EMITTANCE OF HIGH CURRENT BEAMS IN THE PRESENCE OF DRIFT TUBE AND LONGITUDINAL GUIDING MAGNETIC FIELD

Emittance formulas of a beam in the guiding magnetic field, where electrons undergo a rotary motion, are deduced. In the case of uniform distribution of space charge, the relation between emittance and the canonical angular momentum of the beam is given. For non-linear distributions a third term must be added to the formula given by T.P. Wangler, which is the contribution of the rotating energy of the beam.