Shielding device for an irradiation unit and irradiation method

摘要

The present invention relates to a method for obtaining a shielding element for minimizing the penumbra of a beam of hadrons outside a target area, the hadron beam being guided in a longitudinal direction by an irradiation unit, and the beam having a width (σ). The method includes:
(i) defining a closed or open contour of said target area;(ii) providing a block having a longitudinal thickness capable of blocking the passage of said beam and having a lateral surface perpendicular to said longitudinal thickness;(iii) forming an aperture of a shape similar to said contour and crossing said longitudinal thickness of said block for letting through said beam, said aperture forming a longitudinal internal surface; and(iv) trimming said block so as to form a longitudinal external surface around said longitudinal internals surface, said longitudinal internal and longitudinal external surfaces delimiting a side wall.

主权项

1. A method for obtaining a shielding element for minimizing the penumbra of a scanning hadron pencil beam outside a target area, said hadron beam being scanned over the target area by an irradiation unit, said beam having a width (σ), the method comprising:
(i) defining a closed or open contour of said target area; (ii) providing a block having a longitudinal thickness configured to block the passage of said hadron pencil beam and having a lateral surface perpendicular to said longitudinal thickness; (iii) forming an aperture of a shape similar to said contour of said target area, the aperture extending the length of the longitudinal thickness of said block in order to let through said hadron pencil beam, said aperture forming a longitudinal internal surface; and (iv) trimming said block so as to form a longitudinal external surface around said longitudinal internal surface, said longitudinal internal and longitudinal external surfaces delimiting a side wall, the side wall having a side thickness everywhere greater than at least once the width (σ) of the hadron pencil beam, and, in at least one location, less than five times the width (σ) of the hadron pencil beam.