Keyword: injection
Paper Title Other Keywords Page
MOOB01 Beam Commissioning of SuperKEKB Rings at Phase-2 operation, detector, feedback, MMI 6
 
  • M. Tobiyama, M. Arinaga, J.W. Flanagan, H. Fukuma, H. Ikeda, H. Ishii, S.H. Iwabuchi, G.M. Mitsuka, K. Mori, M. Tejima
    KEK, Ibaraki, Japan
  • G. Bonvicini
    Wayne State University, Detroit, Michigan, USA
  • E. Mulyani
    Sokendai, Ibaraki, Japan
  • G.S. Varner
    University of Hawaii, Honolulu,, USA
 
  The Phase 2 commissioning of SuperKEKB rings with Belle II detector began in Feb. 2018. Staring the commissioning of positron damping ring (DR), the injection and storage of the main rings (HER and LER) smoothly continued in Apr., 2018. The first collision has been achieved on 26th Apr. with the detuned optics (200 mm x 8 mm). Performance of beam instrumentation systems and the difficulties encountered during commissioning time will be shown.  
slides icon Slides MOOB01 [11.232 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-MOOB01  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPA02 Beam Diagnostics for SuperKEKB Damping Ring in Phase-II Operation radiation, timing, operation, MMI 29
 
  • H. Ikeda, M. Arinaga, J.W. Flanagan, H. Fukuma, H. Ishii, S.H. Iwabuchi, G.M. Mitsuka, K. Mori, M. Tejima, M. Tobiyama
    KEK, Ibaraki, Japan
 
  The SuperKEKB damping ring (DR) commissioning started in February 2018, before main ring (MR) Phase-II operation. We constructed the DR in order to deliver a low-emittance positron beam. The design luminosity of SuperKEKB is 40 times that of KEKB with high current and low emittance. A turn-by- turn beam position monitor (BPM), transverse feedback system, synchrotron radiation monitor (SRM), DCCT, loss monitor using ion chambers, bunch current monitor and tune meter were installed for beam diagnostics at the DR. An overview of the instrumentation and status will be presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-MOPA02  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPB14 SSRF Beam Operation Stability Evaluation Using Bunch by Bunch Beam Position Method* SRF, damping, operation, storage-ring 104
 
  • N. Zhang
    SSRF, Shanghai, People's Republic of China
  • Y.B. Leng, Y.M. Zhou
    SINAP, Shanghai, People's Republic of China
 
  Funding: * Work supported by National Natural Science Foundation of China (No.11575282 No.11375255 No.11305253)
In order to improve the efficiency and quality of light in top-up mode at SSRF, disturbance caused by leakage fields mismatch during injection should be minimized and stable. This could be evaluated by analysis of bunch by bunch residual betatron oscillation data, using this method, instability of tune distribution and damping repeatability could also be calculated. So we could evaluate the beam operation stability by the data analysis and discuss in the paper.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-MOPB14  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPB12 Machine Studies with Libera Instruments at the SLAC Spear3 Accelerators booster, brilliance, feedback, synchrotron 284
 
  • S. Condamoor, W.J. Corbett, D.J. Martin, S. C. Wallters
    SLAC, Menlo Park, California, USA
  • M. Cargnelutti, P. Leban
    I-Tech, Solkan, Slovenia
  • L.W. Lai
    SSRF, Shanghai, People's Republic of China
  • Q. Lin
    Donghua University, Shanghai, People's Republic of China
 
  Turn-by-turn BPM readout electronics were tested on the SPEAR3 booster synchrotron and storage ring to identify possible improvements for the booster injection process and to characterize processor performance in the storage ring. For this purpose, Libera Spark and Libera Brilliance+ instruments were customized for the booster (358.4 MHz) and storage ring (476.3 MHz) radio-frequencies, respectively, and tested during machine studies. Even at low single-bunch booster beam current, the dynamic range of the Libera Spark readout electronics provided excellent transverse position measurement capability during the linac-to-booster injection process, the energy ramp-up phase and during beam extraction. Booster injection efficiency was also analyzed as a function of linac S-band bunch train arrival time. In the SPEAR3 storage ring turn-by-turn Libera Brilliance+ measurement capability was evaluated for single and multi-bunch fill patterns as a function of beam current. The single-turn measurement resolution was found to be better than 10 microns for a single 3 mA bunch. The horizontal single-bunch damping time was then determined with the 238 MHz bunch-by-bunch feedback system on and off.  
poster icon Poster TUPB12 [1.531 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-TUPB12  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPC12 Beam Transverse Quadrupole Oscillation Measurement in the Injection Stage for the HLS-II Storage Ring quadrupole, storage-ring, betatron, 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.
 
