Abstract: An earth-boring drilling tool comprises a cutting element. The cutting element comprises a substrate, a diamond table, and at least one sensing element formed from a doped diamond material disposed at least partially within the diamond table. A method for determining an at-bit measurement for an earth-boring drill bit comprises receiving an electrical signal generated within a doped diamond material disposed within a diamond table of a cutting element of the earth-boring drill bit, and correlating the electrical signal with at least one parameter during a drilling operation.

Abstract: A bipolar cell for a reactor for treatment of electrolyte such as waste water and effluent or for electrosynthesis comprises end electrodes and at least one bipolar electrode therebetween. The or each bipolar electrode comprises a diamond sheet. The cell includes a porous support structure, for example in the form of spacers, a lattice of plastic rods, or a woven mesh, between each end electrode and the adjacent diamond sheet, there being porous support structure between the or each pair of adjacent diamond sheets, the support structures acting to contact or support the or each diamond sheet.

Abstract: Disclosed herein are methods of manufacturing synthetic CVD diamond material including orienting and controlling process gas flow in a microwave plasma reactor to improve performance. The microwave plasma reactor includes a gas flow system with a gas inlet comprising one or more gas inlet nozzles disposed opposite the growth surface area and configured to inject process gases towards the growth surface area. The method comprises injecting process gases towards the growth surface area at a total gas flow rate equal to or greater than 500 standard cm3 per minute wherein the process gases are injected into the plasma chamber through the one or more gas inlet nozzles with a Reynolds number in a range 1 to 100.

Abstract: A method of forming an instrumented cutting element comprises forming a free-standing sintered diamond table having at least one chamber in the free-standing sintered diamond table, providing a doped diamond material within the at least one chamber, and attaching a substrate to the free-standing sintered diamond table to form an instrumented cutting element. The instrumented cutting element includes the doped diamond material disposed within the sintered diamond table on the substrate. A method of forming an earth-boring tool comprises attaching at least one instrumented cutting element to a body of an earth-boring tool. The at least one instrumented cutting element has a diamond table bonded to a substrate. The diamond table has at least one sensing element disposed at least partially within the diamond table. The at least one sensing element comprises a doped diamond material.

Abstract: An earth-boring drilling tool comprises a cutting element. The cutting element comprises a substrate, a diamond table, and at least one sensing element formed from a doped diamond material disposed at least partially within the diamond table. A method for determining an at-bit measurement for an earth-boring drill bit comprises receiving an electrical signal generated within a doped diamond material disposed within a diamond table of a cutting element of the earth-boring drill bit, and correlating the electrical signal with at least one parameter during a drilling operation.

Abstract: A microwave plasma reactor for manufacturing synthetic diamond material via chemical vapour deposition, the microwave plasma reactor comprising: a plasma chamber defining a resonant cavity for supporting a primary microwave resonance mode having a primary microwave resonance mode frequency f; a plurality of microwave sources coupled to the plasma chamber for generating and feeding microwaves having a total microwave power P? into the plasma chamber; a gas flow system for feeding process gases into the plasma chamber and removing them therefrom; and a substrate holder disposed in the plasma chamber and comprising a supporting surface for supporting a substrate on which the synthetic diamond material is to be deposited in use, wherein the plurality of microwave sources are configured to couple at least 30% of the total microwave power P? into the plasma chamber in the primary microwave resonance mode frequency f, and wherein at least some of the plurality of microwave sources are solid state microwave sources.

Abstract: A microwave plasma reactor for manufacturing synthetic diamond material via chemical vapour deposition, the microwave plasma reactor comprising: a plasma chamber; a substrate holder disposed in the plasma chamber and comprising a supporting surface for supporting a substrate on which the synthetic diamond material is to be deposited in use; a microwave coupling configuration for feeding microwaves from a microwave generator into the plasma chamber; and a gas flow system for feeding process gases into the plasma chamber and removing them therefrom; wherein the microwave plasma reactor further comprises an electrically conductive plasma stabilizing annulus disposed around the substrate holder within the plasma chamber.

Abstract: An earth-boring drilling tool comprises a cutting element. The cutting element comprises a substrate, a diamond table, and at least one sensing element formed from a doped diamond material disposed at least partially within the diamond table. A method for determining an at-bit measurement for an earth-boring drill bit comprises receiving an electrical signal generated within a doped diamond material disposed within a diamond table of a cutting element of the earth-boring drill bit, and correlating the electrical signal with at least one parameter during a drilling operation.

