| Paper | Title | Page |
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| MOIXA04 | Operational Experience for RIKEN Superconducting Linear Accelerator | 30 |
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| The RIKEN superconducting heavy-ion linac, so-called SRILAC, has been successfully operating for almost four years, and continuously deliver a heavy ion beam for a super-heavy-element synthesis experiment. The effects of a broken coupler in the early days and four years of operation have resulted in increased X-ray emission levels in several superconducting cavities, which have been successfully corrected by pulse conditioning. This talk will share the experiences and lessons learned from four-year operation with low beta SC-cavities. | ||
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Slides MOIXA04 [4.517 MB] | |
| DOI • | reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOIXA04 | |
| About • | Received ※ 06 July 2023 — Revised ※ 10 July 2023 — Accepted ※ 19 August 2023 — Issue date ※ 22 August 2023 | |
| Cite • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |
| MOPMB086 | Development of Non-Destructive Beam Envelope Measurements in SRILAC with Low Beta Heavy Ion Beams Using BPMs | 319 |
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The RIKEN SRILAC* has been providing heavy ion beams of a few puA for the synthesis of new superheavy elements since June 2020, utilizing 10 superconducting quarter-wavelength resonators (SC-QWRs). Although the beam supply has been stable, it is crucial to measure and control the beam dynamics in the SRILAC to increase the beam intensity up to 10 puA. However, destructive monitors cannot be used to avoid the generation of dust particles and outgassing. Beam has been precisely tuned by monitoring the beam center using Beam Energy Position Monitors (BEPMs)** and the reactions of vacuum monitors. In our study, we are developing a method for estimating the beam envelope by combining the quadrupole moments from BEPMs, which consist of four cosine-shape electrodes, with calculations of the transfer matrix***. While this method has been applied to electron and proton beams, it has not been practically demonstrated for heavy ion beams in beta – 0.1 regions. By combining BEPM simulations, we are making the progress towards the reproduction of experimental results, overcoming specific issues associated with low beta. We will report on the current status of our developments.
* K. Yamada et al., in Proc. SRF’21, paper MOOFAV01(2021). ** T. Watanabe et al., in Proc. IBIC’20, paper FRAO04 (2020). *** R. H. Miller et al., in Proc. HEAC’83, pp. 603–605 (1983). |
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Poster MOPMB086 [10.338 MB] | |
| DOI • | reference for this paper ※ doi:10.18429/JACoW-SRF2023-MOPMB086 | |
| About • | Received ※ 30 June 2023 — Revised ※ 01 July 2023 — Accepted ※ 19 August 2023 — Issue date ※ 22 August 2023 | |
| Cite • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |
| WEPWB085 | Degradation and Recovery of Cavity Performance in SRILAC Cryomodules at RIBF | 784 |
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| The RIKEN superconducting (SC) heavy-ion linear accelerator (SRILAC) has been providing beam supply for super-heavy elements synthesis experiments since its commissioning in January 2020. However, the long-term operation of SC radio-frequency (RF) cavities leads an increase in the X-ray levels caused by field emissions resulting from changes in the inner surface conditions. More than half of the ten SC 1/4 wavelength resonators (SC-QWRs) of SRILAC, operating at a frequency of 73 MHz, have experienced an increase in X-ray levels, thus, requiring adjustments to the acceleration voltage for continuous operation. While several conditioning methods have been employed for SC cavities, a fully established technique is yet to be determined. To address this situation, a relatively simple conditioning method was implemented at RIKEN. The proposed method uses high-voltage pulsed power and imposes a low load on the cavities. | ||
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Poster WEPWB085 [12.789 MB] | |
| DOI • | reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB085 | |
| About • | Received ※ 13 June 2023 — Revised ※ 26 June 2023 — Accepted ※ 27 June 2023 — Issue date ※ 01 July 2023 | |
| Cite • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |
| WEPWB101 | Present Status of RIKEN Power Couplers for SRILAC | 823 |
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| The heavy ion linac of the RIKEN, utilizing superconducting technology, began operations in September 2019. Over the following 13 months, two of the ten superconducting accelerating cavities experienced vacuum leaks from the vacuum windows of the fundamental power couplers (FPCs). Currently, additional vacuum windows are installed on all ten FPCs and the beam supply continues without encountering any major issues with the FPCs. Additionally, the fabrication of ten replacement FPCs has been completed, addressing the underlying issues that led to the deterioration of the vacuum window strength. Currently, we are conducting radio frequency (RF) process of the new FPCs. In addition, we are designing a bias applying component to suppress multipacting in the FPCs. This paper reports the status of these issues related to the FPCs at the RIKEN. | ||
| DOI • | reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB101 | |
| About • | Received ※ 19 June 2023 — Revised ※ 27 June 2023 — Accepted ※ 28 June 2023 — Issue date ※ 14 July 2023 | |
| Cite • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |