Accelerators and Facilities

Advanced Accelerators

Paper	Title	Page
TU101	Engineering and Building RF Structures - The Works	237
	D. Schrage LANL, Los Alamos, New Mexico
	The translation of the physics designs of linear accelerators into engineering and manufacturing requirements is discussed. The stages of conceptual design, prototyping, final design, construction, and installation are described for both superconducting (LANL β = 0.175 Spoke Cavity) and normal-conducting (APT/LEDA 6.7 MeV RFQ) accelerators. An overview of codes which have linked accelerator cavity and thermal/structural analysis modules is provided.
	Transparencies
TU102	Survey of Advanced Acceleration Techniques	242
	C.J. Joshi UCLA, Los Angeles, California
	In this talk I will review the recent progress on the production, manipulation, transport, acceleration and focusing of relativistic electron beams using advanced techniques. In particular, I will report recent progress on cathode-less electron injectors, IFEL bunchers and accelerators, plasma accelerating and transport structures, and electron and positron beam focusing using plasmas. The plasma structures for acceleration can be excited either by laser beams or charged-particle beams. The acceleration gradients in either case can be enormous. For unmatched beams the betatron radiation loss, as the beam oscillates transversely in the high gradient accelerating structure, can generate a high brightness x-ray beam. These x-rays can, in turn, be used to generate positrons. Work done by different groups around the world will be reviewed.
	Transparencies
TUP14	Status of the RFI Linac Prototype	321
	D.A. Swenson, W.J. Starling LLC, Albuquerque, New Mexico
	A prototype of the Rf Focused Interdigital (RFI) linac structure is currently under construction at Linac Systems. The RFI linac structure is basically an interdigital (or Wideröe) linac structure with rf quadrupole focusing incorporated into each drift tube. The 200 MHz RFI prototype, consisting of a short RFQ linac followed by a short RFI linac, will accelerate a 20 mA beam of protons from an injection energy of 25 keV to an output energy of 2.50 MeV in a total linac structure length of 1.44 meters. The linac structures are designed for continuous (cw) operation, and will be tested initially at a 33% duty factor. The peak structure power of 66 kW and peak beam power of 50 kW will be supplied by a 144 kW, 33% duty rf power system. A microwave ion source will supply the proton beam and an articulated Einzel lens will steer and focus the beam into the RFQ aperture. The mechanical design of the linac structures will be presented, the calculated performance will be described, the status of the components will be reported. The prototype is scheduled to come into operation in the fall of this year.
THP74	Laser Produced Ions as an Injection Beam for Cancer Therapy Facility	782
	A. Noda, M. Hashida, Y. Iwashita, S. Nakamura, S. Sakabe, S. Shimizu, T. Shirai, H. Tongu Kyoto ICR, Kyoto H. Daido JAERI APRC, Ibaraki-ken A. Fukumi, Z. Li, K. Matsukado NIRS, Chiba-shi T. Hosokai, H. Iijima, K. Kinoshita, M. Uesaka, T. Watanabe, K. Yoshii UTNL, Ibaraki T. Takeuchi DOP Nagoya, Nagoya
	Ion production from a solid target by a high-power short pulse laser has been investigated to replace the injector linac of the synchrotron dedicated for cancer therapy. As the high power laser, the laser with the peak power of 100 TW and minimum pulse duration of 20 fs which has been developed at JAERI Kansai Research Establishment, is assumed. Laser produced ions with 100% energy spread is energy selected within ±5% and then phase rotated with use of the RF electric field synchronized to the pulse laser, which further reduces the energy spread to ±1%. The scheme of the phase rotation is presented together with the experimental results of laser production from the thin foil target.
THP75	Superconducting Accelerating Structure with Gradient as 2 Times Higher as TESLA Structure	785
	P. V. Avrakhov, V.E. Balakin PTC LPI, Protvino, Moscow Region
	A proposed new accelerating structure for TESLA is assumed to have an effective gradient 2 times more than existing 9-cell cavity. This structure is an interlaced combination of two side-cavity-coupled standing wave substructures with λ/4 cells length. Intercell coupling provides side-coupled cavities made from a special shape waveguide section. The high accelerating gradient is accomplished by 4 factors: The shortened accelerating cells have transit time factor 0.9 instead of 0.64 for conventional standing wave cells with λ/2 length. The side magnetic coupling has made it possible to reduce the cells beam aperture that reduce relation between the maximum surface field and the acceleration gradient. Stronger intercell coupling allows extending the accelerating cavity and improving a duty factor of linac. Availability of the side coupling elements enables to use them for power input and HOM-couplers. It reduces intercavity distance and enhances duty factor too.