New Science from new Technology: NanoSIMS and RIMS Peter Hoppe Max-Planck-Institute for Chemistry IAU Meeting 2006 Prague August 21, 2006

Outline 1. Introduction 2.NanoSIMS 50 Ion Microprobe 3.RIMS - Charisma 4.NanoSIMS Studies 4.1. Submicrometer-sized Presolar Grains 4.2. Isotopic Homogeneity within Presolar Grains 4.3. Presolar Silicates 4.4. Coordinated NanoSIMS-TEM Studies 5.RIMS Studies 5.1. SiC Mainstream Grains 5.2. SiC X Grains 6.Summary

Introduction (I) Presolar Minerals

Introduction (II) Presolar SiC Populations

Introduction (III) Noble gas mass spectrometry of bulk samples (late 1980s, early 1990s) Noble gas mass spectrometry of bulk samples (late 1980s, early 1990s) Conventional SIMS (late 1980s, 1990s, early 2000s) Conventional SIMS (late 1980s, 1990s, early 2000s) RIMS (late 1990s) RIMS (late 1990s) NanoSIMS (2000s) NanoSIMS (2000s) Isotope Analyses of Presolar Grains

Introduction (IV) NanoSIMS: NanoSIMS: Analysis of submicrometer-sized presolar dust Analysis of submicrometer-sized presolar dust In-situ search for presolar dust In-situ search for presolar dust Investigation of isotopic heterogeneity within grains Investigation of isotopic heterogeneity within grains RIMS: RIMS: Isotopic compositions of heavy elements in individual grains Isotopic compositions of heavy elements in individual grains The Role of NanoSIMS and RIMS

NanoSIMS 50 (I) Commercial ion microprobe from Cameca Commercial ion microprobe from Cameca Introduction to field of cosmochemistry in 2001 (Washington University, St. Louis and MPI for Chemistry, Mainz) Introduction to field of cosmochemistry in 2001 (Washington University, St. Louis and MPI for Chemistry, Mainz) Three fundamental features: Three fundamental features: 1. Small beam size (down to 50 nm for Cs + -ions) 2. High transmission at high mass resolution (30x higher than in the IMS3f for conditions used for O-isotopic measurements) 3. Simultaneous detection of up to five isotopes (minimum mass separation is M/30, i.e., isotopes up to mass 30 (Si) can be measured simultaneously

NanoSIMS 50 (II)

RIMS - Charisma Most advanced (in the field): CHARISMA (Chicago-Argonne Resonant Ionization Spectrometer for Mass Analysis) Most advanced (in the field): CHARISMA (Chicago-Argonne Resonant Ionization Spectrometer for Mass Analysis) Laser ablation + laser ionization + TOF-MS Laser ablation + laser ionization + TOF-MS Superior to SIMS for trace elements, especially such with small ion yields in SIMS Superior to SIMS for trace elements, especially such with small ion yields in SIMS Basically a single-element-method Basically a single-element-method First applications: Fe, Sr, Zr, Mo, Ru, and Ba in single presolar SiC & graphite grains First applications: Fe, Sr, Zr, Mo, Ru, and Ba in single presolar SiC & graphite grains Prospects: Prospects: “Useful yield” of current setup ~ 1 % “Useful yield” of current setup ~ 1 % Planned modification: aiming at ~ 30% Planned modification: aiming at ~ 30%

CHARISMA – Schematics (I)

CHARISMA – Schematics (II)

Most presolar grains are submicrometer in size Most presolar grains are submicrometer in size Previous characterization was biased Previous characterization was biased NanoSIMS made it possible to obtain information on previously largely unexplored presolar grain types: NanoSIMS made it possible to obtain information on previously largely unexplored presolar grain types: Sub-population of presolar SiC with specific Si- isotopic signature Sub-population of presolar SiC with specific Si- isotopic signature Presolar spinel (MgAl 2 O 4 ) Presolar spinel (MgAl 2 O 4 ) NanoSIMS Studies (I) Submicrometer-sized Presolar Grains

NanoSIMS Studies (II) Zinner et al., 2005 O in Presolar Spinel

NanoSIMS Studies (III) Isotopic homogeneity can be studied within micrometer-sized presolar grains Isotopic homogeneity can be studied within micrometer-sized presolar grains In most cases isotopic compositions turned out to be homogeneous In most cases isotopic compositions turned out to be homogeneous Isotopic heterogeneities: Isotopic heterogeneities: TiC within graphite TiC within graphite SiC from supernovae SiC from supernovae Isotopic Homogeneity within Presolar Grains

