An X-ray tube, including: an envelope (11) that holds inside thereof at a predetermined pressure; a filament (12) for emitting electrons and a focus electrode (13) provided in the envelope: and a target (15) for generating X-ray provided in the envelope facing to the filament (12) and the focus electrode (13), wherein the envelope (11) has an envelope body (11a) and an X-ray window portion (16) having a higher X-rays transmissivity and a higher electric conductivity than the envelope body (11a), when the X-ray window portion (16) or the anode (14) is set to a lower electric potential than both of an electric potential of the anode (14) or the X-ray window portion (16) and an electric potential of the filament (12) and the focus electrode (13), detection of at least one of an ion current (Ii) or an electron current (Ie) through the X-ray window portion (16) or the anode (14) is possible.

Computed tomography (CT) imaging system has at least one processing unit configured to receive operator inputs that include a modified system feature and a clinical task having a task object and also receive operator inputs for determining a task-based image quality (IQ) metric. The task-based IQ metric represents a desired overall image quality of image data for performing the clinical task. The image data acquired using a reference system feature. The at least one processing unit is also configured to determine an exposure-control parameter based on the task object, the modified system feature, and the task-based IQ metric. The at least one processing unit is also configured to direct the x-ray source to generate the x-ray beam during the CT scan, wherein at least one of the tube current or the tube potential during the CT scan is a function of the exposure-control parameter.

Computed tomography (CT) imaging system has at least one processing unit configured to receive operator inputs that include a modified system feature and a clinical task having a task object and also receive operator inputs for determining a task-based image quality (IQ) metric. The task-based IQ metric represents a desired overall image quality of image data for performing the clinical task. The image data acquired using a reference system feature. The at least one processing unit is also configured to determine an exposure-control parameter based on the task object, the modified system feature, and the task-based IQ metric. The at least one processing unit is also configured to direct the x-ray source to generate the x-ray beam during the CT scan, wherein at least one of the tube current or the tube potential during the CT scan is a function of the exposure-control parameter.

A method for generating X-ray radiation, the method including providing a liquid target in a chamber, directing an electron beam towards the liquid target such that the electron beam interacts with the liquid target to generated X-ray radiation, estimating a number of particles produced from the interaction between the electron beam and the liquid target by measuring a number of positively charged particles in the chamber and eliminating a contribution from scattered electrons to the estimated number of particles, and controlling the electron beam, and/or a temperature in a region of the liquid target in which the electron beam interacts with the target, such that the estimated number of particles is below a predetermined limit. Also, a corresponding X-ray source.

Methods and systems for measuring structural and material characteristics of semiconductor structures based on combined x-ray reflectometry (XRR) and x-ray photoelectron spectroscopy (XPS) are presented herein. A combined XRR and XPS system includes an x-ray illumination source and x-ray illumination optics shared by both the XRR and XPS measurement subsystems. This increases throughput and measurement accuracy by simultaneously collecting XRR and XPS measurement data from the same area of the wafer. A combined XRR and XPS system improves measurement accuracy by employing XRR measurement data to improve measurements performed by the XPS subsystem, and vice-versa. In addition, a combined XRR and XPS system enables simultaneous analysis of both XRR and XPS measurement data to more accurately estimate values of one of more parameters of interest. In a further aspect, any of measurement spot size, photon flux, beam shape, beam diameter, and illumination energy are independently controlled.

Methods and systems for measuring structural and material characteristics of semiconductor structures based on combined x-ray reflectometry (XRR) and x-ray photoelectron spectroscopy (XPS) are presented herein. A combined XRR and XPS system includes an x-ray illumination source and x-ray illumination optics shared by both the XRR and XPS measurement subsystems. This increases throughput and measurement accuracy by simultaneously collecting XRR and XPS measurement data from the same area of the wafer. A combined XRR and XPS system improves measurement accuracy by employing XRR measurement data to improve measurements performed by the XPS subsystem, and vice-versa. In addition, a combined XRR and XPS system enables simultaneous analysis of both XRR and XPS measurement data to more accurately estimate values of one of more parameters of interest. In a further aspect, any of measurement spot size, photon flux, beam shape, beam diameter, and illumination energy are independently controlled.

An X-ray tube, including: an envelope (11) that holds inside thereof at a predetermined pressure; a filament (12) for emitting electrons and a focus electrode (13) provided in the envelope: and a target (15) for generating X-ray provided in the envelope facing to the filament (12) and the focus electrode (13), wherein the envelope (11) has an envelope body (11a) and an X-ray window portion (16) having a higher X-rays transmissivity and a higher electric conductivity than the envelope body (11a), when the X-ray window portion (16) or the anode (14) is set to a lower electric potential than both of an electric potential of the anode (14) or the X-ray window portion (16) and an electric potential of the filament (12) and the focus electrode (13), detection of at least one of an ion current (Ii) or an electron current (Ie) through the X-ray window portion (16) or the anode (14) is possible.

An X-ray tube, including: an envelope (11) that holds inside thereof at a predetermined pressure; a filament (12) for emitting electrons and a focus electrode (13) provided in the envelope: and a target (15) for generating X-ray provided in the envelope facing to the filament (12) and the focus electrode (13), wherein the envelope (11) has an envelope body (11a) and an X-ray window portion (16) having a higher X-rays transmissivity and a higher electric conductivity than the envelope body (11a), when the X-ray window portion (16) or the anode (14) is set to a lower electric potential than both of an electric potential of the anode (14) or the X-ray window portion (16) and an electric potential of the filament (12) and the focus electrode (13), detection of at least one of an ion current (Ii) or an electron current (Ie) through the X-ray window portion (16) or the anode (14) is possible.

Presented systems and methods facilitate efficient and effective generation and delivery of radiation. A radiation generation system can comprise: a particle beam gun, a high energy dissipation anode target (HEDAT); and a liquid anode control component. In some embodiments, the particle beam gun generates an electron beam. The HEDAT includes a solid anode portion (HEDAT-SAP) and a liquid anode portion (HEDAT-LAP) that are configured to receive the electron beam, absorb energy from the electron beam, generate a radiation beam, and dissipate heat. The radiation beam can include photons that can have radiation characteristics (e.g., X-ray wavelength, ionizing capability, etc.). The liquid anode control component can control a liquid anode flow to the HEDAT. The HEDAT-SAP and HEDAT-LAP can cooperatively operate in radiation generation and their configuration can be selected based upon contribution of respective HEDAT-SAP and the HEDAT-LAP characteristics to radiation generation.

At least one power supply produces a voltage between a cathode and an anode. The cathode and anode are operable such that electrons emitted from the cathode interact with the anode with energies corresponding to the voltage. The electrons interact with the anode at a focal spot to generate X-rays. The power supply provides the cathode with a cathode current. An electron detector is positioned relative to the anode, and a backscatter electron signal is measured from the anode. The measured backscatter electron signal is provided to a processing unit, which determines a cathode current correction and/or a correction to the voltage between the cathode and the anode using the measured backscatter electron signal and a correlation between anode surface roughness and backscatter electron emission.