Chemical aerosol Raman detector

Abstract

A sensitive chemical aerosol Raman detector (CARD) has been developed for the trace detection and identification of chemical particles in the ambient atmosphere. CARD includes an improved aerosol concentrator with a concentration factor of about 40 and a CCD camera for improved detection sensitivity. Aerosolized isovanillin, which is relatively safe, has been used to characterize the performance of the CARD. The limit of detection (SNR = 10) for isovanillin in 15 s has been determined to be 1.6 pg/cm, which corresponds to 6.3 × 10 molecules/cm or 0.26 ppb. While less sensitive, CARD can also detect gases. This paper provides a more detailed description of the CARD hardware and detection algorithm than has previously been published.

In Situ Gas Monitoring by Fiber-Coupled Raman Spectrometry for H₂-Risk Management in Nuclear Containment During a Severe Nuclear Accident

“…Finally, researchers of the Massachusetts Institute of Technology (MIT, Lexington, MA, USA) also performed freespace Raman measurements with a double-pass transverse arrangement, a high-throughput spectrometer (F/1.8) and large surface CCD [16]. They obtained LODs of the order of the ppm for an integration time of 15 s and a power of 10 W.…”