Models of ion beam interactions for the stability analysis of migma

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Vol. 271; no. 1; pp. 112 - 116
• Main Authors: Gnavi, Graciela, Gratton, Fausto T.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.08.1988
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/0168-9002(88)91132-1

The stability of the central region of the triple delta distribution function for a migma is shown to be reducible to the analysis of fourth and sixth order ordinary differential equations for radial electrostatic modes, including axial oscillations and electron shielding effects. A normal mode study shows that a cylindrically counterstriming ion instability appears for ω pi > ω ci . This effect should attenuated by the introduction of some spread in pθ. It is noted that a spherical system of counterstreaming beams is stable for radial modes. An instability of the Harristpe is discussed with a migma slab model, which includes finite axial extent and a bias electric field. It is suggested that a microinstability observed during the Migma IV experiment was stabilized by the combined influence of small axial wavelenghts and electron heating.