poster icon Poster TUPC12 [0.467 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-TUPC12  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEOB01 New Beam Loss Detector System for EBS-ESRF SRF, detector, operation, vacuum 346
 
  • L. Torino, K.B. Scheidt
    ESRF, Grenoble, France
 
  In view of the construction and the commissioning of the new Extremely Brilliant Source (EBS) ring, a new Beam Loss Detector (BLDs) system has been developed, installed and tested in the present European Synchrotron Radiation Facility (ESRF) storage ring. The new BLD system is composed of 128 compact PMT-scintillator based BLDs, distributed evenly and symmetrically at 4 BLDs per cell, controlled and read out by 32 Libera Beam Loss Monitors (BLMs). The detectors fast response and the versatility of the read-out electronics allow to measure fast losses with an almost bunch-by-bunch resolution, as well as integrated losses useful during the machine operation. In this paper the different acquisition modes will be explained and results obtained during injection and normal operation will be presented.  
slides icon Slides WEOB01 [8.727 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-WEOB01  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPA18 Development of Longitudinal Beam Profile Diagnostics for Beam-beam Effects Study at VEPP-2000 electron, synchrotron, positron, collider 410
 
  • M.V. Timoshenko, V.M. Borin, O.I. Meshkov, Yu. A. Rogovsky, D.B. Shwartz, Yu.M. Zharinov
    BINP SB RAS, Novosibirsk, Russia
  • V.L. Dorokhov
    BINP, Novosibirsk, Russia
 
  The comprehensive development of beam longitudinal profile measurement systems based on stroboscopic optical dissector has started at VEPP-2000 electron-positron collider complex. The dissector was setted and commissioned at booster ring BEP that was deeply upgraded (2013-2015) to achieve top energy of 1 GeV. Bunch lengthening with current was studied at BEP with its new RF-cavity. In addition the method of synchrotron frequency measurement by dissector was applied. After dissector checkouts at BEP the similar studies were carried out with a single beam at VEPP-2000 storage ring in parallel with streak-camera measurements. Good agreement of results was observed. Series of single-turn longitudinal and vertical bunch profiles snapshots was made by streak-camera with respect to delay after counter beam injection. The unexpected longitudinal beam dynamics was observed for intensities above the beam-beam threshold. These studies together with beam-beam coherent oscillations spectra seen by pickups are of a great interest for understanding of flip-flop phenomenon which establish a fundamental luminosity limit at VEPP-2000 operating with round beams.  
poster icon Poster WEPA18 [2.269 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-WEPA18  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPB06 Time-Synchronous Measurements of Transient Beam Dynamics at Spear3* feedback, diagnostics, controls, experiment 441
 
  • Q. Lin, Z.H. Sun
    Donghua University, Shanghai, People's Republic of China
  • W.J. Corbett, D.J. Martin, K. Tian
    SLAC, Menlo Park, California, USA
 
  Funding: Work supported by the China Scholarship Council and the US Department of Energy Contract DE-AC03-76SF00515, Office of Basic Energy Sciences.
Multi-bunch beam instabilities can often be controlled with high-speed digital bunch-by-bunch feedback systems. The detected motion is based on charge centroid measurements that, for short bunches, cannot resolve intrabunch charge dynamics. To compliment the BxB data, we installed a fast-gated camera with a rotating mirror to sweep visible-light synchrotron radiation across the camera CCD. The SR measurements present a complimentary view of the motion. For this work we generated transient beam events in SPEAR3 using the BxB feedback system and synchronously observed the motion on the camera. Results are presented for a high-order multibunch beam instability and for single bunch drive-damp experiments.

