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Roy A. Walters, Ph.D. PE Vice President, Research and Development Ocean Optics, Inc. PowerPoint Presentation
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Roy A. Walters, Ph.D. PE Vice President, Research and Development Ocean Optics, Inc.

Roy A. Walters, Ph.D. PE Vice President, Research and Development Ocean Optics, Inc.

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Roy A. Walters, Ph.D. PE Vice President, Research and Development Ocean Optics, Inc.

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  1. Unknown Material Analysis in Less Than A SecondMan Portable LIBS A Tool for First Responders in Homeland Defense Roy A. Walters, Ph.D. PE Vice President, Research and Development Ocean Optics, Inc. Winter Park, Florida Roy.Walters@OceanOptics.com

  2. What is LIBS? Nd-YagLaser One 7 ns laser pulse 0.000000007 seconds LIBS3000 Spectrometer Computer - Standard PC 15,000 K plasma, much hotter than the sun’s surface but for only 20 microseconds Analyze Identify < 0.5 sec

  3. Who is a First Responder? • Fire Department, Police, Public Health • Specifically - an organization of specially trained people serving a single city or a region • Includes • Haz-Mat team • Swat team • Medical emergency team • etc.

  4. What does the First Responder want an instrument to do? • Find out what “it” is and not have to touch it or get very close • If “it” isn’t pure material, find out what other things might be in it

  5. Where and how does it have to work? • Rain, snow, night, bright sunlight, hot days • Portable with hours of time between battery charges • Must be light and easy to carry • Must be reliable • Must give immediate answers

  6. Sodium hydroxide Sodium carbonate Adipic Acid Aluminum Sulfate hydrate Ammonium Nitrate Urea Terephthalic Acid 1,2-propanediol (aka propylene glycol) viscous and non-flammable Acetic acid carbon black potassium carbonate (pot ash) Titanium dioxide Arsenic oxidebarium carbonate (for barium metal) Cadmium chromium Lead Mercury Nickel Zinc sodium fluoride Etc.                             There are 70 or so of these What do we need to identify?Not so nasty stuff

  7. Bad Materials • Explosives or their residues and IEDs • Stable (RDX, TNT, C4, etc) LIBS does not explode them • Unstable (London event) • Explosive or corrosive gasses • Biological materials (bacillus spores) • Poisons • Drugs

  8. MP-LIBS A full laboratory High-Resolution Broadband LIBS system in a portable backpack Head’s-up display Backpack contains broadband high-resolution spectrometer, laser power supply, computer, and battery Hand-held probe contains laser, joystick for control, and focus optics Microplasma/ LIBS Event

  9. First responder in Full Class A protection Suit MP-LIBS should be inside suit MP-LIBS

  10. MP-LIBS Outside Backpack LIBS3000-gh spectrometer Computer with cell phone and wireless network Argon Bottle for Special targets

  11. How do we identify complex substances? LIBS Spectrum

  12. We have stored the 2-dimensional barcode of items of interest! Position Position Amplitude Amplitude ultraviolet Blue Green Red Infrared

  13. Mathematics • Correlation • Checks everything in the catalog, tells you what is closest and grades it, 1.0 being perfect, 0.0 being no correlation • 2 types • Linear – all peak heights count according to how high they are • Rank – Big peaks count more than little ones

  14. What else do we do? • PCA - a type of analysis • PPA - Primary peak analysis • What’s missing from the closest matches, or what is additional • PPC - Peak picking correlation • Get rid of the junk between the big peaks

  15. Then What? • It’s time to vote to determine the winner • An example, pick the 10 highest scorers and for each calculate • Score = 0.2 x (Rank Correlation) + 0.3 x (Linear Correlation) + 0.2 x PCA + 0.1 x PPA + 0.2 x (Peak Pick Correlation) Then display the top 5 matching items and their scores

  16. BG 1.00 BT 0.59 Sugar 0.49 Salt 0.47 Creamer 0.46

  17. What else are we doing?30 + meter long distance LIBS