Continuous discharge monitor for borehole drilling using directed energy.

Abstract

Apparatus and methods for monitoring discharge from boreholes to determine the composition of soil material removed from the boreholes are described. [Solution] Monitoring can be performed in real time as the borehole is being deepened with a millimeter-wave drilling beam. This technology allows for real-time monitoring of the elemental composition of soil materials (e.g., rocks, minerals, crystals, metals, etc.) within a borehole created by a directed energy beam that melts and vaporizes the soil material along its path. By using a continuous emission monitor (CEM) in combination with directed energy drilling of the borehole, the surface of precious metals and commercial metals can be rapidly investigated.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims the benefit of priority under 35 U.S.C. § 119(e) to U.S. Patent Application No. 63 / 291,744, filed on December 20, 2021, entitled "Continuous Emissions Monitor for Directed - Energy Borehole drilling", which is hereby incorporated by reference in its entirety. Government Support This invention was made with government support under award number DE - AR0001051 awarded by the Department of Energy. The government has certain rights in this invention.

Background Art

[0002] High - power, directed - energy beams at microwave or millimeter - wave (MMW) frequencies can be used, inter alia, for generating geothermal energy and for mining, to drill boreholes in rock. These drilling beams heat the rock to thousands of degrees Celsius, melting and vaporizing the rock. The vaporized rock can be ejected from the borehole to the surface by high - pressure gas, which also prevents the collapse of the borehole.

Summary of the Invention

[0003] This technology allows for real-time monitoring of the elemental composition of soil materials (e.g., rocks, minerals, crystals, metals, etc.) within a borehole generated by a directed energy beam that melts and vaporizes the soil material along its path. The extracted material / exhaust from such high-temperature drilling processes is typically over 1000°C and may contain small particles and vapors that can be analyzed by a continuous emission monitor (CEM). Using a CEM in combination with directed energy drilling of boreholes enables rapid surface investigation of precious and commercial metals. In one implementation, a CEM for directed energy borehole penetration utilizes a portion of the directed energy beam to excite the extracted exhaust, making elements detectable for real-time identification at the borehole site.

[0004] A CEM can monitor boreholes drilled with a millimeter-wave directed energy beam as follows: The exhaust gas produced by vaporizing soil material with a millimeter-wave directed energy beam is directed into a plasma chamber. In the plasma chamber, the exhaust gas is heated to a plasma state, which excites the exhaust gas components and generates light emission. A spectrometer, which can be calibrated periodically, performs spectroscopic measurements of the plasma emission. These spectroscopic measurements are then used to determine the composition of the exhaust gas.

[0005] Plasma can be generated within a plasma chamber by a portion of the MMW radiation associated with an MMW directed energy beam. This portion of millimeter-wave MMW radiation can be collected from reflected light of MMW radiation moving into or out of a borehole. Directing the exhaust gas produced by vaporizing soil material with a portion of the MMW radiation into the plasma chamber may involve ejecting particles in a gas stream from the borehole to a sample tube connected to the plasma chamber.

[0006] A CEM for monitoring the composition of soil material in a borehole, generated by a millimeter-wave directed energy beam, may include a plasma chamber and a spectrometer. The plasma chamber contains plasma generated by the portion of millimeter-wave radiation used to form the directed energy beam, which heats the vaporized gas and particles expelled from the borehole. A spectrometer, electromagnetically communicating with the plasma chamber, measures the emission spectrum from the plasma chamber. This spectrum indicates the composition of the soil material collected from the borehole.

[0007] The spectrometer may be a grating spectrometer configured to monitor at least one band with a spectral resolution of 0.02 nm or greater, a bandwidth of 20 nm, and a center wavelength in the 200 nm to 800 nm region.

[0008] The CEM also includes a mirror positioned within the plasma chamber for focusing a portion of the MMW directed energy beam into a spot, and a sample tube extending into the plasma chamber for emitting vapor and particles from the borehole into the plasma chamber near the spot. The CEM may also include a calibration chamber fluidly communicating with the plasma chamber for providing a calibration sample to the plasma chamber. The CEM may further include a reflected power isolator electromagnetically communicating with the plasma chamber to couple a portion of the MMW radiation outside the transmission line that guides the MMW radiation to the bottom of the borehole.

