Author: Kim, E.-S.
Paper Title Page
MOPOTK022 A Design Study of Injector System for Synchrotron Light Source 485
SUSPMF054   use link to see paper's listing under its alternate paper code  
 
  • C. Kim, E.-S. Kim, C.S. Park
    KUS, Sejong, Republic of Korea
 
  This work presents a design study of a 200 MeV electron linear accelerator consisting of an electron gun, bunchers, and accelerator structures. We aimed to design the linac with low emittance and low energy spread. A coasting beam from a thermionic electron gun is bunched using a series of buncher cavities: sub-harmonic buncher (SHB), a pre-buncher (PB), and a Buncher. The bunched beam is then accelerated up to 200 MeV with 4 cascaded accelerating structures. The SHB was designed with one-cell standing wave structure for improving the bunching efficiency. The two types of the 500 MHz SHB were considered: elliptical and coupled-cavity linac types. We also investigated constant-gradient and constant-impedance types of 3 GHz multi-cell traveling wave resonators for following buncher cavities and accelerating structures. Depending on the type, geometries of each traveling wave structure (TWS) cavity were determined, and then the electromagnetic fields were calculated. RF powers and phases of each cavity along this linac system were optimized using beam dynamics simulation. Furthermore, the beam distributions in the transverse direction are adjusted using solenoid magnets in the lowenergy section as well as quad triplets in the high-energy section.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK022  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 10 June 2022 — Issue date ※ 17 June 2022
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MOPOTK023 Beam Dynamics Studies on the 50 MeV Electron Linear Accelerator for Ultra-High Dose Rates 489
 
  • Y. Lee, C. Kim, E.-S. Kim, C.S. Park
    KUS, Sejong, Republic of Korea
  • H.-S. Lee, H.S. Shin
    VITZRONEXTECH, Ansan-si, Gyeonggi-do, Republic of Korea
 
  Electron beams with ultra-high dose rates (>40 Gy/s), which enable effective radiotherapy to act on deep-seated tumors in less than a second, can be generated by linear accelerators. To successfully achieve FLASH radiotherapy, we have performed the 50 MeV linear accelerator design studies. The designed electron accelerator consists of a thermionic electron gun, sub-harmonic buncher, buncher and 2.856 GHz traveling wave structure. In this report the design layout and particle tracking simulation results of the 50 MeV electron linac with high beam current are presented in detail.
FLASH radiotherapy
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK023  
About • Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 15 June 2022
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TUPOTK025 Design Study of the Third Harmonic Superconducting Cavity for a Bunch Lengthening 1258
 
  • J.Y. Yoon, E.-S. Kim
    KUS, Sejong, Republic of Korea
  • J.H. Han, H.S. Park
    Kiswire Advanced Technology Ltd., Daejeon, Republic of Korea
  • E. Kako
    KEK, Ibaraki, Japan
 
  The bunch lengthening by the 3rd harmonic cavity reduces the electron collisions in a bunch and increases the Touschek lifetime of a storage ring. We performed the multi-physics simulations including the electromagnetic, thermal, and mechanical analysis of the cavity. In the electromagnetic simulation, the geometry is optimized for the required performance of the cavity. The elliptical double-cell geometry is selected to increase the accelerating voltage and reduce the power losses of the cavity. Thermal/mechanical analyses were performed to check the deformation of the thermal and pressure contraction. The prototype cavity does not require the power coupler as it is a passive type. The conceptual design and copper prototype of the 3rd harmonic cavity will be described in this paper. Based on this design, the fabrication of Niobium cavity is in progress.
Superconducting RF, Cavity
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOTK025  
About • Received ※ 02 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 09 July 2022
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THPOST034 Development of Magnetic Harmonics Measurement System for Small Aperture Magnets 2517
SUSPMF122   use link to see paper's listing under its alternate paper code  
 
  • J.M. Hwang, J. Bahng
    Korea University Sejong Campus, Sejong, Republic of Korea
  • E.-S. Kim
    KUS, Sejong, Republic of Korea
 
  Storage ring has been improved to achieve high brightness of x-ray light source by making beam size and beam emittance smaller and enlarging the beam intensity. To achieve requirements such as a small beam emittance, the magnets need to have a larger magnetic field gradient and complex function with small aperture size. Since the complex structure and small beam size accompany with large errors in beam dynamics by high order field distortion of the magnets, it is important to measure the harmonics of the magnet in order to measure and improve it. Traditional field measurement methods such as hall probe and rotating loop have difficulty in measuring the harmonics of a magnet with a small aperture due to restrictions that physical size of the hall sensor and loop-card respectively. We developed Single Stretched Wire (SSW) method for the magnetic field measurement method on a small aperture magnet, in particular harmonics of the magnet. The system consists of a thin wire, accurate actuator system, and voltmeter. We describe the development of the SSW system and the result of the performance test by using our system in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST034  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 22 June 2022 — Issue date ※ 02 July 2022
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