To achieve high quality x-ray imaging, it is important to be able to control the production of x-rays in an x-ray generator. This is achieved by an x-ray generator comprising an array of electron field emitters for producing paths of electrons, target material comprising x-ray photon producing material configured to emit x-ray photons in response to the incidence of produced electrons upon it, an array of magnetic-field generators for affecting the paths of the produced electrons from the array of electron field emitters such that one or more paths are divertable away from the x-ray photon producing material so as to reduce the production of x-ray photons by the said one or more paths of electrons, the generator further comprising a sensing circuit arranged to measure the amount of electrical charge emitted by one or more electron emitter, and a controller for controlling the array of magnetic-field generators in response to the amount of electrical charge measured.

A rotary anode driving device includes a DC power supply, an inverter circuit which is connected to the DC power supply and includes a plurality of switching elements and, the inverter circuit generates an AC voltage from a DC voltage of the DC power supply, and outputs the AC voltage to a stator coil which generates a rotating magnetic field of an X-ray tube; a pulse width modulation (PWM) waveform generator configured to generate an AC voltage of two phases or three phases as the AC voltage from the DC voltage by performing PWM control of the switching elements of the inverter circuit; and a capacitor connected in series to an input side of a stator coil of at least one phase of the stator coil, the capacitor having an electrostatic capacitance constituting a series resonant circuit with the stator coil to which the capacitor is connected.

A power supply for an x-ray emitter is disclosed. A voltage source of the power supply is configured to provide an acceleration voltage or a heating voltage between a first internal contact and a second internal contact to, in a first operating mode, supply the x-ray emitter with power. The power supply includes a control device configured, in a second operating mode, to detect a voltage between the first and the second internal contact and/or to detect a current via the first and/or second internal contact. As a function of the detected voltage and/or of the detected current, the control device is configured to activate a warning device for giving a warning and/or to transmit a warning signal. A method is further disclosed.

According to one embodiment, an X-ray CT apparatus includes processing circuitry. The processing circuitry is configured to acquire set tube current waveform, and specify, based on the set tube current waveform, a period of a first tube current and a period of a second tube current lower than the first tube current. The processing circuitry is further configured to determine a waveform of a grid voltage such that a first grid voltage is applied during a period corresponding to the period of the first tube current and a second grid voltage, which is higher than the first grid voltage, is applied during a period corresponding to the period of the second tube current.

A method for controlling an X-ray source configured to emit, from an X-ray spot on a target, X-ray radiation generated by an interaction between an electron beam and the target, wherein the X-ray spot is determined by the field of view of an X-ray optical system of the X-ray source. The method includes providing the target, providing the electron beam forming an electron spot on the target and interacting with the target to generate X-ray radiation, and adjusting a width and total power of the electron beam such that a maximum of the power density profile in the electron spot is below a predetermined limit, and such that a total power delivered to the target in the X-ray spot is increased.

Some embodiments include a system, comprising: an enclosure configured to enclose a vacuum; a cathode disposed within the enclosure; an anode disposed within the enclosure configured to receive a beam of electrons from the cathode; a motor disposed within the enclosure and configured to rotate the anode in response to a drive input; and a circuit electrically connected to the drive input, and configured to generate a phase signal based on a voltage of the drive input and a current of the drive input, the phase signal indicating a phase difference between the voltage of the drive input and the current of the drive input.

The X-ray generator includes a booster for boosting a first DC voltage supplied from a voltage source to a second DC voltage higher than the first DC voltage, at least one capacitor for receiving the second DC voltage and generating a charging voltage on the basis of the second DC voltage, a converter for converting the charging voltage into a driving voltage, an X-ray source for receiving the driving voltage and emitting X-rays according to the driving voltage, and a controller for controlling the booster, the converter, and the X-ray source. The controller calculates a cooling time required for cooling the X-ray source to a predetermined temperature or lower, determines the magnitude of the second DC voltage according to the cooling time, and applies the second DC voltage to the capacitor for the cooling time.

This application disclosures a method for calibrating filament current data of an X-ray tube. The method includes obtaining a first value of tube current to be calibrated and a value of filament current to be calibrated, the tube current to be calibrated and the filament current to be calibrated corresponding to a first calibration point; performing an emission operation based on the first value of the tube current to be calibrated and the value of the filament current to be calibrated; determining an actual value of the tube current during the emission operation; determining a difference between the actual value of the tube current and the first value of the tube current to be calibrated; and calibrating, based on the difference, the first calibration point.

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.