Paper | Title | Page |
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WEPLM67 | Optimization of a Single-Cell Accelerating Structure for Rf Breakdown Test With Short Rf Pulses | 747 |
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RF breakdown is one of the major limitations to achieve high gradient acceleration for future structure-based normal conducting linear colliders. Previous statistic research shows that the breakdown rate is proportional to Ea30 * tp5, which indicates that the accelerating gradient Ea could be improved by using shorter RF pulses (tp). An X-band 11.7~GHz metallic single-cell structure has been designed for RF breakdown study up to 273~MV/m using short pulses (~3ns) generated by a 400~MW power extractor at Argonne Wakefield Accelerator (AWA) facility. The structure has also been scaled to 11.424~GHz for the long pulse (100-1500~ns) breakdown study driven by a klystron and a pulse compressor at Tsinghua X-band High Power Test-stand (TPoT-X), with the gradient up to 246~MV/m with 200~MW input power. | ||
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLM67 | |
About • | paper received ※ 05 September 2019 paper accepted ※ 26 November 2019 issue date ※ 08 October 2019 | |
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WEPLM68 | Design of a Dielectric-Loaded Accelerator for Short Pulse High Gradient Research | 751 |
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The short-pulse two-beam acceleration approach is a promising candidate to meet the cost and luminosity requirements for future linear colliders. Dielectric-loaded structure has been intensely investigated for this approach because of its low fabrication cost, low RF loss, and potential to withstand GV/m gradient. An X-band 11.7~GHz dielectric-loaded accelerator (DLA) has been designed for high power test with short RF pulses (3~ns) generated from a power extractor driven by high charge bunches at Argonne Wakefield Accelerator (AWA) facility. The gradient is expected to be over 100~MV/m with the maximum input power of 400~MW. | ||
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLM68 | |
About • | paper received ※ 05 September 2019 paper accepted ※ 27 November 2019 issue date ※ 08 October 2019 | |
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MOZBB2 | Experiments with Metamaterial-Based Metallic Accelerating Structures | 78 |
MOPLH20 | use link to see paper's listing under its alternate paper code | |
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Funding: U.S. Department of Energy, Office of Science, Office of High Energy Physics under Award No. DE-SC0015566 at MIT and No. DE-AC02-06CH11357 at ANL We present experimental studies of metamaterial (MTM) structures for wakefield acceleration. The MTM structure is an all-metal periodic structure with its period much smaller than the wavelength at X-band. The fundamental TM mode has a negative group velocity, so an electron beam traveling through the structure radiates by reversed Cherenkov radiation. Two experiments have been completed at the Argonne Wakefield Accelerator (AWA), namely the Stage-I and Stage-II experiments. Differences between the two experiments include: (1) Structure length (Stage-I 8 cm, Stage-II 20 cm); (2) Bunch number used to excite the structure (Stage-I up to 2 bunches, Stage-II up to 8 bunches). In the Stage-I experiment, two bunches with a total charge of 85 nC generated 80 MW of RF power in a 2 ns long pulse. In the Stage-II experiment, the highest peak power reached 380 MW in a 10 ns long pulse from a train of 8 bunches with a total charge of 224 nC. Acceleration of a witness bunch has not been demonstrated yet, but the extracted power can be transferred to a separate accelerator for two-beam acceleration or directly applied to a trailing witness bunch in the same structure for collinear acceleration. |
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Slides MOZBB2 [8.172 MB] | |
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOZBB2 | |
About • | paper received ※ 27 August 2019 paper accepted ※ 04 September 2019 issue date ※ 08 October 2019 | |
Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |
MOZBB3 |
Conceptual Design of a Compact 500 MeV Short-Pulse Two-Beam Acceleration Demonstrator at Argonne Wakefield Accelerator | |
MOPLH27 | use link to see paper's listing under its alternate paper code | |
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Short-pulse two-beam acceleration (SP-TBA) is an advanced acceleration concept that can potentially meet the luminosity and cost requirements in future linear colliders and XFELs. In this concept, a high charge drive beam travelling through a structure excites short wakefield field (<20 ns) which is used to accelerate a low charge main beam in a parallel structure. A SP-TBA program is under development at the Argonne Wakefield Accelerator (AWA) facility where 300 MW generated power, 150 MeV/m acceleration gradient, and simplified staging have been successfully achieved. Based on the ongoing effort of novel dielectric disk structure, fast kicker/septum, and improved beam quality, a fully-functional demonstrator that can fit into AWA’s current bunker is proposed to demonstrate key technologies required by SP-TBA based machines: GW power generation, >250 MV/m acceleration, drive beam distribution/transportation, successive main beam acceleration, etc. The 70 MeV drive beam will be decelerated by four power extractors in two stages so as to boost the main beam energy from 15 MeV to 500 MeV by the four corresponding accelerators. The conceptual design will be presented in detail. | ||
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Slides MOZBB3 [6.853 MB] | |
Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |