J-PARC BL01 チョッパー分光器「四季」
梶本亮一, 中村充孝, 稲村泰弘, 池内和彦a, 飯田一樹a, 石角元志a, 鈴木淳市a, 中島健次, 河村聖子,中谷 健, 神原 理, 田中浩道, 山内康弘, 青山和弘, 細谷倫紀, 桐山幸治a, 相澤一也, 新井正敏
J-PARCセンター 物質・生命科学ディビジョン 中性子利用セクション&共通技術開発セクションa総合科学研究機構東海事業センター (CROSS東海) 利用研究促進部

Specifications of the Instrument

Chopper Spectrometer 4SEASONS
Chopper-type time-of-flight inelastic neutron scattering instrument toinvestigate dynamics of spins and atoms in condensed matters– Middle resolution & High intensity– Wide-angle detector coverage & High measurement effeciency

Moderator: Coupled, liquid H2 (BL01)
Flight paths: L1 = 18 m (moderator-sample), L2 = 2.5 m (sample-detector),
L3 = 1.7 m (Fermi chopper-sample)
Incident energy: 5 < Ei < 300 meV
Vacuum Chamber
Energy resolution: ΔE/Ei > 5% (E = 0)
SampleDetector: 3He PSD
Monochromating Chopper– 16.4 atm, ф3/4”×2.5 m(Fermi Chopper)– −35˚ – +55˚ ; horizontal(– +130˚ ; final state)– −25˚ – +27˚ ; vertical
Band Choppers
Sample environment: 4K CCR(Disk Choppers)

Research target– Novel spin and lattice dynamics in superconductors, quantum magnets,
frustrated magnets, dielectric materials, etc. in the range of 100-102 meV.
Public beamline since fiscal 2011
Chopper Sample

Source(Moderator)

Measurement principle

White Beam→

Energy and momentum that arereceived by sample:

Detectors

Distance=LTime of flight=t

Neutrons changing
their energies

Monochromate

Neutron Pulse

T0 Chopper
Elastic Scattering

E(t)=Ei−Ef(t), Q(t)=ki−kf(t)(functions of time)

Detectors(inside the vacuum chamber)

InelasticDistance L
DetectorEf, kf

L2(=2.5m)
SampleL3(=1.7m)

Ei, ki

ChopperSupermirror-CoatedGuide Tube (elliptically converged)

Detectors

Monochromatic Beam

L1(=18m)
Polychromatic Beam
40msec0Recent Scientific Outputs

Time-of-Flight t

Magnetic excitations in the cupurate oxide
superconductor La1.90Sr0.10CuO4

Energy and Momentum Resolutions:
Measurements and Calcurations

Magnetic excitations in electron-doped ironpnictide superconductors LaFeAsO1-xDx
S. Iimura et al., Phys. Rev. B 88, 060501(R) (2013)

K. Sato et al., J. Korean Phys. Soc. 62, 1836 (2013)
K. Sato et al., JPS Conf. Proc., to be published

K. Iida et al., Suppl. of J. Phys. Soc. Jpn., to be publishedSC1

SC2valley(Left) Inelastic scattering profiles ofC4H2I2S at T = 50 K measured
with several Eis.
(Right) Measured and calcurated
energy resolutions.
S. Iimura et al., Nat. Commun.

LaFeAsO1-xHx
LaFeAsO1-xFx(Left) Elastic scattering profile ofAl2O3 at room temperature
measured with several Eis.
(Right) Measured and calcurated
momentum resolutions

SC1Tc
SC1

SC2

Recent Updates and Problems

BackgroundDetectors

Still high background exists at high Ei and low angle

Upgrades several shielding parts
Polyethylene blocks around thesample chamber

 T0 chopper

Increase the number ofthe 3He detectors

B4C-resin inside theget-lost tube

Sintered B4C on thebeam catcher

Radial CollimatorChoppers• High-speed (50 Hz) operation is still unavailable, which sacrifices theneutron flux at high energies (Ei > ~100 meV).
• The maximum rotation speed is limited to 350 Hz, which degrades theresolution at high energies.
• It will be replaced by the new chopper rotor. The available flux is
expected to much increase with this rotor.
• In addition, a new supermirror-coated Fermi chopper will be installed,which enhances the flux in the multi-Ei measurements.
• Both the chopper will be installed in the end of fiscal 2013 or until
summer in 2014 at latest.
Intensity at sample (n/s/cm 2)

20mm:200Hz
20mm:300Hz
20mm:600Hz
long:200Hz
long:300Hz
long:600Hz

1x106

5x105

010

So far
Installed in 2013
Will be installed in 2014

Design of the new Fermi rotor
2013

2014

100
Ei (meV)

Publications

ガイド管、検出器等の設置

チョッパー、真空制御系等の設置

真空散乱槽、遮蔽体等の設置

設計・開発・発注≈SNS (850 kW~1.4 MW)

300 kW

ビームパワー

特別推進採択設計開始
実験装置設置申請合格

12月 完成式典

1.