[0009] All combinations of the aforementioned concepts and additional concepts discussed in more detail below (on the premise that such concepts are not contradictory) are assumed to be part of the subject matter of the invention disclosed herein. In particular, all combinations of the subject matter described in the claims, as stated at the end of this disclosure, are assumed to be part of the subject matter of the invention disclosed herein. Any terms explicitly used herein, which may be described in any disclosure incorporated by reference, should be given meanings that are most consistent with the specific concepts disclosed herein. [Brief explanation of the drawing]

[0010] The drawings are for illustrative purposes only and are not intended to limit the scope of the subject matter of the invention. The drawings are not necessarily to exact scale, and in some cases, various aspects of the subject matter of the invention disclosed herein may be exaggerated or enlarged in the drawings to facilitate understanding of different features. In the drawings, similar reference letters generally refer to similar features (e.g., functionally similar and / or structurally similar elements).

[0011] [Figure 1] Figure 1 shows a millimeter-wave (MMW) directional energy drilling system with a continuous emission monitor (CEM) for borehole material extraction / exhaust.

[0012] [Figure 2] Figure 2 shows a plasma chamber for exciting atomic emission of a portion of the borehole material / exhaust using power extracted from the main directed energy drilling beam in the system of Figure 1.

[0013] [Figure 3] Figure 3 shows a calibration source that can be coupled to the plasma chamber in Figure 2.

[0014] [Figure 4] Figure 4 shows a lattice spectrometer for simultaneously monitoring atomic emission from many elements with fine spectral resolution.

[0015] [Figure 5] Figure 5 shows the parameters of the diffraction grating spectrometer.

[0016] [Figure 6A] Figure 6A lists the spectral emissions at approximately 240 nm for various elements that may be present in soil materials.

[0017] [Figure 6B] Figure 6B lists the spectral emissions at approximately 320 nm for various elements that may be present in soil materials.

[0018] [Figure 6C] FIG. 6C lists the spectral emissions at about 346 nm for various elements that may be included in the soil material.

[0019] [Figure 6D] FIG. 6D lists the spectral emissions at about 398 nm for various elements that may be included in the soil material.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] 1. Millimeter Wave Directed Energy Drilling System FIG. 1 shows a millimeter wave (MMW) directed energy drilling system 100 having a plasma chamber 190 for analyzing the exhaust from the borehole 110. The system 100 includes a high-power MMW source 120, such as a gyrotron, that generates high-power millimeter wave radiation 103 in the frequency range of 30 - 300 GHz at an output level of 0.1 - 2.0 MW. The high-power MMW radiation is coupled to a high-power transmission line 130 or waveguide that directs this high-power MMW radiation 103 to the bottom of the borehole 110. The high-power transmission line 130 or waveguide may include or be formed from a conductive material such as copper. A mylar bend 132 may be used to fold the transmission line 130 and redirect the high-power MMW radiation 103 from a first direction to a second direction (e.g., from a horizontal direction to a downward vertical direction to the borehole 110). When the high-power MMW drilling beam 105 is emitted from the distal end of the transmission line 130, it diffracts such that the diameter of the borehole 110 is larger than the transmission line 130 by melting and vaporizing the soil material at the bottom of the borehole 110, creating an annular space for the collection or discharge of the vaporized soil material within the exhaust stream 145.

[0021] The high-power transmission line 130 may be formed as a tube that also guides gas 135 to the bottom of the borehole 110. Near atmospheric pressure (e.g., 15-150 psi), the gas can be air, nitrogen, hydrogen, methane, or carbon dioxide. At high pressures towards supercritical fluid states (e.g., >2,000 psi), the gas 135 can be a noble gas such as argon. The gas is injected into the high-power transmission line via a transmission line gas manifold 137. The injected gas 135 is permeable to millimeter-wave radiation 130 and is at a pressure and velocity sufficient to prevent arc discharge. The gas ejects small particles (e.g., less than 10 μm in diameter) of vapor and vaporized soil material out of the annular space surrounding the distal end 138 of the high-power transmission line 130 as an exhaust flow 145.

[0022] The borehole 110 is capped by an exhaust pipe 112 and a through-waveguide seal 114. The through-waveguide seal 114 seals the borehole 110 and directs the exhaust flow 145 through the exhaust pipe 112. A sample tube 146, made of a metal or ceramic such as Inconel or alumina, which may exist in a high-temperature exhaust environment (e.g., at least 800°C or at least 1000°C), is inserted into the exhaust pipe 112 so as to be led out of the borehole 110, and redirects a portion of the exhaust flow 145 as a wake to the plasma chamber 190. The sample tube 146 may be near the borehole 110 or located some distance away from the borehole, allowing the gas to be cooled as needed. The sample tube 146 may be connected to a sample port on the plasma chamber 190, allowing the gas to flow into the plasma chamber. The wake flow rate to the plasma chamber 190 may be in the range of 5 to 25 ml / min. The exhaust wake can be less than 0.01%, 0.001%, or 0.0001% of the total exhaust flow, and can be greater than 1000 scfh (470 L / min). The exhaust wake may, but does not need to be, a homogeneous or uniform sample of the entire exhaust flow for finding potentially commercially valuable reserves.

