@article{oai:iwate-u.repo.nii.ac.jp:00009941,
 author = {Takahashi, K and Oguni, K and Yamada, H and Fujiwara, T},
 issue = {8},
 journal = {Physics of Plasmas},
 month = {Aug},
 note = {Ion acceleration is achieved in a low-pressure solenoid-free plasma expanded by permanent magnet arrays. Although a permanent magnet normally forms cusp magnetic fields which prevents plasma
diffusion and double layer formation, by employing double concentric arrays of permanent magnets, a constant field area, and a diverging magnetic field can be generated near the outlet of the plasma
source. In the source, a rapid potential drop with 4 cm thickness from 50 V to 20 V is generated at the diverging field area for 0.35 mTorr and a supersonic ion beam accelerated through the potential drop is observed in the diffusion chamber. The beam energy can be increased up to over 40 eV with a decrease in gas pressure.},
 pages = {084501-1--084501-4},
 title = {Ion acceleration in a solenoid-free plasma expanded by permanent magnets},
 volume = {15},
 year = {2008}
}