4P036!"#$%&%'()*+,-.&/.0/12.34567(89:;<=>;? @ABC;DE @FGAHI;JK @FLAMN;OP @FQFRAS;T @FU;VWXYZ[\]^_`a@AbcdW GAecHfg LAecdh QAiZj`klmZjRAecnoX Up;;!"#$!%&$'($)&*+,-&./0(123456789:;2345#!"&<=6>?@ABCD;EF6G?@HIJKLMN@OP(QR(STU6VWOXYZ[\(]U^@W0U*+_U`ab@!"&cdJefa;ghiO jklmn
opq(rsSTUtu vwxyz{k| & }~jv aWhXYZ6M@HIJBi@ 6rI6@IhVWh(r&!"($!&XYZ]U6/@OP&&]6WX  Z]U_U`ab@!"($!&*+,-a@cd6ghW@ kjjmn
X  Z]U`0*+&abgh1@,&¡¢&£¤B^@]U6./@HIabgh¥*+&,-¦§_¨6©ª@«`¬­y{®x¯j°B^@m±²³´µ´²STU6¶aVWOB0¶I/·¸J¹aXYZº»&UB^@OP

¼6½gh!

"¾¿&*+,-&./JÀÁB^@mÂ;JÃ(XYZ]U0ÄÅÆaWh0]UÇÈJÉWOP(ÊË§;/JÌÍ(cd0=Î;ÏÐaIÑÒghW@HIJ9WmÓHBop0(bÔÕÎ;/JÀaFigure 1. X  Z[\I]U&CYEn

Top view

Áa;@bÖa(ÊÇÈ;_U×6ØÙÎa]hiOm­y{®x¯Ú aÛO&0(ÜOa]OX

Side view

YZ]U_U×&ÇÈÝA&OP&ÞUU3ßàUáJâã^@OP äxyå¯zækçèæyéê IëfBW@ì

detector
mirrorsbgrating
O1s emission

B^@míî&_U×&U3ß6ïðOÒÒñò&óôõ6ö÷@HIB(ÇÈ6 økl ù¢§Ýfrom water

Before using
focusing optics

After using
focusing optics
N1s emission

AM@HIJÀÁB^@mnfrom Si3N4 window­y{®x¯ú aÛO&0(H&U3ß6VWh/c7

H 2 O w ater (liquid)O 1s non‑resonant X ES

A rea intensity
200981

MNO(ûüý$!&XYZ]Uþÿ³µ"î=B^@mH&þÿ³µ& è!

6/O#$%õ0(­y{®x¯ø &&]U\Õ`ab@[\þÿ³µa'(BÛO)*+±01234ab@5õ³&#$,& -./-jê%õB^@mH&5õ³0ý&[\&67bÔqÉ#$^@OP(H&5õ³9:&#$%õ8B%õº»B0ý$!%&ûü;<J=>ÎaMN@mXY
Z]U0XYZ[\abgh1O&?@&Intensity [arb. unit]

65BeforeAfter43250359

10450

500550

CCD Pixel(1 pixel = 13.5 ! m)

Figure 2. äxyå¯zækçèæyéêAÇÈÝA&OP&U3ßn
¬B°n U3ß&CDEmFZ0íî&_U×&Uá(GHyxxçxêIIôJ OK_6LhW@MZJÇÈ
ÝA&OP&óôõabghö÷MNOUám¬N°n O
ýÂÃ& -jê ]U6./OP& ..Q RS×A&Z
þÿ³µ mT8JU3ßö÷U(V8JU3ßö÷Wm¬é°n OýÂÃ& -jê ]U6þÿ³µ XÛOq&mFZJU3ßö÷U(MZJU3ßö÷Wmn¡¢&£¤B^@OP(#$%õ6ûü&[\a^O1s XAS

Liquid acetic acidZh(¹[XYZ]U6./@HIBý$!%&ûü_+­y{®x¯ø¬B°0)*+±,& -./-jê01234a#$%õ6]Zh/O¹[XYZ]Uþÿ³µB^@mè! 6

Aqueous Acetic acid

Intensity (arb.unit)&*+,-;<6\ÔSh./@HIJBi@mn

pH 13.05
pH 4.73
pH 0.81Water

ýü2^µ_`aIbü6¤Âghc2M@I(düB^@û
*+±2J./MN@mfgWHIa ­y{®x¯ø¬B°a0(þÿ³µJñh_B^ÃZMN@ÀÁ=6Ûi@(0giÔIOj]UkJ./MN@mla(mü=Imb,=&ñ¤&&no6¤Âgh(%p& è!