[0023] As exhaust gases and particles from the wake enter the plasma chamber 190, they are ionized and heated by MMW radiation, forming a plasma. A portion of the MMW radiation 103 can be collected (e.g., using an output coupler) and directed into the plasma chamber 190, decomposing, heating, and vaporizing particles in the wake and exciting the resulting gas. In some cases, the collected radiation is injected into the plasma chamber through the gas purge inlet 127. The gas can be excited. Due to the strong electric field from the focused MMW radiation 103, gas molecules may be ionized, electrons may be accelerated, and the gas in the plasma chamber 190 is excited. The excitation of the gas into the plasma can generate light radiation for spectroscopic measurement, analysis, and determination of the components in the exhaust flow 145.

[0024] A portion of the high-power MMW emission 103 (e.g., approximately 1–3 kW) is guided to the plasma chamber 190 by a sampling transmission line 131. In some implementations, a reflected power isolator 180 may be inserted along the high-power transmission line 130, as shown in Figure 1, to sample the power reflected again from the molten target at the bottom of the borehole 110. A window seal 125 and a gas purge inlet 127 at or near the interface between the reflected power isolator 180 and the sampling transmission line 131 prevent plasma propagation from the plasma chamber 190 to the high-power transmission line 130.

[0025] The spectrometer 185 analyzes the light emission from the plasma in the plasma chamber 190 to provide a representation of the elemental composition of the vaporized soil material from the borehole 110. A fiber optic cable 195 transmits infrared (IR), visible light, and / or ultraviolet (UV) light emitted by the plasma from the plasma chamber 190 to the spectrometer 185. The spectrometer measures 10 μg / m³ 3 To determine the elemental composition of vaporized soil material with better sensitivity, the emission spectrum is resolved with sufficient detail and sensitivity.

[0026] The plasma chamber 190 and spectrometer 185 can be calibrated by a calibration source 197 connected to a sample tube 146. The calibration source 197 injects known concentrations of the element of interest on command to provide a span signal for calibrating the elemental concentration in the exhaust flow 145 from the borehole 110. During calibration, the exhaust flow 145 may or may not be valved off from the plasma chamber by a control valve 148 in the sample tube 146. Alternatively, the control valve 148 may or may not be used to valve off the gas from the calibration source. In some cases, the control valve 148 may not be included in the system. The elements of interest include, but are not limited to, commercially valuable metals such as copper, nickel, or lithium, and precious metals such as gold, platinum, or silver. Calibration may be performed periodically or in real time as needed to reveal the potentially changing composition of the exhaust flow 145 due to the chemicals of different rock layers, for example, when the borehole 110 is deepened and penetrated by a high-power millimeter-wave drilling beam 105. Changes in the chemical properties of the soil material layer may affect the plasma efficiency of atomic emission excitation by changing the temperature and density of plasma electrons, which in turn may change the electron atomic excitation efficiency.

[0027] Any monitoring device 170 coupled to the miter bend 132 may monitor the depth and / or rate of drilling of the borehole 110 using a small-signal monitoring signal (not shown) co-propagating with the high-power millimeter-wave radiation 103 along the high-power transmission line 130. The monitoring signal may be pulsed, chirp, or constant frequency and may have a different frequency from the high-power millimeter-wave radiation 103. The monitoring signal may be reflected off the rock face or material at the bottom of the borehole 110. This reflection propagates along the high-power transmission line 130 to the monitoring device 170, which senses the interference of the reflection with a local oscillator. The interference may be used to derive the depth and / or rate of drilling of the borehole 110. Further details of the monitoring device are provided in "Rate This may be described in U.S. Patent Application No. 63 / 291,731 entitled “Rate of Penetration / Depth Monitor for a Millimeter-Wave Beam Made Hole” and its corresponding concurrently filed non-provisional international application entitled “Rate of Penetration / Depth Monitor for a Borehole formed with Millimeter-Wave Beam” (Agent Reference Number MIT-23062WO01), both of which are incorporated herein by reference in their entirety.

