| Paper | Title | Page |
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| WEPD52 | THz Radiation Sources based on RF-linac at Chiang Mai University | 492 |
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| A THz radiation source in a form of coherent radiation from short electron bunches has been constructed at the Plasma and Beam Physics (PBP) research facility, Chiang Mai University. The accelerator system consists of an RF-gun with a thermionic cathode, an alpha-magnet as a magnetic bunch compressor, and a SLAC-type linear accelerator. Coherent transition radiation emitted from short electron bunches passing through an Al-vacuum interface was used as the THz radiation source. This THz radiation can be used as a source of the THz imaging system and THz spectroscopy. Details of the accelerator system and THz radiation production will be presented. A plan for extension to accommodate Free Electron Lasers (FEL) optimized for mid-infrared and far-infrared/THz radiation will also be discussed. | ||
| MOPD61 | Laser Pulse Train Management with an Acousto-optic Modulator | 189 |
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| Photo injector laser systems for linac based FELs often have the capability of generating pulse trains with an adjustable length. For example, the currently installed laser at the Photo Injector Test Facility at DESY, Zeuthen Site (PITZ) can generate pulse trains containing up to 800 pulses. Repetition frequencies are 10 Hz for the pulse trains and 1 MHz for the pulses within a train, respectively. Mostly due to thermal effects caused by absorption in amplifier and frequency doubling crystals, pulse properties are changing slightly within a pulse train and also shot-to-shot, depending on the pulse train length. To increase stability and repeatability of the laser it is desirable to run it under constant conditions. To achieve this while still being able to freely choose pulse patterns a pulse picker to sort the wanted from the unwanted pulses can be installed at the laser output. A promising candidate for this functionality is an acousto-optic modulator which currently is being tested at PITZ. First experimental results will be presented and discussed towards the possibility of including this device into an FEL photo injector. | ||
| MOPD59 | PITZ Status, Recent Measurements and Tests | 181 |
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| The photo injector test facility at DESY, Zeuthen site (PITZ) is dedicated to the development and optimization of a high-brightness electron source for the European XFEL. Recently a significant upgrade has been done at the facility. A new RF system has been installed for the PITZ gun, enabling higher attainable peak power in the cavity which is important for efficient LLRF regulation. First long-term tests for a stable gun operation at high duty cycle have been performed. Two major components for electron beam diagnostics - a transverse deflecting cavity for time resolved electron bunch characterization, and a second high energy dispersive arm for precise longitudinal phase space measurements - have been installed. First results of their commissioning will be reported. | ||
| WEPD53 | Linac-based THz Imaging at Chiang Mai University | 496 |
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Funding: the Thailand Center of Excellence in Physics (ThEP), the National Research Council of Thailand (NRCT) and the Thailand Research Fund (TRF) At the Plasma and Beam Physics Research Facility (PBP), Chiang Mai University, intense THz radiation is generated in a form of coherent transition radiation from femtosecond electron bunches. The THz radiation is used as a source of THz imaging system which was successfully setup and tested. The radiation is focused onto a sample which will be scanned using an xy-translation stage. The transmission or reflection at different points of the sample are recorded to construct a THz image. Details of the setup and the experimental results from the system will be presented. The THz imaging to accommodate a future IR-THz Free Electron Laser (FEL) will also be discussed. |
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