Surface-micromachined Multi-pole Electromagnets: Compact Electron Optics and Undulators
Jun 03, 2014
from 09:00 AM to 11:00 PM
|Where||Engr. IV Bldg., Tesla Room 53-125|
|Contact Name||Jere Harrison|
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Advisor: Professor Rob N. Candler
Charged particle beams underlie many high-impact instruments in science and medicine, such as coherent light sources at X-ray energies where nature has not provided a solid-state gain media. These soft- and hard-X-ray laser systems are in high demand, but their extreme size and cost has led to a scarcity that limits scientific progress and prevents independent reproduction of experiments. The urgent need for new technologies to make these capabilities accessible has come at a time when the maturing of MEMS manufacturing techniques is enabling micro-technology to interact strongly with physical systems.
In this seminar, the first application of MEMS electromagnets to charged particle beam optics is presented. These combined-function (2-D steering & focusing) 4-pole electromagnets with 600-μm bore and 55-μm-thick magnet yoke are fabricated with a novel MEMS process and provide a technology demonstration for compact short-period undulator light sources. Experiments with a 34 keV electron beam demonstrate adjustable steering and focusing with up to 24-mT magnetic field intensity and 183-T/m magnetic field gradient, exceeding all commercially available macro-scale beam focusing optics and comparable to the highest-gradient focusing optics demonstrated. An electron-beam-probe magnetometry technique is used to spatially characterize the field in the confined micro-scale bore of the device. Future scaling of these devices to the demonstrated limits of our fabrication process promises magnetic field intensity and gradient exceeding 400 mT and 10 kT/m.
Jere Harrison is currently a Ph.D. candidate in the Electrical Engineering Department at UCLA. He received his M.S. degree in Electrical Engineering from UCLA in 2011 and B.S. degree in Electrical Engineering from Arizona State University in 2008. His research is in magnetic MEMS and focused on microfabricated electromagnets. He has coauthored 12 peer-reviewed journal papers and conference presentations and 4 patents.