Development of C-band (5712 MHz) high power waveguide components

Matsumoto, Hiroshi; Shintake, T.; Akasaka, N.; Baba, H.; Miura, Atsushi

doi:10.1109/pac.1997.749746

Cited by 5 publications

(6 citation statements)

References 2 publications

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“…It has also been proposed and successfully tested in the injector linac of the electron-positron collider Su-perKEKB [7,8] The two main projects that adopted C-band structures are the Japanese FEL project [1,2] in Spring-8 and the SwissFEL project at PSI [5]. In the first project travelling wave (TW) damped structures have been adopted for multi-bunch operation [4,[9][10][11][12][13][14]. The damping of the High Order Modes (HOM) is realized with the choke mode technique.…”

Section: Introductionmentioning

confidence: 99%

The C-Band accelerating structures for SPARC photoinjector energy upgrade

et al. 2013

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The use of C-Band structures for electron acceleration and production of high quality beams has been proposed and adopted in several linac projects all over the world. The two main projects that adopted such type of structures are the Japanese Free Electron Laser (FEL) project in Spring-8 and the SwissFEL project at Paul Scherrer Institute (PSI). Also the energy upgrade of the SPARC photo-injector at LNF-INFN (Italy) from 150 to more than 240 MeV will be done by replacing a low gradient S-Band accelerating structure with two C-band structures. The structures are Traveling Wave (TW) and Constant Impedance (CI), have symmetric axial input couplers and have been optimized to work with a SLED RF input pulse. The paper presents the design criteria of the structures, the realization procedure and the low and high power RF test results on a prototype. The high power tests have been carried out by the Frascati INFN Laboratories in close collaboration with the Japanese Laboratory KEK. Experimental results confirmed the feasibility of the operation of the prototype at 50 MV/m with about 10 6 breakdowns per pulse per meter. Such high gradients have not been reached before in C-Band systems and demonstrated the possibility to use C-band accelerators, if needed, at such high field level. The results of the internal inspection of the structure after the high power test are also presented.

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Section: Introductionmentioning

confidence: 99%

The C-Band accelerating structures for SPARC photoinjector energy upgrade

et al. 2013

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“…-WR137 inside dimensions: 1.372 ′′ × 0.622 ′′ -WR159 inside dimensions: 1.59 ′′ × 0.795 ′′ -WR187 inside dimensions: 1.872 ′′ × 0.872 ′′ Maximum rf power transmitted via oxygen-free high conductivity (OFHC) copper WR187 waveguide may be up to 350 MW peak in vacuum [60]. High-power experiments have shown that the main reason for the rf breakdown is a poor-quality inner waveguide surface.…”

Section: Specification Of Their Inside Dimensions Is As Followsmentioning

confidence: 99%

“…The flange pair should be capable of transmitting 160 MW peak RF power. A leak rate should be -34 - A new type unisex waveguide flange has been developed at KEK [60] to increase reliability and reduce cost; it comes from the RIKEN-DESY WR187 flange as shown in figure 24.…”

Section: • Rf Flangementioning

confidence: 99%

Status and future plans for C³ R&D

Nanni,

Breidenbach,

et al. 2023

J. Inst.

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C3 is an opportunity to realize an e + e - collider for the study of the Higgs boson at √s = 250 GeV, with a well defined upgrade path to 550 GeV while staying on the same short facility footprint [2,3]. C3 is based on a fundamentally new approach to normal conducting linear accelerators that achieves both high gradient and high efficiency at relatively low cost. Given the advanced state of linear collider designs, the key system that requires technical maturation for C3 is the main linac. This paper presents the staged approach towards a facility to demonstrate C3 technology with both Direct (source and main linac) and Parallel (beam delivery, damping ring, ancillary component) R&D. The primary goal of the C3 Demonstration R&D Plan is to reduce technical and cost risk by building and operating the key components of C3 at an adequate scale. This R&D plan starts with the engineering design, and demonstration of one cryomodule and will culminate in the construction of a 3 cryomodule linac with pre-production prototypes. This R&D program would also demonstrate the linac rf fundamentals including achievable gradient and gradient stability over a full electron bunch train and breakdown rates. It will also investigate beam dynamics including energy spread, wakefields, and emittance growth. This work will be critical to confirm the suitability of the C3 beam parameters for the physics reach and detector performance in preparation for a Conceptual Design Report (CDR), as well as for follow-on technology development and industrialization. The C3 Demonstration R&D Plan will open up significant new scientific and technical opportunities based on development of high-gradient and high-efficiency accelerator technology. It will push this technology to operate both at the GeV scale and mature the technology to be reliable and provide high-brightness electron beams. The timeline for progressing with C3 technology development will be governed by practical limitations on both the technical progress and resource availability. It consists of four stages: Stage 0) Ongoing fundamental R&D on structure prototypes, damping and vibrations. Stage 1) Advancing the engineering maturity of the design and developing start-to-end simulations including space-charge and wakefield effects. This stage will include testing of strucutres operating at cryogenic temperatures. Beam tests would be performed with high beam current to test full beam loading. Stage 2) Production and testing of the first cryomodule at cryogenic temperatures. This would provide sufficient experimental data to compile a CDR and it is anticipated for Stage 2 to last 3 years and to culminate with the transport of photo-electrons through the first cryomodule. Stage 3) Updates to the engineering design of the cryomodules, production of the second and third cryomodule and their installation. Lower charge and lower emittance beams will be used to investigate emittance growth. The successful full demonstration of the 3 cryomodules to deliver up to a 3 GeV beam and achieve the C3five gradient will allow a comprehensive and robust evaluation of the technical design of C3 as well as mitigate technical, schedule, and cost risks required to proceed with a Technical Design Report (TDR).

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“…Specification of their inside dimensions is as follows. WR137 inside dimensions: 1.372" x 0.622" WR159 inside dimensions: 1.59" x 0.795" WR187 inside dimensions: 1.872" x 0.872" Maximum rf power transmitted via oxygen-free high conductivity (OFHC) copper WR187 waveguide may be up to 350 MW peak in vacuum [19]. High-power experiments have shown that the main reason for the rf breakdown is a poor-quality inner waveguide surface.…”

Section: • Specification Of Waveguide Networkmentioning

confidence: 99%

“…A new type unisex waveguide flange has been developed at KEK [19] to increase reliability and reduce cost; it comes from the RIKEN-DESY WR187 flange as shown in Figure 12.…”

Section: • Rf Flangementioning

confidence: 99%