Stigmatic Isotope Imaging Method for Biology and Cosmochemistry
Naoya Sakamoto and Hisayoshi Yurimoto
Isotope Imaging Laboratory, Hokkaido University, Sapporo 060-0810, JAPAN (naoya@ep.sci.hokudai.ac.jp)

Presolar Grain

Molecular Cloud Water

Presolar Silicate

Meteorite

First Solid in the Solar System

Molecular cloud origin model for thesystematic mass independent fractionation ofoxygen in the Solar System predicted “heavy”
water enriched in 17,18O (Yurimoto andKuramoto, 2004, Sciecne). Such material
happened to be detected during presoalr
grain survey. The material shows nano-scale
symplectite structure composed of FeS andFe3O4 that formed by aqueous alteration of17,18O enriched water (Sakamoto et al.,2007, Science).

10µm
16O

17O

18O

17O/16O

MgCaAl

18O/16O

Meteorites contain isotopically anormalous grains thought to beof extrasolar origin. Stigmatic isotope imaging allows us to survey
in broad area quickly. (Nagashima et al., 2004, Nature)
5 µm

Cosmic Symplectite

Ca-Al rich inclusions in meteorites are ag-gregates of the first solids in the solarsystem. Conbination of chemical and isotopic
zoning of melilite single crystal in the Ca-Al
rich inclusions can reveal its formation conditions in the solar nebula. (Park et al., 2011)

Moon Water
Apollo 11 sample

Adsorbed hydrogen

1HApatite

Crack

Stigmatic Isotope Imaging
1200

Apollo mission brought many lunar rocks

Reconstruction
2-D ion detector

800
600
SMOW

Stigmaticback to the earth. Recently, we detectedsignificant amounts of water is enriched induterium. The Isotopograph cleary showsthat apatite has a high hydrogen concentration compared to surrounding anhydrous minerals. (Greenwood et al., 2011,Nature Geoscience)

1000

D‰ScanningCrack

12039,4312039,4210044,1210044,644
75055,55
14053,25614053,257
12040,211
14305,303
14305,95
12013,148
10047,228
79215,74
12064,872395,6

400
200
0-200
-400
-0.2

00.2

0.4

0.6

0.8

1

1.2

1.4

OH (wt.%)Lens, Magnet
0-D ion detector
Scan coil
Focused beam

Broad beam・High spatial resolution with a fine probe size・Long measurement time for wide area
- High precision analysis is difficult for wide area

・Spatial resolution is limited by ion optics
・Wide area with high Intensity signals- High precision analysis

Mutualism in Plants

2-D Ion Detector “SCAPS”
Performance (in case of ims1270)

SCAPS (Stacked CMOS Active Pixel Sensor)
12ion

SecondaryelectronPixelelectrode12 C14N

nucleus15N/14N

C14N

10mm

cell wall

2 m

Si Device

Fungus penetrates the cells of the roots of a vascular plant

Measurement time : 5 sec
Field of view : 50 x 70 µm
Spatial resolution : 300nm
Primary beam : Cs+, 1nA

Direct ditection of ion
Integral type No deadtime
Wide dynamic range
Robustfungusand interacts materially. Isotopographs show dynamical exchange of 15N-doped fertilizer between a plant and arbuscular mycorrhiza. (Kuga et al., in prep)< 30nmBone growthBone growth of animals is visualized

by feeding 44Ca-doped food during a set
time period. Steped concentration is observed in inner and outer parts.(KimuraSuda et al., in prep)

Imaging Depth

Gene
12C14N

10µm

18O

18O-RNA

18O (shallow)

30Si

44Ca/40Ca

18O (deep)

Bulk diffusion

18O

Grain boundary diffusion
50µm

The demand of visualization methods without additional

tracer disturbing the natural environments is incrasing in themedical field.The Isotopograph shows incorporation of 18Odoped RNA into cells. (Hamasaki et al., in prep).

Depth50µm

Stigmatic imaging method realizes practical imaging depth profiling because probe cur-rent can increase without degradation of spatial resolution. Figures show snapshots from18
O imaging depth profiling for 18O-diffused ZnO polycrystal (Sakaguchi et al., in prep).

44Ca/40Ca