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The André E. Lalonde Accelerator Mass Spectrometry Lab at the University of Ottawa. Liam Kieser, Ian Clark, Jack Cornett and Xiaolei Zhao, University of Ottawa Ted Litherland, University of Toronto . Instrumentation Session, CAP 2014 Congress, Laurentian University, June 17. Overview. - PowerPoint PPT Presentation
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Liam Kieser, Ian Clark, Jack Cornett and Xiaolei Zhao, University of OttawaTed Litherland, University of Toronto
Instrumentation Session, CAP 2014 Congress, Laurentian University, June 17
The André E. Lalonde Accelerator Mass Spectrometry Lab
at the University of Ottawa
1. Introduction – What is AMS?
b) Ion-Gas Reactions and Isobar Separation
3. Advances in AMS Technology
Overview
4. The New Facility at uOttawa - Summary
a) Negative Ion Chemistry in the Ion Source
a) Basic Description – Advantages, Applications, Challengesb) Lab Photo Tour – Principal Componentsc) Critical Component – the ion source
a) Earth and Planetary Sciences2. Design Goals for the Lalonde Lab
b) Bio-medical and Pharmaceutical Sciences
A. E. Lalonde AMS Lab
c) Anthropological and Cultural Sciencesd) AMS Research and Innovation
Accelerator Mass Spectrometry (AMS)A synthesis of:
Conventional mass spectrometry, Particle accelerator technology -- usually a tandem
electrostatic accelerator
and
Advantages:■ Molecular interference free measurements
(Molecules destroyed in the charge changing process)
■ Measurements with extremely low dark current(High energy -- 100s of keV to 10s of MeV provide single atom counting capability and some degree of atom identification)
■ Atomic isobar elimination is special cases14C (14N), 26 Al (26Mg), 129I (129Xe), 202Pb (202Hg)
Ion Source
Filter or Analyzer
Sample Detector
Ions
Heavier Ions
Lighter Ions
Applications:
Challenges:•Need to make negative ions of the analyte
(Tandem accelerator operation)
•Atomic isobars can be difficult to eliminate(except in the special cases)
•Concentration or isotope ratio measurements for long-lived radio-isotopes or rare atoms for dating or tracing
e.g. 3H, 10Be, 14C, 26Al, 36Cl, 41Ca, Ag, 129I, Pt group, actinides
•Used in Archaeometry, Astrophysics, Biology, Bio-medical research and clinical practice, Earth, Environmental and Planetary science, Materials research, Pharmacology
•Some sample materials require extensive, labour-intensive preparatione.g. 10Be, 14C
•Levels ranging from 1 part in 1010 to 1 part in 1016
Accelerator Mass Spectrometry (ctd)
AMS System Schematic:
Tandem Accelerator
Low Energy MassSpectrometry
Negative Ion Source
High EnergyMass Spectrometry
Gas Ionization Detector for rare species
Faraday Cups for abundant species
Sample
Gas-Filled ElectronStripper Canal
3 MV Power Supply
Electric Analyzer
Magnetic Analyzer
Magnetic Analyzer
Electric Analyzer
Accelerator Mass Spectrometry (ctd)
AMS System: View from Low Energy End
Accelerator Mass Spectrometry (ctd)
AMS System: View from above the High Energy End
Accelerator Mass Spectrometry (ctd)
The Ion Source
→Development of the negative ion caesium sputter source in the 1970s made AMS possible
Requirements:
►Large ion current (at least 10s of μA, 100s good if possible)to obtain sufficient counting statistics for low concentration
of rare species with a large ratio to abundant species ►Stable operation for a variety of sample matrices►Relatively low memory of previously analysed samples
►Produce negative ions from a wide range of elements
Extraction Cone (ground potential)
Sample (Target)-35 kV
Caesium IonizerSource Head Base -28kV
Caesium Vapour feed
Ion Source
HVE SO-110 200 sample, solid/gas ion source
Sample Carousel
Source Head
Electric Analyser
Ion Source:
Source Head Flange
Target Cooling Lines
Caesium IonizerTarget holder
Caesium Vapour Feed
On Maintenance Stand In Place
Source head base / support -28 kV
Target holder -35 kV
Target Wheel
– capacity: 200 targets in 4 circles of 50
– access time to neighbour-ing target: ~2 seconds
Ion Source:
Target Assembly
– provides the micro- environment for the conversion of CO2 intonegative carbon ions– one assembly must be prepared for each 14C measurement
For solid materials– compress into a 1.3 mm Φ
pellet in a replaceable Al or SS cylinder
For gases
Ion Source:
A. E. Lalonde AMS Lab Design Goals
For Earth and Planetary Sciences:
For Bio-medical and Pharmaceutical Sciences:
For Anthropological and Cultural Sciences:
- as wide a range of elements and isotopes as possible – from 3H to 244Pu- a full complement of ancillary equipment and sample preparation techniques
IRMS, ICP-MS, Noble gas MS, electron microprobe
- separate ion source lines to accommodate higher levels of tracer isotopes- gas ion source capability for interface to other analytical instruments, e.g.
