Design and Initial Operation of a Shallow-Focusing, Annular, Extraction Applied-Magnetic-Field Diode.

摘要

A 150-cm(expn 2) applied-magnetic-field diode has been designed and fielded on Gamble II to produce a focused proton beam for self-pinched ion-beam-transport studies. For a beam divergence of 20 mrad, the diode should focus 200 kA of protons to < 2-cm radius at 70 cm from the anode. The diode is insulated with magnetic-fields from two coils driven by a main current of up to 50 kA and 100-(micro)s risetime. An opposite-polarity current pulse of 2-ins half-period, prior to the main pulse, is used to position the B-field separatrix near the anode and remove angular momentum from the extracted beam.