| Paper | Title | Page |
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| WEPWO073 | RF Design Optimization for New Injector Cryounit at CEBAF | 2471 |
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Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. A new injector superconducting RF (SRF) cryounit with one new 2-cell, β=0.6 cavity plus one refurbished 7-cell, β=0.97, C100 style cavity has been re-designed and optimized for the engineering compatibility of existing module for CEBAF operation. The optimization of 2-cell cavity shape for longitudinal beam dynamic of acceleration from 200keV to 533keV and the minimization of transverse kick due to the waveguide couplers to less than 1 mrad have been considered. Operating at 1497MHz, two cavities has been designed into a same footprint of CEBAF original quarter cryomodule to deliver an injection beam energy of 5MeV in less than 0.27o rms bench length and a maximum energy spread of 5keV. |
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| WEPFI085 | Source and Extraction for Simultaneous Four-hall Beam Delivery System at CEBAF | 2896 |
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Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. A new design for simultaneous delivery of the electron beam to all four 12 GeV CEBAF experimental halls* requires a new 750 MHz RF separator system in the 5th pass extraction region, a 250 MHz repetition rate for its beams, and addition of a fourth laser at the photo-cathode gun. The proposed system works in tandem with the existing 500 MHz RF separators and beam repetition rate on the lower passes. The new 5th pass RF separators will have the same basic design but modified to run at 750 MHz. The change to the beam repetition rate will be at the photo-cathode gun through an innovative upgrade of the seed laser driver system using electro-optic modulators. The new laser system also allows addition of the fourth laser. The new RF separators, the new laser system and other hardware changes required to implement the Four-Hall operation delivery system will be discussed in this paper. * Simultaneous Four-Hall Operation for 12 GeV CEBAF, Proceedings of this conference. |
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| THPFI091 | Simultaneous Four-hall Operation for 12 GeV CEBAF | 3502 |
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Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The CEBAF accelerator at Jefferson lab will have a new experimental hall, Hall D, added to its existing three halls as a part of the ongoing 12 GeV upgrade. Under the present CEBAF design, there is no option for sending beam to all four halls simultaneously. At least one hall has to stay down during the machine operation. A new pattern for interleaving the beam bunches is introduced that allows simultaneous operation of all four halls and provide opportunity for additional future experimental beams. The new configuration presents only a minimal change to the existing CEBAF extraction system. In fact all the lower pass extractions will stay as they are and only the frequency of 5th-pass horizontal RF separator will change. In order to make room for the new Hall D beam among the existing three beams, the beam repetition rate is reduced only for the halls taking beam at the highest pass. This and other details of the new configuration and beam pattern will be presented and discussed. A separate paper in this conference will cover the implementation choices including changes to the beam source and extraction region.* * "Source and Extraction for simultaneous Four-Hall beam delivery system at CEBAF", proceedings of this conference. |
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