Four Beam Generation for Simultaneous Four-Hall Operation at CEBAF

Reza Kazimi, Joseph Grames, John Hansknecht, Alicia Hofler, George Lahti, Tomasz Plawski, Matt Poelker, Riad Suleiman, Yan Wang, Petit-Jean-Genaz, Christine (Ed.), Kim, Dong Eon (Ed.), Kim, Kyung Sook (Ed.) (+2 others)
As part of the CEBAF 12 GeV upgrade at Jefferson Lab, a new experimental hall was added to the existing three halls. To deliver beam to all four halls simultaneous-ly, a new timing pattern for electron bunches is needed at the injector. This pattern change has consequences for the frequency of the lasers at the photogun, beam behavior in the chopping system, beam optics due to space charge, and setup procedures. We have successfully demonstrated this new pattern using the three existing drive
more » ... ee existing drive lasers. The implementation of the full system will occur when the fourth laser is added and upgrades to the Low Level RF (LLRF) are complete. In this paper we explain the new bunch pattern, the challenges for setting and measuring the pattern such as 180° RF phase ambiguity, addition of the fourth laser to the laser table and LLRF upgrade.
doi:10.18429/jacow-ipac2016-thpoy060 fatcat:775v7sdqcvcfjh2k4glendnzau