[0028] 2. Plasma Chamber Figure 2 shows the plasma chamber 190 in more detail. The plasma chamber 190 is a hermetically sealed millimeter-wave power leakage enclosure into which the high-power MMW radiation 103 collection section 104 and the exhaust wake 202 are introduced. The millimeter-wave radiation 103 is emitted into the free space of the plasma chamber 190 toward a focusing mirror 210 that focuses the MMW radiation 103 into a diffraction-limited spot 220 with a width of approximately 2 to 4 wavelengths. This increases the electric field strength of the spot 220 to approximately 10 kV / cm or more, generating and maintaining the plasma 205.

[0029] The sample tube 146 passes partway through the plasma chamber 190. Its output aperture 149 is at the approximate edge of the focused spot 220 formed after the MMW radiation 103 is reflected from the focusing mirror 210. The exhaust gas wake 202 exits the sample tube 146 and enters the focused spot 220, and the focused MMW radiation 103 and plasma 205 (if present) may heat the exhaust wake 202. Heating may make particles, if present in the wake 202, more readily decompose. The heated exhaust may also act as a thermionic emitter to fix the plasma 205 in the wake 202 at the focused spot 220. A starting spark from a Tesla coil or antenna wire may be used to initiate decomposition from a low-temperature start.

[0030] The optical fiber cable 195 is introduced through a small hole in the plasma chamber 190 to visualize the plasma 205 and transmit the IR light, visible light, and / or UV light emission to the spectrometer 185 for analysis.

[0031] The output exhaust pipe 230 directs the gas from the plasma chamber 190 to the final exhaust. The output exhaust pipe 230 is maintained at a pressure slightly lower than the gas input from the sample tube 146 and the sampling transmission line 131. The output exhaust pipe 230 is also twisted to induce millimeter-wave mode conversion and is fabricated from a millimeter-wave opaque dielectric and / or low-electrical-conductivity metal to efficiently absorb higher-order modes. The twisting of the absorbing material and its use reduce or prevent the propagation of millimeter-wave output from the plasma chamber 190 to the environment.

[0032] 3. Calibration source Figure 3 shows an example of a calibration source 197 for more detailed quantitative monitoring of elemental concentrations in the borehole exhaust flow 145. The calibration source 197 is used when the known concentration of the element being monitored is, for example, 100 μg / m³. 3 Aerosol 305 is periodically introduced into the exhaust wake 202 to provide span calibration that matches the unknown atomic emission level.

[0033] Calibration source 197 can generate aerosol 305 as follows: For example, a calibrated standard solution 310 of the element to be monitored, in which the concentration of each element in a weak acid solution is 200 μg / ml, is pumped into a nebulizer 330 (e.g., a Mienhard nebulizer) by a peristaltic pump 320 at a nominal rate of about 1 ml / min. The nebulizer 330 is operated by a compressed gas flow (e.g., nitrogen at a flow rate of about 1 l / min) from a cylinder 340 or other supply source and a gas flow controller 350. The nebulizer 330 converts the liquid standard solution 310 into an aerosol that is filtered into large droplets by a spray chamber 360. The filtered liquid with large droplets is collected in a waste container 370 attached to the spray chamber 360 by a sealed connection.

[0034] The concentrations of the standard solution elements injected into the exhaust downstream 202 should be precisely known for quantitative monitoring. Concentration C can be determined by the following formula:

number

[0035] 4.Spectrometer Atomic emission from neutral atoms, rather than ionized atoms, can dominate the emission spectrum from atmospheric pressure plasmas due to typical electron temperatures below 1 eV, as local thermodynamic equilibrium limits the number of high-energy electrons that can ionize atoms. Table 1 lists some of the prominent neutral atomic emission wavelengths in air for metallic and rare-earth elements in the UV wavelength range. Spectrometer 185, with fine resolution for these wavelengths, can be used to distinguish species in the plasma. A spectral resolution better than 0.05 nm is desirable across the emission spectrum range. Spectrometer 185 may also have a broad spectral range to cover as many elements as possible. [Table 1] JPEG2026102557000004.jpg192170 Table 1. Prominent UV atomic emission wavelengths for metals and rare earth elements

[0036] Figure 4 shows a spectrometer 185 that monitors emissions from many elements in the exhaust wake 202 (Figure 2) with fine spectral resolution. Spectrometer 185 includes an inlet slit 405, a concave input mirror 410, a grating 420, several concave output mirrors 430, and several linear detector arrays 440. (Similar performance can be achieved with many small spectrometers having a narrow wavelength range.) Figure 4 shows three concave output mirrors 430 and linear detector arrays 440, but other spectrometers may have more or fewer concave output mirrors and linear detector arrays.

