Ne and Ar isotopic analysis by a multicollector noble gas mass spectrometer Suruchi Goel and S.V.S. Murty Physical Research Laboratory, Ahmedabad – 38.

Slides:



Advertisements
Similar presentations
BACKGROUND THEORY AND TERMINOLOGY FOR ELECTRON MICROSCOPY FOR CyberSTEM PRESENTATIONS.
Advertisements

Olszewski-Day 3 The Analyzer The analyzer is where the beam of ions generated in the ion source is separated into multiple beams each representing a single.
What is this ROCK??? Any guesses? Ok clue!!! It is not from Earth Yesss!! MARS!! Is there any way, we can figure out what its compounds are? What is it.
Module 2: Analytical methods and separation techniques.
Inductively Coupled Plasma Mass Spectrometry or ICP-MS
Zumdahl’s Chapter 3 Stoichiometry Chapter Contents Aston’s Atomic Mass The Mole Molar Mass % Composition Molecular Formulae Chemical Equations Balancing.
Mass Spectrometry Inlet system Ion Source Mass Analyzer Ion Detector.
Instrumental Chemistry Chapter 11 Atomic Mass Spectrometry.
Atomic Masses/Mass Spectroscopy. How do we calculate atomic mass? 1) Masses of Isotopes 2) Fraction of the abundance of each isotope o usually a percentage.
Mass Spectroscopy Quantitative Chemical Analysis Harris, 6th Edition
1 States of Matter “State” refers to form or physical appearance – whether the sample of matter exists as solid, liquid, or gas. The state of a sample.
Photoelectron Spectroscopy Lecture 7 – instrumental details –Photon sources –Experimental resolution and sensitivity –Electron kinetic energy and resolution.
Types of Analyses Single Collector –Uses only one collector or detector –This is the case with a Daly or EM Advantages: –Need only one detector –Peaks.
Mass Spectrometer Mass spectrometere is a very powerful method to analyse the structure of organic compounds.
Lecture 11 Magnetic field Generators and Transformers Motors Galvanometers Mass Spectrometer Cyclotron.
Chapter 7 THE MICROSCOPE.
Light. White light emits light at all wavelengths. Excitation of certain elements or the electrical excitation of certain elements give rise to an atomic.
Chad Orzel Union College Physics Radioactive Background Evaluation by Atom Counting C. Orzel Union College Dept. of Physics and Astronomy D. N. McKinsey.
PC4250 Secondary Ion Mass Spectrometry (SIMS). What is SIMS? SIMS is a surface analysis technique used to characterize the surface and sub-surface region.
Secondary ion mass spectrometry (SIMS)
Fig Linear relationships of H,C,N,O and S heavy isotope contents to  values. Large natural abundance  variations from to +100o/oo correspond.
The nucleus. Rutherford's nuclear atom (1902 ‑ 1920) Ernest Rutherford was interested in the distribution of electrons in atoms. Two of his students,
Tree Rings
Molecular mass spectrometry Chapter 20 The study of “molecular ions” M + e -  M e -
Matter Unit Learning Goal #2: Summarize the major experimental evidence that led to the development of various models, both historic and current.
1 Chemical Analysis by Mass Spectrometry. 2 All chemical substances are combinations of atoms. Atoms of different elements have different masses (H =
Mass Spectroscopy 1 Mass Spectroscopy (Mass Spec) Applying Atomic Structure Knowledge to Chemical Analysis.
Measurement of “Difficult” Elements and Isotopes Using a Hexapole ICPMS Zenon Palacz, Simon Meffan-Main. Micromass U.K. Ltd.
Other modes associated with SEM: EBIC
LRT2004 Sudbury, December 2004Igor G. Irastorza, CEA Saclay NOSTOS: a spherical TPC to detect low energy neutrinos Igor G. Irastorza CEA/Saclay NOSTOS.
7-1 Chapter 7 THE MICROSCOPE. 7- Criminalistics, 10e Richard Saferstein © 2011, 2007, 2004, 2001, 1998, 1995 Pearson Higher Education, Upper Saddle River,
The Apparatus…. Ionic target studies…. Neutral target studies…. Queens University Belfast University College London.
Introduction to Plasma- Surface Interactions Lecture 3 Atomic and Molecular Processes.
7-1 Atomic Mass Spectroscopy General Features Mass Spectrometers §Sources Atomic mass spectroscopy determines elements by mass §Mass to charge ratio §Lower.
THE MICROSCOPE Chapter 7. Introduction A microscope is an optical instrument that uses a lens or a combination of lenses to magnify and resolve the fine.
Starter: Spec links 1.06–1.10. Green pens out! Spec links 1.06–1.10.
Advanced Analytical Chemistry – CHM 6157® Y. CAIFlorida International University Updated on 9/26/2006Chapter 3ICPMS Interference equations Isobaric.
High Accuracy and High Precision Uranium Isotopic Analysis by DRC-ICP-MS Steve Beres July 2008.