&þÿ³µ6qrhs@I(­y{®x¯ø¬N°aÛ

ObÖatuavW£w6Ûmx:a(/MNOWyN& è! &þÿ³µqmü=Imb,

ÃNhW@ûü&e èB ab@/ZIbÍ£w@mH&bÖa(ÊW v B&XYZ]&./6VWN&*+,-a;ghW@_+JÑ&ÍÃW&ÈBî@Â6@HIJÀÁB^@mã]XB]Um§&./6ÅaO

È&`#Ó&Õ=;Ña¤Wh&;ÏÐ6ÖB^@mn

1
2
34
5
67891011;

540545Photon Energy / eV

550

Figure 4 &]U\Õ`ab@ý(ûü(ûüý$!& -jê X  Z[\þÿ³µ mn
A : pH 11.44
B : pH 6.30
C : pH 5.71
D : pH 5.20
E : pH 4.73
F : pH 4.30
G : pH 3.73
H : pH 3.28
I : pH 0.29

520525Emission Energy / eV%&ñh_&È6POJ(­y{®x¯ø¬é°B^@mbÍ;;;qrst;

Aqueousacetic acid515cb
Intensity (arb. units)|}{²~6Wþÿ³µ0(]Uþÿ³µO1s XES

535&ñh_&n]Za;gh

W@HIJ_ÂgOmH&ñh_6¤Âgh(z{Uþÿ³µa
Intensity (arb. unit)]Uþÿ³µ=B&þÿ³µ530,J*e@OP(*+,-aq è! ab@c

Aqueous acetic acid1.0

pH 4.73

Experimental
Reconstructedmolar fractionü0)

0.8
0.6

AnionicformNeutralform

0.4
0.2
0.0

515

520525Emission energy / eV2468pHFigure 3. ¬B°n ûüý$!& -./-jê!12¹[ab@]Uþÿ³µ & è! c2m'(BÛObÖa(j]UkJ./MN@m¬N°n è!øú &/¬Z°6(mü=¬MZ°Imb,=¬FZ°B&/&no¬Z°IbÍ£w@HI6ÛOEm¬é°n mü=Imb,=B&/6VWh(%p& è! a<@ ¯®æxBnçxn¬.!ú.--!°I zyçzyénçxn¬.!ú.--°&È6oSO¬gi&°mûü&e èB ab@/ZIbÍ£whW@HIJ_Â@mn

J. H. Guo, Y. Luo, A. Augustsson, et al., Physical Review Letters 89 (2002).
P. Wernet, D. Nordlund, U. Bergmann, et al., Science 304, 995 (2004).
B. Winter, E. F. Aziz, U. Hergenhahn, et al., Journal of Chemical Physics 126, 124504 (2007).
O. Fuchs, M. Zharnikov, L. Weinhardt, et al., Physical Review Letters 100, 027801 (2008).
T. Tokushima, Y. Harada, O. Takahashi, et al., Chemical Physics Letters 460, 387 (2008).
uvwxNTTyATN z{.|} 150nm . Si3N4 ~( :9*
T. Tokushima, Y. Horikawa, Y. Harada, et al., Physical Chemistry Chemical Physics 11, 1679 (2009).
Y. Horikawa, T. Tokushima, Y. Harada, et al., Physical Chemistry Chemical Physics, to be published(2009).
Y. Harada, M. Taguchi, Y. Miyajima, et al., Journal of the Physical Society of Japan 78 (2009).
>?, MNOP,ST, nW 63 (2008).
T. Tokushima, Y. Harada, H. Ohashi, et al., Review of Scientific Instruments 77 (2006).