IPAC2022 - List of Authors (Rimjaem, S.)

Paper	Title	Page
MOPOPT049	Study on Energy Spectrum Measurement of Electron Beam for Producing MIR-FEL at PBP-CMU Electron Linac Laboratory	367
SUSPMF093	use link to see paper's listing under its alternate paper code
	P. Kitisri, S. Rimjaem, K. Techakaew Chiang Mai University, Chiang Mai, Thailand S. Rimjaem ThEP Center, Commission on Higher Education, Bangkok, Thailand
	At the PBP-CMU Electron Linac Laboratory (PCELL), we aim to produce a mid-infrared free-electron laser (MIR-FEL) for pump-probe experiments in the future. The electron beam is generated from a thermionic cathode radio-frequency (RF) gun with a 1.5-cell cavity before going to an alpha magnet. In this section, some part of the beam is filtered out by using energy slits. The selected part of the beam is then further accelerated by an RF linear accelerator (linac) to get higher energy. This work focuses on the measurement of energy spectrum of electron beam for producing mid-infrared free-electron laser (MIR-FEL). Since our bunch compressor (BC) for the MIR-FEL beamline is an achromat system, the longitudinal distributions of electron beam at the entrance and the exit of the BC are almost the same. Thus, we can measure the longitidinal properties of the beam before it travels to the BC. By using a dipole magnet and a Faraday cup with a slit, we can measure energy spectrum of electron beam before entering the BC. In this study, the ASTRA code is used to investigate the properties of electron beam as well as to design the measuring system. The design results including systematic error of the measuring system are presented and discussed in this contribution. The results from this work can be used as the guideline for the measuring system construction as well as the beam operation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT049
About •	Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 09 July 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPOPT050	Systematic Study of Electron Beam Measuring Systems at the PBP-CMU Electron Linac Laboratory	371
SUSPMF094	use link to see paper's listing under its alternate paper code
	K. Techakaew, S. Rimjaem Chiang Mai University, Chiang Mai, Thailand
	The linear accelerator system at the PBP-CMU Electron Linac Laboratory (PCELL) is used to produce electron beam with suitable properties for generating coherent teragertz (THz) radiation and mid-infrared free-electron laser (MIR FEL). Optimization of machine parameters to produce short electron bunches with low energy spread and low transverse emittance was focused in this study. We conducted ASTRA simulations including three-dimentional (3D) space charge algorithm and 3D field distributions for radio-frequency (RF) electron gun and all magnets to develop measuring systems. Electron beam energy and energy spread were investigated downstream the RF gun and the RF linac using an alpha magnet and a dipole spectrometer, respectively. The transverse beam emittance was studied using the quadrupole scan technique. By filtering proper portion of electrons before entering the linac, the beam with average energy of 20 MeV and energy spread of 0.1-1% can be achieved for a bunch charge of 100 pC. The systematic error is less than 10% for measuring average energy and energy spread while it is less than 31% for measuring transverse emittance when placing the screen of at least 1.0 m behind the scanning quadrupole magnet. The results of this study were used to develop the measuring setups in our system.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT050
About •	Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 12 June 2022 — Issue date ※ 13 June 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOPT027	Numerical Simulation of a Superradiant THz Source at the PITZ Facility	1063
	N. Chaisueb, S. Rimjaem Chiang Mai University, Chiang Mai, Thailand P. Boonpornprasert, M. Krasilnikov, X.-K. Li, A. Lueangaramwong DESY Zeuthen, Zeuthen, Germany S. Rimjaem ThEP Center, Commission on Higher Education, Bangkok, Thailand
	An accelerator-based THz source is under development at the Photo Injector Test Facility at DESY in Zeuthen (PITZ). The facility can produce high brightness electron beams with high charge and small emittance. Currently, a study on development of a tunable high-power THz SASE FEL for supporting THz-pump, X-ray-probe experiments at the European XFEL is underway. An LCLS-I undulator, a magnetic chicane bunch compressor, and THz pulse diagnostics have been installed downstream the previously existing setup of the PITZ beamline. Additional to the SASE FEL, a possibility to generate superradiant THz undulator radiation from short electron bunches is under investigation, which is the focus in this study. Numerical simulations of the superradiant THz radiation by using sub-picosecond electron bunches with energy of 6 - 22 MeV and bunch charge up to 2 nC produced from the PITZ accelerator are performed. The results show that the radiation with a spectral range of 0.5 to 9 THz and a pulse energy in the order of sub-uJ can be obtained. The results from this study can be used as a benchmark for the future development.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT027
About •	Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 07 July 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOPT028	THz Undulator Radiation Based on Super-Radiant Technique at Chiang Mai University	1067
	E. Kongmon IST, Chiang Mai, Thailand N. Chaisueb, S. Rimjaem Chiang Mai University, Chiang Mai, Thailand S. Rimjaem ThEP Center, Commission on Higher Education, Bangkok, Thailand
	A linear accelerator system at the PBP-CMU Electron Linac Laboratory is used as an electron source for generating coherent THz radiation and MIR-FEL. To achieve high power THz radiation, the super-radiant technique using pre-bunched electrons and undulator magnet is utilized. In this study, we investigate the generation of such radiation with comparable properties as the FEL. The beamline composes of a 180-degree magnetic bunch compressor, a 2 m-electromagnet undulator, quadrupole magnets and diagnostic devices. This work includes the undulator design and investigation on properties of electron beam and THz radiation. Based-on the results of beam dynamic study, the optimized electron beams have an energy in a range of 10^-16 MeV, a bunch charge of 100 pC, and a bunch length of 300 fs. The radiation with frequency covering from 0.5 to 3 THz yields a peak power of 5.21 MW at 1.15 THz. This information was used as an initial parameter for undulator design by using the CST-EM Studio software. It has 19.5 periods with a period length of 100 mm. The design results show that the maximum magnetic field is 0.2317 T. The results of this study are used as the guideline for construction of the undulator and the THz-FEL beamline.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT028
About •	Received ※ 08 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 27 June 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

