| Paper | Title | Page |
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| MOPC02 | Improvement of Termination Field of Bulk HTSC Staggered Array Undulator | 96 |
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We have proposed a bulk High Temperature Superconductor Staggered Array Undulator (Bulk HTSC SAU) to achieve higher undulator field, shorter period, and variable K-value without changing gap[1]. The purpose of this study is to revise the controversial point, that bulk HTSC SAU generates strong wicked magnetic field on its terminations, which scatters electron beam. Therefore we studied a new method to correct the field. We developed a physical model which based on Bean model to deal with the bulk superconducting material and then constructed a simulation code. By using the calculation results, we developed the correction method by adding bulk material on the edge of undulator. Measurement of the magnetic field of a prototype of bulk HTSC SAU with this method has been performed. We confirm that the numerical calculation well describe the experimental results. In this conference, numerical and experimental results of our end field termination method will be presented.
[1] R. Kinjyo, T. Kii, H. Zen, K Higashimura, K Masuda, K. Nagasaki, H. Ohgaki, Y.U. Jeong "Bulk High-TC Super Conductor Staggered Array Undulator" Proceedings of FEL2008 |
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| TUPA02 | Development of Material Analysis Facility in KU-FEL | 190 |
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A mid infrared-free electron laser (MIR-FEL) (5-20 μm) facility (KU-FEL: Kyoto University Free Electron Laser) has been constructed for contributing to researches on energy science at Institute of Advanced Energy, Kyoto University. Up to now 12-14 μm FEL beam has been generated. When MIR-FEL with the wavelength matched to the molecular vibration mode is irradiated to the material, a particular chemical bond in the material will be selectively excited, or dissociated [1]. The selective photochemical reaction can be applied for surface modification and the evaluation of material in biochemistry, chemistry, and solid physics. Therefore, material analysis facility in combination with MIR-FEL is constructed. In the material analysis facility, advanced analysis systems such as photoluminescence measurement system, photoelectron spectroscopy, super centrifuge and high performance liquids chromatography, ICP emission spectroscopy, and high speed atomic force spectroscopy are installed. In this meeting, the development of material analysis facility will be introduced.
[1] Jhon C.Tully, Science, 312(2006) 1004 |
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| WEPB17 | Evaluation of Lasing Range with a 1.8 m Undulator in KU-FEL | 417 |
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| In KU-FEL (Kyoto University FEL) 12-14 μm FEL has been available by using a 40 MeV S-bend linac and 1.6 m undulator. We are going to install 1.8 m undulator which was used in JAEA to extend the lasing range of KU-FEL. Numerical evaluation of the lasing range has been carried out by using GENESIS1.3. However, this work used an ideal undulator field data which was measured by JAEA in several years before. Therefore we re-measured the undulator field for different gaps. Then we evaluated the FEL gain and possible lasing range with 1.8 m undulator using measured undulator field. The undulator field measurement, FEL gain calculations and evaluation of lasing range in KU-FEL will be presented in the conference. | ||
| WEPB19 | Enhancement of Undulator Field in Bulk HTSC Staggered Array Undulator with Hybrid Configuration | 424 |
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Funding: This work was supported by the Grant-in-Aid for Scientific Research B and JSPS Fellows by the Ministry of Education, Culture, Sports, Science and Technology of Japan The purpose of this study is enhancement of the undulator field and it's stability in bulk high temperature superconductor staggered array undulator by introducing hybrid configuration. The authors made the magnetic field calculations with some hybrid configurations consists of bulk HTSCs, ferromagnetic pieces and permanent magnets. We also made prototype measurements. The results shows the hybrid configuration can generates stronger and more uniform magnetic field than bulk-HTSCs-only configuration. In this conference, numerical and experimental results of the hybrid configuration will be presented. |
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| THPA34 | Assessment of Thermionic Emission Properties and Back Bombardment Effects for LaB6 and CeB6 | 557 |
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| Back Bombardment (BB) effect limits wide usage of thermionic RF guns. BB effect induces not only ramping-up of a cathode’s temperature and beam current, but also degradation of cavity voltage and beam energy during the macropulse. In this research we are clarifying BB phenomenon and find out cathode material properties contribution on BB effect. Therefore, assessment of emission properties and comparison of BB effect in LaB6 and CeB6 are introduced. Emission properties for these materials are measured in temperature range between 1600 and 2100 K. Then, heating property of materials is investigated against BB effect by numerical calculation of stopping range and deposited heat. Finally, change in cathode temperate and corresponding change in current density during 6 μs pulse duration is determined. Experimental results estimates work functions at 1800 K for LaB6 and CeB6 were 2.8 and 2.75 eV respectively. Our simulation of BB effect shows that for a pulse of 6 μs duration, LaB6 cathode experiences a large change in temperature compared with CeB6. The change in current density is two times higher. The experimental and simulation results will be presented in the meeting | ||