| 摘要 |
The proton accelerator includes a source which generates a beam of protons which enters the accelerator at one end is successively accelerated to 10, 100 and 200 MeV by 3-microsecond pulses, or 70 MW peak power, from a 2.008 MHz klystron unit. By suitable dimensioning the individual accelerating cells, a high shunt impedance is assured. In the low energy sections, focussing units interposed between successive accelerating sections have alternating field directions 90 degrees apart. This alternation extends into higher energy sections. Optionally, the accelerator structure (61) may pass through cylindrical magnetic focussing structures (60), having windings (A,B,C,D), in helical slots (62,63,64,65), series connected (62-63, 63-64, etc) at each end, the transverse field (B1-B4) varying directionally along the cylinder. Alternatively, axially aligned windings are cyclically rotated between slotted corners of square-section focussing structures. USE - Esp. in proton therapy.
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