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
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOPT030	Design and Simulation of the MIR-FEL Generation System at Chiang Mai University	1074
SUSPMF012	use link to see paper's listing under its alternate paper code
	S. Sukara, K. Kongmali, S. Rimjaem Chiang Mai University, Chiang Mai, Thailand H. Ohgaki Kyoto University, Kyoto, Japan
	At the PBP-CMU Electron Linac Laboratory, the system to generate MIR-FEL using the electron linac has been developed. In this contribution, the design and simulation results of the MIR-FEL generation system are presented. The system is designed as the oscillator-FEL type consisting of two mirrors and a 1.6-m permanent planar undulator. The middle of the undulator is determined as the laser beam waist position. Both two mirrors are the concave gold-coated copper mirrors placing upstream and downstream the optical cavity, which has a total length of 5.41 m. The FEL is designed to coupling out at a hole with diameter of 2 mm on the upstream mirror. The optical cavity is optimized to obtain high FEL gain and high FEL power using GENESIS 1.3 simulation code. The electron beam with energy of 25 MeV is used in the consideration. As a result, the MIR-FEL with central wavelength of 13.01 ’m is obtained. The optimum upstream and downstream mirror curvatures are 3.091 m and 2.612 m, respectively, which give the Rayleigh length of 0.631 m. This optical cavity yields the power coupling ratio of 1:1000 and the FEL gain of up to 40%. The extracted MIR-FEL peak power in 100 kW scale is obtained at the coupling hole. The construction of the practical MIR-FEL system is conducted based on the results from this study.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT030
About •	Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 01 July 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

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
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

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
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

