Principle
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It is based on the following principles:
1) Action of sharp points: Charges are leaked from pointed ends of charged conductors. This creates an electric wind (as moving air is ionized) which moves away from the conductor.
2) The property that the charge given to a hollow conductor is transferred to the outer surface and is distributed uniformly on it.
Construction
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'S' is a large spherical conducting shell of radius few meters. C1 and C2 are the two supporting pillars. An insulating material like silk acts like a conveyor belt wound over two pulleys P1 and P2. The pulleys move with the help of a motor. B1 and B2 are two spray combs. D is the discharge tube where ions to be accelerated are placed. The ion source lies at the head of the tube inside the shell and the other end is earthed. The whole generator is enclosed in a steel chamber C with gas at high pressure.
Working
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The spray comb B1 leaks charges due to action of sharp points and positive charge are sprayed on the belt. As the belt moves up due to induction, negative charges are induced on the spray comb B2 and an equal positive charge is induced on the farther end of B2. Thus, charge shifts to the outer surface of S.
Due to discharging action of sharp points B
2, negatively charged electric wind is set up which neutralises the positive charge on the belt. The uncharged belt again collects the positive charge from B
1 and the process continues. Thus, the positive charge on S goes on accumulating and hence the potential goes on increasing. The ion sources experience a greater repulsive force and hence gets accelerated and hits the target nucleus kept below.
