@article{oai:repo.qst.go.jp:00045992,
 author = {W.Y., Choi Viann and Ng, C.K.M. and Nikezic, Dragoslav and Konishi, Teruaki and K.N., Yu Peter and 小西 輝昭},
 issue = {1},
 journal = {Nuclear Instruments & Methods in Physics Research Section A},
 month = {Dec},
 note = {One approach for alpha-particle radiobiological experiments is to use solid-state nuclear track detectors (SSNTDs) as support substrates to record the -particle hit positions on the targets. To facilitate accurate characterization of the hit positions as well as the incident alpha-particle energies, micro-collimators are required in these experiments to restrict the incident  particles to those with small deviations from normal incidence with respect to the collimator. In the present paper, we fabricated micro-collimators which restricted alpha-particles to those with deviations as low as 12o. Specially etched polyallyldiglycol carbonate (PADC) films, which are a kind of SSNTD, with a thickness 70 µm were prepared from commercially available PADC films. These were then irradiated by 4.83 MeV/n oxygen ions generated from the heavy-ion medical accelerator in Chiba (HIMAC), Japan. The irradiated films were chemically etched for at least 2.7 h to achieve etched-through air channels to form the micro-collimators. The micro-collimators formed by etching the irradiated films for 2.7, 3, 4 h were experimentally shown to be able to restrict alpha-particles to those very close to normal incidence, while that formed by etching the irradiated film for 4.5 h started to allow alpha-particles with larger deviations from normal incidence to pass through, the latter being likely due to overlapping of air channels from excessive etching.},
 pages = {6--11},
 title = {Micro-collimators fabricated by chemical etching of thin polyallyldiglycol carbonate polymer films exposed to oxygen ions},
 volume = {631},
 year = {2010}
}