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Comparison of experimental result and transfer matrix model of combined function bending magnet
Hahn Garam,이재유,Ha Taekyun,Kim Dotae,Ko Jinjoo,신승환 한국물리학회 2021 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.79 No.2
This paper describes solutions to calibrate the photon beam from the gradient bending magnet and to minimize the cross-talk between blades in the photon-beam position monitors in beamlines at Pohang Light Source II. The cross-talk was reduced by 99% applying the sensitivity normalization for each electrodes. The precise calibration was also achieved by considering additional kicks in the gradient bending magnet. The focusing force by quadrupole component in the bending magnet gives rise to an effect that simultaneously changes the vertical displacement of the source point and the emission angle. Experimental results agreed well with the transfer matrix calculations.
김찬미,Eun-San Kim,Garam Hahn 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.69 No.9
The Korea Heavy Ion Medical Accelerator consists of an injector and a synchrotron for an ion medical accelerator that is the first carbon-ion therapy system in Korea. The medium energy beam transport(MEBT) line connects the interdigital H-mode drift tube linac and the synchrotron. We investigated the beam conditions after the charge stripper by using the LISE++ and the SRIM codes. The beam was stripped from C4+ into C6+ by using the charge stripper. We investigated the performance of a de-buncher in optimizing the energy spread and the beam distribution in z-dW/W (direction of beam progress-beam and energy) phase. We obtained the results of the tracking simulation and the error analysis by using the TRACK code. Possible misalignments and rotations of the magnets were considered in the simulations. States of the beam were examined when errors occurred in the magnets by the applying analytic fringe field model in TRACK code. The condition for the beam orbit was optimized by using correctors and profile monitors to correct the orbit. In this paper, we focus on the beam dynamics and the error studies dedicated to the MEBT beam line and show the optimized beam parameters for the MEBT.
Orbit Error Correction on the High Energy Beam Transport Line at the KHIMA Accelerator System
Chawon Park,Heejoong Yim,Garam Hahn,Dong Hyun An 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.69 No.6
For the purpose of treatment of various cancers and medical research, a synchrotron based medical machine has been developed under the Korea Heavy Ion Medical Accelerator (KHIMA) project and is scheduled for use to treat patient at the beginning of 2018. The KHIMA synchrotron is designed to accelerate and extract carbon ion (proton) beams with various energies from 110 to 430 MeV/u (60 to 230 MeV). Studies on the lattice design and beam optics for the High Energy Beam Transport (HEBT) line at the KHIMA accelerator system have been carried out using the WinAgile and the MAD-X codes. Because magnetic field errors and misalignments introduce deviations from the design parameters, these error sources should be treated explicitly, and the sensitivity of the machine’s lattice to different individual error sources should be considered. Various types of errors, both static and dynamic, have been taken into account and have been consequentially corrected with a dedicated correction algorithm by using the MAD-X program. Based on the error analysis, the optimized correction setup is decided, and the specifications for the correcting magnets of the HEBT lines are determined.
An Seohyeon,Lee Se Byeong,Kim Tae Jeong,Hahn Garam 한국물리학회 2024 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.84 No.1
This study presents a beam profle monitor composed of a vacuum chamber housing, a scintillator screen, a digital camera, and a custom control circuit based on Raspberry Pi for an accurate measurement of beam profles with a high spatial resolution which is crucial for beam quality assessment and control for the therapeutic beamline. A simple position calibration that uses perspective transform was conducted to map from the pixel space to real space. Additionally, we investigated fnding a proper noise fltering methods to mitigate stray and impulsive noises. We found that the non-local de-noising algorithm outperformed than median flter for reducing noise in a high-frequency region. As a demonstration of utilization of the profle monitor, we measured transverse beam emittances along the x and y axes using quadrupole scanning technique, which were resulted in 2.715±0.017 and 4.619±0.018 π mm mrad, respectively.
Development of a Beam Buncher for the KIRAMS-30 Cyclotron
Yang, Tea Gun,Jung, In Su,Kang, Gun Uk,An, Dong Hyun,Hahn, Garam,Kang, Joon Sun,Hong, Bong Hwan,Chang, Hong Suk,Yim, Hee Joong,Kim, Yu-Seok,Kim, Geun-Beom,Park, Yeunsoo,Kwon, Key Ho,Cho, Jun Dong Korean Physical Society 2010 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.56 No.6