[0037] A fiber optic cable 195 guides plasma emission to an inlet slit 405, which may be approximately 10 nm wide and is the focal point of a concave input mirror 410. The concave input mirror 410 images the light transmitted through the slit 405 onto a grating 420, which diffracts different spectral components at angles proportional to their wavelengths. Concave output mirrors 430 distribute the diffraction pattern at different angles, focusing different portions of the diffracted light from the grating onto their respective linear detector arrays 440. In Figure 4, there is one linear detector array 440 for each concave output mirror 430. Each detector array 440 monitors the wavelength region blocked by the corresponding concave output mirror 430. In other implementations, one linear detector array or one two-dimensional detector array may be used to record emissions reflected from all output mirrors 430. The detector arrays 440 are connected to a computer, processor, and / or other signal processing electronic equipment (not shown) for signal analysis, data storage, and / or display.

[0038] The dimensions, angle, wavelength resolution, and detector array bandwidth of a grating spectrometer can be determined by the following three equations: Equation 2 is the equation for the standard grating diffraction angle, Equation 3 is the equation for the wavelength resolution, and Equation 4 is the equation for the detector array bandwidth. θ D =arcsin(λn-sinθ i ) (2)

number

[0039] Figure 5 shows the parameters in Equations 2 to 4. These parameters are defined as follows: θ D -Diffraction angle from lattice 420 θ i - Incidence angle on grid 420 λ-wavelength n-lattice groove density Distance from L-output mirror 430 to detector array 440 w-width of one sensor pixel 442 in detector array 440 Total length of Y-detector array 440

[0040] Table 2 shows the calculation results using Equations 2 to 4 for a grating spectrometer 185 having a grating groove density of 2400 gr / mm and four 2048-pixel linear detector arrays 440 having pixels with a width of 14 μm. The detector arrays 440 can monitor different bands with a spectral resolution of less than 0.016 nm. Each band is approximately 16 nm wide and, in this embodiment, has wavelengths in the 200 nm to 800 nm range. This spectrometer can detect any of 35 elements in the exhaust wake, including commercially valuable metals such as copper, aluminum, nickel, titanium, lithium, palladium, gold, and silver. Other spectrometers may have a different number of bands (e.g., three, five, or six), bandwidths (e.g., 20 nm, 25 nm, 30 nm), and / or spectral resolutions (e.g., 0.1 nm, 0.2 nm, 0.3 nm, etc.) and may be able to detect a different number and types of elements. [Table 2] Table 2. Diffraction angle, resolution, and bandwidth of a 2048-pixel linear detector array with a diffraction grating of 2400 gr / mm and pixels with a width of 14 μm.

[0041] Figures 6A to 6D enumerate spectral emissions in four bands for various elements that can be used to detect the presence of valuable elements. Figure 6A shows emissions in the 240 nm band, Figure 6B shows emissions in the 320 nm band, Figure 6C shows emissions in the 346 nm band, and Figure 6D shows emissions in the 398 nm band. For many elements, two or more wavelengths can be detected, ensuring clear identification of the element. Many rare earth elements are present together with silicon and carbon. Monitoring silicon concentration indicates the type of soil material being drilled. The presence of carbon indicates involvement with hydrocarbon compounds. Additional channels can be added to increase the number of elements monitored. Thus, a comprehensive and rapid investigation of the subsurface chemical properties within the borehole 110 can be achieved using this technique while the borehole is being drilled.

