(19) |
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(11) |
EP 0 202 097 A3 |
(12) |
EUROPEAN PATENT APPLICATION |
(88) |
Date of publication A3: |
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02.12.1987 Bulletin 1987/49 |
(43) |
Date of publication A2: |
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20.11.1986 Bulletin 1986/47 |
(22) |
Date of filing: 12.05.1986 |
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(84) |
Designated Contracting States: |
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CH DE FR GB LI SE |
(30) |
Priority: |
13.05.1985 US 733175
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(71) |
Applicant: VARIAN ASSOCIATES, INC. |
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() |
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(72) |
Inventors: |
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- Tanabe, Eiji
()
- Bayer, Matthew
()
- Trail, Mark
()
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(54) |
Small diameter standing-wave linear accelerator structure |
(57) @ A compact, small diameter, standing-wave linear accelerator structure suitable
for industrial and medical applications is disclosed. The novel structure utilizes
a new type of coupling cavity for Pi/2 mode, standing-wave operation. The coupling
cavity fits into the webs between the accelerating cavities substantially within the
diameter of the accelerating cavities. This is made possible by keeping the center
section of the cavity thin to concentrate the electric field vector at the center
of a section of the cavity and by enlarging the ends of a section of the coupling
cavity to accommodate the magnetic field vector. This structure offers a significant
reduction in overall diameter over the side-coupled, annular ring, and existing coaxial
coupled structures, while maintaining a high shunt impedance and large nearest neighbor
coupling (high group velocity). A prototype 4 MeV, 36 cm long, S-band accelerator
incorporating the new structure has been built and tested.