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
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOMS026	Monte Carlo Simulation of Electron Beam in Phantom Water for Radiotherapy Application	3011
SUSPMF128	use link to see paper's listing under its alternate paper code
	P. Apiwattanakul, C. Phueng-ngern, S. Rimjaem, J. Saisut Chiang Mai University, Chiang Mai, Thailand P. Lithanatudom IST, Chiang Mai, Thailand P. Nimmanpipug, S. Rimjaem, J. Saisut ThEP Center, Commission on Higher Education, Bangkok, Thailand
	Radiotherapy (RT) is an effective treatment that can control the growth of cancer cells. There is a hypothesis suggests that secondary electrons with an energy of a few eV produced from RT play an important role on cancer’s DNA strand break. In this study, the Monte Carlo simulation of electron beam irradiation in phantom water is performed to investigate the production of low-energy electrons. Electron beams produced from an radio-frequency linear accelerator (RF linac) are used in this study. The accelerator can generate the electron beam with adjustable energy of up to 4 MeV and adjustable repetition rate of up to 200 Hz. With these properties, the electron dose can be varied. We used ASTRA software to simulate the electron beam dynamics in the accelerator and GEANT4 toolkit for studying interactions of electrons in water. The energy of electrons decreases from MeV scale to keV-eV scale as they travel in the water. From simulations, the dose distribution and depth in phantom water were obtained for the electron dose of 1, 3, 5, 10, 25, and 50 Gy. Further study on effect of low-energy electron beam with these dose values on cancer DNAs will be performed with GEANT4-DNA simulation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS026
About •	Received ※ 08 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 25 June 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOMS039	Investigation on Intermolecular Interactions in Ionic Liquids Using Accelerator-based THz Transition Radiation	3053
	P. Nanthanasit, S. Rimjaem Chiang Mai University, Chiang Mai, Thailand N. Chattrapiban, P. Nimmanpipug, S. Rimjaem ThEP Center, Commission on Higher Education, Bangkok, Thailand M. Jitvisate Suranaree University of Technology, Nakhon Ratchasima, Thailand
	Ionic liquids (ILs) are interesting material that can be used in many applications. Spectroscopic measurement using accelerator-based terahertz transition radiation (THz TR) is one of potential techniques to investigate their intermolecular interactions by observing the vibra-tional bands in the terahertz region due to TR’s excep-tional properties: coherent, broadband, and high intensi-ty. This work aims to study intermolecular interactions of ILs using the THz TR produced from an electron beam at the PBP-CMU Electron Linac Laboratory. The THz TR with the frequency range of 0.3-2.5 THz can be produced from electron beam of energy 10-25 MeV. This radiation is produced and transported to the experimental area, where it is used as the coherent and polarization selective light source for the Fourier transform infrared (FTIR) spectrometer. The absorption spectrum in the THz region of the ILs is then measured. In addition, to explain the experimental results deeply, theoretical calculations using the density functional theory are performed. In this contribution, we present the results from experiment and computational calculation that can be used together to describe the intermolecular interactions in ILs.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS039
About •	Received ※ 08 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 02 July 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

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
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

