| Paper |
Title |
Page |
| RPAE076 |
The Commission of Hefei Light Source After Reconstruction
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3967 |
| |
- H. Xu, H. He, W. Li, G. Liu, L. Liu, S. Shang, B. Sun, L. Wang
USTC/NSRL, Hefei, Anhui
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After the new four-kicker injection bump system was mounted, it was found that the magnetic field of four–kicker magnet through the same pulse current is different each other, the reason is which the width of pulse magnet fields is not same, so the four-kickers can not form completely local bump, and produce large global orbit distortion,and lead to beam loss. At last we found that the films of ceramic chambers were not plated evenly. The new rf system have two low level control circle circuits, which are the frequency and amplitude automatic adjustment systems. Because the energy of injection electron beam is 200MeV, and radiation damping is weak, so the gain of amplitude circuit was adjusted to the small value not to disturb beam.The beam load is large,and Robinson instability happen easily, so the small detune angle is preset. The Octupoles were inserted in ring for damping instability, and over compensated chromaticity was adjusted.Superconductor wiggler bring the variation of beta function, and the beam life time decreased from 8 hours to about 3 hours. By adjusting the beta functions close to situation ago, the beam lifetime was improved.
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| RPPT036 |
200 MeV Linac Upgrade for FEL
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2464 |
| |
- Y.G. Zhou, S. Dong, H. He, L.G. Li
USTC/NSRL, Hefei, Anhui
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The present status of Hefei 200 MeV RF linac are given. By upgrading its present thermal cathode system into the photo cathode system and implement RF phase locked system, using Hefei 200 MeV RF linac as FEL driver is investigated.
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| RPPT045 |
A Method to Calibrate Beam Position Monitor at HLS 200 MeV LINAC
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2896 |
| |
- J.-H. Li, Y. Cao, H. He, K. Jin, P. Lu, B. Sun, J. P. Wang, Y. Wang, P. Zheng
USTC/NSRL, Hefei, Anhui
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In order to improve injection efficiency of HLS 200Mev LINAC, we redesign a new strip line beam position monitor system, which is consisted of a strip line structure and a signal processing system. We decide on an online calibration method based on beam to find out the geometry centre displacement and relative gain offset. Before the BPM testing bench has been prepared, we make a simulation based on the model accounted for all factors influencing signal amplitudes and get the calibrating results. At last, we analyze the nonlinearity effect on the calibration results.
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| RPPT047 |
Development of Measurement and Transverse Feedback System at HLS
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2974 |
| |
- J.H. Wang, H. He, W. Li, J.H. Liu, L. Liu, B. Sun, Y.L. Yang, K. Zheng, Z.R. Zhou
USTC/NSRL, Hefei, Anhui
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In order to observe and cure coupled bunch (CB) instabilities caused by the high order modes (HOMs) of the RF cavity and the resistive wall impedance of the Ring vacuum chamber, which were ineluctable during the operation of the accelerator, an observer system characterized by bunch by bunch measurement of transverse ßoscillation and longitudinal synchrotron phase oscillation has been constructed and commissioned at Hefei Light Source (HLS); meanwhile a transverse bunch-by-bunch feedback system is under construction. The design and development of the systems, as well as diagnostics results of machine instabilities will be presented in this paper.
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