397 research outputs found
A Proof-Of-Principle Cavity-Based X-Ray Free-Electron-Laser Demonstrator at the European XFEL
No full textThis thesis is centered on the foreseen realization and performance of a proof-of-principle cavity based (hard) X-ray FEL (CBXFEL) demonstrator experiment at the European XFEL facility. A CBXFEL promises to address the prominent issue of longitudinal coherence and (stable) high, narrow bandwidth spectral flux in the hard X-ray regime, in which the usually employed self amplified spontaneous emission (SASE) scheme is severely lacking.In order to study the highly coupled system of FEL production, X-ray propagation and the crystals’ thermal response, affecting the reflection characteristics, a computational frame-work was set up. It chains the popular Genesis-1.3 FEL program with the self-written,highly optimized parallel X-ray Cavity Propagator (pXCP) wavefront propagation code and a finite element (FE) based modeling of the strongly non-linear thermal diffusion. In order to properly account for low-temperature thermal transport with an increased relevance of phonon boundary scattering, thermal conductivities obtained from first-principles simu-lation are used.Thorough simulations are carried out, which account for realistic electron bunch distri-bution, inter RF-pulse bunch fluctuations and various possible errors of the X-ray optics.They reveal that with well inside state of the art optical tolerances, a simplistic two crystalback scattering setup would fulfill the main goal of the demonstrator, which is to proof that seeding and exponential radiation build with spectral narrowing occurs. However, due tothe strong heating of the crystals and the following thermoelastic response, stable operationat high peak brilliance will not be feasible. Following the principle, experimental nature ofthe CBXFEL demonstrator setup, these effects will need to be properly measured. Usingthis data, counter measures can be developed towards the future realization of a permanentCBXFEL source at the European XFEL facility
Recent Developments in Hard X-ray FELs
No full textThe successful commissioning of the PAL-XFEL, SwissFEL and European XFEL in the last year has increased the number of operating hard X-Ray FELs together with SACLA and LCLS to five. This talk will try to summarize the status of the facilities, compare similarities and differences and give an outlook of what is to be expected in the coming years
Latest Developments in X-Ray FELs and Future Perspectives
No full textThe successful commissioning of the PAL-XFEL, SwissFEL and European XFEL in the last year has increased the number of operating hard X-Ray FELs together with SACLA and LCLS to five. This talk will try to summarize the status of the facilities, compare similarities and differences and give an outlook of what is to be expected in the coming years
Optical Layout of the TESLA 5 GeV Damping Ring
No full textThe TESLA linear collider needs damping rings to achieve the required small transverse emittances for optimum luminosity. Due to the TESLA pulse structure the damping rings are about 17 km long. The resulting unusual ratio of circumference to energy leads to a large space charge tune shift. The originally proposed damping ring [1] has thus been redesigned for higher energy. This paper describes the optical design of the 5 GeV TESLA damping ring
European XFEL Accelerator Update
No full textSummarizes European XFEL performance and noteable events of 2020
European XFEL Construction Status
No full textThe European XFEL is under construction in the Hamburg region, Germany. It will provide FEL radiation in the range from 260 eV up to 24 keV out of three undulators that can be operated simultaneously with up to 27000 pulses/second. The FEL is driven by a 17.5 GeV linear accelerator based on TESLA-type superconducting accelerator modules. This paper gives an update on the project status and an outlook towards the commissioning and fist operation
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