Publications
Publication Information
| Title | CEBAF injector achieved world's best beam quality for three simultaneous beam sith a wide range of bunch charges |
| Authors | Reza Kazimi, Kevin Beard, Jay Benesch, Arne Freyberger, Joseph Grames, Tommy Hiatt, Andrew Hutton, Geoffrey Krafft, Nikolitsa Merminga, Bernard Poelker, Michael Spata, Michael Tiefenback, Byung Yunn, Yuhong Zhang |
| JLAB number | JLAB-ACO-04-251 |
| LANL number | (None) |
| Other number | (None) |
| Document Type(s) | (Meeting) |
| Associated with EIC: | No |
| Supported by Jefferson Lab LDRD Funding: | No |
|
Meeting Poster compiled for EPAC 2004 | |
| Publication Abstract: | The CEBAF accelerator provides interleaved 499 MHz electron beams, spanning 5 decades in beam intensity (a few nA to 200 mA), to three experimental halls simultaneously. The physics program became more challenging when the G0 experiment was approved, requiring more than six times higher bunch charge than is routine. This experiment requires up to 8 million electrons per bunch at a reduced repetition rate of 31 MHz, while the lowest current hall simultaneously receives 100 electrons per bunch. A bunch destined for one hall may experience significant space charge forces, while the next bunch may have negligible space charge. This disparity in beam intensity must be maintained while delivering best ever values in rms beam quality, including relative energy spread (<2.5x10-5) and normalized transverse emittance (<1 mm-mrad). Space charge difficulties emerge in the 10m long, 100 keV section of the CEBAF injector during initial bunch formation and spin manipulation. A series of changes was introduced to meet the new requirements, including adding new magnets, replacing photoinjector lasers, modifying typical laser parameters, stabilizing RF systems, and changing standard operating procedures. In this paper, we discuss these modifications in detail, including the agreement between the experimental results and detailed simulations. |
| Experiment Numbers: | other |
| Group: | Operations |
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| Accepted Manuscript: | |
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