| 摘要 |
The invention concerns a neutron beam generator which includes a particle accelerator for accelerating, in pulsed manner, a particle beam e.g. deuterons, produced by an ion source. The generator also includes a gas cell 42 containing gas e.g. deuterium, with which the particle beam is to interact to produce the required neutron beam. There is an evacuated passage 26 for transporting the accelerated particle beam to the gas cell and a port 38, 40 between the gas cell 42 and the passage 26. Port control means 50 is provided which is synchronised with the accelerated particle beam pulses and which operates to open the port to allow the accelerated particle beam pulses to enter the gas cell through the port and to close or obstruct the port, thereby to prevent or reduce leakage of gas from the gas cell through the port, between such pulses. |
