New Mass Spectrometers University of Hawaii 2005 Partnership Project

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New Mass SpectrometersUniversity of
Hawaii2005Partnership Project
UNCLASSIFIED
9/2007 NCMR Technology Review
F. Scott Anderson
This presentation is UNCLASSIFIED
UNCLASSIFIED
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Project Information

• New Mass Spectrometers for NBC Environmental
  Characterization
• University of Hawaii/HIGP
• Lead F. Scott Anderson (50)
• UH Personnel
• Eric Pilger Physicist (50)
• Keith Nowicki Physicist (100)
• Sarah Sherman Geochemist (100)
• Jeffrey Bosel Physicist (100)
• Gary McMurtry - Spectroscopist (10)
• Karen Stockstill (Postdoc 50, but leveraged from
  NASA NAI)
• Sophie Fung (Fiscal Officer 50)
• Malie Smith - Clerical (50)
• Partners
• Southwest Research Institute MB-TOF Dave Young
  (10), Greg Miller (50)
• Atom Sciences LA-RI-MS Tom Whitaker (20)
• Sandia Shock Design Testing Tony Mittias
  (15)
• Jet Propulsion Laboratory ESI-RFMS Advising
  Steven Smith (20)

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Program Details

• Date of award 3/2005
• Date of receipt of funds 11/2005
• Date work actually started 11/2005
• Percent of funds spent to date
• Year 1 100
• Year 2 20 (no funds yet received)

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Funding Issues
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Objectives

• EI RFMS
• RFMS Shock tolerant mass filtering method
• EI Atmospheric chemistry
• Leverages NASA MIDP
• LA-RI-MS
• RI-MS for in-situ high precision isotope
  detection
• New MBTOF MS
• Leverages NASA PIDDP, NAI, ONR IED

• Outline
• RFMS
• Principle
• Current progress
• Results
• Future direction
• LARIMS
• Principle
• Previous results
• Current Progress
• Future direction
• Program direction

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Part 1 EI-RFMS
UNCLASSIFIED
UNCLASSIFIED
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RFMS Principle
Detector - FC - Imager
Mass Disperser - 4 pole - 8 pole
Ionizer - Filament - EGA
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RFMS Progress

• Improved ion source
• Detector
• Improved imaging detector
• Initiated CMOS design under external funding
• Developed data interpretation algorithms
• Repackaged RFMS
• Increased RF ion source voltage capability
• Software port to Linux
• Tested vacuum system
• Low power
• Shock tolerant

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1. Tested Circular Filament Source

• Beam spot size same
• Improved efficiency
• Reduced power
• Enhanced longevity
• Improved shape
• Uses less sample

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1. Pressure vs signal strength
Picoammeter Limit
MCPCCD
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1. Pressure vs Resolution
1.2e-6 torr
3E-7 torr
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1. Ion Source

• Beam Size
• Resolving power proportional to beam/dispersion
  ratio
• OTS models about 50 times too coarse
• Will require complex design for desired 10 micron
  beam
• Sub-contracted design of improved model in
  progress

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2. Detector

• MCP/Phosphor screen coupled with CCD Camera
• MCP provides ion counting capability
• CCD provides
• 16 bit resolution (gtDNR)
• 1-106 msec integration time
• lt100 msec read time
• Improved speed and sensitivity

2"
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2. CMOS Detector Design
21 mm
Active area
20.88 mm
gt93 active without active edge processing
928 x 128 pixels 118,784
4.3M transistors
Nuclear Instr. Meth. A565 (2006)
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3. Algorithms

• Spot Finding
• If deformed, don't know ring position or shape a
  priori
• Automate ID of size location of spot/ring
• Self calibration
• Steer beam without RF to 4 x-y voltage offsets
• Maps offset voltage vs camera location
• Improves extraction of spectrum
• Use mapping to determine exact part of image for
  spectral extraction

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4. Repackaging

• Needed to repackage existing RFMS components
• Wanted portable unit to allow wider range of
  sampling
• Needed more flexibility of components for
  changing out elements and placement

4"
8"
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4. Repackaging
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5. Higher Voltages

• Acceleration
• Smaller beam
• Uniform detector response
• Purchased higher voltage power supplies
• Dispersion
• Required by higher acceleration
• Potential for greater dispersion
• Improved amplifier from 10V to 250V

8"
12"
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6. Linux Port

• Full Computer Control
• Required for Portability and Miniaturization
• Allows for more extensive testing of parameter
  space
• Utilized small, controllable modules D/A
  converter
• More robust OS
• Faster than Labview

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7. Low Power Vacuum

• Non-Evaporable Getter (NEG)
• Performance similar to other systems
• At minimum leak rate, lasted gt1 week
• Ion Pump
• 20 mW power usage

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Result M0.1-2000, R10, SNRgt1000

• Imaging detector
• R10
• SNR gt1000
• M 0.1-2000
• Air
• FC43
• 10X Faster
• 10X Less Sample

