Patent ID: 7898193

Claim:
A slot resonance coupled standing wave particle accelerator comprising: a hollow accelerator body having an elongate outer wall that is substantially coaxial with a longitudinal axis that defines a beam line, said accelerator body having a pair of transverse end walls at the opposite ends of said outer wall and a plurality of spaced transverse interior walls therebetween, said outer wall and said transverse end and interior walls forming a plurality of accelerator cells positioned in sequence along said axis, including a pair of reflective end cells located at each end of said accelerator body adjacent said end walls, each cell defining a resonant accelerator cavity in which a radiofrequency standing wave is maintained, and wherein said resonant cavities have substantially the same resonant frequency; an input port opening into at least one of said cells for introducing a high power radiofrequency input signal operable to maintain a standing wave in said accelerator body; adjacent pairs of said cells each sharing a common interior wall, each interior wall having a resonant slot passing therethrough that connects the resonant cavities on each side of said common interior wall, each resonant slot being offset from said longitudinal axis of said accelerator body and having a major axis extending substantially transverse to the radial direction with respect to said longitudinal axis of said accelerator body, each slot having a resonant frequency comparable to said resonant frequency of said cavities, said slots and said cavities having overlapping passbands such that the frequency of said input signal is selected to drive and maintain the accelerator in a π/2 mode, such that adjacent cavities are magnetically coupled by said resonant slots in said interior walls and the passband associated with said standing wave is continuous in the vicinity of said π/2 mode; each interior wall having a pair of nose cones that extend from opposite sides of said interior wall into the cavities on opposite sides of said interior wall, and each end wall having a single nose cone extending into the cavity adjacent to said end wall, each pair of nose cones extending into a cavity being opposed to one another and terminating in tips which are spaced from one another to form a gap between said tips, said nose cones and said transverse walls having central bores that are aligned to form a beam tube that extends the length of said accelerator body along said beam line and which has an injection end and an emission end, through which charged particles may be introduced, accelerated as they pass through said gaps, and emitted; said cells being shaped and sized such that the distance between midpoints of said gaps of adjacent cavities is approximately βλ, where λ is the free space wavelength of the resonant standing wave in said cavities and β is the velocity of a particle passing through said cavity; and wherein said end cells are tuned such that said nodes of said standing wave occur in said slots.