Journal article
Measurement of ultralow vertical emittance using a calibrated vertical undulator
KP Wootton, MJ Boland, RP Rassool
Physical Review Special Topics Accelerators and Beams | Published : 2014
Open access
Abstract
Very few experimental techniques are useful for the direct observation of ultralow vertical emittance in electron storage rings. In this work, quantitative measurements of ultralow (pm rad) electron beam vertical emittance using a vertical undulator are presented. An undulator radiation model was developed using the measured magnetic field of the APPLE-II type undulator. Using calibrated experimental apparatus, a geometric vertical emittance of Ïy=0.9±0.3pmrad has been observed. These measurements could also inform modeling of the angular distribution of undulator radiation at high harmonics, for proposed diffraction-limited storage ring light sources.
Grants
Funding Acknowledgements
This research was undertaken on the soft X-ray beam line and storage ring at the Australian Synchrotron, Victoria, Australia. K. P. W. gratefully acknowledges useful discussions with Takashi Tanaka (SPring-8) regarding the implementation of measured magnetic field distributions within the SPECTRA code. K. P. W. gratefully acknowledges useful discussions with Rohan Dowd, Yaw-Ren Eugene Tan and Bruce C. C. Cowie (Australian Synchrotron) during these experiments. K. P. W. gratefully acknowledges the David Lachlan Hay Memorial Fund (The University of Melbourne) for financial support during the preparation of this article.