Mass Analyzers : Time-of-flight Mass Spectrometry CU- Boulder CHEM 5181 Mass Spectrometry & Chromatography Joel Kimmel Fall 2007.
Molecular Mass. Mass of Atom Measured in atomic mass unit (amu) 1 amu = 1.66 x g Defined by assigning the mass of 12 amu to the carbon-12 isotope.
Radioactive Nuclide Nuclide which is unstable. It emits radiation & changes into another kind of atom.
Electrons. Models of the Atom Electrons Electrons do not orbit the nucleus like the planets orbit the sun. Electrons are located in the electron cloud.
INCIDENCE ANGLE, θ The solar incidence angle, θ, is the angle between the sun’s rays and the normal on a surface. For a horizontal plane, the incidence.
Optimizing Peak Separation for Simultaneous Pu and U Measurements Shane Knockemus US EPA / NAREL May 3, 2005.
7-1 ©2011, 2008 Pearson Education, Inc. Upper Saddle River, NJ FORENSIC SCIENCE: An Introduction, 2 nd ed. By Richard Saferstein THE MICROSCOPE Chapter.
The Microscopes. The Microscope 1. The microscope is an optical instrument that uses a lens or combination of lenses to magnify and resolve the fine details.
DOR: Electron Configuration/Quantum 1) Draw the orbital diagram for Si 2) Which of the following ions has 5 unpaired electrons? a) Ti +4 b) Co +2 c) V.
N - principle quantum number - determines distance from the nucleus and energy l - orbital angular momentum quantum number l = 0, 1, 2,… n-1 m l - magnetic.
Mass Spectrometry Relative atomic masses and the mass of individual isotopes can be determined using a mass spectrometer. The principle behind mass spectrometry.
Lecture 8 Radiometric Dating
Part 2: Many-Electron Atoms and the Periodic Table.
7-1 Chapter 7 THE MICROSCOPE. 7- Criminalistics, 10e Richard Saferstein © 2011, 2007, 2004, 2001, 1998, 1995 Pearson Higher Education, Upper Saddle River,
Chapter 29 Mass Spectrometry. 29 A Principles of mass spectrometry In the mass spectrometer, analyte molecules are converted to ions by applying energy.
Atomic Structure Topic The mass spectrometer Describe and explain the operation of a mass spectrometer Describe how the mass spectrometer.
Evolution GC-MS/MS: Pesticide analysis in canola oil Evolution GC-MS/MS: Pesticide analysis in canola oil Vivian Watts 1, Ingo Christ 1, Mark Misunis 2.
Presentation on.  There are many methods for measuring of fiber structure. Such as:  The absorption of infrared radiation  Raman scattering of light.
THE MASS SPECTROMETER WHAT IS A MASS SPECTROMETER
Atomic Masses/Mass Spectroscopy
Continuous Flow Isotope Ratio Mass Spectrometry
Department of Tandem Accelerators
1G. Nicolaou, 1M. Yamauchi, 1,2H. Nilsson, 1M. Wieser, 3A. Fedorov, 1D
ROSINA, COSAC & PTOLEMY Reviewer: Heather Franz 2/15/16 – 2/17/16
Instrumental Chemistry
Atmosphere.
How do we know about the climate from thousands of years ago?
Presentation transcript:

Ne and Ar isotopic analysis by a multicollector noble gas mass spectrometer Suruchi Goel and S.V.S. Murty Physical Research Laboratory, Ahmedabad – Introduction Precise isotopic measurements of Ne and Ar are very important in the identification of minute changes that result from specific physical or nuclear processes. Cosmic ray produced 21 Ne in the surface rocks on Earth [1], nucleogenic 21 Ne in U, Th rich minerals [2], 36 Ar production through 35 Cl(n,γ) 36 Cl(β-) 36 Ar in salt deposits, Ar isotopes of trapped air in ice cores as climate markers [3], determination of the primordial abundance of the isotope 40 Ar [4] etc. have great potential in serving as chronological tools as well as tracers to decipher physical processes in the past. Compared to the usual peak jumping techniques employed by a single collector mass spectrometer, a multicollector mass spectrometer provides an advantage for achieving higher precision, in terms of reduced analysis time and consequently the memory effects, particularly when dealing with small gas amounts. Here we describe the Ne and Ar analysis using a noble gas mass spectrometer (Noblesse, procured from Nu Instruments, UK) with three collectors (one Faraday cup/or multiplier, and two multipliers). 