Results of the SINGAP Neutral BeamAccelerator Experiment at JAEA

摘要

IRFM (CEA Cadarache) and JAEA Naka have entered into a collaboration in order totest a SINGAP [1] accelerator at the JAEA Megavolt Test Facility (MTF) at Naka, Japan.Whereas at the CEA testbed the acceleration current was limited to 0.1 A, at JAEA 0.5 A isavailable. This allows the acceleration of 15 H- beamlets in SINGAP to be tested and a directcomparison between SINGAP and MAMuG [2] to be made. High-voltage conditioning in theSINGAP configuration has been quite slow, with 581 kV in vacuum achieved after 140 hours ofconditioning. With 0.1 Pa of H2 gas present in the accelerator 787 kV could be achieved. Theconditioning curve for MAMuG is 200 kV higher. SINGAP beam optics appears in agreementwith calculation results. A beamlet divergence better than 5 mrad was obtained. SINGAPaccelerates electrons to a higher energy than MAMuG. Measurements of the power interceptedon one of the electron dumps have been compared with EAMCC code [3] calculations. Based onthe experiments described here, electron production by a SINGAP accelerator scaled up to ITERsize was estimated to be too high for comfort