Author: Sumitomo, Y.
Paper Title Page
MOPO024 Development of High Power Coherent Terahertz Wave Sources at Lebra 125 MeV Linac in Nihon University 78
 
  • T. Sakai, K. Hayakawa, Y. Hayakawa, K. Nogami, Y. Sumitomo, Y. Takahashi, T. Tanaka
    LEBRA, Funabashi, Japan
  • H. Ogawa, N. Sei
    AIST, Tsukuba, Ibaraki, Japan
 
  Funding: This work was supported by JSPS KAKENHI Grant Number JP16K17539 and JP16H03912.
Research and Development of a high performance electron linac for the generation of FEL, Parametric X-ray Radiation (PXR) and THz waves has been continued at the Laboratory for Electron Beam Research and Application (LEBRA) of Nihon University as a joint research with KEK and National Institute of Advanced Industrial Science and Technology. The transport systems of the THz wave were installed in the vacuum chamber on the downstream side of the bending magnet of the PXR and FEL beam-line. The CER and the CSR are generated by the bending magnet each of the beam line. In addition, the CTR using thin metal foil is also generated. The average power of the CTR wave was measured approximately 1 mJ/macro-pulse (pulse width 4.5 µs) near the CTR wave beam source point in the frequency range of 0.1 - 2.5 THz. In addition, the energy of the CER as high as 0.2 mJ/macro-pulse were achieved with the experimental room. Furthermore, CER of the generated the FEL beam line can also be guided from the bending magnet on the downstream side of the undulator without disturbing the FEL oscillations. THz transport beam-lines and the characteristics of the THz waves are discussed in this report.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO024  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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MOPO073 Coherent Edge Radiation Sources in Linac-Based Infrared Free-Electron Laser Facilities 154
 
  • N. Sei, H. Ogawa
    AIST, Tsukuba, Ibaraki, Japan
  • K. Hayakawa, Y. Hayakawa, K. Nogami, T. Sakai, Y. Sumitomo, T. Tanaka
    LEBRA, Funabashi, Japan
  • H. Ohgaki, H. Zen
    Kyoto University, Kyoto, Japan
 
  Funding: This study was financially supported by JSPS KAKENHI Grant Number JP16H03912.
National Institute of Advanced Industrial Science and Technology has been studied far-infrared coherent radiation at Linac-based infrared free-electron laser (FEL) facilities in col-laboration with Nihon University and Kyoto University. To obtain high FEL gain at Laboratory for Electron Beam Research and Application (LEBRA) in Nihon University and at Kyoto Uni-versity Free Electron Laser (KU-FEL), the electron-bunch length is compressed to less than 1 ps in their undulator sections. Short electron bunches are suitable for generating intense coher-ent radiation, and we have already developed some terahertz-wave sources based on the coher-ent synchrotron radiation and the coherent transition radiation [1-3]. However, it was difficult to observe them with sufficient intensity without disturbing the infrared FEL oscillations. Then, we now develop coherent edge radiation emitted from downstream bending magnets in the un-dulator sections. It can be extracted from the undulator sections without disturbing the FEL os-cillations. In this presentation, the observed coherent radiation at LEBRA and KU-FEL will be reported on.
[1] N. Sei et al., J. Phys. D: Appl. Phys. 46, (2013) 045104.
[2] N. Sei et al., Nucl. Instr. and Meth. A, 832, (2016) 208.
[3] N. Sei et al., Jpn. J. Appl. Phys.: 56, (2017) 032401.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO073  
About • paper received ※ 29 August 2018      issue date ※ 18 January 2019  
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THPO127 The Effect of Energy Fluctuation on the Multi-bunch Acceleration in E-driven ILC Positron Source 958
 
  • M. Kuriki, H. Nagoshi
    HU/AdSM, Higashi-Hiroshima, Japan
  • S. Kashiwagi
    Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
  • K. Negishi
    Iwate University, Morioka, Iwate, Japan
  • T. Okugi, T. Omori, M. Satoh, Y. Seimiya, J. Urakawa, K. Yokoya
    KEK, Ibaraki, Japan
  • Y. Sumitomo
    LEBRA, Funabashi, Japan
  • T. Takahashi
    Hiroshima University, Graduate School of Science, Higashi-Hiroshima, Japan
 
  E-Driven method is a technical backup for positron source for ILC. In the positron source, the positron is generated and accelerated in a multi-bunch format with gaps in a macro-pulse. We employ AM (Amplitude Modulation) to suppress the transient beam-loading, but a small fluctuation is still expected, depending on the compensation accuracy. In this article, the positron yield which is ratio of numbers of positrons over electrons, is evaluated as a function of the compensation accuracy. With this result and the detail investigation of the beam loading compensation accuracy by AM, the positron yield of E-Driven Positron source for ILC is evaluated.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO127  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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