Systems and methods for cargo scanning and radiotherapy using a traveling wave linear accelerator based X-ray source using pulse width to modulate pulse-to-pulse dosage
AssigneeAccuray Incorporated
InventorsStephen Wah-Kwan Cheung, Roger Heering Miller, Juwen Wang
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Abstract
Provided herein are systems and methods for operating a traveling wave linear accelerator to generate stable electron beams at two or more different intensities by varying the number of electrons injected into the accelerator structure during each pulse by varying the width of the beam pulse, i.e., pulse width. The electron beams may be used to generate x-rays having selected doses and energies, which may be used for cargo scanning or radiotherapy applications.
Claims21
A traveling wave linear accelerator for generating a plurality of dose rates and energies of electrons, the traveling wave linear accelerator comprising:
- an electron gun modulator configured to adjust a pulse width and a beam injection time of a beam of electrons from an electron gun;
- a frequency/power controller configured to determine a frequency and a power of a radio frequency (RF) signal to be generated;
- and
- an intensity controller operatively associated with the electron gun modulator and the frequency/power controller, the intensity controller configured to receive a plurality of intensity/energy adjustment commands and to respectively determine a pulse width, a beam injection time, an RF power factor, and a frequency adjustment factor based on each intensity/energy adjustment command to provide a respective output dose rate and energy of electrons;
- wherein, for each intensity/energy adjustment command, the electron gun modulator receives the determined pulse width and the determined beam injection time and adjusts the pulse width and the beam injection time of the beam of electrons and the frequency/power controller receives the frequency adjustment factor and the RF power factor and adjusts the frequency and power of the RF signal such that the traveling wave linear accelerator generates electrons having the respective output dose rate and energy.
A method for generating a plurality of dose rates and energies of electrons using a traveling wave linear accelerator, the traveling wave linear accelerator comprising an electron gun modulator configured to adjust a pulse width and a beam injection time of a beam of electrons from an electron gun and a frequency/power controller configured to adjust a frequency and a power of a radio frequency (RF) signal to be generated, the method comprising:
- receiving at an intensity controller a plurality of intensity/energy adjustment commands and respectively determining a pulse width, a beam injection time, an RF power factor, and a frequency adjustment factor based on each intensity/energy adjustment command to provide a respective dose rate and energy of electrons;
- and for each intensity/energy adjustment command:
- adjusting the pulse width and beam injection time of electrons from the electron gun at the electron gun modulator using the determined pulse width and the determined beam injection time;
- determining the frequency and power of the RF signal to be generated at the frequency/power controller based on the RF power factor and the frequency adjustment factor;
- and
- generating electrons having the respective output dose rate and energy using the traveling wave linear accelerator.
Dependencies are inferred from the claim text.