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
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOMS047	Design of Radiation Shielding for the PBP-CMU Electron Linac Laboratory	3073
SUSPMF132	use link to see paper's listing under its alternate paper code
	P. Jaikaew, N. Khangrang Chiang Mai University, PBP Research Facility, Chiang Mai, Thailand M. Jitvisate Suranaree University of Technology, Nakhon Ratchasima, Thailand S. Rimjaem Chiang Mai University, Chiang Mai, Thailand S. Rimjaem ThEP Center, Commission on Higher Education, Bangkok, Thailand
	The local radiation shielding is designed for the electron linear accelerator beam dump at the PBP-CMU Electron Linac Laboratory (PCELL) with the aim to control the annual ambient dose equivalent during the operation. The study of radiation generation and design of radiation shielding is conducted based on the Monte Carlo simulation toolkit GEANT4. The study results include an annual ambient dose equivalent map and design of local shielding for the first bam dump downstream the linac section. With this design, the leaking radiation outside the accelerator hall is completely blocked and the average annual ambient dose equivalent on the rooftop of the hall is within the IAEA safety limit for the supervised area. The shielding model will then be used as a guideline for the construction in the near future.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS047
About •	Received ※ 07 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 15 June 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOMS056	An Overview of the Applications of MIR and THz Spectroscopy in Astrochemistry Studies	3102
	C. Suwannajak, U. Keyen, A. Leckngam, N. Tanakul NARIT, Chiang Mai, Thailand W. Jaikla, S. Pakluea, P. Wongkummoon Chiang Mai University, PBP Research Facility, Chiang Mai, Thailand M. Jitvisate Suranaree University of Technology, Nakhon Ratchasima, Thailand P. Nimmanpipug, S. Rimjaem ThEP Center, Commission on Higher Education, Bangkok, Thailand S. Pakluea, S. Rimjaem, P. Wongkummoon Chiang Mai University, Chiang Mai, Thailand T. Phimsen SLRI, Nakhon Ratchasima, Thailand
	Interstellar complex molecules can be found in molecular clouds which are spread throughout our galaxy. Some of these molecules are thought to be the precursors of bio-molecules. Therefore, understanding the formation processes of those interstellar complex molecules is crucial to understanding the origin of the building blocks of life. There are currently more than a hundred known complex molecules discovered in interstellar clouds. However, the formation processes of those molecules are not yet well understood since they occur in very extreme conditions and very short time scale. Ultrafast spectroscopy can be applied to study those processes that occur in the time scale of femtoseconds or picoseconds. In this work, we present an overview of the applications of MIR and THz pump-probe experiments in astrochemistry studies. An experimental setup to simulate space conditions that mimic the environments where the interstellar complex molecules are formed is currently being developed at the PBP-CMU Electron Linac Laboratory. Then, we present our development plan of the experimental station and its current status.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS056
About •	Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 23 June 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

MOPOPT049

Study on Energy Spectrum Measurement of Electron Beam for Producing MIR-FEL at PBP-CMU Electron Linac Laboratory

367

SUSPMF093

use link to see paper's listing under its alternate paper code

P. Kitisri, S. Rimjaem, K. Techakaew
Chiang Mai University, Chiang Mai, Thailand
S. Rimjaem
ThEP Center, Commission on Higher Education, Bangkok, Thailand

At the PBP-CMU Electron Linac Laboratory (PCELL), we aim to produce a mid-infrared free-electron laser (MIR-FEL) for pump-probe experiments in the future. The electron beam is generated from a thermionic cathode radio-frequency (RF) gun with a 1.5-cell cavity before going to an alpha magnet. In this section, some part of the beam is filtered out by using energy slits. The selected part of the beam is then further accelerated by an RF linear accelerator (linac) to get higher energy. This work focuses on the measurement of energy spectrum of electron beam for producing mid-infrared free-electron laser (MIR-FEL). Since our bunch compressor (BC) for the MIR-FEL beamline is an achromat system, the longitudinal distributions of electron beam at the entrance and the exit of the BC are almost the same. Thus, we can measure the longitidinal properties of the beam before it travels to the BC. By using a dipole magnet and a Faraday cup with a slit, we can measure energy spectrum of electron beam before entering the BC. In this study, the ASTRA code is used to investigate the properties of electron beam as well as to design the measuring system. The design results including systematic error of the measuring system are presented and discussed in this contribution. The results from this work can be used as the guideline for the measuring system construction as well as the beam operation.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT049

About •

Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 09 July 2022

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPOPT050

Systematic Study of Electron Beam Measuring Systems at the PBP-CMU Electron Linac Laboratory

