| Paper | Title | Page |
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| TUPTS106 | First Commissioning of LCLS-II CW Injector Source | 2171 |
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Funding: The work is supported by DOE under grant No. DE-AC02-76SF00515 The LCLS-II injector source includes a 186MHz CW rf-gun, a 1.3 GHz CW rf-buncher, a loadlock system for photocathode change, two main solenoids, and a few essential diagnostics. The electron beam is designed to operate at a high repetition rate, up to 1-MHz. Since summer of 2018 we started LCLS-II injector source commissioning immediately after the major installation was completed. Initial commissioning showed the rf-gun was severely contaminated with hydrocarbons and very limited power <600W could be fed into the gun cavity. After a few significant processes, we eventually removed the hydrocarbons and successfully delivered desired rf power of 80 kW to the gun. This paper reports first com-missioning results including gun bakeout and vacuum processing, CW RF-gun and buncher operation with nom-inal power, and measurements of rf stability and dark current. |
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| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS106 | |
| About • | paper received ※ 10 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019 | |
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| THPRB045 | A Novel Microwave Switch-Based LLRF System for Long-Term System Phase Drift Calibration | 3915 |
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| The long-term phase drift is one of the important issue for the stability of the Low level RF system. The signal crosstalk and temperature effect on the RF field detectors will significantly limited the performance of the phase detecting precise and the phase locking. A novel micro-wave switch-based LLRF system has been developed in Tsinghua accelerator lab. The microwave switch are ap-plied to in the chopper circuit to turn continuous signal into pulse signal in the time domain to avoid the mutual signal interference. In this paper the LLRF system based on microwave switch is present. The preliminary long-term experiments result shows the phase stability can achieve about 50fs RMS slow drift; and the peak-to-peak value of the slow drift was (~2°C p-p) over 4 days. | ||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB045 | |
| About • | paper received ※ 22 April 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019 | |
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| THPRB046 | The Preliminary Long-Term Slow Drift Calibration Study in Low-Level Rf System | 3918 |
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| The phase drift of the RF signal in the low-level radio frequency (LLRF) system is observed in the long-term operation, which limits the performance and stability of the LLRF system. The long-term drift was reproduced in the lab. Its effect and sources of error were explored in the simple LLRF46 board and the simplest LLRF system. It is founded that the temperature will significantly lead to the phase distortion of the two signal channels, although with the same electron device. The distortion will finally cause the long-term drift with temperature floating. A fixed phase calibration signal (CAL signal) is applied to deal with the signal channels difference. The preliminary tests were conducted and the results were analysed. | ||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB046 | |
| About • | paper received ※ 22 April 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019 | |
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |