Keyword: betatron
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MOPB08 Evaluation of the Transverse Impedanse of Pf in-Vacuum Undulator Using Local Orbit Bump Method factory, undulator, impedance, simulation 89
 
  • O. Tanaka, M. Adachi, K. Harada, R. Kato, N. Nakamura, T. Obina, R. Takai, Y. Tanimoto, K. Tsuchiya, N. Yamamoto
    KEK, Ibaraki, Japan
 
  When a beam passes through insertion devices (IDs) with narrow gap or beam ducts with small aperture, it receives a transverse kick from the impedances of those devices. This transverse kick depends on the beam trans-verse position and beam parameters such as the bunch length and the total bunch charge. In the orbit bump method, the transverse kick factor of an ID is estimated through the closed orbit distortion (COD) measurement at many BPMs for various beam currents [1]. In the present study, we created an orbit bump of 1 mm using four steering magnets, and then measured the COD for two cases: when the gap is opened (the gap size is 42 mm) and when the gap is closed (the gap size is 3.83 mm). The ID's kick factors obtain by these measurements are compared with those obtain by simulations and analytical evaluations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-MOPB08  
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MOPB09 Comparison Among Different Tune Measurement Schemes at HLS-II Storage Ring storage-ring, pick-up, detector, experiment 93
 
  • L.T. Huang, X.Y. Liu, P. Lu, M.-X. Qian, B.G. Sun, J.G. Wang, J.H. Wei, F.F. Wu, Y.L. Yang, T.Y. Zhou
    USTC/NSRL, Hefei, Anhui, People's Republic of China
 
  Tune measurement is one of the most significant beam diagnostics at HLS-II storage ring. When measuring tune, higher tune spectral component and lower other compo-nents are expected, so that the tune measurement will be more accurate. To this end, a set of BBQ (Base Band Tune) front-end based on 3D (Direct Diode Detection) technique has previously developed to improve the effec-tive signal content and suppress other components. Em-ploying the BBQ front-end, four different tune measure-ment schemes are designed and related experiments per-formed on the HLS-II storage ring. Experimental results and analysis will be presented later.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-MOPB09  
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TUOB02 Optics Measurements in Storage Rings: Simultaneous 3-Dimensional Beam Excitation and Novel Harmonic Analysis optics, dipole, synchrotron, coupling 177
 
  • L. Malina, J.M. Coello de Portugal, J. Dilly, P.K. Skowroński, R. Tomás
    CERN, Geneva, Switzerland
 
  Optics measurements in storage rings employ turn-by-turn data of transversely excited beams. Chromatic parameters need measurements to be repeated at different beam energies, which is time-consuming. We present an optics measurement method based on adiabatic simultaneous 3-dimensional beam excitation, where no repetition at different energies is needed. In the LHC, the method has been successfully demonstrated utilising AC-dipoles combined with RF frequency modulation. It allows measuring the linear optics parameters and chromatic properties at the same time without resolution deterioration. We also present a new accurate harmonic analysis algorithm that exploits the noise cleaning based on singular value decomposition to compress the input data. In the LHC, this sped up harmonic analysis by a factor up to 300. These methods are becoming a "push the button" operational tool to measure the optics.  
slides icon Slides TUOB02 [1.117 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-TUOB02  
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TUPC09 Initial Results from the LHC Multi-Band Instability Monitor detector, operation, synchrotron, electron 314
 
  • T.E. Levens, T. Lefèvre, D. Valuch
    CERN, Geneva, Switzerland
 
  Intra-bunch transverse instabilities are routinely measured in the LHC using a "Head-Tail Monitor" based on sampling a wide-band BPM with a high-speed digitiser. However, these measurements are limited by the dynamic range and short record length possible with typical commercial oscilloscopes. This paper will present the initial results from the LHC Multi-Band Instability Monitor, a new technique developed to provide information on the beam stability with a high dynamic range using frequency domain analysis of the transverse beam spectrum.  
poster icon Poster TUPC09 [17.388 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-TUPC09  
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TUPC12 Beam Transverse Quadrupole Oscillation Measurement in the Injection Stage for the HLS-II Storage Ring quadrupole, storage-ring, injection, electron 325
 
  • F.F. Wu, F.L. Gao, L.T. Huang, X.Y. Liu, P. Lu, B.G. Sun, J.G. Wang, J.H. Wei, T.Y. Zhou
    USTC/NSRL, Hefei, Anhui, People's Republic of China
 
  Funding: Supported by the National Science Foundation of China (Grant No. 11705203, 11575181, 11605202) and the National Key Research and Development Program of China(No. 2016YFA0402000)
Beam transverse quadrupole oscillation can be excited in the injection stage if injected beam parameters(twiss parameters or dispersion) are not matched with the parameters in the injection point of the storage ring. In order to measure the beam transverse quadrupole oscillation in the injection stage for the HLS-II storage ring, some axially symmetric stripline BPMs were designed. Transverse quadrupole component for these BPMs was simulated and off-line calibrated. Beam transverse quadrupole oscillation has been measured when beam was injected into the HLS-II electron storage ring. The spectrum of the transverse quadrupole component showed that beam transverse quadrupole oscillation is very obvious in the injection stage and this oscillation isn't the second harmonic of beam betatron oscillation. The relationship between transverse quadrupole oscillation and beam current was also analyzed and the result shows that the relationship is not linear.
 
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DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-TUPC12  
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WEPC02 Synchrotron Emittance Analysis Procedure at MedAustron emittance, synchrotron, MMI, simulation 490
 
  • L. Adler, A. De Franco, F. Farinon, N. Gambino, G. Guidoboni, C. Kurfürst, S. Myalski, M.T.F. Pivi, C. Schmitzer, I. Strašík, A. Wastl
    EBG MedAustron, Wr. Neustadt, Austria
 
  MedAustron is a synchrotron based medical accelerator facility for particle therapy providing protons and carbon ions with clinical energies from 60 MeV to 250 MeV and 120 MeV/n to 400 MeV/n respectively. The facility features four irradiation rooms, three of which are dedicated to clinical operation and a fourth one to non-clinical research. Commissioning of all fixed lines has been completed for protons, while the commissioning for carbon ions and a proton gantry is ongoing. For the commissioning of carbon ions, precise measurements of the transverse beam emittance in the synchrotron are of importance, to minimize beam losses and to correct for possible emittance variations due to the different clinically relevant beam intensities defined by a degrader at the end of the Linac. The transverse beam emittance in the MedAustron synchrotron is measured via scraping at non-dispersive regions of the ring. The analysis procedure as well as emittance reconstruction accuracy for simulated data will be described in this paper, together with measurement results from the carbon commissioning.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-WEPC02  
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