371

SUSPMF094

use link to see paper's listing under its alternate paper code

K. Techakaew, S. Rimjaem
Chiang Mai University, Chiang Mai, Thailand

The linear accelerator system at the PBP-CMU Electron Linac Laboratory (PCELL) is used to produce electron beam with suitable properties for generating coherent teragertz (THz) radiation and mid-infrared free-electron laser (MIR FEL). Optimization of machine parameters to produce short electron bunches with low energy spread and low transverse emittance was focused in this study. We conducted ASTRA simulations including three-dimentional (3D) space charge algorithm and 3D field distributions for radio-frequency (RF) electron gun and all magnets to develop measuring systems. Electron beam energy and energy spread were investigated downstream the RF gun and the RF linac using an alpha magnet and a dipole spectrometer, respectively. The transverse beam emittance was studied using the quadrupole scan technique. By filtering proper portion of electrons before entering the linac, the beam with average energy of 20 MeV and energy spread of 0.1-1% can be achieved for a bunch charge of 100 pC. The systematic error is less than 10% for measuring average energy and energy spread while it is less than 31% for measuring transverse emittance when placing the screen of at least 1.0 m behind the scanning quadrupole magnet. The results of this study were used to develop the measuring setups in our system.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT050

About •

Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 12 June 2022 — Issue date ※ 13 June 2022

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOPT027

Numerical Simulation of a Superradiant THz Source at the PITZ Facility

1063

N. Chaisueb, S. Rimjaem
Chiang Mai University, Chiang Mai, Thailand
P. Boonpornprasert, M. Krasilnikov, X.-K. Li, A. Lueangaramwong
DESY Zeuthen, Zeuthen, Germany
S. Rimjaem
ThEP Center, Commission on Higher Education, Bangkok, Thailand

An accelerator-based THz source is under development at the Photo Injector Test Facility at DESY in Zeuthen (PITZ). The facility can produce high brightness electron beams with high charge and small emittance. Currently, a study on development of a tunable high-power THz SASE FEL for supporting THz-pump, X-ray-probe experiments at the European XFEL is underway. An LCLS-I undulator, a magnetic chicane bunch compressor, and THz pulse diagnostics have been installed downstream the previously existing setup of the PITZ beamline. Additional to the SASE FEL, a possibility to generate superradiant THz undulator radiation from short electron bunches is under investigation, which is the focus in this study. Numerical simulations of the superradiant THz radiation by using sub-picosecond electron bunches with energy of 6 - 22 MeV and bunch charge up to 2 nC produced from the PITZ accelerator are performed. The results show that the radiation with a spectral range of 0.5 to 9 THz and a pulse energy in the order of sub-uJ can be obtained. The results from this study can be used as a benchmark for the future development.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT027

About •

Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 07 July 2022

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOPT028

THz Undulator Radiation Based on Super-Radiant Technique at Chiang Mai University

1067

E. Kongmon
IST, Chiang Mai, Thailand
N. Chaisueb, S. Rimjaem
Chiang Mai University, Chiang Mai, Thailand
S. Rimjaem
ThEP Center, Commission on Higher Education, Bangkok, Thailand

A linear accelerator system at the PBP-CMU Electron Linac Laboratory is used as an electron source for generating coherent THz radiation and MIR-FEL. To achieve high power THz radiation, the super-radiant technique using pre-bunched electrons and undulator magnet is utilized. In this study, we investigate the generation of such radiation with comparable properties as the FEL. The beamline composes of a 180-degree magnetic bunch compressor, a 2 m-electromagnet undulator, quadrupole magnets and diagnostic devices. This work includes the undulator design and investigation on properties of electron beam and THz radiation. Based-on the results of beam dynamic study, the optimized electron beams have an energy in a range of 10^-16 MeV, a bunch charge of 100 pC, and a bunch length of 300 fs. The radiation with frequency covering from 0.5 to 3 THz yields a peak power of 5.21 MW at 1.15 THz. This information was used as an initial parameter for undulator design by using the CST-EM Studio software. It has 19.5 periods with a period length of 100 mm. The design results show that the maximum magnetic field is 0.2317 T. The results of this study are used as the guideline for construction of the undulator and the THz-FEL beamline.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT028

