| Paper | Title | Page |
|---|---|---|
| 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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| TUPB010 | Dynamics Design on 70-250Mev Proton Linac | 102 |
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| Charged proton beams have broad application prospects, and research on compact S-band proton linear accelerators is increasingly heating up in recent years. For radiation therapy, to achieve the conventional penetration range of water-equivalent tissues, protons with energy of 70 to 230MeV are required. The design of electromagnetic structure is closely related to particle dynamics design. A flexible and controllable particle dynamic tracking code (PDT) through both traveling wave and standing wave acceleration has been compiled to simulate particle trajectory and satisfy automatic tuning of the various components in the entire acceleration chain. The linac with a total length of approximately 8.2m composed of 16 tanks of backward traveling wave structures and permanent magnet quadrupole lenses was designed, operating at an RF frequency of 2.856GHz with a target acceleration gradient of 30MV/m, and accelerating proton beam from 70MeV to 250MeV while maintaining low emittance and high transmission efficiency. | ||
| DOI • | reference for this paper ※ doi:10.18429/JACoW-SAP2023-TUPB010 | |
| About • | Received ※ 09 July 2023 — Accepted ※ 12 July 2023 — Issued ※ 11 August 2023 | |
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| TUPB018 | The Design of Nonlinear Regenerative Extraction in 250MeV Protron Superconducting Synchrocyclotron | 123 |
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| The objective of this article is to apply the regenerative extraction system to a 250MeV proton superconducting synchrocyclotron. The parameters of the regenerative extraction system are determined by iteratively calculating the appropriate magnetic field and particle trajectory in the region where the magnetic field and particle trajectories interact. This is then combined with the magnetic channel system to achieve the extraction of the beam from the accelerator. In the article, the particle orbit dynamics analysis and the design of relevant parameters for the regenerative extraction system were successfully implemented using Matlab programming. The simulation results showed that the stability in the vertical direction has the greatest impact on the extraction efficiency and determination of the regenerative magnetic field parameters. In order to maximize the particle extraction efficiency, the radial displacement of particles in the last few turns should pass through two identical nodes. | ||
| DOI • | reference for this paper ※ doi:10.18429/JACoW-SAP2023-TUPB018 | |
| About • | Received ※ 09 July 2023 — Revised ※ 11 July 2023 — Accepted ※ 12 July 2023 — Issued ※ 04 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 | |
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