Abstract: A free-standing non-planar polycrystalline CVD synthetic diamond component which comprises a nucleation face and a growth face, the nucleation face comprising smaller grains than the growth face, the nucleation face having a surface roughness Ra no more than 50 nm, wherein the free-standing non-planar polycrystalline CVD synthetic diamond component has a longest linear dimension when projected onto a plane of no less than 5 mm and is substantially crack free over at least a central region thereof, wherein the central region is at least 70% of a total area of the free-standing non-planar polycrystalline CVD synthetic diamond component, wherein the central region has no cracks which intersect both external major faces of the free-standing non-planar polycrystalline CVD synthetic diamond component and extend greater than 2 mm in length.

Abstract: An earth-boring drilling tool comprises a cutting element. The cutting element comprises a substrate, a diamond table, and at least one sensing element formed from a doped diamond material disposed at least partially within the diamond table. A method for determining an at-bit measurement for an earth-boring drill bit comprises receiving an electrical signal generated within a doped diamond material disposed within a diamond table of a cutting element of the earth-boring drill bit, and correlating the electrical signal with at least one parameter during a drilling operation.

Abstract: A microwave power delivery system for supplying microwave power to a plurality of microwave plasma reactors (8), the microwave power delivery system comprising: a tuner (14) configured to be coupled to a microwave source (4) and configured to match impedance of the plurality of microwave plasma reactors to that of the microwave source; and a waveguide junction (18) coupled to the tuner and configured to guide microwaves to and from the plurality of microwave plasma reactors, wherein the waveguide junction comprises four waveguide ports including a first port coupled to the tuner, second and third ports configured to be coupled to respective microwave plasma reactors, and a fourth port coupled to a microwave sink (20), wherein the waveguide junction is configured to evenly split microwave power input from the tuner through the first port between the second and third ports for providing microwave power to respective microwave plasma reactors, wherein the waveguide junction is configured to decouple the second a

Abstract: A free-standing non-planar polycrystalline CVD synthetic diamond component which comprises a nucleation face and a growth face, the nucleation face comprising smaller grains than the growth face, the nucleation face having a surface roughness Ra no more than 50 nm, wherein the free-standing non-planar polycrystalline CVD synthetic diamond component has a longest linear dimension when projected onto a plane of no less than 5 mm and is substantially crack free over at least a central region thereof, wherein the central region is at least 70% of a total area of the free-standing non-planar polycrystalline CVD synthetic diamond component, wherein the central region has no cracks which intersect both external major faces of the free-standing non-planar polycrystalline CVD synthetic diamond component and extend greater than 2 mm in length.

Abstract: The present disclosure relates to substrates for use in microwave plasma reactors. Certain substrates include a cylindrical disc of a carbide forming refractory metal having a flat growth surface on which CVD diamond is to be grown and a flat supporting surface opposed to said growth surface. The cylindrical disc may have a diameter of 80 mm or more. The growth surface may have a flatness variation no more than 100 mm The supporting surface may have a flatness variation no more than 100 mm.

Abstract: A microwave plasma reactor for manufacturing a synthetic diamond material via chemical vapour deposition, the microwave plasma reactor comprising: a plasma chamber (2); a substrate holder (4) disposed in the plasma chamber for supporting a substrate on which the synthetic diamond material is to be deposited in use; a microwave coupling configuration (12) for feeding microwaves from a microwave generator (8) into the plasma chamber; and a gas flow system (13,16) for feeding process gases into the plasma chamber and removing them therefrom, wherein the microwave coupling configuration for feeding microwaves from the microwave generator into the plasma chamber comprises: an annular dielectric window (18) formed in one or several sections; a coaxial waveguide (14) having a central inner conductor (20) and an outer conductor (22) for feeding microwaves to the annular dielectric window; and a waveguide plate (24) comprising a plurality of apertures (28) disposed in an annular configuration with a plurality of arms

Abstract: A microwave plasma reactor for manufacturing synthetic diamond material via chemical vapour deposition, the microwave plasma reactor comprising: a plasma chamber; a substrate holder disposed in the plasma chamber for supporting a substrate on which the synthetic diamond material is to be deposited in use; a microwave coupling configuration for feeding microwaves from a microwave generator into the plasma chamber; and a gas flow system for feeding process gases into the plasma chamber and removing them therefrom; wherein the gas flow system comprises a gas inlet nozzle array comprising a plurality of gas inlet nozzles disposed opposite the substrate holder for directing process gases towards the substrate holder, the gas inlet nozzle array comprising: at least six gas inlet nozzles disposed in a substantially parallel or divergent orientation relative to a central axis of the plasma chamber; a gas inlet nozzle number density equal to or greater than 0.