About •

Received ※ 08 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 27 June 2022

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

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

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOPT030

Design and Simulation of the MIR-FEL Generation System at Chiang Mai University

1074

SUSPMF012

use link to see paper's listing under its alternate paper code

S. Sukara, K. Kongmali, S. Rimjaem
Chiang Mai University, Chiang Mai, Thailand
H. Ohgaki
Kyoto University, Kyoto, Japan

At the PBP-CMU Electron Linac Laboratory, the system to generate MIR-FEL using the electron linac has been developed. In this contribution, the design and simulation results of the MIR-FEL generation system are presented. The system is designed as the oscillator-FEL type consisting of two mirrors and a 1.6-m permanent planar undulator. The middle of the undulator is determined as the laser beam waist position. Both two mirrors are the concave gold-coated copper mirrors placing upstream and downstream the optical cavity, which has a total length of 5.41 m. The FEL is designed to coupling out at a hole with diameter of 2 mm on the upstream mirror. The optical cavity is optimized to obtain high FEL gain and high FEL power using GENESIS 1.3 simulation code. The electron beam with energy of 25 MeV is used in the consideration. As a result, the MIR-FEL with central wavelength of 13.01 ’m is obtained. The optimum upstream and downstream mirror curvatures are 3.091 m and 2.612 m, respectively, which give the Rayleigh length of 0.631 m. This optical cavity yields the power coupling ratio of 1:1000 and the FEL gain of up to 40%. The extracted MIR-FEL peak power in 100 kW scale is obtained at the coupling hole. The construction of the practical MIR-FEL system is conducted based on the results from this study.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT030

About •

Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 01 July 2022

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

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

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

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

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

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

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOMS026

Monte Carlo Simulation of Electron Beam in Phantom Water for Radiotherapy Application

3011

SUSPMF128

use link to see paper's listing under its alternate paper code

P. Apiwattanakul, C. Phueng-ngern, S. Rimjaem, J. Saisut
Chiang Mai University, Chiang Mai, Thailand
P. Lithanatudom
IST, Chiang Mai, Thailand
P. Nimmanpipug, S. Rimjaem, J. Saisut
ThEP Center, Commission on Higher Education, Bangkok, Thailand

Radiotherapy (RT) is an effective treatment that can control the growth of cancer cells. There is a hypothesis suggests that secondary electrons with an energy of a few eV produced from RT play an important role on cancer’s DNA strand break. In this study, the Monte Carlo simulation of electron beam irradiation in phantom water is performed to investigate the production of low-energy electrons. Electron beams produced from an radio-frequency linear accelerator (RF linac) are used in this study. The accelerator can generate the electron beam with adjustable energy of up to 4 MeV and adjustable repetition rate of up to 200 Hz. With these properties, the electron dose can be varied. We used ASTRA software to simulate the electron beam dynamics in the accelerator and GEANT4 toolkit for studying interactions of electrons in water. The energy of electrons decreases from MeV scale to keV-eV scale as they travel in the water. From simulations, the dose distribution and depth in phantom water were obtained for the electron dose of 1, 3, 5, 10, 25, and 50 Gy. Further study on effect of low-energy electron beam with these dose values on cancer DNAs will be performed with GEANT4-DNA simulation.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS026

About •

Received ※ 08 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 25 June 2022

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOMS039

Investigation on Intermolecular Interactions in Ionic Liquids Using Accelerator-based THz Transition Radiation

3053

P. Nanthanasit, S. Rimjaem
Chiang Mai University, Chiang Mai, Thailand
N. Chattrapiban, P. Nimmanpipug, S. Rimjaem
ThEP Center, Commission on Higher Education, Bangkok, Thailand
M. Jitvisate
Suranaree University of Technology, Nakhon Ratchasima, Thailand

