4. Caesium (Cs) "consumption"

It is currently estimated that Cs will need to be injected into each ion source at a rate of ≈20 mg/h in order to reach the required extracted negative ion current. With quasi-continuous operation and that Cs injection rate, >1 kg will have been injected into each source every 6 years. It has been found that most of the injected Cs remains in the ion source and significantly less than 1 kg of Cs is almost certain to cause operational problems. There are three possible ways to overcome this problem:

