| Paper | Title | Other Keywords | Page |
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| MOPCP057 | A Compact Solution for DDS-Generator, Turn-on and Protections in RF Accelerator Systems | controls, cyclotron, pick-up, resonance | 159 |
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| A single compact rack that includes a Direct Digital Synthesizer generator, a turn-on and protection system provides the smart solution in RF accelerator systems. It synthesizes a high stable RF signal up to 120 MHz, turns the power on into the RF cavities through a step-ramp modulator, protects the RF system against mismatching, sparks and multipactoring. A preliminary prototype has been designed, assembled and tested on the RF system of the k-800 superconducting cyclotron at Infn-Lns. This solution is part of the new computer-based RF control system. The hardware, software, and first test results will be shown in this paper. | |||
| MOPCP058 | Commissioning Experience of the RF System of K500 Superconducting Cyclotron at VECC | cyclotron, controls, vacuum, impedance | 162 |
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Funding: Department of Atomic Energy, Govt. of India. Radio frequency system of Superconducting cyclotron at VECC, has been developed to achieve accelerating voltage of 100 kV max. with frequency, amplitude and phase stability of 0.1 ppm, 100 ppm and ±0.5 degree respectively within 9~27 MHz frequency. Each of the three half-wave coaxial cavity is fed with rf power (80kW max.) from a high power final rf amplifier based on Eimac 4CW150,000E tetrodes. Initially, the whole three-phase RF system has been tuned for operation with RF power to the cavities at 19.1994 MHz and thereafter commissioned the cyclotron with neon 3+ beam at external radius at 14.0 MHz. In this paper, we present brief description of the rf system and behaviour observed during initial conditioning of the cavities with rf power and the way to get out of multipacting zone together with discussion on our operational experience. We have so far achieved dee voltage up to 52 kV at 14 MHz with 20 kW of RF power fed at each of the three dees and achieved vacuum level of 4.5 x 10-7 mbar inside the beam chamber. We also present discussion on the problems and failures of some RF components during commissioning stage and rectifications done to solve the same. |
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| MOPCP059 | Theoritical Analysis and Fabrication of Coupling Capacitor for K500 Superconducting Cyclotron at Kolkata | coupling, vacuum, cyclotron, extraction | 165 |
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| K500 SC cyclotron has already been constructed and commissioned after spiraling Ne3+ internal beam with 70 nA upto extraction radius(670 mm) at Variable Energy Cyclotron Centre at Kolkata, India. Several problems have been experienced related to the coupling capacitor of the radio frequency system including it's sever burning during commissioning of the cyclotron. Making of the dissimilar joints between alumina ceramic and copper of the coupling capacitor demands the usage of vacuum furnace to avoid the cracking of the ceramic. Therefore exhaustive analysis has been carried out to facilitate the in-house fabrication of the coupling capacitor without using the vacuum furnace in case of emergency. The maximum allowable rate of temperature rise for the ceramic and the optimum thickness ration of the copper to ceramic has been estimated. Finally fabrication of the coupling capacitor has been carried out in-house without employing vacuum furnace. At present the coupling capacitor is performing well as maximum 57 kV DEE voltages were been achieved the till date. This paper presents the details of the analysis and experiences gain during the fabrication of the coupling capacitor. | |||
| MOPCP098 | Influence of RF Magnetic Field on Ion Dynamics in IBA C400 Cyclotron | cyclotron, ion, acceleration, resonance | 251 |
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| Magnetic components of RF field in C400 cyclotron being under development by IBA makes noticeable influence on ion dynamics. In particular, increase in the dees voltage along radius leads to corresponding phase compression of a bunch. Influence of the RF magnetic field on the bunch center phase deviation during acceleration and on radial ion axial motions have been also estimated numerically. RF magnetic field changes a central ion phase by only 2° RF. Calculations have also shown that RF magnetic field makes visible but pretty small influence on the radial motion of the ions ensuring some decrease in the radial amplitudes. No visible impact of the RF magnetic field on the axial motion has been detected. The results are compared for the two RF magnetic field maps: (i) obtained by Microwave Studio and, (ii) computed from RF electric field map by means of Maxwell' equations. | |||