Keyword: betatron
Paper Title Other Keywords Page
MOPP031 Optimisation of the ISIS Proton Synchrotron Experimental Damping System damping, kicker, synchrotron, feedback 166
 
  • A. Pertica, D.W. Posthuma de Boer, R.E. Williamson
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  • J. Komppula
    CERN, Meyrin, Switzerland
 
  The ISIS Neutron and Muon Source, located in the UK, consists of a H linear accelerator, a rapid cycling proton synchrotron and two extraction lines delivering protons onto heavy metal targets. One of the limiting factors for achieving higher intensities in the accelerator is the head-tail instability present in the synchrotron, around 2ms after injection. In order to mitigate this instability, an experimental damping system is being developed for the ISIS synchrotron. Initial tests using a split electrode BPM as a pickup and a ferrite loaded kicker as a damper showed positive results. This paper describes the different developments made to the damping system and planned improvements to optimize its performance for use in normal operations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-MOPP031  
About • paper received ※ 04 September 2019       paper accepted ※ 09 September 2019       issue date ※ 10 November 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WECO02 Towards an Adaptive Orbit-Response-Matrix Model for Twiss-Parameter Diagnostics and Orbit Correction at Delta storage-ring, electron, feedback, software 477
 
  • S. Koetter, T. Weis
    DELTA, Dortmund, Germany
 
  At DELTA, a 1.5-GeV electron storage ring operated by the TU Dortmund University, preliminary tests of an adaptive orbit-response-matrix model were conducted. Closed orbit perturbations corrected by the slow orbit feedback can be buffered and used to update a fit of the bilinear-exponential model with dispersion (BE+d model). This model is a representation of the orbit-response matrix depending on the beta functions, the betatron phases and the tunes in both planes. This work introduces a new fitting recipe to obtain good estimates of the aforementioned quantities and evaluates a BE+d-model represented orbit-response matrix for orbit correction. Numerical studies are shown along with measurement results.  
slides icon Slides WECO02 [0.657 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WECO02  
About • paper received ※ 04 September 2019       paper accepted ※ 08 September 2019       issue date ※ 10 November 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WECO03 Tune Computation via Model Fitting to Swept Machine Response Measurement synchrotron, feedback, operation, resonance 482
 
  • M.G. Abbott, G. Rehm
    DLS, Oxfordshire, United Kingdom
 
  At Diamond Light Source we compute the horizontal and vertical tunes by fitting a simple multi-pole resonator model to the measured electron beam frequency response. The transverse (and longitudinal) tune response is measured by sweeping an excitation across the range of possible tune frequencies and synchronously measuring the IQ response. The multi-pole resonator model is a good fit to the measured behaviour, but the fitting process is surprisingly challenging. Problems include noisy measurements, very complex beam responses in the presence of increasing chromaticity, poor data when the beam is close to instability, and a number of challenges with the stability of the algorithm. The tune fitting algorithm now in use at Diamond has been developed and refined over many years. It is finally stable enough to work reliably throughout most beam operating conditions. The algorithm involves alternating peak finding and non-linear fitting, with a fairly naive mathematical approach; the main focus is on providing reliable results.  
slides icon Slides WECO03 [1.059 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WECO03  
About • paper received ※ 04 September 2019       paper accepted ※ 09 September 2019       issue date ※ 10 November 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPP030 Betatron Phase Advance Measurements Using the Gated Turn-by-turn Monitors at SuperKEKB coupling, luminosity, detector, closed-orbit 585
 
  • G. Mitsuka, K. Mori, M. Tobiyama
    KEK, Ibaraki, Japan
 
  In the SuperKEKB commissioning Phases 2 (Feb.-Jul., 2018) and 3 (from Mar. 2019), the betatron phase advances between adjacent beam position monitors have been measured using a total of 138 gated turn-by-turn monitors. A fast RF gating of the monitors enables turn-by-turn beam position detections by focusing only on an artificially-excited non-colliding bunch, while leaving colliding bunches unaffected. Betatron phase advances measured by the gated turn-by-turn monitors and accordingly obtained betatron functions were consistent with the closed orbit measurements. High signal-to-noise ratio were achieved by advanced signal extraction methods such as NAFF, SVD, and independent component analysis.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WEPP030  
About • paper received ※ 03 September 2019       paper accepted ※ 10 September 2019       issue date ※ 10 November 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPP035 Using Tune Measurement Systems Based on Diode Detectors for Quadrupolar Beam Oscillation Analysis in the Frequency Domain operation, injection, detector, pick-up 609
 
  • M. Gąsior, T.E. Levens
    CERN, Geneva, Switzerland
 
  Requirements for diagnostics of injection matching and beam space charge effects have driven studies at CERN using high sensitivity tune measurement systems based on diode detectors for the observation of quadrupolar beam oscillations in the frequency domain. This has led to an extension of such tune systems to include a channel optimised for quadrupolar oscillation measurements. This paper presents the principles of such measurements, the developed hardware and example measurements.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WEPP035  
About • paper received ※ 03 September 2019       paper accepted ※ 10 September 2019       issue date ※ 10 November 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)