Assume that a plasma temperature of is reached in a laser-fusion device. (a) We have to find the most probable speed of a deuteron at this temperature; (b) and calculate the distance such a deuteron would move in the confinement time of

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(a)

The Maxwellian speed distribution, for a classical gas at temperature T and containing N molecules, is

The most probable speed is the speed at which has its maximum value. We find it by requiring that .

That is

The mass of a deuteron atom will be

Therefore, the most probable speed of a deuteron at will be

(b)

The distance a deuteron having a speed of would move in the confinement time of will be