Instabilities of an electron cloud in a Penning trapP. Paasche, C. Angelescu, S. Ananthamurthy, D. Biswas, T. Valenzuela and G. WerthEur. Phys. J. D, 22 2 (2003) 183-188DOI: https://doi.org/10.1140/epjd/e2002-00239-3