Degrader comprising boron carbide

It is the objective of the present invention to provide a degrader that has excellent degrading capabilities with, for the same energy loss in the degrader, a lower emittance increase as currently used materials, without generating a strong neutron flux and without having severe toxic characteristics. This objective is achieved according to the present invention by a degrader (2) for use in the field of the application of a particle beam (6), comprising degrading active material wherein the degrading active material comprises Boron Carbide B4C. This degrader has an amount of multiple scattering that is lower than in graphite for the same energy loss. The use of B4C increases the transmission by at typically 35% for the beam degradation to low energies, which is a significant and useful amount of beam intensity increase in particle therapy. The B4C-material does not become more radio-active than graphite, so that there will be no additional problems at service activities. Further, B4C as degrading active material does not have severe toxic properties

A gantry for particle therapy as an arm rotating in the longitudinal plane

The present invention discloses a system (2, 2') for particle beam therapy, comprising as seen in the flow direction of the particle beam (4): a) an adjustable gantry (10, 10') for the beam delivery to a target volume, said gantry comprising: a1) a beam coupling section (6) for the incoming particle beam (4); said incoming particle beam (4) being oriented substantially horizontally thereby defining a horizontal plane; a2) a first beam bending section (8, 8') comprising a number of beam deflection and/or focusing magnets (12, 14) wherein the first bending section (8, 8') either bends the particle beam (4) with an adjustable angle into the vertical plane, or with 90 degrees in the horizontal plane, but with the mechanical possibility to rotate with an adjustable angle along the axis of the incoming particle beam (4); a3) a beam transport section (16) receiving the particle beam (4) leaving the first beam bending section (8, 8') and guiding the particle beam (4) to a second beam bending section (18); a4) the second beam bending section (18) comprising a number of beam deflection magnets and/or beam focusing magnets; a5) a beam nozzle (20) comprising a window for the exit of the particle beam (4); and b) a patient table/chair (22) being rotatable in the horizontal plane or in a plane being parallel to the horizontal plane and optionally being adjustable vertically, wherein: c) the gantry (10, 10') is supported by a tilting mechanism(24) allowing the gantry (10, 10') to be tilted vertically by an angle Φ1, Φ1 ԑ [-90°; +90°], wherein the gantry (10, 10') comprises a pivot (7, 7') being disposed in the region of the first bending section (8, 8'); and d) a rotation mechanism (26) beingdisposed in a way that the second beam bending section (18) and the beam nozzle (20) being rotatable by an angle Φ2, Φ2 ԑ [-180°; +180°] around a direction given by the angle Φ

Particle therapy gantry with an energy degrader and an achromatic final bending system

The present invention provides a movable gantry (2') for delivery of a particle beam using beam scanning technique, for example for the cancer treatment in human tissue; comprising: a) an inlet section (6) for an accelerated particle beam comprising a number of quadrupole magnets; b) a first bending section (8) and optionally a second bending section (12) comprising a number of dipole and quadrupole magnets and optionally further magnets for beam correction; c) a transfer section comprising a number of quadrupole magnets and optionally further magnets for beam correction and a degrader (D); d) a last beam bending section (16) comprising a number of separate and/or combined dipole/quadrupole/higher order multipole magnets forming an achromatic section, wherein all magnets of this achromatic last bending section (16) are located downstream of the degrader (D); any dispersion in this achromatic last bending section (16) is suppressed so that it will have a momentum acceptance of more than ±5%; e) a scanning section (15) comprising two separate or one combined fast deflection magnets (K1, K2) that deflect the beam at the iso-center in a direction perpendicular to the beam direction to perform lateral scanning; and f) a beam nozzle section (18) comprising a beam nozzle and optionally beam handling equipment, such as further beam degrading or modifying elements and/or beam quality related beam verifying elements. This combination of a degrader mounted in the gantry and a design of the gantry's beam transport magnets with a large momentum acceptance creates a possibility to increase the energy acceptance of the last bending section in the gantry and implement new dose application techniques, such as a fast change of proton energy at the patient without changing the magnetic field of the last bending section in the gantry

Study of Coil Configuration and Local Optics Effects for the GaToroid Ion Gantry Design

GaToroid, a novel configuration for hadron therapy gantry, is based on superconducting coils that gen- erate a toroidal magnetic field to deliver the beam onto the patient. Designing the complex GaToroid coils requires careful consideration of the local beam optical effects. We present a Python-based tool for charged particle transport in complex electromagnetic fields. The code implements fast tracking in arbitrary three-dimensional field maps, and it is not limited to specific or regular reference trajectories, as is generally the case in accelerator physics. The tool was used to characterise the beam behaviour inside the GaToroid system. It automatically determines the reference trajectories in the symmetry plane and analyses three-dimensional beam dynamics around these trajectories. Beam optical parameters in the field region were compared for various magnetic configurations of GaToroid. This paper introduces the new tracker and shows the benchmarking results. Furthermore, first- order beam optics studies for different arrangements demonstrate the main code features and serve for the design optimisation