(4φ）
No.4̲2ndI(θ) = a+b*cos2θ+c*cos4θχ square = 20.5447

eliminary

No.1
No.2

degree of freedom : 17
下側累積確率0.753
上側累積確率The photodisintegration of Be through the 1/2 state3
and1.5
cluster dipole resonance was measured. The cross sectionof the 1/2+ state is consistent with the 2001 data and the
1.5
mpare the resonancethe cluster
係数値 標準偏差22 strength withdata of the radioactive isotope measurements. The observed
81.0Be) and threeule [50–52] for the two-body
a=1.5773e-05 1.3e-07
係数値(n-標準偏差resonance strength is consistent with the cluster dipole sumsystems:
b=3.0916e-06 1.95e-07=1.5714e-05 1.29e-07
rule. However, the sum rule degenerates in the two-body
1.01 ab10.5
c=4.61e-07 1.6e-07=2.899e-06 1.83e-07(n- 8 Be) and three-body (n-α-α) systems. Consequently, the"$present result does not distinguish whether a neutron oscillates
N Z # Ni Zi
0.0.
(10)
σE1 (E)dE = 60 0.50A −0
in the two-body or three-body configuration. A new n-α-αAiicoincidence experimentis needed
to investigate
the configura- 0
20406080
20406080
100
020608000
20406080100polarization 40
axis VS NeutronDetector[degree]tion.
Atheoreticalstudy
isencouraged
toinvestigate
thenaturepolarization axis VS NeutronDetector[degree]+of the1/2polarization
state and the nuclear structure of the cluster dipole
theAngle to the polarization
m of Eq. (10) is the Thomas-Reiche-KuhnAngle(TRK) to9
resonanceinBe.
resenting the E1 response of a nucleus in thexchange forces. After subtracting the intrinsic
from the constituent clusters from the entire
ACKNOWLEDGMENTS
sum rule represents the E1 response arising from+0.247

2015年2月27日 卒論発表

カウント数を増やした計測精度向上が必要。

100100放射化法による中性子放出角度分布測定
放射化計測では中性子の偏光依存は弱く見える
崩壊をイメージングプレートに転写
20406080

10012000140mm

1160180200220240

垂直偏光γ1400120040放射化
natDy-1
25x25mm
0.25mm t

164Dy(n) 165Dy(β-) 165Ho

20

モデレーター(ポリエチレン)
10x10cm
5cm t

電子ビーム： 1GeV / 300mA
レーザー：
1.064nm / 17W
γエネルギ： 16.7 MeV (20%)γフラックス： 5x106 γ/s
照射時間：4 時間

21403

600

400

160

natDy-34200
180

金ターゲット200

natDy-2

800

120

100mm

80

natDy-410mmφx40mm

1000

60n0

放射化サンプル内に強度分布が観測された。モデレーターの最適設計が必要。

LastiThank you !

University of HYOGO

謝辞：本研究は、以下の支援のもと行われた。
(1) JST A-STEP 課題番号：AS2721002c「コンパクト中性子源とその産業応用に向けた基盤技術の構築／レーザー駆動
中性子源の開発と高速ラジオグラフィーへの応用」(2) 科学研究費補助金 基盤研究(B)

研究課題番号

15H03665「直線偏光ガンマ線で生成された中性子非対称性測定による新しいプローブ」

17