Abstract: A polycrystalline chemical vapour deposited (CVD) diamond wafer comprising: a largest linear dimension equal to or greater than 70 mm; a thickness equal to or greater than 1.3 mm; and one or both of the following characteristics measured at room temperature (nominally 298 K) over at least a central area of the polycrystalline CVD diamond wafer, said central area being circular, centred on a central point of the polycrystalline CVD diamond wafer, and having a diameter of at least 70% of the largest linear dimension of the polycrystalline CVD diamond wafer: an absorption coefficient ?0.2 cm?1 at 10.6 ?m; and a dielectric loss coefficient at 145 GHz, of tan ??2×10?4.

Abstract: A polycrystalline chemical vapour deposited (CVD) diamond wafer comprising: a largest linear dimension equal to or greater than 125 mm; a thickness equal to or greater than 200 ?m; and one or both of the following characteristics measured at room temperature (nominally 298 K) over at least a central area of the polycrystalline CVD diamond wafer, said central area being circular, centred on a central point of the polycrystalline CVD diamond wafer, and having a diameter of at least 70% of the largest linear dimension of the polycrystalline CVD diamond wafer: an absorption coefficient?0.2 cm?1 at 10.6 ?m; and a dielectric loss coefficient at 145 GHz, of tan ??2×10?4.

Abstract: The invention relates to a speaker dome comprising: a polycrystalline diamond dome body formed of a material of high stiffness with a Young's modulus greater than 50 GPa and having respective inner and outer surfaces; and a coating on at least one side of the dome body, wherein the coating comprises an optically refractive metal compound layer which is semi-transparent and which forms one or more colors via interference of reflected light from front and rear surfaces of the layer. The invention also relates to a diamond component comprising: a diamond body; and a coating on at least one side of the diamond body, wherein the coating comprises at least two layers including a first layer bonded to the at least one side of the diamond body and a second layer disposed over the first layer, the second layer being an optically refractive metal compound coating which is semi-transparent and which forms one or more colors via interference of reflected light from front and rear surfaces of the second layer.

Abstract: A microwave plasma reactor for manufacturing a synthetic diamond material via chemical vapour deposition, the microwave plasma reactor comprising: a plasma chamber (2); a substrate holder (4) disposed in the plasma chamber for supporting a substrate on which the synthetic diamond material is to be deposited in use; a microwave coupling configuration (12) for feeding microwaves from a microwave generator (8) into the plasma chamber; and a gas flow system (13,16) for feeding process gases into the plasma chamber and removing them therefrom, wherein the microwave coupling configuration for feeding microwaves from the microwave generator into the plasma chamber comprises: an annular dielectric window (18) formed in one or several sections; a coaxial waveguide (14) having a central inner conductor (20) and an outer conductor (22) for feeding microwaves to the annular dielectric window; and a waveguide plate (24) comprising a plurality of apertures (28) disposed in an annular configuration with a plurality of arms

Abstract: A microwave plasma reactor for manufacturing synthetic diamond material via chemical vapor deposition, the microwave plasma reactor comprising: a microwave generator configured to generate microwaves at a frequency f; a plasma chamber comprising a base, a top plate, and a side wall extending from said base to said top plate defining a resonance cavity for supporting a microwave resonance mode between the base and the top plate; a microwave coupling configuration for feeding microwaves from the microwave generator into the plasma chamber; a gas flow system for feeding process gases into the plasma chamber and removing them therefrom; a substrate holder disposed in the plasma chamber and comprising a supporting surface for supporting a substrate; and a substrate disposed on the supporting surface, the substrate having a growth surface on which the synthetic diamond material is to be deposited in use, wherein the substrate dimensions and location within the resonance cavity are selected to generate a localized a