| Paper | Title | Other Keywords | Page |
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| MOPRO070 | Study on Ground Vibration Characteristics of Iranian Light Source Facility | ground-motion, synchrotron, operation, data-analysis | 243 |
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| In this study the results of ground vibration measurement for the site of Iranian Light Source Facility (ILSF) has been investigated. Light source buildings are very sensitive to the ground weak motions. Sources for the ground vibrations could be Cultural noise from human activities like traffic and industrial works. In order to satisfy requirements for level of the ground vibrations, a perfect ground vibration survey has been conducted and compared with other same projects. Two broad-band seismometers were utilized for surveying the ground vibration at ILSF site. The raw data were pre-processed as well as analyzed in term of seismology and engineering aspects. Spectrum amplitudes along with powers of the vibration amplitudes were calculated at the time domain. The power spectral density of vibration displacements were extracted from the measurements and were compared with results of other synchrotron projects. The results show that the dedicated site for ILSF is in the appropriate condition in the point view of ground vibration issues. | |||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO070 | ||
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| MOPRI038 | Study on Quantum Efficiency of NEA-GaAs with Various Thermal Treatments; The Increase in Quantum Efficiency by the Low Temperature Treatment. | electron, ion, experiment, vacuum | 682 |
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| Negative electron affinity (NEA) surface are formed by deposition of Cs atoms on p-GaAs, and the drastic increase in the electron emission is observed by the Yo-Yo method. It is necessary to remove oxide layers of GaAs surface for the NEA surface formation, therefore the thermal treatment was carried out prior to the NEA activation. We have discussed the quantum efficiency (QE) with different thermal history. GaAs surfaces cleaned with organic solvents were thermally treated with the temperature sequence of 773K, 823K, and 723K. The NEA activation was carried out at every temperature. The QE less than 1% was obtained with 773K of treatment temperature on the initial surface. Then the QE increased at 10% after treatment at higher 823K. Successive increase of the QE to 13% was observed with a reduced temperature treatment at 723K. The GaAs surfaces after the thermal treatment in the high temperature region with the NEA activation are different from the as-cleaned-GaAs surfaces probably in stoichiometry or morphology due to desorption of As and Ga atoms. The role of thermal treatment with NEA activation is the modification of surface properties important for elevating the QE. | |||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI038 | ||
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| TUPRI116 | Engineering Data Management for the ILC Site Specific Design Phase | lattice, positron, linear-collider, collider | 1839 |
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| In August 2013, the Japanese ILC Site Evaluation Committee has recommended the Kitakami area in northern Japan as the technically preferred site for the International Linear Collider (ILC) in Japan. With this decision, the ILC planning has moved into a new stage where the Technical Design Report baseline design has to be adapted to the specific site, and refined in preparation for a possible construction project. Engineering data management provides the methods and supporting tools to create and maintain the design data throughout the entire life of the ILC project. The Management and integration of engineering data from the design teams around the globe that contribute to the ILC requires a carefully structured body of documentation, clearly defined processes including configuration control, and efficient vision sharing through 3D modelling. | |||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI116 | ||
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| WEPME005 | Enhanced Field Emission and Emitter Activation on Flat Dry-ice Cleaned Cu Samples | electron, vacuum, factory, gun | 2261 |
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Enhanced field emission (EFE), resulting in dark currents and electric breakdowns, is one of the main gradient limitations for the CLIC accelerating structures (actual design Eacc = 100 MV/m, Epeak = 240 MV/m *). Measurements on diamond-turned, flat (Ra = 158 nm) Cu samples showed first EFE at surface fields Es = 130 MV/m. In order to reduce EFE, we have installed a commercial dry ice cleaning (DIC) system in a clean room environment (class iso 5). Accordingly, the number density of emitters (N) was significantly decreased by DIC from N = 52 /cm² to N = 12 /cm² at Es = 190 MV/m. Furthermore we have tested two diamond-turned and chemically etched (SLAC treatment, Ra = 150 nm) Cu samples after DIC resulting in EFE onset at 230 MV/m. Locally measured I(V) curves of the strongest emitters yielded field enhancement factors b = 10 – 90 (10 – 85) on the diamond-turned (chemically etched), respectively. SEM and EDX investigations of the located emission sites revealed surface defects and few particulates (Al, Ca, Si) as origin of the EFE. Moreover, strong emitter activation effects were observed. A possible breakdown mechanism based on this EFE activation will be discussed.
* A. Grudiev and W. Wuensch, Proceedings of LINAC2010, Tsukuba, Japan, pp. 211 - 213 |
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| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPME005 | ||
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| WEPME054 | Design and Fabrication of the Novel-type Ceramic Chamber | vacuum, HOM, detector, electron | 2393 |
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| A ceramic chamber of novel type has been designed and fabricated. The uniformity of its inner thin film of deposited metal is improved to have a thickness error about 1 %. The average straightness error of the chamber (length 550 mm) is developed to be less than 55 μm. To fabricate the ceramic chamber of novel type, we first cleaned and joined the two halves; the metal films were deposited by sputtering. These two halves were next sealed with a glass powder colloid to become a ceramic tube. The rate of outgassing of this colloid is 3.57×10-12 Torr L s−1 cm-2 after baking. The ceramic tube was connected to a stainless-steel flange with the aid of a glass powder colloid and TIG welding. This ceramic test chamber will be installed in the experimental system to analyze the residual gas. | |||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPME054 | ||
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| THPRO125 | Synchronous Data Acquisition System for TPS and its Applications | data-acquisition, ground-motion, emittance, interface | 3186 |
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| Orbit stability in 100 nm range is essential for a very small emittance synchrotron light source. However, all kinds of vibration source such as cultural noise and technical noise might deleterious the orbit stability. A synchronous data acquisition system is promising to study connection of orbit motion and various vibration related sources. In this report, we present a synchronous data acquisition system which integrates the measurement of beam position and vibration and then this system will deploy for the Taiwan Photon Source (TPS). To test the applicability of the system, systematic study orbit motion caused by vibration using this system was performed at Taiwan Light Source (TLS). Preliminary results will summary in this report. | |||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRO125 | ||
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