Observation of magnetic resonances in electron clouds in a positron storage ring

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Vol. 621; no. 1; pp. 33 - 38
• Main Authors: Pivi, M.T.F., Ng, J.S.T., Cooper, F., Kharakh, D., King, F., Kirby, R.E., Kuekan, B., Spencer, C.M., Raubenheimer, T.O., Wang, L.F.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-09-2010
• Subjects: Accelerators; Aluminum; Clouds; Coating; Electron analyzer; Electron cloud instability; Electron clouds; Modulation; Positron storage rings; Positrons; Remedies; Secondary emission; Storage rings (particle accelerators); Positron storage rings; Secondary emission; Electron analyzer; Electron cloud instability
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/j.nima.2010.04.052

The first experimental observation of magnetic resonances in electron clouds is reported. The resonance was observed as a modulation in cloud intensity for uncoated as well as TiN-coated aluminum surfaces in the positron storage ring of the PEP-II collider at SLAC. Electron clouds frequently arise in accelerators of positively charged particles, and severely impact the machines’ performance. The TiN coating was found to be an effective remedy, reducing the cloud intensity by three orders of magnitude.