| Paper | Title | Other Keywords | Page |
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| MOP009 | Generation of Low-energy Electron Beam Using KURRI-LINAC | electron, acceleration, gun, linac | 67 |
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Electron beam can be accelerated in two accelerator tubes up to 46 MeV at KURRI-LINAC. The development of irradiation field is planned to provide lower energy electron beam. For this purpose we had regulated several parameters, which results showed that low energy electron beam was obtained by acceleration in only the first accelerator tube, without the second one, which was filled with microwave from klystron operated at reduced voltage. Moreover, the timing between electron emission and microwave introduction into the first accelerator tube was varied to increase the electron energy loss in the second one, thereby reducing high-energy component of the beam. In this study we obtain lower energy electron beam by the following regulations: 1) the increase of the emission current from the electron gun relative to energy filled into the first accelerator tube results in the decrease of acceleration energy for each electron and 2) the total control of the timing and the buncher phase of microwave and the width of electron pulse eliminates a part of electron expected to be high-energy component. The regulations described above yield the low-energy electron beam with peak of 5.2 MeV. |
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| MOP080 | Design Optimisation of the Re-bunching Cavities for the Front End Test Stand at RAL | cavity, impedance, simulation, rfq | 238 |
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The Medium Energy Beam Transport (MEBT) line for the Front End Test Stand (FETS) at Rutherford Appleton Laboratory (RAL) will transport a 60 mA, 2ms, 50 pps H- beam at 3 MeV. Its main components include a number of quadrupoles, re-bunching cavities and a fast-slow chopping system with dedicated beam dumps, as well as a diagnostics beam line. In this paper we present the design approach for the MEBT re-bunching cavities. A description is given for the proposed geometry and the main design choices are examined. In addition, the latest RF simulations results performed with 2D and 3D electromagnetic codes are presented including optimisation details and manufacturing plans. |
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| THP091 | Simulations of Ion Beam Loss in RF Linacs with Emphasis on Tails of Particle Distributions | linac, rfq, simulation, beam-losses | 956 |
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Design of ion linacs with ion currents of several milli-amps necessitates detailed simulations of beam loss. At high intensities, even a small amount of beam loss can result in significant radio-activation of the linac components. Particle loss can result from longitudinal tails created in the bunching and pre-accelerating process, whereas strong transverse focusing and collimation limit the development of a transverse tail. In modern RF ion linacs, bunching and pre-acceleration take place in a radio frequency quadrupole (RFQ). We present a new approach for beam loss calculations that places emphasis on the tails of the particle distributions. This scheme is used for simulating the SARAF proton/deuteron linac, a 176 MHz complex designed to operate in CW mode at 4 mA beam current. We describe implementation of a RFQ accelerating element in the GPT 3D simulation code. We discuss our scheme for highlighting the tails of the particle distributions generated by the RFQ. These distributions are used as input to simulations of the RF superconducting linac, where subsequent particle loss is calculated. This technique allows us to increase beam loss statistics by a significant factor. |