A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z  

Yoshida, Y.

Paper Title Page
THPMN036 Simulation Study on Attosecond Electron Bunch Generation 2796
 
  • K. Kan, T. Kondoh, J. Yang, Y. Yoshida
    ISIR, Osaka
 
  Pulse radiolysis, a stroboscopic method with an ultrashort electron bunch and an ultrashort light, is essential for the observation of ultrafast reactions. The time resolution of pulse radiolysis depends on the electron bunch length. In Osaka University, a 98-fs electron bunch was generated by using a photocathode electron linac for a development of femtosecond pulse radiolysis*. Furthermore, a sub-femtosecond/attosecond pulse radiolysis will be proposed to study the ionization and thermalization processes in attosecond time region. In order to realize such a high time resolution, the possibility of attosecond electron bunch generation based on the photocathode RF gun linac and a magnetic bunch compressor was studied. In the simulation, the bunch length growth due to charge, emittance, accelerating phase and magnetic fields were investigated to generate an attosecond electron bunch.

* J. Yang, T. Kondoh, K. Kan, T. Kozawa, Y. Yoshida and S. Tagawa: Nucl. Instrum. Methods Phys. Res., Sect. A 556 (2006) 52-56

 
THPMN038 Dynamic Optical Modulation of the Electron Beam for the High Performance Intensity Modulated Radiation Therapy 2802
 
  • T. Kondoh, H. Kashima, J. Yang, Y. Yoshida
    ISIR, Osaka
 
  Radiation therapy attracts attention as one of cancer therapies nowadays. Recently, the radiation therapy of cancer is developing to un-uniform irradiation as IMRT, for reduce dose to normal tissue and concentrate dose to cancer tissue. A photo cathode RF gun is able to generate a low emittance electron beam pulse using a laser light pulse. We thought that a photo cathode RF gun can generate intensity modulated electron beam by optical modulation at the incident optics dynamically. Because of a low emittance, the modulated electron beam pulse is able to accelerate keeping shape. Accelerated electron pulses will be converted to X-ray pulses by a metal target bremsstrahlung method or by a laser inverse Compton scattering method. For the high performance intensity modulated radiation therapy (IMRT), dynamic optical modulation of the electron beam pulse were studied using a Photo cathode RF gun LINAC. Modulated and Moving electron beam will be reported.  
THPMN039 Femtosecond Electron Beam Dynamics in Photocathode Accelerator 2805
 
  • J. Yang, K. Kan, T. Kondoh, Y. Yoshida
    ISIR, Osaka
 
  Ultrashort electron beams, of the order of 100 fs, are essential to reveal the hidden dynamics of intricate molecular and atomic processes in nanofabrication through experimentation such as time-resolved electron diffraction and femto-chemistry. The transverse and longitudinal dynamics of ultrashort electron beam in a photocathode linear accelerator were studied for femtosecond electron beam generation. The emittance growth and bunch length increase due to the rf and the space charge effects in the rf gun were investigated with the laser injection phase. The dependences of the emittance, bunch length and energy spread on the bunch charge were measured experimentally and compared with the theoretical simulation. The increase of the bunch length due to the space charge effect was also investigated during the bunch compression in magnetic field.