High power actively Q-switched downhole LIBS analysis systems
AssigneeEnergy, United States Department of
InventorsDustin Langdon McIntyre, Daniel Allen Hartzler
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Abstract
An actively Q-switched laser induced breakdown spectroscopy (LIBS) probe, utilizing an optical fiber, a pump beam transmitted through the optical fiber, a coupler, and a lens for collimating the pump beam. The actively Q-switched laser, coupled to a sensor which provides information to a computer that controls a high voltage pulser providing a pulse to a Pockels cell located within the laser which can selectively cause the laser to pulse, resulting in high energy pulses and a second lens for focusing the output pulse such that it creates a plasma or spark. The light from the spark is captured and directed back through an optical system to remote equipment for elemental and/or molecular analysis.
Claims19
A laser induced breakdown spectroscopy (LIBS) probe, comprising:
- a topside control system comprising a pumping source;
- an optical fiber, a pump beam transmitted through the optical fiber, wherein the optical fiber is connected to the topside control system and a downhole sensory system comprising:
- a coupler connected to the optical fiber;
- a first lens, the first lens connected to the coupler, the first lens having a predetermined shape and a first lens coating, the first lens collimating the pump beam;
- an actively Q-switched laser, the actively Q-switched laser coupled to a sensor which provides information to a computer that controls a high voltage pulser, the high voltage pulser providing a pulse to the actively Q-switched laser which can selectively cause the laser to pulse, resulting in high energy pulses;
- and a second lens for focusing an output pulse such that it creates a plasma or spark.
A laser induced breakdown spectroscopy (LIBS) system comprising:
- a topside control system comprising an optical pumping source connected to an optical fiber;
- and
- a downhole LIBS probe comprising:
- an adjustable focus lens arrangement connected to the optical fiber;
- an actively Q-switched (AQSW) laser connected to the adjustable focus arrangement;
- a sample area connected to at least a beam of the laser;
- and
- a spectral emission control connected to at least one of the optical fibers and the optical pumping source;
- a selective mirror located between the optical fiber and the actively Q-switched laser which selectively reflects a non-powering wavelength and directs an output to an AQSW control;
- the AQSW control selectively activating the AQSW laser based on a non-powering wavelength sent from the optical pumping source, allowing for remote control of the AQSW laser's output, wherein the optical pumping source is part of a topside control system comprising the pumping source, a computer, a trigger, and a spectrometer for receiving information returned through the optical fiber.
A method for operating an actively Q-switched laser induced breakdown spectroscopy (LIBS) probe, the method comprising:
- starting a topside control unit connected to the LIBS probe by an optical fiber, wherein the LIBS probe is positioned downhole;
- determining whether to use a previously loaded program;
- determining whether to use a previously used pump level;
- setting up a spectrometer to read information returned by the LIBS probe through the optical fiber;
- determining pump frequency and duration;
- pulse pumping to the LIBS probe;
- generating high energy pulses at the LIBS probe, the pulses producing high energy plasma;
- returning optical data on the higher energy plasma to the spectrometer through the optical fiber;
- and
- producing a measurement.
Dependencies are inferred from the claim text.