Paper | Title | Page |
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TUPB009 | General Design of 180 MHz RFQ for BNCT | 99 |
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Accelerator based boron neutron capture therapy (AB-BNCT) is a promising cancer treatment technology. An overall design have been proposed of a 180 MHz radio frequency quadrupole (RFQ) accelerator for BNCT. The particularity of dynamic design of the RFQ is that the average aperture radius changes along the accelerator. Beam dynamics design results show that the length of accelerator which accelerates protons from 35 keV to 2.81 MeV is 5.07 m, and the transmission up to 99.65%. In terms of radio frequency (RF) structure design, two shapes of cross section of cavity were simulated and compared, i.e., quadrilateral cavity and octagonal cavity. The results show that quadrilateral cavity performed better and was finally selected. Meanwhile, in order to keep the frequency of dipole mode away from the working quadrupole mode, 20 pairs of Pi-mode stabilizer rods are considered. The simulation results show that a large mode separation of more than 20MHz between the operating quadrupole mode and nearest dipole mode can be obtained, this is sufficient to deal with the errors caused by machining and misalignment. | ||
DOI • | reference for this paper ※ doi:10.18429/JACoW-SAP2023-TUPB009 | |
About • | Received ※ 09 July 2023 — Revised ※ 11 July 2023 — Accepted ※ 15 July 2023 — Issued ※ 24 July 2024 | |
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TUPB019 | Beam Dynamics in Superconducting Proton Linac | 126 |
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Funding: This work was supported by the National Natural Science Foundation of China (Grant Nos. 11375122 and 11875197). Beam loss control is a crucial research direction in high-current superconducting linear accelerators (SCL). The research findings include firstly, for continuous beams, when tune depression eta > 0.7, zero current periodic phase advance (σ0t) can partially exceed 90° during transport in solenoid and quadrupole doublet periodic focusing channels. Different results occur when eta < 0.7. Secondly, in the solenoid system, σ0t can partially exceed 90° without significant impact on beam quality. In the quadrupole doublet focusing system, the partial breakdown of 90° affects beam quality. Thirdly, Similar conclusions hold for acceleration effects. Fourthly, numerical analysis shows that double-period structures have more stringent design criteria than fully period structures. The double-period structure can cause envelope instability even if σ0t < 90°. Fifthly, the primary factor causing halo is the 2:1 resonance. Additionally, when eta is small, higher-order resonances can also cause halo. |
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DOI • | reference for this paper ※ doi:10.18429/JACoW-SAP2023-TUPB019 | |
About • | Received ※ 09 July 2023 — Revised ※ 11 July 2023 — Accepted ※ 12 July 2023 — Issued ※ 08 April 2024 | |
Cite • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |