Author: Thongbai, C.
Paper Title Page
TUPOPT029 Infrared Free-Electron Laser Project in Thailand 1070
 
  • S. Rimjaem, N. Chaisueb, P. Kitisri, K. Kongmali, E. Kongmon, P. Nanthanasit, S. Pakluea, J. Saisut, S. Sukara, K. Techakaew, C. Thongbai
    Chiang Mai University, Chiang Mai, Thailand
  • P. Apiwattanakul, P. Jaikaew, W. Jaikla, N. Kangrang
    Chiang Mai University, PBP Research Facility, Chiang Mai, Thailand
  • M. Jitvisate
    Suranaree University of Technology, Nakhon Ratchasima, Thailand
  • M.W. Rhodes
    ThEP Center, Commission on Higher Education, Bangkok, Thailand
 
  The infrared free-electron laser (IR FEL) project is established at Chiang Mai University in Thailand with the aim to provide experimental stations for users utilizing accelerator-based terahertz (THz) and mid-infrared (MIR) radiation. Main components of the system include a thermionic RF gun, an alpha magnet as a bunch compressor and energy filter, a standing-wave RF linac, a THz transition radiation (THz-TR) station, two magnetic bunch compressors and beamlines for MIR/THz FEL. The system commissioning is ongoing to produce the beams with proper properties. Simulation results suggest that the oscillator MIR-FEL with wavelengths of 9.5-16.6 um and pulse energies of 0.15-0.4 uJ can be produced from 60-pC electron bunches with energy of 20-25 MeV. The super-radiant THz-FEL with frequencies of 1-3 THz and 700 kW peak power can be produced from 10-16 MeV electron bunches with a charge of 50 pC and a length of 200-300 fs. Furthermore, the THz-TR with a spectral range of 0.3-2.5 THz and a pulse power of up to 1.5 MW can be obtained. The MIR/THz FEL will be used as high-brightness light source for pump-probe experiments, while the coherent THz-TR will be used in time-domain spectroscopy.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT029  
About • Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 16 June 2022
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TUPOPT054 Generation of Coherent THz Transition Radiation for Time Domain Spectroscopy at the PBP-CMU Electron Linac Laboratory 1129
SUSPMF019   use link to see paper's listing under its alternate paper code  
 
  • S. Pakluea
    Chiang Mai University, PBP Research Facility, Chiang Mai, Thailand
  • M. Jitvisate
    Suranaree University of Technology, Nakhon Ratchasima, Thailand
  • S. Rimjaem, J. Saisut, C. Thongbai
    Chiang Mai University, Chiang Mai, Thailand
  • S. Rimjaem, J. Saisut, C. Thongbai
    ThEP Center, Commission on Higher Education, Bangkok, Thailand
 
  The accelerator system at the PBP-CMU Electron Linac Laboratory is used to generate terahertz transition radiation (THz-TR). Due to broad spectrum, it can be used as the light source for THz time-domain spectroscopy (TDS) to measure both the intensity and phase of the THz signal. This contribution presents the generation of the THz-TR produced from 10-20 MeV electron beams and the system preparation for THz TDS. The electron bunches, which are compressed to have a length of femtosecond scale at the experimental station, is used to generate the THz-TR using a 45°-tilted aluminum foil as a radiator. The radiation properties including angular distribution, polarization and radiation spectrum are measured in the accelerator hall and at the TDS station. The radiation spectral range covers up to 2.3 THz with the peak power of 0.5 - 1.25 MW is expected. The effects of electron bunch distribution, divergence of the beam and influence of optical components on the radiation properties were studied. The results show that the considered effects have a significant impact on the TR properties. The Information will be used in the TR characterization that is needed to be interpreted carefully.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT054  
About • Received ※ 08 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 27 June 2022 — Issue date ※ 04 July 2022
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WEPOTK036 Progress on Electron Beam Optimization for FLASH Radiotherapy Experiment at Chiang Mai University 2146
SUSPMF078   use link to see paper's listing under its alternate paper code  
 
  • K. Kongmali, P. Apiwattanakul, S. Rimjaem, J. Saisut, C. Thongbai
    Chiang Mai University, Chiang Mai, Thailand
  • P. Apiwattanakul, N. Kangrang
    Chiang Mai University, PBP Research Facility, Chiang Mai, Thailand
  • M. Jitvisate
    Suranaree University of Technology, Nakhon Ratchasima, Thailand
  • P. Lithanatudom
    IST, Chiang Mai, Thailand
 
