Abstract: A method, apparatus, system, and computer program product for automatically determining exposure time for an intraoral image. The method includes acquiring a low dose pilot projection image of an object to be imaged, performing a sanity check to ensure that a usable exposure is attainable, estimating a remaining exposure time required for an additional projection image, taking the additional projection image and adding the two images together to generate a final image wherein the dose delivered to the x-ray detector is influenced by patient specific dental anatomy.

Abstract: A method, apparatus, system, and computer program product for automatically determining exposure time for an intraoral image. The method includes acquiring a low dose pilot projection image of an object to be imaged, performing a sanity check to ensure that a usable exposure is attainable, estimating a remaining exposure time required for an additional projection image, taking the additional projection image and adding the two images together to generate a final image wherein the dose delivered to the x-ray detector is influenced by patient specific dental anatomy.

Abstract: The position of the sample is measured and used to correct for any off-axis motion during tomography using x-ray projection microscope system with a rotation stage system. The position is sensed using a precision-machined, low-CTE gold-coated cylinder or disc and three to five capacitive distance sensors. The correction can then be performed purely as image processing in software, by applying an appropriate shift in X and Y of the captured x-ray projections. A calibration is often necessary for each system (gold disc plus sensors plus sample stage) to account for any machining errors of the gold disc or positioning errors of the capacitive sensors. This calibration should also be repeated whenever any maintenance is performed on the metrology setup.

Abstract: A process to determine the porosity and/or mineral content of mineral samples with an x-ray CT system is described. Based on the direct-projection techniques that use a spatially-resolved x-ray detector to record the x-ray radiation passing through the sample, 1 micrometer or better resolution is achievable. Furthermore, by using an x-ray objective lens to magnify the x-ray image in a microscope configuration, a higher resolution of up to 50 nanometers or more is achieved with state-of-the-art technology. These x-ray CT techniques directly obtain the 3D structure of the sample with no modifications to the sample being necessary. Furthermore, fluid or gas flow experiments can often be conducted during data acquisition so that one may perform live monitoring of the physical process in 3D.

Abstract: An x-ray source comprises a structured anode that has a thin top layer made of the desired target material and a thick bottom layer made of low atomic number and low density materials with good thermal properties. In one example, the anode comprises a layer of copper with an optimal thickness deposited on a layer of beryllium or diamond substrate. This structured target design allows for the use of efficient high energy electrons for generation of characteristic x-rays per unit energy deposited in the top layer and the use of the bottom layer as a thermal sink. This anode design can be applied to substantially increase the brightness of stationary, rotating anode or other electron bombardment-based sources where brightness is defined as number of x-rays per unit area and unit solid angle emitted by a source and is a key figure of merit parameter for a source.

Abstract: An x-ray microscope uses a microfocus x-ray source with a focus spot of less than 10 micrometers and a Wolter condenser having a magnification of about four or more for concentrating x-rays from the source onto a sample. A detector is provided for detecting the x-rays after interaction with the sample, and an x-ray objective is used to form an image of the sample on the detector. The use of the Wolter optic addresses a problem with microfocus sources that arise when the size of the focal spot that must then be imaged onto the sample with the condenser is smaller than the field of view.