Ionic liquids (ILs) are interesting material that can be used in many applications. Spectroscopic measurement using accelerator-based terahertz transition radiation (THz TR) is one of potential techniques to investigate their intermolecular interactions by observing the vibra-tional bands in the terahertz region due to TR’s excep-tional properties: coherent, broadband, and high intensi-ty. This work aims to study intermolecular interactions of ILs using the THz TR produced from an electron beam at the PBP-CMU Electron Linac Laboratory. The THz TR with the frequency range of 0.3-2.5 THz can be produced from electron beam of energy 10-25 MeV. This radiation is produced and transported to the experimental area, where it is used as the coherent and polarization selective light source for the Fourier transform infrared (FTIR) spectrometer. The absorption spectrum in the THz region of the ILs is then measured. In addition, to explain the experimental results deeply, theoretical calculations using the density functional theory are performed. In this contribution, we present the results from experiment and computational calculation that can be used together to describe the intermolecular interactions in ILs.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS039

About •

Received ※ 08 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 02 July 2022

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

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

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

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

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOMS047

Design of Radiation Shielding for the PBP-CMU Electron Linac Laboratory

3073

SUSPMF132

use link to see paper's listing under its alternate paper code

P. Jaikaew, N. Khangrang
Chiang Mai University, PBP Research Facility, Chiang Mai, Thailand
M. Jitvisate
Suranaree University of Technology, Nakhon Ratchasima, Thailand
S. Rimjaem
Chiang Mai University, Chiang Mai, Thailand
S. Rimjaem
ThEP Center, Commission on Higher Education, Bangkok, Thailand

The local radiation shielding is designed for the electron linear accelerator beam dump at the PBP-CMU Electron Linac Laboratory (PCELL) with the aim to control the annual ambient dose equivalent during the operation. The study of radiation generation and design of radiation shielding is conducted based on the Monte Carlo simulation toolkit GEANT4. The study results include an annual ambient dose equivalent map and design of local shielding for the first bam dump downstream the linac section. With this design, the leaking radiation outside the accelerator hall is completely blocked and the average annual ambient dose equivalent on the rooftop of the hall is within the IAEA safety limit for the supervised area. The shielding model will then be used as a guideline for the construction in the near future.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS047

About •

Received ※ 07 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 15 June 2022

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOMS056

An Overview of the Applications of MIR and THz Spectroscopy in Astrochemistry Studies

3102

C. Suwannajak, U. Keyen, A. Leckngam, N. Tanakul
NARIT, Chiang Mai, Thailand
W. Jaikla, S. Pakluea, P. Wongkummoon
Chiang Mai University, PBP Research Facility, Chiang Mai, Thailand
M. Jitvisate
Suranaree University of Technology, Nakhon Ratchasima, Thailand
P. Nimmanpipug, S. Rimjaem
ThEP Center, Commission on Higher Education, Bangkok, Thailand
S. Pakluea, S. Rimjaem, P. Wongkummoon
Chiang Mai University, Chiang Mai, Thailand
T. Phimsen
SLRI, Nakhon Ratchasima, Thailand

Interstellar complex molecules can be found in molecular clouds which are spread throughout our galaxy. Some of these molecules are thought to be the precursors of bio-molecules. Therefore, understanding the formation processes of those interstellar complex molecules is crucial to understanding the origin of the building blocks of life. There are currently more than a hundred known complex molecules discovered in interstellar clouds. However, the formation processes of those molecules are not yet well understood since they occur in very extreme conditions and very short time scale. Ultrafast spectroscopy can be applied to study those processes that occur in the time scale of femtoseconds or picoseconds. In this work, we present an overview of the applications of MIR and THz pump-probe experiments in astrochemistry studies. An experimental setup to simulate space conditions that mimic the environments where the interstellar complex molecules are formed is currently being developed at the PBP-CMU Electron Linac Laboratory. Then, we present our development plan of the experimental station and its current status.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOMS056

About •

Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 23 June 2022

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)