ECRIS2012 - List of Keywords (cathode)

Paper	Title	Other Keywords	Page
TUPP17	Installation and Operation of a 28 GHz Gyrotron for the RIKEN Superconducting ECR Ion Source	ion, ion-source, detector, power-supply	71
	J. Ohnishi, Y. Higurashi, T. Nakagawa RIKEN Nishina Center, Wako, Japan
	The RIKEN 28-GHz ECRIS uses a gyrotron microwave source fabricated by Mitsubishi Electric Corporation. The maximum output power is 10 kW. The gyrotron produces TE02-mode microwaves, which are converted into the TE01 mode by a mode converter. In the first test on the gyrotron performed using a dummy load, we observed the 50-300 Hz ripples of ~500 W in the output power of 1-7 kW, and it was difficult to make a stable operation in the low-power. These ripples were reduced to one-tenth by stabilizing the cathode voltage and then the gyrotron could produce microwaves from < 0.5 kW stably. The operation of the ion source with the 28 GHz gyrotron was started in 2011 and the ion source supplied U and Xe beams to the RIBF for two months. The power of the microwaves fluctuated slowly in the range of 870-1250 W, which influenced the beam current from the ion source. This fluctuation was caused by a slight change of the current of the solenoid of the gyrotron depending on the room temperature. We replaced the power supply with new one which has a current stability of 10ppm per day, and stabilized the microwave power in the range of 5% in the operation of 2 kW successfully.

Paper

Title

Other Keywords

Page

TUPP17

Installation and Operation of a 28 GHz Gyrotron for the RIKEN Superconducting ECR Ion Source

ion, ion-source, detector, power-supply

71

J. Ohnishi, Y. Higurashi, T. Nakagawa
RIKEN Nishina Center, Wako, Japan

The RIKEN 28-GHz ECRIS uses a gyrotron microwave source fabricated by Mitsubishi Electric Corporation. The maximum output power is 10 kW. The gyrotron produces TE02-mode microwaves, which are converted into the TE01 mode by a mode converter. In the first test on the gyrotron performed using a dummy load, we observed the 50-300 Hz ripples of ~500 W in the output power of 1-7 kW, and it was difficult to make a stable operation in the low-power. These ripples were reduced to one-tenth by stabilizing the cathode voltage and then the gyrotron could produce microwaves from < 0.5 kW stably. The operation of the ion source with the 28 GHz gyrotron was started in 2011 and the ion source supplied U and Xe beams to the RIBF for two months. The power of the microwaves fluctuated slowly in the range of 870-1250 W, which influenced the beam current from the ion source. This fluctuation was caused by a slight change of the current of the solenoid of the gyrotron depending on the room temperature. We replaced the power supply with new one which has a current stability of 10ppm per day, and stabilized the microwave power in the range of 5% in the operation of 2 kW successfully.