  At present, one of diseases that kills many people worldwide is cancer. The FLASH radiotherapy (RT) is a promising cancer treatment under study. It involves the fast delivery of RT at much higher dose rates than those currently used in clinical practice. The very short time of exposure leads to the destruction of the cancer cells, while the nearby normal cells are less damaged as compared with conventional RT. This work focuses on study of FLASH-RT experiment using electron beams produced from the accelerator system at the PBP-CMU Electron Linac Laboratory. The structure and properties of our electron pulses with microbunches in picosecond time scale and macropulses in microsecond time scale match well to FLASH-RT requirement. To optimize the condition for experiment, the electron beam simulations are performed by varying energy, charge and bunch length. The 25 MeV electrons energy before hitting the window for 50 and 100 pC bunch length have a bunch length of 1.16 and 1.97 ps. The transverse rms beam sizes of 50 pC and 100 pC bunch charges have the differences between ASTRA and GEANT4 from 7.90 % to 34.0 %. The optimized electron beam properties from this study will be used as the guideline for further simulation and experiment preparation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK036  
About • Received ※ 08 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 20 June 2022 — Issue date ※ 22 June 2022
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THPOST021 Beam Dynamics Simulations of Linear Accelerator for Natural Rubber Vulcanization at Chiang Mai University 2491
 
  • J. Saisut, S. Rimjaem, C. Thongbai
    Chiang Mai University, Chiang Mai, Thailand
  • M. Jitvisate
    Suranaree University of Technology, Nakhon Ratchasima, Thailand
  • S. Rimjaem, J. Saisut, C. Thongbai
    ThEP Center, Commission on Higher Education, Bangkok, Thailand
 
  The Linear accelerator system for natural rubber vulcanization has been developed at the Plasma and Beam Physics Research Facility, Chiang Mai University, Thailand. The main components of the accelerator system consist of a DC electron gun with a thermionic cathode, an RF linear accelerator, an RF system, a control system, and an irradiation system. The electron beam properties for natural rubber vulcanization are predicted from the beam dynamics simulation starting from a cathode to the titanium exit window. The electron beam generation and the particle in cell simulation inside the DC electron gun are performed using CST Studio Suit software. The electron distribution at the gun exit from the CST output is covered to be an input distribution of the ASTRA beam dynamics simulation program. The electron beam enters linac and is accelerated by RF filed inside the linac. The ASTRA simulation code is used to track electron trajectories including the space-charge interaction and the simulation starts from linac entrance to the exit windows. The electron beam properties for various conditions are evaluated and will be used for further simulations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST021  
About • Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 03 July 2022
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THPOMS040 Present Status of Linear Accelerator System for Natural Rubber Vulcanization at Chiang Mai University 3057
 
  • C. Thongbai, P. Jaikaew, E. Kongmon, S. Rimjaem, J. Saisut, P. Wongkummoon
    Chiang Mai University, Chiang Mai, Thailand
  • N. Khangrang
    Chiang Mai University, PBP Research Facility, Chiang Mai, Thailand
  • M.W. Rhodes, S. Rimjaem, J. Saisut, C. Thongbai
    ThEP Center, Commission on Higher Education, Bangkok, Thailand
 
  At the Plasma and Beam Physics (PBP) Research Fa-cility, Chiang Mai University (CMU), an electron beam accelerator system for natural rubber irradiation has been under development and is currently under the commissioning. The research project is carried out with the aim to modify an old medical linac, retired from the clinical operation, for rubber latex vulcanization and materials irradiation using electron beams. The accelerator system consists of a DC-thermionic cathode electron gun, a standing-wave RF linear accelerator, an RF system, a control system, beam diagnostic systems, and an irradia-tion system. The components were completely assembled, and the RF system was tested. The RF processing has been performed and some of the electron beam properties have been measured. This contribution presents some experimental results while developing and testing the various sub-systems of this accelerator. The present status of development and some vulcanization results will also be reported in this contribution.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS040  
About • Received ※ 07 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 04 July 2022
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THPOMS041 Design and Parameterization of Electron Beam Irradiation System for Natural Rubber Vulcanization 3061
SUSPMF131   use link to see paper's listing under its alternate paper code  
 
  • P. Wongkummoon
    Chiang Mai University, PBP Research Facility, Chiang Mai, Thailand
  • N. Kangrang, S. Rimjaem, J. Saisut, C. Thongbai
    Chiang Mai University, Chiang Mai, Thailand
  • M.W. Rhodes
    IST, Chiang Mai, Thailand
 
  Electron beam irradiation is a process to modify or improve the properties of materials with less chemical residue. In natural rubber vulcanization, a proper electron absorbed dose is about 50-150 kGy. In this study, the experimental station is designed to investigate the deposition of the electron beam in natural rubber. Electron beams generated from an RF linac are used in this study. This accelerator can generate the beam with energies in the range of 1-4 MeV and an adjustable repetition rate of up to 200 Hz. We can optimize these parameters to maximize the throughput and uniformity of electron dose in the vulcanization. The simulation results from GEANT4 were used to narrow down the appropriate parameters in the experiment. In the early stage of the study, water was used as a sample instead of natural rubber. The dose distribution was obtained by placing a B3 film dosimeter under a water chamber. The water depth was varied from 0.5 to 2.0 cm. The simulation results provide the dose distribution to compare with the experimental results. In a further study, the beam irradiation in natural rubber with these optimal parameters and vulcanization tests will be performed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS041  
About • Received ※ 08 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 03 July 2022
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