| Paper | Title | Page |
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| TUPAN046 | A Modification Plan of the KEK 500MeV Booster to an All-ion Accelerators (An Injector-free Synchrotron) | 1490 |
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A medium-energy synchrotron capable of accelerating all ion species based on a novel technology of the induction synchrotron* has been proposed as an all-ion accelerator (AIA)**. The AIA without any specific injector employs a strong focusing lattice and induction acceleration, driven by novel switching power supplies. All ions, including cluster ions with any charge state, are accelerated in a single accelerator. A plan to modify the existing KEK 500 MeV Booster to the AIA is under consideration. Its key aspects, such as an ion-source, a low-field injection scheme and induction acceleration***, are described. Deep implant of moderate-energy heavy ions provided from the AIA into various materials may create a new alloy in bulk size. Energy deposition caused by the electro-excitation associated with passing of swift ions through the material is known to largely modify its structure. The similar irradiation on metal in a small physical space of less than a mm in diameter and in a short time period less than 100 nsec is known to create a particularly interesting warm dense-matter state. The AIA capable is a quite interesting device as a driver to explore these new paradigms.
* K. Takayama, et al., "Experimental Demonstration of the Induction Synchrotron", PAC07.** K. Takayama, et al., PCT/JP2006/308502 (2006).*** T. Dixit, et al., PAC07. |
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| TUPAN065 | Proton Beam Quality Improvement by a Tailored Target Illuminated by an Intense Short-Pulse Laser | 1538 |
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Suppression of a transverse proton divergence is focused by using a controlled electron cloud. When an intense short pulse laser illuminates a foil plasma target, first electrons are accelerated and they form a strong electric field at the target surface, then protons can be accelerated by the strong field created. An electron cloud is limited in the transverse direction by plasma at the protuberant part, if the target has a hole at the opposite side of the laser illumination*. The proton beam is accelerated and also controlled by the transverse shaped electron cloud, and consequently the transverse divergence of the beam can be suppressed. In 2.5D particle-in-cell simulations, the transverse shape of the electron cloud is controlled well.
* R. Sonobe, S. Kawata, et. al., Phys. Plasmas 12 (2005) 073104. |
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| TUPAN066 | Half-mini Beta Optics with a Bunch Rotation for Warm Dense Matter Science Facility in KEK | 1541 |
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An all-ion accelerator (AIA) is a quite interesting device as a driver to explore a Warm Dense Matter (WDM) state*. The irradiation onto a target at a small focal spot (< a few mm) with a short pulse duration (< 100 nsec) is required to create an interesting WDM state. The final focus is carried out through a half-mini beta beam line placed after the kickout from the AIA. The half-mini beta beam line should be designed with the space-charge effect due to the high current beam. The design includes effects of a large momentum spread caused by a fast bunch rotation. The beam optics concerned with the effects of space-charge and the large momentum spread during the half-mini beta system is designed for the WDM science in KEK AIA Facility.
* E. Nakamura, et al., "A Modification Plan of the KEK 500MeV Booster to an All-ion Accelerators (An Injector-free Synchrotron)", PAC07. |
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| THPAN048 | Numerical Solver with CIP Method for Fokker Planck Equation of Stochastic Cooling | 3336 |
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A Fokker Planck equation for a Stochastic cooling* is solved by using the CIP method**. The Fokker Planck equation can be described in a convection-diffusion equation as a function of time and energy. The equation is a non linear form and the evolution of the distribution function should be numerically solved. The CIP method, which is an effective scheme to solve the convection term numerically, is applied to the Fokker Planck equation of the Stochastic cooling. By using the CIP method for the numerical solver, we can effectively calculate the time-dependent Fokker Planck equation in more few computational costs. The developed numerical solver can give us the energy spectrum of the particle distribution during the beam cooling. The simulation results show the good agreements compared with the experimental results.
* S. Van der Meer, CERN/PS/AA/78-22, 1978.** T. Yabe and T. Aoki, Comp. Phys. Commun. 66 (1991) 219. |
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| THPAN049 | Particle Dynamics at Stagnation Point during Longitudinal Bunch Compression of High Current Beams | 3339 |
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Funding: This work is supported by MEXT (Ministry of Education, Culture, Sports, Science and Technology) and JSPS (Japan Society for the Promotion of Science) No.17740361. For researches in high energy density physics and inertial confinement fusion by using heavy ion beams, high-current beam dynamics should be understood well. The heavy ion beam is longitudinally compressed by a head-to-tail velocity tilt applied from high-power induction voltage modules. In this study, emittance growth due to the longitudinal bunch compression is numerically investigated by using a particle-in-cell simulation. The code developed is dealt with three dimensional particle motions, and 2D transverse electric field is solved by Poisson equation coupled with 1D longitudinal electric field. We indicate the particle dynamics due to the non-linear longitudinal-transverse coupling effect around the stagnation point in the longitudinal compression. |