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Part 2 LA-RI-MS
UNCLASSIFIED
UNCLASSIFIED
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Geolocation

• Isotope ratios vary as a function of locale
• Light isotopes fractionate by atmospheric
  processes
• Heavy isotopes ratios a function of geology
• Sr others used to locate origins of
• Roman mercenaries (Schweissing Grupe, 2003)
• "Iceman" (Hoogerwerff et al, 2001)
• Prehistoric slaves (Cox Sealy, 1997)
• Horses identities (Ayliff et al, 2004)
• Explosives (McGuire, 2005 Siegel, 2003)
• Sr isotopes concentrate in body
• Teeth Fixed during first 10 years of life
• Bones Months - years of last residence
• Hair 0.5-50 days (Ayliff et al, 2004)

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Geology

• Rocks have 87Rb, decays to 87Sr
• Older rocks have higher 87Sr/86Sr ratio's
• Water acquires signature of local geology
  (Montgomery et al, 2006)
• Sr isotopes absorbed in body orally (Kelly et al,
  2005)
• Food water
• 50-1000 ppm
• Typically measurement 0.001 to 0.0001 (Bentley
  et al, 2006)
• Requirement
• Separate 87Rb-87Sr R300K
• 87Sr/86Sr .02

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Precision Abundance Goals
For fixed ablation volume
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How LD-RI-MS Mode Works
Laser Desorption Resonance Ionization Mass Spec

• Laser desorption
• 99.9 Neutrals
• 0.1 Prompt Ions
• Remove prompt ions
• RI remaining neutrals
• Only selected element (Sr or Rb) ionized
• Detect with isotopes with MS

Tuned only for Sr or Rb
Resonance Ions
Sample
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Resonance Ionization

• All elements possess unique energy levels
• Unique energy (l) to raise e- to each level
• Use set of tuned lasers to stimulate excitation
  steps for a given element
• More lasers provide more selectivity
• Applied to gas phase

5s6d1D2
Energy (eV)
5d2D5/2
5s6p1P01
5p2 P3/2
5s2 1S0
5s2 S1/2
Sr
Rb
Base state
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LA-RI-MS Lab Setup

• System Overview

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LA-RI-MS Previous Work

• Celestite LARIMS (note scale 0.12V)

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Previous Results

• Only need 460, 554 at 2-5 mJ
• 2 photon ionization from power in 554
• 1064 not required, may reduce lasers from 3 -gt 2
• 87Sr/86Sr precision goal 0.0002
• Old best 87Sr/86Sr precision
• Celestite (200,000 ppm) 0.0041
• Basalt (1000 ppm) 0.0081
• Basalt glass (100 ppm) 0.0109

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LDRIMS Progress

• Test LD RI laser attenuation ?
• Avoid off mass spec axis LD ?
• Enable RI laser translation to intersect neutrals
  closer to sample, improving efficiency ?
• Improve LD process ?
• Improve ion removal ?
• Increase precision accuracy ?
• Minimize RI laser power ?
• Install mini non-jittering laser
• Complete MBTOF development LD testing

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4. Improving LD

• Previously had trouble making pits of sufficient
  volume
• Gas in laser needed replenishing
• As 45 ablation proceeds
• Pit deepens
• Fractionation worsens
• Conical features form
• May represent stronger points in a material

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4. Precision vs Shots (Depth)

• As LA proceeds, 45 ablation pit deepens
• Ejecta directed away from mass spectrometer
• Precision degrades

Adapted from Ma et al, 1995
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5. Improve Ion Removal

• Scheme prompt ions from RI imperfect
• Required higher voltage than expected arcing
• LA ions had more energy than anticipated
• New plan use RTOF/MBTOF
• Increase initial e-field to accelerate prompt
  ions into MS hard
• Energy high enough to penetrate mirrors
• Reduce field for RI so ions bounce

Mirror
TOF
Ions
Detector
Mirror
Ions
Detector
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6. Precision Accuracy

• Improvements come from
• Improvements in analysis software
• New custom Sr standards
• Improvements in the instrument
• Test LD RI laser attenuation ?
• Avoid off mass spec axis LD ?
• Enable RI laser translation to intersect neutrals
  closer to sample, improving efficiency ?
• Improve LD process ?
• Improve ion removal ?
• Install mini non-jittering laser

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6. Precision Accuracy

• Spectra show power jitter
• Determine 1st PC
• Align to 1st PC
• Sort in order of fit to 1st PC
• Vertical
• Mean
• Standard Deviation
• Derive
• Accuracy from sum of the means
• Precision from STDDEV summed in quadrature,
  divided by of spectra
• Include spectra until precision degrades

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6. Solid Sr Standards

• Need standards for instrument testing
• Large (r0.25)
• Solid (not powdered)
• Uniform
• Single xal
• Glass
• Abundance 1-10K ppm
• Measured using SOA method
• No such standards are available
• Custom standards developed
• Manufacture difficult
• Measurement lengthy