 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-WEPB06  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPB13 Beam-Gas Imaging Measurements at LHCb detector, luminosity, experiment, vacuum 459
 
  • G.R. Coombs, M. Ferro-Luzzi, R. Matev
    CERN, Geneva, Switzerland
 
  The LHCb detector is one of the four large particle physics experiments situated around the LHC ring. The excellent spatial resolution of the experiment's vertex locator (VELO) and tracking system allows the accurate reconstruction of interactions between the LHC beam and either residual or injected gas molecules. These reconstructed beam-gas interactions gives LHCb the ability, unique among experiments, to measure the shape and the longitudinal distribution of the beams. Analysis methods were originally developed for the purpose of absolute luminosity calibration, achieving an unprecedented precision of 1.2% in Run I. They have since been extended and applied for online beam-profile monitoring that is continuously published to the LHC, for dedicated cross-calibration with other LHC beam profile monitors and for studies of the dynamic vacuum effects due to the proximity of the VELO subdetector to the beam. In this talk, we give an overview of the LHCb experience with beam-gas imaging techniques, we present recent results on the outlined topics and we summarise the developments that are being pursued for the ultimate understanding of the Run II measurements.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-WEPB13  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPC15 Machine Learning Applied to Predict Transverse Oscillation at SSRF diagnostics, SRF, network, storage-ring 512
 
  • B. Gao, J. Chen, Y.B. Leng, Y.M. Zhou
    SINAP, Shanghai, People's Republic of China
 
  A fast beam size diagnostic system has been developed at SSRF (Shanghai Synchrotron Radiation Facility) storage ring for turn-by-turn and bunch-by-bunch beam transverse oscillation study. This system is based on visible synchrotron radiation direct imaging system. Currently, this system already has good experimental results. However, this system still has some limitations, the resolution is subject to the point spread function and the speed of online data processing is limited by the complex algorithm. We present a technique that applied machine learning tools to predict transverse oscillation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-WEPC15  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THOB01 Injection Transient Study Using 6-Dimensional Bunch-by-bunch Diagnostic System at SSRF* SRF, extraction, kicker, diagnostics 542
 
  • Y.M. Zhou, Y.B. Leng, N. Zhang
    SSRF, Shanghai, People's Republic of China
  • B. Gao
    SINAP, Shanghai, People's Republic of China
 
  Beam instability often occurs in the accelerator and even causes beam loss. The beam injection transient process provides an important window for the study of beam instability. Measurement of the bunch-by-bunch dynamic parameters of the storage ring is useful for accelerator optimization. A 6-dimensional bunch-by-bunch diagnostic system has been successfully implemented at SSRF. The measurements of transverse position and size and longitudinal phase and length are all completed by the system. Button BPM is used to measure beam position, phase, and length, and the synchrotron radiation light is used to beam size measurement. Signals are sampled simultaneously by a multi-channel acquisition system with the same clock and trigger. Different data processing methods are used to extract the 6-dimensional information, where the delta-over-sum algorithm for beam position extraction, the Gaussian fitting algorithm for beam size extraction, zero-crossing detection algorithm for beam phase extraction and the two-frequency method for bunch length extraction. The system set up and performance will be discussed in more detail in this paper.  
slides icon Slides THOB01 [7.413 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-THOB01  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THOB02 Energy Loss Measurements with Streak Camera at ALBA storage-ring, simulation, synchrotron, insertion 548
 
  • A.A. Nosych, B. Bravo, U. Iriso
    ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
 
  Analyzing streak camera images of the beam injected into a Storage Ring with no RF voltage allows calculating several parameters, like the energy loss per turn and the energy mismatch between injected and stored beams. These measurements are based on the analysis of the centroid drift path of a bunch as it spirals inwards, changing its rotation period. This drift is clear and measurable in single and multi-bunch modes in several horizontal sweep speeds of the streak. With this technique we also measure the momentum compaction factor and observe its change with respect to the insertion devices' open/closed states. The obtained values are comparable with theoretical expectations, as well as with values measured by other means.  
slides icon Slides THOB02 [3.030 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2018-THOB02  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)