HLS-Ⅱ儲存環(huán)工作點測量系統(tǒng)的開發(fā)及應用.pdf

1、Through half a century's development of the particle accelerator science, synchrotron based on strong focusing principle has been a standard concept for the highenergy particles acceleration.Compared with synchrotrons, s

2、torage rings focus not only on the achievable maximum of the particle energy but also on the equality of theparticle beam.Of special interest is to use electron storage rings as synchrotron radiation light sources which

3、provide the users with brilliant photons.
　　The new storage ring is the main part of the upgrade Hefei Light Source (HLS-Ⅱ)which determines the performance of the light source.For storage rings, tune is a keyparameter

4、.Tune is defined as the betatron oscillation number of a particle travellingonce around the circular accelerators, which reveals the overall focusing "sensed"bythe particle in the ring.The precise measurement for the tun

5、e not only helps avoid thebeam loss due to resonance but also provides researchers rich information about theextra effects on the beam focusing.
　　A Swept-Frequency Excitation (SFE) based tune measurement system has b

6、eendeveloped for the HLS-Ⅱ storage ring during the upgrade project of HLS-Ⅱ in 2011-2014.This dissertation introduces the development details and applications of the SFEbased tune measurement system of the HLS-Ⅱ storage

7、ring.
　　It is clear from the analysis of the beam transverse spectrum that tune can be obtained from the beam position signal.However, the radiation damping effect has animpact on the tune observation.Thus a RF dipole

8、 kicker needs to be added on the beamto excite significant betatron oscillation.
　　The development of the SFE based tune measurement system consists three parts: hardware construction, software structure and the syste

9、m commissioning.Spectrumanalyzer is the heart of the system which determines the system performance.Withcorresponding signal exciting circuit and signal processing circuit, tune can be extracted from the strip-line BPM.T

10、he task of the control system development is to controlthe spectrum analyzer under the EPICS frame work.The system has a measurementresolution better than 0.00007 with a refresh rate of 1 Hz, which meets the physicalneed

11、s.
　　The SFE based tune measurement system has been widely used during the commissioning of the HLS-Ⅱ storage ring.Based on the tune shift principle, the betatronfunction, natural chromaticity, corrected chromaticity

12、are measured during the commissioning.The betatron function is measured using quadrupole modulation.The naturalchromaticity and the corrected chromaticity are measured using the dipole modulationand RF modulation respect

13、ively.The measurements play important rules in the commissioning work of the HLS-Ⅱ storage ring.As a direct measure of the ring circumference,the central RF frequency is also measured using sextupole modulation.The obtai

14、nedcentral RF frequency demonstrates that the the circumference deviation from the designvalue is less than 1 mm.
　　This work is supported by National Natural Science Foundation of China (11105141,11175173) and the up