Osaka University/RCNP, Osaka
The Research Center for Nuclear Physics (RCNP) cyclotron cascade system has been operated to provide high quality beams for various experiments. In order to increase the physics opportunities, the Azimuthally Varying Field (AVF) cyclotron facility was upgraded recently. A flat-topping system and an 18-GHz superconducting Electron Cyclotron Resonance (ECR) ion source were introduced to improve the beam’s quality and intensity. A new beam line was installed to diagnose the characteristics of the beam to be injected into the ring cyclotron and to bypass the ring cyclotron and directly transport low energy beams from the AVF cyclotron to experimental halls. A separator is equipped to provide RI beams produced by fusion reactions at low energy and by projectile fragmentations at high energy. Development has continued to realize the designed performance of these systems.
RIKEN, Wako
At RIKEN RIB-factory (RIBF) an accelerator complex as an energy booster which consists of superconducting ring cyclotron (SRC), intermediate-stage ring cyclotron (IRC) and fixed-frequency ring cyclotron (FRC) provides very heavy ion beams like uranium with an energy of 345 MeV/u. The total beam power obtained up to now at the SRC is as high as 3 kW in the case of 48Ca with an intensity of 170 pnA. Recently we have succeeded in achieving stable and reliable operation of rf system for new cyclotrons. In this paper the present performance of the rf system and a recent development is reported.
INFN/LNL, Legnaro
Recently we developed a novel measurement apparatus that simplify the tests of superconducting cavities. A few commercial electronic boards, mounted in a devoted chassis and controlled by a PC, operate most of the functions usually carried out by standard RF instrumentation. The set up allows the measurements of resonators in the 80-700 MHz frequency range and we used it to characterize resonators both in the ALPI vault and in off-line tests. Upgraded control program carries out all the typical procedures, related to the cavity measurements in classical VCO-PLL system. It allows to adjust and to measure the RF forward power, to find and update the cavity resonant frequency, to calibrate the pick-up signal, to monitor the transmitted power, to adjust the coupler position. The implemented automatic procedures permit to measure the cavity decay time, to trace the Q-curve, to perform CW and pulse RF conditioning, to calibrate cables and measurement instruments. The same software applies to the other two measurement systems routinely used at Legnaro to test resonators up to 6 GHz frequency.