Micro purge of plasma region

摘要

An analysis system includes a laser source generating a laser beam for creating a plasma at a location on a sample. A spectrometer is responsive to photons emitted by the sample at said location and has an output. At least one nozzle is configured to deliver inert gas from a source locally to the location on the sample. A controller is responsive to a trigger signal and is configured to activate the laser source generating a series of laser pulses, open a valve to purge the location locally on the sample, and close the valve after one or more laser pulses.

主权项

1. A battery powered, portable LIBS analyzer comprising:
a laser source generating a laser beam received by an adjustable focusing lens for creating a plasma at a location on a sample; a spectrometer responsive to photons emitted by the sample at said location and having an output; a cartridge of inert gas; a nozzle configured to deliver inert gas from the cartridge locally to said location on the sample; a valve between the cartridge of inert gas and the nozzle; a trigger mechanism generating a trigger signal; and a controller, responsive to the trigger signal, and configured to:
initiate a focusing cycle by pulsing the laser while adjusting the focusing lens based on said spectrometer output to focus the laser beam at one location on the sample,initiate a cleaning cycle to clean said location by pulsing said laser for a number of pulses based on the output of said spectrometer,initiate an analysis cycle by pulsing said laser while controlling said valve to purge said location with inert gas and analyzing said spectrometer output,move the laser beam to a new location on the sample, andrepeat said cleaning cycle and said analysis cycle at said new location.