Abstract: An ion source for use in a particle accelerator includes at least one cathode. The at least one cathode has an array of nano-sized projections and an array of gates adjacent the array of nano-sized projections. The array of nano-sized projections and the array of gates have a first voltage difference such that an electric field in the cathode causes electrons to be emitted from the array of nano-sized projections and accelerated downstream. There is a ion source electrode downstream of the at least one cathode, and the at least one cathode and the ion source electrode have the same voltage applied such that the electrons enter the space encompassed by the ion source electrode, some of the electrons as they travel within the ion source electrode striking an ionizable gas to create ions.

Abstract: A method for determining spatial distribution of a property within a volume of subsurface formations includes generating an initial model of spatial distribution of a property of the formations using available data related to the property distribution within the volume. A forward model is generated in the wavenumber domain of spatial distribution of a potential field. Measurements of a physical parameter having a potential field obtained at spaced apart locations above the volume and/or in at least one wellbore penetrating the volume are entered. A revised model of spatial distribution of the potential field is generated by interpolating the measurements of the parameter. The interpolating is performed in the wavenumber domain. A revised model of spatial distribution of the physical property is generated by inversion in the wavenumber domain of the revised potential field model.

Abstract: A method for determining spatial distribution of a property within a volume of subsurface formations includes generating an initial model of spatial distribution of a property of the formations using available data related to the property distribution within the volume. A forward model is generated in the wavenumber domain of spatial distribution of a potential field. Measurements of a physical parameter having a potential field obtained at spaced apart locations above the volume and/or in at least one wellbore penetrating the volume are entered. A revised model of spatial distribution of the potential field is generated by interpolating the measurements of the parameter. The interpolating is performed in the wavenumber domain. A revised model of spatial distribution of the physical property is generated by inversion in the wavenumber domain of the revised potential field model.

Abstract: A system and method for use in a downhole tool having a fluid density measurement device positioned therein are provided. In one example, the method includes deploying the downhole tool at a first station in a borehole. The downhole tool is moved from the first station to a second station in the borehole. A plurality of fluid density values of fluid within the borehole between the first and second stations are measured using the fluid density measurement device in the downhole tool. The plurality of fluid density values may represent a continuous log of fluid densities between the first and second stations.

Abstract: A neutron generator and method of constructing the same. The generator includes a grid configured to produce an ionizable gas when heated by electrons impinging thereon. A cathode emits electrons to heat the grid and to collide with produced ionizable gas atoms to generate ions. Neutrons are generated from a collision of ions impinging on a target in the generator. A tool for subsurface use incorporating the neutron generator.

Abstract: A neutron generator and method of constructing the same. The generator includes a grid configured to produce an ionizable gas when heated by electrons impinging thereon. A cathode emits electrons to heat the grid and to collide with produced ionizable gas atoms to generate ions. Neutrons are generated from a collision of ions impinging on a target in the generator. A tool for subsurface use incorporating the neutron generator.

Abstract: Wellbore apparatus including an elongated tubular adapted for disposal within the wellbore. The tubular having an elongated recess formed on its exterior surface along the longitudinal axis. The recess is adapted to accept and house a component therein. A shield disposed within the recess and adapted to slide to a selected position therein, covering a housed component. The sliding shield and housed component are retained within the recess by a retainer system using minimal fasteners.

Abstract: Acoustic transducers configured with integrated electronics technology are adapted to digitize signal data close to the transducer. The transducers are packaged with a reduced number of elements and sealed for exposure to harsh environments, without oil compensation. A transducer assembly includes a frame, an acoustic transducer element disposed on the frame, and an electronics module disposed on the frame and linked to the acoustic transducer element. The pressure and temperature tolerant electronics module is adapted to process a signal associated with the transducer element.

Abstract: Acoustic transducers configured with integrated electronics technology are adapted to digitize signal data close to the transducer. The transducers are packaged with a reduced number of elements and sealed for exposure to harsh environments, without oil compensation. A transducer assembly includes a frame, an acoustic transducer element disposed on the frame, and an electronics module disposed on the frame and linked to the acoustic transducer element. The pressure and temperature tolerant electronics module is adapted to process a signal associated with the transducer element.

Abstract: Wellbore apparatus including an elongated tubular adapted for disposal within the wellbore. The tubular having an elongated recess formed on its exterior surface along the longitudinal axis. The recess is adapted to accept and house a component therein. A shield disposed within the recess and adapted to slide to a selected position therein, covering a housed component. The sliding shield and housed component are retained within the recess by a retainer system using minimal fasteners.

Abstract: A method and apparatus for characterizing a multiphase mixture by irradiating the mixture with X-rays, collecting the photons that emanate from the mixture in response to the irradiation, generating a signal responsive to the aggregate energy of the collected photons, and analyzing the signal to characterize the mixture. Preferably, the mixture is irradiated by repetitively pulsing an X-ray tube and the photons are collected using a multi-layer detector. The method and apparatus may be used to determine the flow rate, flow velocities, and/or composition of the multiphase mixture. In other embodiments, a plurality of X-ray sources and/or detectors may be used.