| Paper |
Title |
Page |
| TUP050 |
Microwave Helical Undulator-Based Production of Polarized Photons and Positrons
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361 |
| |
- A. Smirnov, D. Yu
DULY Research Inc., Rancho Palos Verdes, California
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Linac-driven undulator technology and capabilities are considered for production of polarized positrons and polarized high-brightness X-rays. Challenging requirements for polarized positron production reveal a number of benefits of a microwave undulator compared with a conventional magnetic undulator: larger gap, simpler construction, shorter length, reduced requirements on tolerances and alignment. Two novel approaches are introduced for open and closed structures: cross-polarized excitation of a circular waveguide and a twisted structure. For the CLIC project the microwave undulator becomes an integral part of the TBA, and as it is naturally powered by the same decelerator. Other applications include emittance dampers, synchrotron radiation sources, and FELs. Additionally the twisted undulator provides unique opportunity for studies of circular dichroism and multi-photon anomalous diffraction (MAD) in protein crystallography.
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| TUP057 |
A Compact, Normal-conducting, Polarized Electron, L-band PWT Photoinjector for the ILC
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376 |
| |
- D. Yu, Y. Luo, A. Smirnov
DULY Research Inc., Rancho Palos Verdes, California
- I. V. Bazarov
Cornell University, Ithaca, New York
- R. P. Fliller
Fermilab, Batavia, Illinois
- P. Piot
Northern Illinois University, DeKalb, Illinois
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The International Linear Collider (ILC) needs a polarized electron beam with a low transverse emittance. High spin-polarization (>85%) is attainable with a GaAs photocathode illuminated by a circularly polarized laser. Low emittance is achievable with an rf photoinjector. DULY Research has been developing an rf photoinjector called the Plane Wave Transformer (PWT) which may be suitable as a polarized electron source for the ILC. A 1+2(1/2) cell, L-band PWT photoinjector with a coaxial rf coupler is proposed for testing the survivability of GaAs cathode. It is planned to produce a high-aspect-ratio beam using a round-to-flat-beam transformation. In addition to its large vacuum conductance, the modified PWT has a perforated stainless steel sieve as a cavity wall, making it easy to pump the structure to better than 10-11 Torr at the photocathode. An L-band PWT gun can achieve a low emittance (0.45 mm-mrad for a 0.8nC round beam) with a low operating peak field (<25MV/m). A low peak field is beneficial for the survivability of the GaAs photocathode because electron backstreaming is greatly mitigated.
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| THP048 |
Band Gap Structures of PBG and Rod-loaded Cavities
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688 |
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- D. Yu, A. Smirnov, R. Yi
DULY Research Inc., Rancho Palos Verdes, California
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The band-gap structures for rod loaded (RL) and photonic band gap (PBG) cavities are calculated with 2D and 3D frequency domain codes. It is shown that an RL cavity with a single circle of rods can exhibit similar behavior as a conventional single-defect PBG cavity. A systematic method of computing the unloaded Q factor using SUPERFISH has been implemented. Results are compared with GdfidL and Gd1 calculations.
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