|Budget Amount *help
¥14,200,000 (Direct Cost : ¥14,200,000)
Fiscal Year 1998 : ¥4,400,000 (Direct Cost : ¥4,400,000)
Fiscal Year 1997 : ¥9,800,000 (Direct Cost : ¥9,800,000)
The objective of this study is to get fundamental characteristics of a bidirectional pulse generator system for external pulse injection and to realize the system for linear induction accelerators. The bidirectional pulse generator system consists of a pulse generator, a cavity and a load. To realize the system, effects of each component of the pulse generator on the output waveform (accelerating voltage waveform) should be investigated. Using an equivalent circuit, the output voltage waveform was simulated. The results were compared with the experimental results obtained using a dummy load, which consists of a resistor and a diode connected in series. As a result, it was found that the inductance of output switch affected the output waveform very much and to get an ideal waveform, the inductance should be reduced. To reduce the inductance, parallel operation of switches is effective.
A laser-triggered switch is known to be adequate for parallel operation, because it has low delay and low jitter. Therefore, characteristics of a laser-triggered switch filled with air, SF_6 or evacuated are experimentally investigated. A Q-switched Nd:YAG laser was used, the wavelength of which is 1064nm, the maximum output energy is 650mJ, and the pulse width is 5-7ns. The third harmonics was also used. Comparing the results obtained with focused and non-focused laser beams, it was shown that the gap separation length was not so long in our case to reveal the difference of the characteristics.
Using a double cavity and an LC inversion generator, an accelerating voltage of 40kV was obtained across the dummy load. A device, which can be used for synchronous operation between the laser and the pulse generator, was made and it is planned to change the current switch and to investigate the characteristics of the bidirectional pulse generator system with a laser-triggered switch.