Presentation on theme: "XAFS beam lines in Japan KEK ・ PF NOMURA Masaharu 1. Overview of XAFS activity 2. Progress of XAFS beam line technology at PF 3. Progress of XAFS beam."— Presentation transcript:
XAFS beam lines in Japan KEK ・ PF NOMURA Masaharu 1. Overview of XAFS activity 2. Progress of XAFS beam line technology at PF 3. Progress of XAFS beam line technology at SPring-8 4. Key points for designing XAFS beam lines
Proposalspublications XAFS activities at Photon Factory
XAFS activities at SPring-8 Valid for a half year
XAFS activities XAFS as a daily tool - transmission, fluorescence, CEY surface XAFS, total reflection XAFS fluorescent XAFS with MSSD towards ultra dilute systems utilization of soft X-ray micro XAFS With polarization control - MCD, NCD… time-resolved XAFS - quick, dispersive… site-resolved XAFS, state resolved XAFS
Photon Factory BL-10B The first XAFS beam line in Japan Since ： 1982 Age ： 22 bending source Still producing many papers. More than 950 publications BL-10B made XAFS as a daily tool.
Photon Factory BL-12C Double crystal mono. + bent cylindrical mirror (Rh coat) Fluorescent XAFS with MSSD since ： 1994 age ： 10 bending source publications ： more than 160 publications Fixed focus position and shape
Photon Factory BL-9A New optics using bent conical mirrors. high flux with high energy resolution Control higher orders by using parallely aligned mirrors 4keV) extension to SX 弯曲円錐台鏡 二結晶分光器 bending source
SPring-8 BL01B1 Since 1997 col. mirrorDXM foc. mirror wide energy range: 4 ～ 117keV high energy resolution 10 9 ～ 10 11 ph/s easy to change lattice plane fully automatic beam line alignment wide experimental hutch various sample environment - furnace, cryostat various detection modes - Lytle detector, MSSD, CEY
Wide energy range of BL01B1 Ca K-edge (4.0 keV) ～ Pb K-edge (82 keV) S/N ratio of measurement system ～ 3*10 4 La K-edge (38.9 keV) XAFS at 10 K Sample: LaAlO 3 pellet By Uruga et al.
SR light Measurement system Precise adjustment Bent radius of mirrors ⇒ Table Diffraction condition ⇒ Rocking scan Fixed-exit beam condition ⇒ Slit scan Height ⇒ Table, Scan Elevation stages, 2nd Mirror, Slits, Experimental base Switch of diffraction plane Change of glancing angle of mirrors Fully automatic beam line alignment system
A branch with standard optics B branch for high-energy X-rays Downstream shutter (B branch) Downstream shutter (A branch) Horizontal-deflected mirrors (A branch)Standard double crystal monochromator (A branch) Single-bounce high- energy monochromator (B branch) SPring-8 BL37XU Undulator source Microbeam experiments ～ 10 10 ph/s in 1 m 2 with KB mirrors
Beam line with focusing system ↓ Fluorescent XAFS with Lytle detector 10mmol dm 3 Cu aq. trans.fluo.
Multi-element SSD S/N = S/(S+B) 1/2, S/B ～ 1/200 Separation of fluorescent signal and scattering is the key. Thus require high energy resolution and high throughput 4×10 -4 Au in AgX Lytle detector Not easy to optimize the condition Not low maintenance load Very expensive Dead time correction is required MSSD 19 素子 SSD
Key points to design XAFS beam lines wide energy range (4(2.2) -- 23 keV or wider) Fairly high energy resolution ( ～ 10 4 ) simple beam line optics fixed, fairly small focused beam negligible higher order content (<10 4 ) mirror (lower E), detune (higher E) various detection modes transmission, fluorescent detection, CEY wide space for sample attachments cryocooler, furnace etc. Nearby chemistry lab., exhaust handling
軟 X 線領域での実験 最近では He 雰囲気中で 転換電子収量法 蛍光法 も可能に ガソリンエンジン油中の添加剤 粘着テープ中のイオウ、塩素 石炭中のイオウ Li 電池電極中のイオウ 空気中のアルゴン 従来は UHV 中で電子収量法
MoS 2 の XAFS Total electron yieldFluorescence & CEY S K Mo L Ⅲ Mo L Ⅱ at BL-11B at BL-9A