A apparatus may include a power supply to receive a first voltage potential and output a second voltage potential that is greater than the first voltage potential and a cathode emitter to emit ions in response to application of the second voltage potential. The apparatus may also include a step down transformer to receive the second voltage potential and output a third voltage potential that is less than the second voltage potential. The apparatus may also include a heating element to, in response to application of the third voltage potential, heat the cathode emitter and lower a work function of the cathode emitter.

A apparatus may include a power supply to receive a first voltage potential and output a second voltage potential that is greater than the first voltage potential and a cathode emitter to emit ions in response to application of the second voltage potential. The apparatus may also include a step down transformer to receive the second voltage potential and output a third voltage potential that is less than the second voltage potential. The apparatus may also include a heating element to, in response to application of the third voltage potential, heat the cathode emitter and lower a work function of the cathode emitter.

A method is described for controlling a tube current for acquiring at least one X-ray image. The method includes performing a preview acquisition of the region under examination; determining a three-dimensionally modulated X-ray attenuation of the region based upon the preview acquisition; determining initial tube-current profiles based upon the X-ray attenuation; defining a tolerance band for subsequent real-time modification of tube currents, a maximum permitted tube-current profile being determined for which an X-ray tube of the X-ray imaging apparatus does not overheat; determining an expected value and a maximum value of a potential patient dose based upon the initial tube-current profiles and the tolerance band; measuring an actual X-ray attenuation during acquisition of the at least one X-ray image; determining adjusted tube-current profiles based upon the actual X-ray attenuation and the initial tube-current profiles; and adjusting the tube current in accordance with the adjusted tube-current profiles determined.

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.

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.

The present application discloses a method for controlling filament current and apparatus. The method comprises: acquiring a current filament current value (S11); determining a current range within which the current filament current value falls (S12); determining a correspondence between a filament current and a control current according to the current range (S13); and determining the current control current according to the current filament current value and the correspondence (S14). The problem of large errors in the control of filament current caused by nonlinear characteristics of a filament transformer can be solved.

The present application discloses a method for controlling filament current and apparatus. The method comprises: acquiring a current filament current value (S11); determining a current range within which the current filament current value falls (S12); determining a correspondence between a filament current and a control current according to the current range (S13); and determining the current control current according to the current filament current value and the correspondence (S14). The problem of large errors in the control of filament current caused by nonlinear characteristics of a filament transformer can be solved.

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.

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.

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.