2. Instrumental Details In the PLANEX Program at PRL, we have recently procured a multi collector noble gas mass spectrometer, Noblesse from Nu Instruments, UK. This mass spectrometer has 75 o magnetic sector and modified Nier-type Ion Source. It has four fixed collectors; one Faraday and three Ion counting electron multipliers. The Faraday (F) and one multiplier (IC0) are behind a slit and an electrostatic deflector is used to send ion beam into one or other of the pair. Hence the three collectors (Faraday or Multiplier [high mass side]), and the other two multipliers (IC1: axial and IC2: low mass side) are used for multi-collection. The multi-collection is achieved by patented method of two lens arrays (called as Quad lenses, since they provide a field equivalent to an electrostatic quadrapole) placed between magnet exit pole and collectors. The Quad lenses allow the achievement of dispersion of ion beams equivalent to physical separation of distance for the three collectors for simultaneous analysis of isotopes of each element (the degree of dispersion varies with the element). The quad lenses can be set at dispersion of one unit, two unit, four unit and six unit mass difference for Ne isotopes ( 20 Ne, 21 Ne, 22 Ne), Ar isotopes ( 36 Ar, 38 Ar, 40 Ar), Kr (e.g. 86 Kr, 82 Kr & 78 Kr simultaneously on three collectors) and Xe isotopes (e.g. 136 Xe, 130 Xe & 124 Xe) respectively. After achieving the proper Z-focusing and source ion settings the quad lenses settings for each element (and for each combination of isotopes) were obtained. The hydrocarbon background like 38 Ar and C 3 H 2 can be pseudo resolved. By the means of Zoom optics (Quads) the magnet can be offset from the peak centre, which is done for the 38 Ar to remain at the pure 38 Ar peak top. This beam dispersion to achieve simultaneous focus of the three isotopes on to three collectors by the quad lenses offers an advantage over mechanical adjustment of collectors spacing that often results in spurt of degassing and increased background. Ne and Ar isotopic analysis by HELIX-MC and ARGUS respectively has also been reported recently [5] & [6]. 4. Results & Discussion For the 1.48E-16 moles of 22 Ne, the 20 Ne/ 22 Ne and 21 Ne/ 22 Ne ratios are 10.78±0.50 and ± resp. for Multi-collection mode, while for Peak Jumping it is 9.91±0.17 and ± resp. From the above 21 Ne/ 22 Ne ratio it is clear that about 3 millions of atoms of 21 Ne can be easily detected with less than 10% uncertainty. The excess of few 10 5 atoms of 21 Ne can then be distinguished. The 40 Ar/ 36 Ar ratio is ±0.35, and 38 Ar/ 36 Ar ratio is ± for 2.03E-15 moles of 38 Ar. The Uncertainty in measured ratios increases with lowered amounts. The ratios in multi-collection modes differ from Peak-Jumping ratios due to different efficiencies of electron multipliers. The instrument settings are still not at optimum level and there is room for improvement by further fine tuning. 5. Conclusion The protocols for analysis of Ne and Ar were made for both multi- collection and Peak Jumping modes. The Multi-collection mode provides advantages over the Peak-Jumping analysis as its reduces analysis time and enable detection of small amounts of gas with precision. 6. References 1.T.Graf et al, Noble Gas Geochemistry and Cosmochemistry, J. Matsuda, Ist Ed., 1994, , Terra Sci., Tokyo. 2.S. Basu, S.V.S. Murty and A. Kumar, Current Sci. 88 (2005), J.P. Severinghaus et al, GCA 67 (2003), F. Begemann et al, APJ 203 (1976), L155-L Y. Marrocchi et al, Geochem. Geophy. Geosys. (2009) /2008GC D.F. Mark et al, Geochem. Geophy. Geosys. (2009) /2009GC Experimental Details The heavy noble gases (Ar, Kr & Xe) were separated from Ne in the Air standard by Liquid N 2 trap on activated charcoal finger and purified by SAES NP10 getters. During the Ne analysis the liq. N 2 trap was kept parallel to mass spectrometer volume in order to reduce the contributions from 40 Ar ++ and 44 CO 2 ++ to 20 Ne and 22 Ne respectively. Different amounts of splits of air standard slug, for each Ne and Ar were taken to obtain variation of ratios with amounts. Fig.1 Variability of the 20 Ne/ 22 Ne (measured) in multi-collection mode as a function of the amount of 22 Ne present in the mass spectrometer. Fig.4 Variability of the 38 Ar/ 36 Ar (measured in multi-collection mode) as a function of the amount of 38 Ar present in the mass spectrometer. Fig.2 Variability of the 21 Ne/ 22 Ne (measured in multi-collection mode) as a function of the amount of 22 Ne present in the mass spectrometer. Fig.3 Variability of the 40 Ar/ 36 Ar (measured in multi-collection mode) as a function of the amount of 40 Ar present in the mass spectrometer. 3. Experimental Details ctd… The Ne was analyzed in both Peak Jumping and Multi-collection mode (in which the 40 Ar and 44 CO 2 peaks were also included). The Argon was analysed in Multi-collection mode with proper centring of isotopes to avoid pseudo resolved background peaks. In Fig.1 & 2. are shown the measured isotopic ratios in multi-collection mode (corrected for 40 Ar ++ and 44 CO 2 ++ contributions) with varying amount of 22 Ne amount. Similarly, Fig.3 & Fig.4 shows Ar isotopic ratios with varying amount as measured in multi-collection mode.