- specific sample prep labs for Radiocarbon, Radiohalides, Exposure age dating, noble gases and stable isotopes
• elemental analyzer for rapid or survey 14C work• GC or HPLC for compound specific 14C work
- similar to earth & planetary science requirements
For AMS Research:- flexible accelerator and peripheral design
- accessible control electronics and software
- sufficient floor space for tests of new injection and detection systems
- support for continuation of research and development projects inherited from IsoTrace and beyond:
c) Reaction Cells and Isobar Separation
b) Integrated 14C Sample Preparation and Analysis
a) Negative Ion Chemistry in the Ion Source
d) Laser – ion interactions ?
Design Goals
a) Enhanced Production of Negative Ions
Many elements do not readily make negative atomic ions
But molecular ions can be used to carry the analyte to the accelerator terminal
Fluoride materials make very strongly bound negative molecular ions and tend to produce much higher currents than those from the pure metal
or Chemistry in the Ion Source
Zhao et al Nuclear Instruments & Methods B 268 (2010) 807–811
2. Advances in AMS Technology
Examples in the following two papers:
Adam Sookdeo, using PbF2 to develop a technique for measuring 210Pb
Cole MacDonald, using CsF2 to develop a technique for measuring 135Cs and 137Cs
System schematic
High Voltage Deck
b) Ion - gas reactions to reduce isobar interferences:
New AMS Technology
Early work done with negative ions in a simple gas volume (Ferguson et al, Chem. Phys. Lett. 15 (1972) 257–259.) showed a chemical dependency of the negative ion destruction cross section.
Work by Doupé, Tomski and Javahery confirmed that S– in a beam of Cl– could be selectively destroyed in NO2.
Funding for a Proof-of-Principle instrument and a patent obtained and the “Isobar Separator for Anions (ISA)” was built successfully tested.
Version uses a single cell for both cooling and reactions
Lab GroundDeceleration
LensesDeceleration
QuadsCooling / Reaction
CellAcceleration Quad, Lenses Lab Ground
To Accelerator
New AMS Technology
System as built –configuration used at IsoTrace
High Voltage Deck(behind lucite shield)
Off-axis Faraday Cup Vacuum Box
Ion Source
New AMS Technology
Exit Einzel LensEntrance Einzel Lens
Electronic Card Cage
Vacuum Baffle
High Voltage DeckInsulator
Stable Beam Attenuator Box Dual Stage Turbo Pump
Interchangeable ISA Column
Isobarex and the Lalonde AMS Lab are collaborating on the installation of a pre-commercial, demonstration version of the ISA.
New AMS Technology
Isobarex Corp. formed to develop and market ISA technology
Lalonde Lab Overall System
New AMS Technology
SIMS-typeIon Source
Innovation Injector Line(U of Toronto components,
Isobarex ISA column)
3 MV Multi-Element AMS system, built by High Voltage Engineering BV
IsobarSeparator
ρ = 1.52 m Inflection Magnet
SO-110-200 Ion Source
SO-110-200 Ion Source
120° Spectrometer Magnetto accept 339 AMU at full
source energyAdditional turbopump and
differential section for terminal stripper
90°, 351 MeV-AMU Analyzing Magnet
65° Cylindrical Electric Analyzer
20° Second High Energy Magnet
2 anode Ionization Detector
Faraday Cup Box54° Rotatable
Electric Analyzer
Investigators, Affiliations and Acknowledgements
Ian D. ClarkW. E. (Liam) KieserR Jack CornettXiao-Lei ZhaoGilles St-JeanChris Charles
A. E. Lalonde AMS Laboratory,University of Ottawa
Lisa CousinsGholamreza JavaheryIlia Tomski
Ionics MassSpectrometry Group
Funding from: NSERC MRS, I2I and Discovery Grants Canada Foundation for Innovation Ontario Research Fund
uOttawa Advanced Research ComplexAndré E. Lalonde AMS Laboratory
Jean-François AlaryChris Charles
Isobarex Corp
A. E. Litherland IsoTrace Laboratory, University of Toronto