Aerosol Properties & Processes: Instruments

Particle Analysis by Laser Mass Spectrometry - Next Generation (PALMS-NG)

PALMS-NG instrument
One PALMS-NG sTOF open on the bench.

The PALMS-NG is the next generation iteration of the traditional NOAA PALMS instrument. PALMS-NG is a bi-polar single-particle mass spectrometer which makes in-situ measurements of the chemical composition of aerosol particles. Aerosols are brought into a vacuum system and individual particles are detected and sized by light scattering as they cross two 405-nm continuous-wave laser beams. The scattered light signal from the second laser also provides a trigger for an excimer laser (193 nm), which is pulsed so its beam hits the particle to desorb and ionize molecules and atoms. These ions are analyzed with two sTOFs (time-of-flight mass spectrometers) to provide a complete mass spectrum from each particle. The instrument is capable of measuring particles from ~0.1 to 5 μm in diameter. Artifacts are minimized because particles never touch a surface. PALMS-NG reports raw number fractions of particle types (e.g., dust, sea-salt, biomass burning), and also quantitative mass concentrations when combined with an independently measured, quantitative size distribution such as the aerosol microphysical properties (AMP).

PALMS-NG instrument installed
PALMS-NG inside the nose of the NASA WB-57 during ACCLIP 2021.

PALMS-NG has flown in the nose of the NASA WB-57F high-altitude research aircraft, which is operated by NASA Johnson Space Center based at Ellington Field in Houston, Texas.

Field Projects / Platforms