| 摘要 |
The invention relates to a cyclotron which can produce a beam of accelerated charged particles that are intended for the irradiation of at least one target ( 200 ). The inventive cyclotron consists of a magnetic circuit which essentially comprises: an electromagnet with at least two poles ( 1, 1 '), namely an upper pole ( 1 ) and a lower pole ( 1 '), which are disposed symmetrically in relation to a mid-plane ( 110 ) which is perpendicular to the central axis ( 100 ) of the cyclotron and which are separated by a gap ( 120 ) containing the circulating charged particles and return flux ( 2 ) in order to close the aforementioned magnetic circuit; and a pair of main induction coils ( 5, 5 ') which are used to create an essentially-constant main induction field in the gap between poles 1 and 1 '. The invention is characterised in that it comprises means of centring the above-mentioned beam, consisting of at least one pair of bucking coils ( 6, 7 ) which are supplied by an electrical source ( 8 ) and which can modulate the intensity of the main induction field produced by the main coils ( 5, 5 '), in order to increase the intensity of the induction field in a first area of the cyclotron and to reduce the intensity of the induction field in a second area of the cyclotron, which is diametrically opposed to the central axis ( 100 ) of the cyclotron.
|
