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TUPMN119 | Energy Recovery Transport Design for Peking University FEL | wiggler, electron, beam-transport, laser | 1191 | ||
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Funding: supported by National 973 Projects and the U. S. Department of Energy Contract No. DE-AC05-06OR23177 |
A free-electron laser based on a superconducting linac is under construction in Peking University. To increase FEL output power, energy recovery is chosen as one of the most potential and popular ways. The design of a beam transport system for energy recovery is presented, which is suitable for the Peking University construction area. Especially, a chicane structure is chosen to change path length at ±20 degree and M56 in the arc is adjusted for fully bunch compression. |
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TUPMS031 | High-energy Picosecond Laser Pulse Recirculation for Compton Scattering | laser, electron, scattering, accumulation | 1251 | ||
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Funding: This work was performed under the auspices of the U. S Department of Energy by the University of California, Lawrence Livermore National Laboratory under Contract No. W-7405-Eng-48. |
Frequency upconversion of laser-generated photons by inverse Compton scattering for applications such as nuclear spectroscopy and gamma-gamma collider concepts on the future ILC would benefit from an increase of average source brightness. The primary obstacle to higher average brightness is the relatively small Thomson scattering cross section. It has been proposed that this limitation can be partially overcome by use of laser pulse recirculation. The traditional approach to laser recirculation entails resonant coupling of low-energy pulse train to a cavity through a partially reflective mirror.* Here we present an alternative, passive approach that is akin to "burst-mode" operation and does not require interferometeric alignment accuracy. Injection of a short and energetic laser pulse is achieved by placing a thin frequency converter, such as a nonlinear optical crystal, into the cavity in the path of the incident laser pulse. This method leads to the increase of x-ray/gamma-ray energy proportional to the increase in photon energy in frequency conversion. Furthermore, frequency tunability can be achieved by utilizing parametric amplifier in place of the frequency converter.
* G. Klemz, K. Monig, and I. Will, "Design study of an optical cavity for a future photon-collider at ILC", Nucl. Instrum. Meth. A 564, 212-224 (2006). |
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TUPMS044 | Design of a 980 MeV Energy Recovery Linac | linac, quadrupole, synchrotron, synchrotron-radiation | 1287 | ||
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Funding: This research was supported by National Science Foundation grant no. DMR-0537588. |
A 980-MeV energy recovery linac with radiofrequency (rf) of 1.5 GHz is designed. Electrons are accelerated by two passages through a 480-MeV superconducting linac, and decelerated by two subsequent passages. Recirculation is accomplished with six 60-degree bending magnets. The threshold current for beam breakup instability exceeds 100 mA. Gaussian bunches with normalized transverse emittances of 0.1 mm-mrad and rms length of 1.85 ps may be compressed by a factor of 180 (to a bunch length of 10 fs) with only a slight increase in transverse normalized emittance. Bunch charges up to 8 pC may be compressed at 980 MeV without excessive degradation from coherent synchrotron radiation, allowing operation with beam currents up to 12 mA. |
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