摘要:
A germanium detector measures an energy spectrum of gamma ray flux. The detector includes a copper cooling layer continuous over a periphery of the columnar germanium crystal. The cooling layer reduces current leakage induced by heat, so that high energy gamma rays can be precisely detected. A combination of a plurality of germanium crystal bodies connected one another to form the germanium crystal of at least 20 cm leads to a more precise detection of high energy gamma rays.
摘要:
Some embodiments include an x-ray system, comprising: a housing; a plurality of overlapping imaging layers disposed in the housing, each imaging layer configured to generate an image in response to a corresponding incident x-ray beam; and a plurality of x-ray markers attached to the housing and disposed to affect the incident x-ray beam for each of the imaging layers.
摘要:
A downhole tool and method for performing a base log sigma measurement of a formation. The tool comprising a nuclear source for irradiating the formation and a detector for obtaining a sigma measurement of the irradiated formation. The tool is mounted close to a drill bit arranged to drill a borehole into the formation and is capable of determining a base log sigma measurement of the formation while drilling into the formation.
摘要:
Some embodiments include an x-ray system, comprising: an x-ray imager including a plurality of imaging layers; an x-ray source configured to generate an x-ray beam; and an x-ray prefilter; wherein: the x-ray prefilter is configured to adjust an energy spectrum of the x-ray beam to create or decrease a level of x-ray fluence of a local minimum between two of a plurality of local maximums.
摘要:
A germanium detector measures an energy spectrum of a gamma ray flux. The detector includes a cooling layer continuous over a periphery of the columnar germanium crystal. The cooling layer reduces current leakage induced by heat, so that high energy gamma rays can be precisely detected. A combination of a plurality of germanium crystal bodies connected one another to form the germanium crystal of at least 20 cm leads to a more precise detection of high energy gamma rays. A method for determining a photonuclear reaction cross section using the germanium detector enables measurement of the energy dependence of a photonuclear reaction cross section at high resolution. The method employs a white gamma ray flux radiated to a nuclide. The germanium detector measures the spectrum of a transmission gamma ray flux transmitted through the nuclide. Peaks are specified in the obtained spectrum. An atomic nucleus can be transformed using a monochromatic gamma ray flux having an energy level corresponding to the peak.
摘要:
A source of fast neutrons and a detector responsive to the thermal neutron population decay rate are utilized in a well logging instrument. The instrument is placed within a sample retention chamber. The neutron generator is periodically pulsed and the neutron detector is gated on at intervals of 100-150, 150-200, and 800-850 microseconds, respectively, following the termination of each burst of fast neutrons. The detected radiations within these intervals are used to indicate the apparent absorption cross section of the small fluid sample within the chamber. The absorption cross section is measured for a number of small samples of known salinity and calculatable true absorption cross section. A relationship is constructed of the true absorption cross section of the samples versus the measured absorption cross sections of the samples. When the chamber is filled with an unknown fluid sample the measured absorption cross section is correlated with the reference curve which will yield single unique true absorption cross section substantially free of diffusion effects for the measured absorption cross section value of the unknown small quantity sample.
摘要:
A method for characterizing an electron beam in a liquid metal jet X-ray source. The method includes providing the electron beam and directing the electron beam to an interaction region; providing an electron beam dump connected to ground potential for receiving the electron beam after it has traversed the interaction region; scanning the electron beam over at least part of the interaction region; measuring X-ray radiation generated by interaction between the electron beam and the electron beam dump during the scanning to obtain an X-ray profile; and calculating an electron beam characteristic based on the X-ray profile. Also, a corresponding liquid metal jet X-ray source.
摘要:
A method for characterizing an electron beam in a liquid metal jet X-ray source. The method includes providing the electron beam and directing the electron beam to an interaction region; providing an electron beam dump connected to ground potential for receiving the electron beam after it has traversed the interaction region; scanning the electron beam over at least part of the interaction region; measuring X-ray radiation generated by interaction between the electron beam and the electron beam dump during the scanning to obtain an X-ray profile; and calculating an electron beam characteristic based on the X-ray profile. Also, a corresponding liquid metal jet X-ray source.