NanoSIMS Studies (IV) 28 Si 48 Ti min max 18 O/ 16 O 17 O/ 16 O 16 O 17 O/ 16 O 18 O/ 16 O 1  m Sah Standard grain Mostefaoui et al., 2002 O in Presolar Corundum

NanoSIMS Studies (V) Besmehn and Hoppe, 2003 Presolar SiC-X

NanoSIMS Studies (VI) Besmehn and Hoppe, Si/ 28 Si 28 Si min max 1  m 28 Si 29 Si/ 28 Si 30 Si/ 28 Si Presolar SiC-X

NanoSIMS Studies (VII) Most presolar minerals can be separated by harsh chemical treatments from meteorites Most presolar minerals can be separated by harsh chemical treatments from meteorites Does not hold for silicates Does not hold for silicates Silicates are the major constituent of O-rich dust around stars Silicates are the major constituent of O-rich dust around stars First silicates discovered in an IDP in 2002 (Messenger et al.); use of NanoSIMS was essential First silicates discovered in an IDP in 2002 (Messenger et al.); use of NanoSIMS was essential O-isotopic mapping of slices of meteorites or IDPs with 100 nm lateral resolution O-isotopic mapping of slices of meteorites or IDPs with 100 nm lateral resolution Presolar Silicates

NanoSIMS Studies (VIII) 16 O 17 O 17 O/ 16 O Acfer 094 Meteorite (Mostefaoui and Hoppe, 2004) Presolar Silicates

NanoSIMS Studies (IX) Simultaneous information on mineralogy, structure, isotopic compositions, and petrological context of presolar materials Simultaneous information on mineralogy, structure, isotopic compositions, and petrological context of presolar materials Preparation of thin sections of individual particles by ultra-microtomy or FIB lift-out Preparation of thin sections of individual particles by ultra-microtomy or FIB lift-out Coordinated NanoSIMS-TEM Studies

NanoSIMS Studies (X) NRL, Carnegie Institution, and MPI Mainz, 2004, unpublished Presolar SiC-X

RIMS Studies (I) Zr in SiC mainstream grains Nicolussi et al., 1997 s-process path

RIMS Studies (II) Lessons from Zr: Mainstream SiC grains come from low-mass AGB stars, probably mostly 1.5– 3 M  ; 5 M  can be excluded Mainstream SiC grains come from low-mass AGB stars, probably mostly 1.5– 3 M  ; 5 M  can be excluded A variety of conditions are required to explain the array of grain compositions A variety of conditions are required to explain the array of grain compositions Models do a good job of explaining most of the data, but low 96 Zr grains remain a difficulty Models do a good job of explaining most of the data, but low 96 Zr grains remain a difficulty Zr in SiC mainstream grains

RIMS Studies (III) 99 Tc in SiC mainstream grains Savina et al., 2004

RIMS Studies (IV) Mo in SiC X grains Pellin et al., 1999 Although previously postulated, a new type of nucleosynthesis was recognized in nature Although previously postulated, a new type of nucleosynthesis was recognized in nature The neutron burst required is a natural consequence of Type II supernova explosions The neutron burst required is a natural consequence of Type II supernova explosions X-grains must come from Type II, not Type Ia supernovae, as such a burst does not occur in SN Ia X-grains must come from Type II, not Type Ia supernovae, as such a burst does not occur in SN Ia

Summary NanoSIMS and RIMS have become well- established tools in presolar grain research NanoSIMS and RIMS have become well- established tools in presolar grain research Important breakthroughs: Important breakthroughs: Extension of isotope analyses to submicrometer-sized grains Extension of isotope analyses to submicrometer-sized grains Study of isotopic homogeneity within micrometer- sized grains Study of isotopic homogeneity within micrometer- sized grains Discovery of presolar silicate grains Discovery of presolar silicate grains Isotope analyses of the heavy elements by RIMS provided important input for a better understanding of neutron-capture reactions in the grain’s parent stars Isotope analyses of the heavy elements by RIMS provided important input for a better understanding of neutron-capture reactions in the grain’s parent stars