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 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 20 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 Number of XAFS proposals 申請課題数 採択課題数 proposals 80 60 40 approved proposals 0 Number of publications XAFS activities at Photon Factory Proposals publications 120 90 valid for 2 years 80 100 70 60 10B 7C 6B 12C 9A 50 40 30 20 10 0 FY year XAFS activities at SPring-8 60 120 申請 採択 100 BL01B1 Valid for a half year 50 publications 40 60 30 2004A 2003B 2003A 2002B 2002A 2001B 2001A 0 2000B 0 2000A 10 1999B 20 1998B 20 1998A 40 1997B 課題数 80 1998 1999 2000 2001 year 2002 2003 2004 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 ： bending source 22 BL-10B made XAFS as a daily tool. Still producing many papers. More than 950 publications Photon Factory BL-12C 1011 Fixed focus position and shape • Double crystal mono. + bent cylindrical mirror (Rh coat) • Fluorescent XAFS with MSSD 1010 flux @ 300mA since： 1994 age： 10 bending source publications： more than 160 publications 109 7C Si(111) w. foc. 12C Si(111) 12C Si(311) 108 0 5 10 15 E/keV 20 25 Photon Factory BL-9A 1012 13B 1*1 9A Si(111) 12C Si(111) flux @ 300mA • New optics using bent conical mirrors. high flux with high energy resolution • Control higher orders by using parallely aligned mirrors <10-6 , E>4keV) extension to SX 1011 1010 0 5 10 E/keV 弯曲円錐台鏡 二結晶分光器 bending source 弯曲円錐台鏡 15 20 SPring-8 BL01B1 col. mirror Since 1997 wide energy range: 4～ 117keV high energy resolution 109～1011ph/s DXM foc. mirror 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*104 30 20 10 0 k3(k) -10 -20 -30 -40 0 5 10 15 20 25 30 k (A-1) La K-edge (38.9 keV) XAFS at 10 K Sample: LaAlO3 pellet By Uruga et al. Fully automatic beam line alignment system Switch of diffraction plane Change of glancing angle of mirrors Precise adjustment Bent radius of mirrors Diffraction condition Fixed-exit beam condition Height ⇒ ⇒ ⇒ ⇒ Table Rocking scan Slit scan Table, Scan Elevation stages, 2nd Mirror, Slits, Experimental base Measurement system SR light SPring-8 BL37XU Downstream shutter (A branch) Standard double crystal Horizontal-deflected mirrors (A branch) monochromator (A branch) Downstream shutter (B branch) Single-bounce highenergy monochromator (B branch) B branch for high-energy X-rays A branch with standard optics Undulator source Microbeam experiments ～1010ph/s in 1mm2 with KB mirrors 120 120 As 100 80 80 60 60 40 40 20 20 0 0 0 40 80 0 120 80 80 60 60 40 40 20 20 0 0 40 80 0 120 80 Cu 40 80 120 80 60 micron 60 micron 1.0 120 Ga 100 0 40 20 0 0 20 40 60 micron 80 60 20 40 60 micron 80 80 micron 20 40 20 0 0 0 20 40 60 micron 80 0.4 0.2 11.86 11.87 X-ray energy / keV 11.88 毛髪中のAs K-XANESスペクトル 60 40 0.6 11.85 0 S 80 0.8 As2O3 職業性 急性 40 20 0 micron 80 Normarized intensity / a.u. Zn 100 Zn 40 120 120 As Cu 100 0 20 40 60 micron 80 ヒ素の暴露経路による分布の違い（上段：職業性、下段：急性） (BL39XU, 3mm/pixel) 11.89 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 Not easy to optimize the condition Not low maintenance load Very expensive Dead time correction is required 4×10-4 Au in AgX Lytle detector MSSD Au5908 8 Au5a38 0.7 (b) (a) 0.6 7 0.5 6 mt mt 0.4 5 0.3 4 0.2 3 2 11.5 0.1 12 12.5 E/keV 19素子SSD 13 0 11.5 ut(raw) ut(cor) 12 E/keV 12.5 13 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 従来はUHV中で電子収量法 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 MoS2のXAFS Total electron yield Fluorescence & CEY S1622 fluo CEY 1.6 0.155 SK 1.4 Mo LⅡ Mo LⅢ 1.2 0.15 0.8 0.145 0.6 0.4 at BL-11B 0.14 0.2 at BL-9A 0 0.135 2480 2520 2560 E/eV 2600 2640 CEY fluo 1
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