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6. Standard Results

• Created from
• Basalt
• Andesite
• Strontianite
• Li-Tri-Borate Flux
• Still working on lt1 ppm
• NSP has expressed interest in samples

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6. Results

• Current best 87Sr/86Sr precision
• Celestite (200,000 ppm) 0.0008 (old 0.0041)
• Basalt (1000 ppm) 0.0018 (old 0.0081)
• Basalt glass (100 ppm) 0.0038 (old 0.0109)
• 5X improvement
• Need 4-20X more improvement for goal
• Reduce jitter
• Improving efficiency

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6. Results
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7. Minimize Laser Power

• To miniaturize instrument
• Seek to minimize laser size complexity
• Proportional to laser output power
• Testbed designed to ensure sufficient power for
  Sr
• 1064 50-100 mJ
• 554 2-20 mJ
• 461 2-20 mJ
• Minimum required unknown
• Other elements lower than expected
• 50-100 µJ

Savina et al, 2003
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7. Power Results for 2 lasers

• Best tuning of l power shows
• Minimizing green
• 461 2 mJ
• 554 400 µJ
• Minimizing blue
• 461 400 µJ
• 554 2 mJ
• Therefore, Sr requires
• 400 µJ of 461 554
• 1.8 mJ other

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7. Further Power Reduction

• Chance of laser photons interacting to cause RI
  1 in 1011
• Hence, need many photons (400 mJ)
• Other spectroscopy demonstrated Herriot or White
  cells
• Increases interaction path length, and odds of RI
• Could reduce required photons by factor of 50-100

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What about Miniaturization?
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8. Mini 206 nm YtterbiumYAG
Damaged by UPS!
Electronics
In 3-8W continuous Out 0.5GW/cm2 (25 mm spot,
400 ps), jitter lt 500 ns, 16x18 cm, solid state
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9. Mini Mass Spectrometer
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9. MBTOF Status

• Planned delay until 9/07
• In return receive miniature NASA flight prototype
• Delivery 12/07
• Planned test with miniature 206 laser 9/07
• Damaged laser delayed test

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Year 2 Side-by-side summary
Tasks as defined by Year 2 SOW
RFMS
LARIMS
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Publications

• Publications
• Anderson, F.S., T. Whitaker, E. Pilger, K.
  Nowicki, S. Sherman, D. Young, G. Miller, B.
  Peterson, J. Mahoney, M. Norman, J. Boyce, J.
  Taylor, H. McSween, The Mars Age eXperiment
  (MAX) A Laser Desorption Resonance Ionization
  Mass Spectrometer for In-Situ Rb-Sr Geochronology
  and Elemental Chemistry, Astrobiology, submitted,
  April 2007.
• Conference presentations
• Anderson, F.S., T. Whitaker, E. Pilger, K.
  Nowicki, S. Sherman, D. Young, G. Miller, B.
  Peterson, J. Mahoney, M. Norman, J. Boyce, J.
  Taylor, H. McSween, Mars Age experiment, 2007
• F. S. Anderson, T.J. Whitaker, K. Nowicki, S.
  Sherman, J. Mahoney, G. Miller, D. Young, B.
  Peterson, In-Situ Geochronology using Resonance
  Ionization, AGU, 2007
• F. S. Anderson, New Mass Spectrometers for NBC
  Environmental Characterization, Intelligence
  Community Summit, 2007
• F. S. Anderson, T.J. Whitaker, E. Pilger, G.
  Miller, D. Young, B. Peterson, J. Mahoney, S.
  Sherman, L. French, M. Norman, S. Sharma, Mars
  Age experiment (MAX), 2006
• Manuscript in preparation
• Anderson, F.S., T. Whitaker, E. Pilger, K.
  Nowicki, S. Sherman, D. Young, G. Miller, B.
  Peterson, J. Mahoney, M. Norman, J. Boyce, J.
  Taylor, H. McSween, A Shock Tolerant Rotating
  Field Mass Spectrometer

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Experiments

• RFMS last 6 months (300 Expts 70 tests)
• Beam shape vs. energy 10 tests
• Spectral runs at different energies 10 tests
• NEG/Ion Pump vacuum test 10 tests
• Current vs. pressure test 10 tests
• Beam shape (fuzziness) vs. pressure 10 tests
• Characterization of Circular filament 10 tests
• LARIMS last 6 months
• LA-RI-MS 350 tests, 172500 spectra taken
• Using custom, well-calibrated samples

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Summary Assessment

• RFMS
• Getting smaller, better
• Vacuum subsystem initial testing positive
• LARIMS
• Results improving
• Size and power requirements improving
• Transition Plan
• TSWG
• Cubic Corporation (JIEDDO, CNTPO, MIO)
• NGA (Geolocation field portal)
• Positive community response
• Need proposed level of funding to meet DIA goals