| Paper | Title | Other Keywords | Page |
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| MOPWA069 | Time-resolved Electron Beam Position Monitor Macropulse Waveform Measurement in MkV Linear Accelerator at University of Hawaii Free Electron Laser Laboratory | electron, FEL, controls, laser | 837 |
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Real time waveform measurements of electron beams will provide valuable data and possibility of online bunch diagnostics in linear accelerators. The University of Hawaii Linear Accelerator utilizes a thermionic LaB6 cathode microwave gun injector and a single section of S-band linear accelerator capable of producing a 40MeV, 1-2 ps bunched electron beam with average current of 200mA over the duration of a 4.5 us macropulse. This beam, pulsed at 4 Hz, produces strong RF signal at 2.856 GHz which is coupled out of the beam-pipe by a family of stripline beam position monitors (BPM's) and read out using custom built logarithmic-difference based electronics installed in 2012.* A high speed Analog to Digital Convertor and Field-Programmable Gate Array will be used to digitize the signal and record the waveform. The goal is to make a cost effective oscilloscope on a chip/board with feasible and functional operation to achieve optimal beam configuration. The circuit board design, in-circuit programming, waveform digitization challenges, and preliminary results from the prototype will be presented at the conference.
* B. T. Jacobson, M. R. Hadmack, J. M. J. Madey, P. Niknejadi "Modular Logarithmic Amplifier Beam Position Monitor Readout System at University of Hawai’i," IBIC Conf. Proc. (2012) |
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| TUPEA010 | FERMI Seeded FEL Progress Report | FEL, laser, electron, undulator | 1182 |
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Funding: Work supported in part by the Italian Ministry of University and Research under grants FIRB-RBAP045JF2 and FIRB-RBAP06AWK3 FERMI, the seeded Free Electron Laser located at the Elettra laboratory in Trieste, Italy, welcomed in December 2012 the first external users on the FEL-1 line. This line is based on a single stage of High Gain Harmonic Generation (HGHG), seeded by a UV laser, and covers wavelengths between 80 and 20 nm. The photon energy reached more than 300 μJ. The second FEL line, FEL-2, covering the lower wavelength range between 20 and 4 nm thanks to a double stage cascaded HGHG scheme, has generated its first coherent photons in October 2012. This is the first experimental demonstration of a seeded free electron laser configured as a two stages cascade operating in the "fresh bunch injection” mode, where the second stage is seeded by the light produced by the first stage. This paper describes the status of the operation and user experiments with FEL-1 and reports about the progress in the commissioning of FEL-2. |
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| WEPWA029 | Undulator Chamber R&D for SXFEL | undulator, vacuum, controls, laser | 2193 |
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| The upcoming construction of Shanghai Soft X-ray Free Electron Laser Facility (SXFEL) will use 18 m small gap undulators. Each undulator is 3 meters long and will work at a minimum gap of 9 mm. This requires a vacuum chamber with an outer height of 8 mm and an elliptic inner aperture. The pressure inside of the chamber shall be less than 10-5 Pa for the beam operation. An oxygen-free copper vacuum chamber was designed and a prototype was developed. This chamber includes three parts, a copper pipe manufactured by stretching, two flanges made of clad metal and a set of supports. The main fabrication procedure and the test results for the chamber prototype are described in this paper. | |||
| WEPFI044 | High Power Test of New SLED System with Biplanar 3-dB Power Divider and Dual Side-wall Coupling Irises for PAL XFEL | coupling, klystron, simulation, cavity | 2803 |
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| The new type of the Stanford Linear Accelerator Energy Doubler (SLED) system for the PAL (Pohang Accelerator Laboratory) XFEL (X-ray Free Electron Laser) is developed to be operated with an RF input power of 80 MW and a pulse width of 4 μs. To prevent the RF breakdown such a high power operation, a biplanar 3-dB power divider and dual side-wall coupling irises structure are used in the new SELD system. It is shown that the field gradient and surface current is reduced from that of the original SLED system using the the finite-difference time-domain (FDTD) simulation. The high power test result of the new SLED system in the PAL XFEL test facility will be presented. | |||
| THPWA003 | Novel Crate Standard MTCA.4 for Industry and Research | LLRF, controls, monitoring, radio-frequency | 3633 |
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Funding: This project is funded by the Helmholtz Association (Helmholtz Validation Fund HVF-0016). MTCA.4 is a novel electronic standard derived from the Telecommunication Computing Architecture (TCA) and championed by the xTCA for physics group, a network of physics research institutes and electronics manufacturers. MTCA.4 was released as an official standard by the PCI Industrial Manufacturers Group (PICMG) in 2011. Although the standard is originally physics-driven, it holds promise for applications in many other fields with equally challenging requirements. With substantial funding from the Helmholtz Association for a two-year validation project, DESY currently develops novel, fully MTCA.4-compliant components to lower the barriers to adoption in a wide range of industrial and research use scenarios. Core activities of the project are: refinement, test and qualification of existing components; market research, market education (web information services, workshops); coordinated development of missing MTCA.4 components; further advancement of the standard beyond the current PICMG specification; investigation of measures to counteract electro-magnetic interferences and incompatibilities; training, support and consultancy. This paper summarizes intermediate results and lessons learned at project half-time. |
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