“Inelastic neutron scattering study of the magnetic fluctuationsin Sr2RuO4,”
K. Iida et al., Phys. Rev. B 84, 060402(R) (2011).

2.

“Magnetic excitation spectra of superconducting Ca-Fe-Pt-Assystem,”M. Sato et al., J. Phys. Soc. Jpn. 80, 093709 (2011).

3.

“s±-like spin resonance in the Iron-based nodal supercoductor
BaFe2(As0.65P0.35)2 observed using inelastic neutron scattering”
M. Ishikado et al., Phys. Rev. B 84, 144517 (2011).

4.

“Neutron scattering of iron-based superconductors,”
S. Shamoto et al., Physica C 471, 639 (2011) (proceedings ofISS2010).

5.

“Inelastic neutron scattering on iron-based superconductor
BaFe2(As,P)2,”
M. Ishikado et al., Physica C 471, 643 (2011) (proceedings ofISS2010).

6.

“Dynamical Spin Susceptibility Studied by Inelastic Neutron
Scattering on LaFeAsO1−xFx,”
S. Shamoto et al., J. Phys.:Conf. Series 340, 012075 (2012)(proceedings of ECNS2011).

200 kW
ISIS (160 kW)
100 kW

2007
4月 共用ビームラインへ移管
12月 供用開始

7.

“On the superconducting pairing mechanism of Fe-basedsystems—Is it new or well-known ?”M. Sato and Y. Kobayashi, Solid State Commun. 152, 668 (2012)(Special Issue on Iron-based Superconductors).

8.

“Study of magnetic excitation spectra of several Fe-pnictide
systems,”
M. Sato et al., J. Phys.: Conf. Series 400, 022105 (2012)(proceedings of LT26).

3月 東日本大震災（2012年1月まで供用停止）

Categories ofbeamtime（装置利用+プロジェクト利用）

Monte Carlo simulation of neutron flux available by theFermi chopper with () and without () supermirror.

M. Nakamura and R. Kajimoto, Suppl. of JPSJ, to be published一般課題 申請課題数（緊急課題・トライアルユース含む）
一般課題 採択課題数

6月 初非弾性散乱実験（実質的な供用開始）

1000

Monte Carlo simulation of neutron flux with thenew rotor () compared with the presentrotor ().

History, Proposals, and Publications

9月 初中性子ビームの受け入れ

Continuously Rotating
Crystal Measurement
Makes the 4D Q-ω mapping moreconvenient(Under development)

1.5x106

Sintered-B4C inside
the collimator

2006

Suppress the multiple scatteringby sample environment(Under trial use) Fermi chopper+29 pieces in 2013+30 pieces in 2014

Incident beam

2005

SC29.

“High-energy magnetic excitations in underdoped
La1.90Sr0.10CuO4,”
K. Sato et al., J. Korean Phys. Soc. 62, 1836 (2013) (proceedingsof ICM2012).

10. “On the superconducting symmetry of Fe-based systems —impurity effect studies and neutron scattering measurements—,”
M. Sato et al., J. Korean Phys. Soc. 62, 1726 (2013) (proceedingsof ICM2012).
11. “Temperature dependence of spin excitations in the frustrated
spin chain system CuGeO3,”
M. Fujita et al., J. Phys. Soc. Jpn. 82, 084708 (2013).
12. “Switching of intra-orbital spin excitations in electron-doped
iron pnictide superconductors",
S. Iimura et al., Phys. Rev. B 88, 060501(R) (2013).
13. “Anisotropic spin excitations in spin-Peierls CuGeO3,”
K. Ikeuchi et al., J. Korean Phys. Soc. 63, 333 (2013)(proceedings of ICM2012).
14. “Inelastic neutron scattering study of phonon anomalies in
La1.5Sr0.5NiO4",
R. Kajimoto et al., J. Phys.: Conf. Series, to be published(Proceedings of LPBMS2013).
15. “On the superconducting symmetry of Fe-based systems—
impurity effects and microscopic magnetic behavior—,”M. Sato et al., Suppl. of J. Phys. Soc. Jpn., to be published(Proceedings of APPC12).
16. “Temperature dependence of spin fluctuations in underdoped
La1.90Sr0.10CuO4”,
K. Sato et al., JPS Conf. Proc., to be published (Proceedings ofSCES2013).

M. Nakamura et al., Nucl. Instr. Meth. A (2013), to be published
K. Ikeuchi et al., J. Phys. Soc. Jpn. 82, SA038 (2013)

Instrument Group JAEA
R. Kajimoto, M. Nakamura, Y. Inamura
 CROSSK. Kamazawa, K. Ikeuchi, K. Iida,
M. Ishikado (Technical support group)