Synchrotron type accelerator and medical treatment system employing the same

A synchrotron type accelerator including:

• at least one deflecting electromagnet arranged on a circulating orbit of a charged particle beam;
• four-poles divergence electromagnets and four-poles convergence electromagnets arranged on said circulating orbit;
• a high frequency applying unit arranged on said circulating orbit for applying a high frequency electromagnetic field to said charged particle beam which circulates and for increasing an amplitude of betatron oscillation of said charged particle beam to a level above a stability limit of resonance;
• a first deflector for beam ejection arranged on said circulating orbit for deflecting said charged particle beam which is excited above said stability limit of the resonance by said high frequency applying unit;
• and a second deflector for beam ejection arranged on said circulating orbit used in pair with said first deflector for beam ejection for introducing said charged particle beam deflected by said first deflector for beam ejection into an ejected beam transporting system;
• wherein said at least one deflecting electromagnet and said second deflector for beam ejection are arranged in this order downstream with respect to said first deflector for beam ejection, and said at least one deflecting electromagnet deflects said charged particle beam deflected by said first deflector for beam ejection toward said second deflector for beam ejection.