Cyclotron for extracting charged particles at various energies

A cyclotron for accelerating a beam of charged particles over an outward spiral path until the beam of charged particles reaches a desired energy, and for extracting the beam to hit a target, the cyclotron comprising:

• a vacuum chamber defined by a gap separating first and second magnet poles centered on a central axis, Z, and symmetrically positioned opposite to one another with respect to a median plane, P, normal to the central axis, Z, and by a peripheral wall sealing the gap and allowing drawing of a vacuum in the gap, the peripheral wall comprising an opening;
• a target support element sealed and coupled to a downstream end of the opening, outside the vacuum chamber, the target support element comprising a tubular channel in fluid communication with the opening and ending at a target holder for holding a target;
• a stripping mechanism for receiving and controlling a position of a first energy extraction kit including a first stripper assembly in the gap, the first stripper assembly comprising:
• a first rotating axle provided with one or more first brackets, each first bracket holding a first stripper having an outer edge at a first distance, ri, from the first rotating axle such that the first rotating axle is parallel to the central axis, Z, and such that the first stripper can rotate about the first rotating axle to a first stripping position, Pi, intercepting the beam of charged particles at a first energy, Ei, modifying the charge of the particles traversing the first stripper and steering the thus modified charged particles along a first extraction path, Si, through the opening in the peripheral gap wall, along the tubular channel, and towards the target holder;
• and
• a second energy extraction kit for driving a beam of modified charged particles of a second energy, Ej, along a second extraction path, Sj, through the opening in the peripheral wall, along the tubular channel, and towards the target holder, wherein the second energy extraction kit comprises:
• a second stripper assembly including:
• a second rotating axle provided with one or more second brackets, each second bracket holding a second stripper having an outer edge at a second distance, rj, from the second rotating axle, such that the second stripper can rotate about the second rotating axle to a second stripping position, Pj, intercepting the beam of charged particles at the second energy, Ej, modifying the charge of the particles traversing the second stripper and driving the thus modified charged particles along a second modified path, Sj, through the opening in the peripheral wall;
• and
• an insert to be sandwiched between a downstream end of the opening and the target support element with an insert channel in fluid communication with both the opening and the tubular channel, for modifying an orientation of the tubular channel to match the second extraction path, Sj, such that the modified charged particles of second energy, Ej, intercept the target holder.

A method for hitting a target with a particle beam of second energy, Ej, comprising the steps of:

• providing a cyclotron configured for extracting a particle beam of a first energy, Ei, and steering the particle beam towards a target, the cyclotron comprising:
• a vacuum chamber comprising an opening,
• a target support element comprising a target holder,
• a stripping mechanism comprising a first energy extraction kit including a first stripper assembly, and
• a second energy extraction kit comprising a bracket, a second stripper assembly, a stripper, and an insert;
• removing the first stripper assembly and removing the target support element;
• mounting the bracket and positioning the stripper at a stripping position, Pj;
• mounting the target support element with the insert sandwiched between a downstream end of the opening and the target support element;
• positioning the target in the target holder;
• and
• accelerating a particle beam along a spiral path intersecting the stripping position, Pj, at the second energy, Ej, and extracting the particle beam along an extraction path, Sj, through the opening and onto the target.