Author: Nagayama, K.
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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.  
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.