Remote Raman & Fluorescence Capabilities for Chemical Detection at University of Hawaii

Size: px

Start display at page:

Download "Remote Raman & Fluorescence Capabilities for Chemical Detection at University of Hawaii"

Basil Dorsey
6 years ago
Views:

1 Remote Raman & Fluorescence Capabilities for Chemical Detection at University of Hawaii Anupam Misra Shiv Sharma HIGP, SOEST, Univ. of Hawaii * Daytime Operation * Long Detection Range (no sample collection) * Fast Response * Portable 5 system (532 nm) (fiber optic coupled) 5 system (532 nm) (direct coupled) 8 system (532 nm) 8 UV system (248 nm) 16 UV system (248 nm) 8 Raman+LIBS system 8 Raman (785 nm) 2 system (532 nm) 3.5 system (tunable UV) 2.5 Raman+LIBS+LINF+LIDAR (532 nm) 12 UV system (248 nm, 266 nm)

2 What is Raman spectroscopy? Why need Raman spectra? Prof. Sir C. V. Raman Nobel Prize 193 Raman spectra Laser Beam splitter Sample Vibrational modes of molecules ω = µ k Spectrograph CCD Notch Filter Depends on atomic mass, bond lengths, bond strength, configuration, etc Unique spectrum for each molecule * Raman Fingerprints: Chemical detection with very high confidence level

(counts) 2 15 1 5 66 853 13 119 992 1178 1588 1584 Nitrobenzene Benzene 5 1 15 2

3 Example of Raman Spectra: Raman spectroscopy can distinguish between very similar chemicals Ethyl benzene Intensity (counts) Nitrobenzene Benzene N O O ω = µ k c = f λ Always the same unique spectrum for a chemical!!!

* Good technique for detecting chemicals you don t want to handle. * No sample preparation (Chemical waste sites, airport) Single pulse Raman detection of Conc.

4 * Good technique for detecting chemicals you don t want to handle. * No sample preparation (Chemical waste sites, airport) Single pulse Raman detection of Conc. Sulfuric Acid from 1 m H 2 SO 4, single pulse excitation, 1 m * 5 as-measured spectra shown Intensity (Counts) mj/pulse, gate width 1 ns, slit 5 µm

Dual Pulse Laser, 532 nm, 15 Hz, 1 mj/pulse (b) One gated intensified

5 Single Pulse Raman from 12 m Detection time = 1 ns System to sample view System Front view Integrated Remote Raman+LIBS System Key Components: (a) Dual Pulse Laser, 532 nm, 15 Hz, 1 mj/pulse (b) One gated intensified detector (ICCD) (c) One high resolution, high throughput spectrograph (d) 8-inch Telescope

Single shot Raman detection of Potassium chlorate & Potassium perchlorate at 12 m * Good reproducibility (showing 5 spectra as measured) * Good quality (High S/N) 25 Target at 12 m

6 Single shot Raman detection of Potassium chlorate & Potassium perchlorate at 12 m * Good reproducibility (showing 5 spectra as measured) * Good quality (High S/N) 25 Target at 12 m Single shot excitation 939 Intensity (Counts x1 4 ) KClO 3 KClO mj, 532 nm, 5 µm slit, laser spot size 1 cm (diameter).

7 Single shot Raman detection of Ammonium Nitrate & Potassium Nitrate at 12 m distance through sealed glass bottles * Good reproducibility (showing 5 measurements- as measured) Intensity (Counts x1 4 ) Target at 12 m Single shot excitation Detection time =.5 µs NH 4 NO 3 KNO KNO NH 4 NO

8 Single shot detection of 8% TNT on silica (NESTT sample) at 12 m distance * Good reproducibility (showing 5 measurements- as measured) 2 8% TNT on silica at 12 m Single shot excitation 1366 Intensity (Counts x1 3 ) 15 1 Detection time =.5 µs (O 2 )

9 Single shot Raman detection of Urea and Sugar at 12 m distance through sealed glass bottles * Good reproducibility (showing 5 measurements- as measured) 1 Target at 12 m Single shot excitation 111 Intensity (Counts x1 4 ) Urea Sugar mj, 532 nm, 5 µm slit, laser spot size 1 cm (diameter).

10 Significant improvement in Raman signal (1 s) * Good reproducibility (5 measurements shown) 4 Gypsum at 12 m 18 Intensity (Counts) s (= 15 pulses) 1 pulse

11 Raman Detection of Mixed grains of chemicals at 12 m distance * 1 s detection time * Good reproducibility (5 measurements shown) Intensity (Counts x 1 4 ) S 185 S 219 S 248 S 44 S 473 S 513 Nap 715 AN 763 Nap 121 Nap 144 AN 1382 Nap 1465 Nap Target at 12 m 1578 Nap S = Sulfur Nap = Naphthalene AN = Ammonium Nitrate mj/pulse, 15 Hz, 532 nm, 5 micron slit, laser spot size 1 cm.

