Author: Fukuda, M.
Paper Title Page
MOPPT005 Present Status of the RCNP Cyclotron Facility 40
 
  • K. Hatanaka, M. Fukuda, K. Kamakura, S. Morinobu, T. Saito, H. Tamura, H. Ueda, Y. Yasuda, T. Yorita
    RCNP, Osaka, Japan
 
  The RCNP cyclotron facility has been stably operated for these years. Demands for heavy ions have been increasing recently. Xe beams were accelerated by the AVF cyclotron for the first time. Developments on components and beam dynamics are presented.  
 
TUPPT009 Development of Rapid Emittance Measurement System 171
 
  • K. Kamakura, M. Fukuda, N. Hamatani, K. Hatanaka, M. Kibayashi, S. Morinobu, K. Nagayama, T. Saito, H. Tamura, H. Ueda, H. Yamamoto, Y. Yasuda, T. Yorita
    RCNP, Osaka, Japan
 
  We have developed a new system to measure the beam emittance. With our conventional emittance measurement system, it takes about 30 minutes to get emittances in both the horizontal and vertical plane. For quick measurements, we have developed a new system consisting of a fast moving slit with a fixed width and a BPM83 (rotating wire beam profile monitor). BPM83 uses a rotating helical wire made of tungsten, the speed is 18 rps. Fast moving slit consists of a shielding plate with two slits, and is inserted into the beam path at an angle of 45 degrees. The slit is driven by PLC controlled stepping motor, and it takes 70 seconds to move the full stroke of 290 mm. While moving the slit, the output from BPM83 and the voltage of potentiometer that corresponds to the slit position are recorded simultaneously. We are using CAMAC for data acquisition. Trigger signals are generated by BPM83 and NIM modules. Data analysis takes about 1 second. With this system we can get the horizontal and vertical emittance plots within 75 seconds. This system will definitely make it easier to optimize parameters of ion sources and the beam transport system.  
 
TUPPT016 Developments of Ion Source Complex for Highly Intense Beam at RCNP 189
 
  • T. Yorita, M. Fukuda, K. Hatanaka, K. Kamakura, S. Morinobu, A. Tamii, H. Ueda, Y. Yasuda
    RCNP, Osaka, Japan
 
  Several developments of Ion Source Complex at RCNP has been carried for the purpose of increasing beam intensity. For an 18 GHz superconducting ECRIS, studies for its beam extraction and transportation have been done. The parameters of extraction systems and electrostatic lens are optimized taking account with magnetic field leakage from AVF Cyclotron. HIP-ECR the 2.45GHz permanent magnet ECR has also been developed for highly intense proton beam.  
 
TUPSH006 Development of a New Active-Type Gradient Corrector for an AVF Cyclotron 230
 
  • M. Fukuda, N. Hamatani, K. Hatanaka, K. Kamakura, S. Morinobu, K. Nagayama, T. Saito, H. Tamura, H. Ueda, Y. Yasuda, T. Yorita
    RCNP, Osaka, Japan
 
  A new gradient corrector with active coils has been developed for beam focusing and bending in the extraction region of the RCNP AVF cyclotron. The gradient corrector is a quadrupole type consisting of a pair of a C-type iron yoke. A sixteen-turn hollow conductor was coiled around each side yoke, and the two iron dipoles generate a linear field gradient independently. A field gradient up to 9 T/m is available for focusing a heavy ion beam with magnetic rigidity up to 1.6 T-m. The position of the gradient corrector is manually changeable within ±20 mm from a beam extraction base line. A field measurement was carried out with a Hall-element and we confirmed generation of the designed field gradient under excitation of the main coil. We have succeeded in focusing an extracted beam at an object point of the beam transport optics by a combination of the gradient corrector and a triplet quadrupole magnet following the gradient corrector. Correction of an extracted beam orbit was also demonstrated by optimizing the coil current and position of the gradient corrector. We will report the design and performance of the new gradient corrector.  
 
TUPSH011 Developments of HTS Magnets at RCNP 242
 
  • K. Hatanaka, M. Fukuda, K. Kamakura, S. Takemura, H. Ueda, Y. Yasuda, K. Yokoyama, T. Yorita
    RCNP, Osaka, Japan
  • T. Kawaguchi
    KT Science Ltd., Akashi, Japan
 
  At RCNP, we have been developing magnets utilizing high temperature super conducting (HTS) wires for this decade. They are a cylindrical magnet, two dimensional scanning coils, a super ferric dipole magnet whose coils have a negative curvature. Recently we built a cylindrical magnet for a practical use. It is used to polarize ultra cold neutrons. The maximum field is higher than 3.5 T at the center. We are fabricating a switching magnet which is excited by pulse currents to realize a time sharing of beams in two target positions. In the paper, we report specifications and performances of these magnets.  
 
WEPPT014 Analysis of Phase Bunching in the Central Region of the JAEA AVF Cyclotron 350
 
  • N. Miyawaki, H. Kashiwagi, S. Kurashima, S. Okumura
    JAEA/TARRI, Gunma-ken, Japan
  • M. Fukuda
    RCNP, Osaka, Japan
 
  Phase bunching generated in the central region of an AVF cyclotron was estimated by a simplified geometric trajectory analysis model for particles traveling from the first to the second acceleration gap. In principle, a rising slope of a dee-voltage at the first acceleration gap is more or less effective for production of the phase bunching. The phase difference between particles at the second acceleration gap depends on combination of four parameters: the acceleration harmonic number (h), a span angle of the dee electrode, a span angle from the first to the second acceleration gap, a ratio between a peak dee-voltage and an extraction voltage of an ion source. In the case of the JAEA AVF cyclotron, the effective phase bunching was realized for h = 2 and 3, and the geometric condition of phase bunching was unrealistic for h = 1. An orbit simulation for the JAEA AVF cyclotron indicated that the initial beam phase width of 40 RF degrees for h = 2 was compressed to 11 RF degrees. The phase bunching evaluation based on the simplified geometric trajectory analysis was consistent with the orbit simulation result, and practical phase bunching was verified by beam phase width measurement.