Method and apparatus for precisely measuring accelerating voltages applied to x-ray sources

A method of calibrating an accelerating voltage indicator of an x-ray apparatus comprising:

• applying an accelerating voltage to an x-ray source to produce x-ray radiation and recording the accelerating voltage indicated by an indicator of the x-ray apparatus;
• diffracting portions of the x-ray radiation that are symmetrically disposed relative to an axis with a single crystal material to produce two spectra of the x-ray radiation, each spectrum including continuous x-ray radiation having an end point energy at the maximum energy of the x-ray radiation;
• forming an image of the spectra of the x-ray radiation including respective end point energies;
• measuring the separation between the respective end point energies of the spectra and, thereby, determining the accelerating voltage applied to the x-ray source;
• comparing the accelerating voltage actually applied to the x-ray source to the indicated accelerating voltage;
• and
• repeating the foregoing steps for a plurality of different accelerating voltages to determine, for each applied accelerating voltage, the accelerating voltage actually applied and the indicated accelerating voltage, thereby calibrating the accelerating voltage indicator.

A method of measuring an accelerating voltage applied to an x-ray source to produce x-rays comprising:

• applying an accelerating voltage to an x-ray source to produce x-ray radiation;
• diffracting a portion of the x-ray radiation with a single crystal material to produce a spectrum of the x-ray radiation including continuous x-ray radiation having an end point energy at the maximum energy of the x-ray radiation;
• forming an image of the spectrum of the x-rays including the end point energy;
• and
• determining one of the wavelength and frequency of the end point energy and, thereby, the accelerating voltage applied to the x-ray source.

A method of calibrating an accelerating voltage indicator of an x-ray apparatus comprising:

• applying an accelerating voltage to an x-ray source to produce x-ray radiation and recording the accelerating voltage indicated by an indicator of the x-ray apparatus;
• diffracting a portion of the x-ray radiation with a single crystal material to produce a spectrum of the x-ray radiation including continuous x-ray radiation having an end point energy at the maximum energy of the x-ray radiation;
• forming an image of the spectrum of the x-rays including the end point energy;
• determining one of the wavelength and frequency of the end point energy and, thereby, the accelerating voltage actually applied to the x-ray source;
• comparing the accelerating voltage actually applied to the x-ray source to the indicated accelerating voltage;
• and
• repeating the foregoing steps for a plurality of different accelerating voltages to determine, for each applied accelerating voltage, the accelerating voltage actually applied and the indicated accelerating voltage, thereby calibrating the accelerating voltage indicator.

An apparatus for measuring an accelerating voltage applied to an x-ray source to produce x-rays comprising:

• an x-ray spectrograph comprising an entrance for admitting two portions of x-ray radiation emitted by an x-ray source;
• a single crystal material disposed to intersect and disperse the portions of the x-ray radiation to produce two x-ray spectra including continuous x-ray radiation having respective end point energies as the maximum energy of the x-ray radiation;
• a scintillation screen emitting light in response to incident x-ray radiation for forming an image in light of the portions of the x-ray radiation dispersed by the single crystal material;
• a charge coupled device camera disposed adjacent the scintillation screen for converting the image in light to electrical signals;
• and
• a computer electrically connected to the charge coupled device camera for analyzing the electrical signals and finding the separation between the end point energies in the image where the intensity of the x-ray spectrum stops changing and remains constant, thereby determining the accelerating voltage applied to the x-ray source.

An apparatus for measuring an accelerating voltage applied to an x-ray source to produce x-rays comprising:

• an x-ray spectrograph comprising an entrance for admitting a portion of x-ray radiation emitted by an x-ray source;
• a single crystal material disposed to intersect and disperse the portion of the x-ray radiation to produce an x-ray spectrum including continuous x-ray radiation having an end point energy as the maximum energy of the x-ray radiation;
• a scintillation screen emitting light in response to incident x-rays for forming an image in light of the portion of the x-ray radiation dispersed by the single crystal material;
• a charge coupled device camera disposed adjacent the scintillation screen for converting the image in light to electrical signals;
• and
• a computer electrically connected to the charge coupled device camera for analyzing the electrical signals and finding the end point energy in the image where the intensity of the x-ray spectrum stops changing and remains constant, thereby determining the accelerating voltage applied to the x-ray source.