@article{kelly_márquez_pirrera_2004,  title={Characterization of a quarter torus filter for vacuum arc ion flux transmission},  volume={34},  ISSN={0103-9733},  url={https://doi.org/10.1590/S0103-97332004000800002},  DOI={10.1590/S0103-97332004000800002},  number={4b},  journal={Brazilian Journal of Physics},  publisher={Sociedade Brasileira de Física},  author={Kelly, H. and Márquez, A. and Pirrera, M.},  year={2004},  month={Dec},  pages={1513–1517} }