Patent · US Expired

X-ray source with selectable focal spot size

US6181771A · kind A · utility

26Cited by
5References
15Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 6, 1999
Grant dateJan 30, 2001
Priority date
Expiry dateMay 6, 2019

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01J2235/162
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

An X-ray source has an emitter for the production of an electron beam and an anode on which the electron beam strikes in an X-ray focal spot, and a magnet system that produces a dipole field and a quadrupole field that is superimposed on this dipole field, for deflecting and focusing the electron beam onto the anode. In addition, an arrangement is provided that operates together with the magnet system for the adjustment of the size of the X-ray focal spot. This arrangement, in order to set a desired size of the X-ray focal spot, adjusts the quadrupole field in so that the X-ray focal spot has a width corresponding to the desired size of the X-ray focal spot, and supplies to the magnet system a wobble signal that influences the dipole field, this wobble signal effecting a periodic displacement of the electron beam in a direction transverse to the extension of the width of the X-ray focal spot. This gives the focal spot an effect length, resulting from the deflection and measured in the direction of the deflection, to achieve a particular ratio of the effective length to the width of the X-ray focal spot.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.