[0042] Devices for continuously monitoring discharges from boreholes drilled by millimeter-wave directional energy drilling beams may be implemented and / or included within drilling systems of various configurations. Exemplary configurations are listed below. Other methods for monitoring discharges may also be implemented. (1) A method for monitoring emissions from a borehole drilled by a millimeter-wave directional energy drilling beam, comprising: receiving exhaust gas generated by vaporizing soil material by the millimeter-wave directional energy drilling beam in a plasma chamber; heating the exhaust gas with electromagnetic radiation in the plasma chamber to generate plasma and light radiation from the plasma; performing a spectroscopic measurement of the light radiation using a spectrometer; and determining the composition of the exhaust gas based on the spectroscopic measurement of the light radiation. (2) The method of (1), further comprising receiving a portion of millimeter-wave radiation used to fabricate a millimeter-wave directed energy drilling beam in a plasma chamber, and focusing the portion of millimeter-wave radiation to provide electromagnetic radiation to generate a plasma. (3) The method of (2), further comprising collecting a portion of the millimeter-wave radiation returned from the reflected light of the millimeter-wave drilling beam from the bottom of the borehole. (4) The method according to any one of (1) to (3), further comprising calibrating a spectrometer. (5) The method according to (4), wherein calibrating a spectrometer is the process of introducing an aerosol from a calibration source into a plasma chamber, the aerosol supplying a known amount of an element from the calibration source to the plasma, measuring the level of light emission from the plasma while the aerosol is present in the plasma, the level of light emission indicating the amount of the element, and determining the amount of the element in the exhaust gas from the level of light emission. (6) The method according to any one of (1) to (5), wherein receiving exhaust gas generated by vaporizing soil material includes receiving particles by gas flow from a borehole into a sample tube connected to a plasma chamber. (7) Soil material in boreholes generated by millimeter-wave directional energy drilling beams A system for monitoring the composition of a material, comprising: a plasma chamber for receiving exhaust gas from a borehole and receiving a portion of the millimeter-wave radiation used to produce a millimeter-wave borehole beam, the plasma chamber being configured to heat the exhaust gas with the portion of the millimeter-wave radiation to generate light emission from the plasma; and a spectrometer electromagnetically communicating with the plasma chamber for measuring the spectrum of light emission from the plasma, wherein the spectrum indicates the composition of the soil material in the borehole. (8) The system according to configuration (7), further comprising a sample tube or sample port connected to a plasma chamber for receiving exhaust gas from a borehole, and an exhaust tube or exhaust port connected to a plasma chamber for exhausting at least exhaust gas from the plasma chamber. (9) The system as described in configuration (8), wherein the sample tube or sample port is made of a material that can withstand temperatures of at least 800°C. (10) The system according to any one of configurations (7) to (9), wherein the spectrometer is a grating spectrometer configured to monitor at least one band having a spectral resolution of 0.02 nm or greater, a bandwidth of 20 nm, and a center wavelength in the region of 200 nm to 800 nm. (11) The system according to any one of configurations (7) to (10), further comprising a mirror placed in the plasma chamber for focusing the millimeter-wave radiation portion to a spot, and a sample tube extending into the plasma chamber for releasing exhaust gas from a borehole into the plasma chamber near the spot. (12) The system according to configuration (11), further comprising an optical fiber cable connected to a plasma chamber and arranged to receive light radiation from a spot and guide the light radiation to a spectrometer. (13) The system according to any one of configurations (7) to (12), further comprising a calibration source in fluid communication with the plasma chamber for supplying an aerosol for calibration of the spectrometer to the plasma chamber. (14) The system according to any one of configurations (7) to (13), further comprising a reflected power isolator in electromagnetic communication with a plasma chamber to couple a portion of the millimeter-wave radiation outside a transmission line that guides the millimeter-wave radiation to the bottom of a borehole in order to form a millimeter-wave directional energy drilling beam. (15) A system for drilling a borehole and monitoring emissions from the borehole, comprising: a high-power millimeter-wave (MMW) source; a waveguide for transporting MMW radiation from the MMW source to the borehole; an exhaust pipe for sealing the borehole and capturing exhaust gases from the borehole while the borehole is being deepened with an MMW drilling beam formed from the MMW radiation; a plasma chamber in fluid communication with the exhaust pipe for receiving the exhaust wake collected from the exhaust gases; and a spectrometer in electromagnetic communication with the plasma chamber for detecting emissions from the plasma formed in the plasma chamber from the exhaust wake. (16) The system according to configuration (15), further comprising a reflected power isolator in electromagnetic communication with the plasma chamber for coupling the portion of the MMW radiation generated by the MMW source to the plasma chamber. (17) The system according to configuration (16), further comprising a mirror placed inside the plasma chamber for focusing the MMW radiation portion onto a spot inside the plasma chamber, and a sample tube extending into the plasma chamber for releasing the exhaust wake into the plasma chamber near the spot. (18) The system according to configuration (17), further comprising an optical fiber cable connected to a plasma chamber and arranged to receive light radiation from a spot and guide the light radiation to a spectrometer. (19) The system according to any one of configurations (15) to (18), wherein the spectrometer is a grating spectrometer configured to monitor at least one band having a spectral resolution of 0.02 nm or greater, a bandwidth of 20 nm, and a center wavelength in the region of 200 nm to 800 nm. (20) The system according to any one of configurations (15) to (19), further comprising a calibration source in fluid communication with the plasma chamber for supplying an aerosol for calibration of the spectrometer to the plasma chamber.

[0043] 6. Conclusion All parameters, dimensions, materials, and configurations described herein are illustrative, and actual parameters, dimensions, materials, and / or configurations will depend on the specific application in which the teachings of the present invention are used. Therefore, it should be understood that the embodiments described herein are presented primarily as examples, and that embodiments of the present invention may be practiced in a manner different from those specifically described and claimed, within the scope of the appended claims and their equivalents. Embodiments relating to the inventions of this disclosure cover individual features, systems, articles, materials, kits, and / or methods described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and / or methods is included within the scope of the inventions of this disclosure, provided that such features, systems, articles, materials, kits, and / or methods are not mutually inconsistent.

