| Paper | Title | Page |
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| MOPSO70 | Crystal Channeling Acceleration Research for High Energy Linear Collider at ASTA Facility | 122 |
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| The density of charge carriers in solids is significantly higher than what was considered above in plasma, and correspondingly, the longitudinal fields of up to 10 TV/m are possible. It was suggested that particles are accelerated along major crystallographic directions, which provide a channeling effect in combination with low emittance determined by an Angstrom-scale aperture of the atomic “tubes.” However, the major challenge of this channeling acceleration is that ultimate acceleration gradients might require relativistic intensities at hard x-ray regime (~ 40 keV), exceeding those conceivable for x-rays as of today, though x-ray lasers can efficiently excite solid plasma and accelerate particles inside a crystal channel. However, the acceleration will take place only in a short time before full dissociation of the lattice. Carbon nanotubes have great potential with a wide range of flexibility and superior physical strength, which can be applied to channeling acceleration and possibly fast cooling. This talk will present past and current efforts on crystal acceleration research and discuss feasible experiments with the ASTA and beyond. | ||
| TUPSO74 | A Coaxially Coupled Deflecting-accelerating Mode Cavity System for Phase-space Exchange (PSEX) | 395 |
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A feasible method to readily remove energy spread (R56 term) due to thick lens effect of a deflecting mode RF-cavity has been widely investigated for emittance exchange in 6D phase-space*,**. By means of theoretical calculation and numerical analysis, it was found that an accelerating cavity effectively cancel the longitudinal phase space chirp. We have extensively investigated the combined deflecting-accelerating mode phase-space exchanger with the simple RF distribution system of the beam-pipe coaxial coupler. EM simulations proved the coupling scheme with eigenmode and S-parameter analyses. Currently we are looking into 3D beam dynamics in the system with tracking/particle-in-cell (PIC) simulations and wakefield analysis. Proof-of-concept (POC) experiment is planned with a high-Q normal conducting cavity built in a cryogenic cooling system (liquid nitrogen) in Fermilab.
* P. Emma, et. al., Phys. Rev. ST Accel. Beams 9, 100702 (2006) ** Zholents and M. Zolotorev, LBNL CBP Seminar (2010) and No. ANL/APS/LS-327(2011) |
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| TUPSO75 | Design Analysis and High Power RF Test of a 3.9 GHz 5-cell Deflecting-mode Cavity in a Cryogenic Operation | 399 |
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A 3.9 GHz deflecting mode (π, TM110) cavity has been long used for six-dimensional phase-space beam manipulation tests [1 - 5] at the A0 Photo-Injector Lab (16 MeV) in Fermilab and their extended applications with vacuum cryomodules are currently planned at the Advanced Superconducting Test Accelerator (ASTA) user facility (> 50 MeV). Despite the successful test results, the cavity, however, demonstrated limited RF performance during liquid nitrogen (LN2) ambient operation that was inferior to theoretical prediction. We have been performing full analysis of the designed cavity by analytic calculation and comprehensive system simulation analysis to solve complex thermodynamics and mechanical stresses. The re-assembled cryomodule is currently under the test with a 50 kW klystron at the Fermilab A0 beamline, which will benchmark the modeling analysis. The test result will be used to design vacuum cryomodules for the 3.9 GHz deflecting mode cavity that will be employed at the ASTA facility for beam diagnostics and phase-space control.
[1] D. A. Edwards, LINAC 2002 [2] Y.-E Sun, PRTAB 2004 [3] P. Piot, PRSTAB2006 [4] J. Ruand et al., PRL 2011 [5] Y.-E. Sun, et al., PRL 2010 |
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