Calibrating for Light backscatter from fractal aggregates

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CALIBRATING FOR LIGHT BACKSCATTER FROM FRACTAL AGGREGATES

description

Calibrating for Light backscatter from fractal aggregates. Why?. [1]. The source. Spherical Liquid Water Droplet Aerosol (m=1.33). Backscatter Setup. CCD Detector. Laser ( λ = 633nm). Aerosol Target. Beam splitter. Beam Dump. Results. Intensity (arbitrary units). Angle (˚). - PowerPoint PPT Presentation

Transcript of Calibrating for Light backscatter from fractal aggregates

Page 1: Calibrating for Light backscatter from fractal aggregates

CALIBRATING FOR LIGHT BACKSCATTER FROM

FRACTAL AGGREGATES

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WHY?

[1]

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THE SOURCE

Spherical Liquid Water Droplet Aerosol (m=1.33)

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BACKSCATTER SETUP

Laser (λ= 633nm)

CCD Detector

Aerosol Target

Beam splitter

Beam Dump

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Angle (˚)

Inte

nsity

(arb

itrar

y un

its)

RESULTS

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Mie ripples, but polydispersity wipes them outGuinier regime: θ~λ/(πd)

SIZING: FORWARD SCATTERING

Laser (λ= 633nm)

CCD Detector

Polarizers Lens IrisAerosol Target

Mirror

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RESULTS

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Backscatter suggests smaller size: ~1.5µmForward scattering suggests bigger size: ~6µm

DLS suggests mid-range size: ~2.5-4µm

Very likely polydisperse.

Backscatter apparatus likely works, but needs more testing.

FINAL RESULTS

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[1]"Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, 2007." IPCC - Intergovernmental Panel on Climate Change. Ed. S. Soloman, D. Qin, M.Manning, and Z. Chen. Internation Panel on Climate Change. Web. 09 Nov. 2011.

REFERENCE