[0044] Furthermore, various concepts of the present invention can be embodied in one or more methods, of which at least one embodiment is provided. The actions performed as part of the method may be ordered differently in some cases. Thus, in some implementations of the invention, each action of a given method may be performed in a different order than that specifically exemplified, which may include performing some actions simultaneously (even though such actions are shown as consecutive actions in the exemplary embodiment).

[0045] All publications, patent applications, patents, and other references mentioned herein are incorporated in their entirety by reference.

[0046] All definitions defined and used herein should be understood to govern dictionary definitions, definitions incorporated by reference in documents, and / or the ordinary meanings of the defined terms.

[0047] As used herein and in the claims, the indefinite articles "a" and "an" should be understood to mean "at least one" unless explicitly stated otherwise.

[0048] As used herein and in the claims, the phrase “and / or” should be understood to mean “either or both” of the elements thus combined, that is, elements that exist conjugate in some cases and disjunct in others. Multiple elements enumerated by “and / or” should be interpreted in the same manner, that is, “one or more” of the elements thus combined. Other elements may exist, at will, whether related to or unrelated to the elements specifically identified by the “and / or” clause. Thus, as a non-restrictive example, when used in combination with open-ended language such as “includes,” a reference to “A and / or B” may, in one embodiment, refer to A only (optionally including elements other than B), in another embodiment, refer to B only (optionally including elements other than A), and in yet another embodiment, refer to both A and B (optionally including other elements), and so on.

[0049] As used herein and in the claims, “or” should be understood to have the same meaning as “and / or” as defined above. For example, when separating items in a list, “or” or “and / or” is inclusive, that is, several or enumerated elements and, optionally, at least one other unenumerated item. It shall be interpreted as including one but also including two or more of them. Conversely, only clearly indicated terms, such as "only one of" or "just one of," or "consisting of" as used in claims, refer to including exactly one element from several or enumerated elements. In general, the term "or" as used herein shall be interpreted only as indicating an exclusive choice (i.e., "one or the other, but not both") when preceded by terms of exclusivity, such as "either," "one of," "only one of," or "just one of." The term "essentially" as used in claims shall have its usual meaning as used in the field of patent law.

[0050] As used herein and in the claims, the term “at least one” in relation to a list of one or more elements means at least one element selected from one or more elements in the list of elements, but not necessarily including at least one of all elements specifically enumerated in the list of elements, nor excluding any combination of elements in the list of elements. This definition also allows for the optional presence of elements other than those specifically identified in the list of elements, whether related to or unrelated to the specifically identified elements, as referred to by the phrase “at least one.” Accordingly, in non-limiting embodiments, "at least one of A and B" (or equivalently "at least one of A or B", or equivalently "at least one of A and / or B") may mean, in one embodiment, at least one optionally comprising two or more A's and no B (and optionally comprising elements other than B); in another embodiment, at least one optionally comprising two or more B's and no A (and optionally comprising elements other than A); and in yet another embodiment, at least one optionally comprising two or more A's and at least one optionally comprising two or more B's (and optionally comprising other elements as needed), and so on.

[0051] In the claims and the above specification, all transitional clauses, such as “equipment,” “includes,” “possess,” “have,” “incorporate,” “involve,” “hold,” and “compose,” should be understood to be open-ended, meaning they include but are not limited to. Only the transitional clauses “consisting of” and “consisting essentially of” shall be considered closed or semi-closed transitional clauses, respectively, as provided in Section 2111.03 of the U.S. Patent and Trademark Office's Patent Examination Procedure Manual.

Claims

1. A system for drilling a borehole and monitoring the discharge from the borehole, A high-power millimeter-wave (MMW) source, A waveguide that carries MMW radiation from the MMW source to the borehole, While the borehole is being deepened by the MMW borehole beam formed from the MMW radiation, an exhaust pipe is provided to seal the borehole and capture exhaust gas from the borehole. A plasma chamber, which is in fluid communication with the exhaust piping, receives the exhaust wake taken from the exhaust gas and receives the portion of the MMW radiation used to heat the exhaust wake, The system comprises a spectrometer that is in electromagnetic communication with the plasma chamber for detecting emissions from the plasma formed in the plasma chamber from the exhaust wake.

2. The system according to claim 1, further comprising a reflected power isolator in electromagnetic communication with the plasma chamber for coupling the portion of the MMW radiation generated by the MMW source to the plasma chamber.