12 Detection of atmosphere, target mineral and both (as measured spectra) Target (Gypsum CaSO 4.2H 2 O) at 5 m * O N H 2 O Atmosphere Intensity (counts) Target 2 Target + atmosphere

13 2 compact Raman+LIBS system Minerals at 9 m, 1 s (3 measurements shown for each mineral) Intensity (Counts x 1 6 ) Dolomite Sulfur Anhydrite Quartz Anatase nm, 3 mj/pulse

14 Remote Raman at 43 meters 1 s detection time, daytime 8 6 NH 4 NO 3 Intensity (Counts) 4 2 KNO 3 KClO 3 Urea

Standoff Raman (532 nm) detection through

vial (2 ml) B: polypropylene (PP) vial (3

7% E: dark brown glass bottle (5 ml) HDPE

15 Standoff Raman (532 nm) detection through sealed containers A: borosilicate glass vial (2 ml) B: polypropylene (PP) vial (3 ml) C: high-density polyethylene (HDPE) bottle (6 ml) D: amber glass bottle (75 ml) A T= 81% B 54% C 18% D 5.6% E 1.7% E: dark brown glass bottle (5 ml) HDPE Water bottle Bubble wraps containing 2 ml glass vials

Single pulse Raman detection of Ammonium Nitrate at 1 m

for each target 3 143 NH 4 NO 3, single pulse excitation, 1 m

HDPE bottle AN in PP bottle 3137 5 AN in brown glass bottle 5

16 Single pulse Raman detection of Ammonium Nitrate at 1 m distance through sealed bottles * 3 as measured spectra shown for each target NH 4 NO 3, single pulse excitation, 1 m Intensity (Counts x1 4 ) AN in HDPE bottle AN in PP bottle AN in brown glass bottle x nm, 55 mj/pulse, gate width 1 ns, slit 5 µm

Raman detection of hidden glass vial of Ammonium Nitrate through plastic bubble wrap * 5 as-measured spectra shown 4 143 1 m, 1 s Intensity

17 Raman detection of hidden glass vial of Ammonium Nitrate through plastic bubble wrap * 5 as-measured spectra shown m, 1 s Intensity (Counts x1 4 ) AN hidden in bubble wrap 3137 bubble wrap only nm, 55 mj/pulse, 15 hz, gate width 1 ns, slit 5 µm

Raman detection of AN through fluorescent label on HDPE bottle 5 4 1 m, 1 s 143 Intensity (Counts x1 6 ) 3

18 Raman detection of AN through fluorescent label on HDPE bottle m, 1 s 143 Intensity (Counts x1 6 ) AN in HDPE bottle HDPE bottle Yellow tape (center) Yellow tape (off set) X

Raman+LIBS Spectrograph with 5 spectral images on one ICCD detector ICCD Image (124 x 256 pixels) Wavelength Range 532.5 612.7 nm 457.3 53.9 nm 64.1 697.9 nm 736.5 869.4 nm 645.2 745.

19 Raman+LIBS Spectrograph with 5 spectral images on one ICCD detector ICCD Image (124 x 256 pixels) Wavelength Range nm nm nm nm nm 14 Intensity (Counts x 1 4 ) Wavelength (nm) Steel, at 9 m, 1 double pulse LIBS, Pulse separation 1 µs, 1 mj/pulse, gate delay 1 µs, gate width 4 µs. ICCD Gain 25

20 Single pulse and double pulse LIBS spectra of Aluminum sheet at 9 m. Intensity (Counts x 1 4 ) * Spectra showing good reproducibility (4 measurements shown) * LIBS signal enhancement in double pulse excitation Al, O Mn Mn, K Mg Mg, N Ca Ca Na Ca Ca Mn Al Mg Ca H Al Al Al Ca Ca Mg O Ca Ca Ca H N K O Wavelength (nm) Gate delay 1 µs, Gate width 2 µs, ICCD gain 1%, Double pulse separation 1 µs, 1 mj/pulse, spot size 1 mm (dia) There are small shot to shot variations.

21 Raman and Fluorescence Imaging LIDAR (RFI-LIDAR) for sea mine detection Ocean LIDAR (532 nm) Issues: * No detection in the top 1-2 m surface layer * Glint problem * Signal from fishes, plants, air bubbles

Single Shot Detection of AN inside HDPE plastic bottle at 2 m Seawater Depth with 532 nm Laser *3 as-measured spectra shown 25 Single pulse excitation 1 ns detection

22 Single Shot Detection of AN inside HDPE plastic bottle at 2 m Seawater Depth with 532 nm Laser *3 as-measured spectra shown 25 Single pulse excitation 1 ns detection Water Intensity (Counts) AN 5 AN Sulfate AN Water Plastic * Can detect explosives in plastic bags underwater * Metals have no Raman signal

23 Detection of both opaque metal object and also the transparent plastic dish using the image contrast. Raman Image Single pulse detection, detection time 3 ns

24 Detection in presence of bio-fluorescence Detection of oil spill One drop (.1 ml) of crude oil in 2 ml of water (5 ppm) Oil film is few micron thick

25 Current projects: 1. NASA Mars22 mission: Los Alamos National Lab SuperCam Instrument 2. NASA EPSCoR: Standoff biofinder+chemical analyzer 3. NASA PICASSO: Standoff Raman Line Scanner 4. NASA STTR: Q Peak Inc. : Small laser for remote Raman+LIBS (phase I) 5. ONR: Underwater Raman system 6. ONR (code 3): Long range (~km) Raman system (low cost drone) Thank you.

Underwater Raman Sensor for Detecting High Explosives and Homemade Explosives (HMEs)

Underwater Raman Sensor for Detecting High Explosives and Homemade Explosives (HMEs) Shiv K. Sharma* Hawaii Institute of Geophysics & Planetology, University of Hawaii (UH) at Manoa, Honolulu, Hawaii,