Fig. 1. Relationship between injection current and capture current

Fig. 2. Diagram of filament power supply

Fig. 3. Filament drive circuit

Fig. 4. Injection current feedback circuit

Fig. 5. Filament driving waveform

Fig. 6. Picture of filament working

Fig. 7. Relationship between injection current and filament voltage duty cycle

Fig. 8. Relationship between injection current and dose rate

Fig. 9. Measurement data of dose rate