3. A mirror placed inside the plasma chamber is used to focus the portion of the MMW radiation onto a spot inside the plasma chamber. The system according to claim 2, further comprising a sample tube extending into the plasma chamber for releasing the exhaust wake into the plasma chamber near the spot.

4. The system according to claim 3, further comprising an optical fiber cable connected to the plasma chamber and arranged to receive light radiation from the spot and guide the light radiation to the spectrometer.

5. The system according to claim 1, wherein the spectrometer is a grating spectrometer configured to monitor at least one band having a spectral resolution of 0.02 nm or more, a bandwidth of 20 nm, and a central wavelength in the region of 200 nm to 800 nm.

6. The system according to claim 1, further comprising a calibration source in fluid communication with the plasma chamber for supplying an aerosol for calibration of the spectrometer to the plasma chamber.

7. A system for drilling a borehole and monitoring the discharge from the borehole, A high-power millimeter-wave (MMW) source, A waveguide that carries MMW radiation from the MMW source to the borehole, While the borehole is being deepened by the MMW borehole beam formed from the MMW radiation, an exhaust pipe is provided to seal the borehole and capture exhaust gas from the borehole. The system comprises a plasma chamber in fluid communication with the exhaust piping for receiving the exhaust wake taken from the exhaust gas and for receiving the portion of the MMW radiation used to heat the exhaust wake.

8. The system according to claim 7, further comprising a reflected power isolator in electromagnetic communication with the plasma chamber for coupling the portion of the MMW radiation generated by the MMW source to the plasma chamber.

9. A mirror placed inside the plasma chamber is used to focus the portion of the MMW radiation onto a spot inside the plasma chamber. The system according to claim 8, further comprising a sample tube extending within the plasma chamber for releasing the exhaust wake into the plasma chamber near the spot.

10. The system according to claim 9, further comprising an optical fiber cable connected to the plasma chamber and arranged to receive the light radiation from the spot and guide the light radiation to the spectrometer.

11. A spectrometer that is in electromagnetic communication with the plasma chamber for detecting emissions from the plasma formed in the plasma chamber from the exhaust wake, the spectrometer being a grating spectrometer configured to monitor at least one band having a spectral resolution of 0.02 nm or more, a bandwidth of 20 nm, and a center wavelength in the region of 200 nm to 800 nm, and the spectrometer, The system according to claim 7, further comprising a calibration source in fluid communication with the plasma chamber for supplying an aerosol for calibration of the spectrometer to the plasma chamber.

12. A system for monitoring the composition of soil material in boreholes generated by a millimeter-wave directional energy drilling beam, A plasma chamber for receiving exhaust gas from the borehole and receiving a portion of the millimeter-wave radiation used to produce the millimeter-wave directional energy borehole beam, wherein the plasma chamber is configured to heat the exhaust gas with the portion of the millimeter-wave radiation in order to generate light emission of plasma emission, The system comprises a sample tube or sample port connected to the plasma chamber for receiving the exhaust gas from the borehole.

13. The system according to claim 12, further comprising an exhaust pipe or exhaust port connected to the plasma chamber for exhausting at least the exhaust gas from the plasma chamber.

14. The system according to claim 12, wherein the sample tube or sample port is made of a material that can withstand a temperature of at least 800°C.

15. A mirror placed within the plasma chamber for focusing the portion of the millimeter-wave radiation into a spot, The system according to claim 12, further comprising a sample tube or sample port disposed to discharge the exhaust gas from the borehole into the plasma chamber so that the exhaust gas flows to the spot.

16. The system according to claim 15, further comprising an optical fiber cable connected to the plasma chamber and arranged to receive the light radiation from the spot and guide the light radiation to the spectrometer.

17. The system according to claim 12, further comprising a spectrometer in electromagnetic communication with the plasma chamber for measuring the spectrum of the light emission from the plasma, the spectrometer being a grating spectrometer configured to monitor at least one band having a bandwidth of 20 nm and a central wavelength in the region of 200 nm to 800 nm, wherein the spectrum indicates the composition of the soil material in the borehole, and has a spectral resolution of 0.02 nm or more.

18. The system according to claim 17, further comprising a calibration source in fluid communication with the plasma chamber for supplying an aerosol for calibration of the spectrometer to the plasma chamber.

19. The system according to claim 12, further comprising a reflected power isolator in electromagnetic communication with the plasma chamber to couple the portion of the millimeter-wave radiation outside a transmission line that guides the millimeter-wave radiation to the bottom of the borehole in order to form the millimeter-wave directional energy drilling beam.

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