H- magnetic beam extractors design for the KOMAC project

Complete design specifications for 260 MeV H- beam extractors are presented . The extractor employs a novel design of a stripper magnet which separatel y handles both the stripping of the H- beam and the bending of the unextrac ted H- beam. The design objective of the extractor is to partially extract a negative hydrogen ion (H-) beam at 260 MeV from the main linac where both protons (H+) and negative hydrogen ions are accelerated up to 1 GeV. Since the extractor adopts the magnetic stripping method, emittance growth is un avoidable for the extracted beam. However, the unextracted H- beam returns to the main linac with no change in the beam profile. The main features of this extractor are: (1) its ability to regulate the intensity of the extrac ted beam and (2) the nondestructive effect on the profile of the H- downstr eam beam. These extractors will be utilized for the Korea Multi-purpose Acc elerator Complex (KOMAC) linear accelerator of 1 GeV cw proton (H+)/negativ e hydrogen (H-) beams with an intensity of 20 mA. (C) 2001 Elsevier Science B.V. AB rights reserved.