Control of current waveform of laser ion source using pulsed magnetic field.

We investigated plasma behavior with a solenoid-generated static and pulsed magnetic field by measuring time evolution in a transverse ion current profile to control the ion current waveform of a laser ion source. The results showed that static magnetic fields cannot enhance the ion current in the slow region of time of flight (TOF). However, a pulsed magnetic field whose magnetic flux density is rising while a plasma passes through the solenoid can enhance the ion current in the same TOF region. The results showed that applying a pulsed magnetic field to a laser-produced plasma is an effective way to control an ion current waveform in a laser ion source to produce an ion beam with a flat-top-shaped pulse. By using a pulsed magnetic field, the ion current waveform peak was held for ∼50 µs.