DIPAC2011 - List of Keywords (injection)

Paper	Title	Other Keywords	Page
MOPD06	Capabilities and Performance of the LHC Schottky Monitors	pick-up, emittance, impedance, proton	44
	M. Favier, T.B. Bogey, F. Caspers, O.R. Jones CERN, Geneva, Switzerland J. Cai, E.S.M. McCrory, R.J. Pasquinelli Fermilab, Batavia, USA A. Jansson ESS, Lund, Sweden
	The LHC Schottky system has been under commissioning since summer 2010. This non destructive observation relies on a slotted waveguide structure resonating at 4.8GHz. Four monitors, one for each plane of the two counter-rotating LHC beams, are used to measure the transverse Schottky sidebands Electronic gating allows selective bunch-by-bunch measurements, while a triple down-mixing scheme combined with heavy filtering gives an instantaneous dynamic range of over 100dB within a 20kHz bandwidth. Observations of both proton and lead ion Schottky spectra will be discussed along with a comparison of predicted and measured performance.
	Poster MOPD06 [3.484 MB]

MOPD07	Newly Installed Beam Diagnostics at the Australian Synchrotron	booster, synchrotron, diagnostics, linac	47
	E.D. van Garderen, M.J. Boland, G. LeBlanc, B. Mountford, A. Rhyder, A. C. Starritt, A. Walsh, K. Zingre ASCo, Clayton, Victoria, Australia
	The Australian Synchrotron (AS) is aiming at implementing Top-Up operations in 2012. To reduce costs only one of the two klystrons in the linac will be used. The electron beam in the linac will only be accelerated to 80 MeV, instead of 100 MeV achieved currently. The injection system will need to be recommissioned. The beam position monitors in the booster have been upgraded and YAG:Ce screens have been added to the booster-to-storage ring (BTS) transfer line. In addition the injection efficiency will be optimized and monitored. For this purpose another Fast Current Transformer has also been installed at the end of the BTS.

MOPD11	High Resolution BPM Upgrade for the ATF Damping Ring at KEK	damping, closed-orbit, controls, diagnostics	59
	N. Eddy, C.I. Briegel, B.J. Fellenz, E. Gianfelice-Wendt, P.S. Prieto, R. Rechenmacher, A. Semenov, D.C. Voy, M. Wendt, D.H. Zhang Fermilab, Batavia, USA N. Terunuma, J. Urakawa KEK, Ibaraki, Japan
	Funding: Work is supported by the joint high energy physics research program of Japan-USA, and by FNAL, operated by Fermi Research Alliance LLC under contract #DE-AC02-07CH11359 with the US Dept. of Energy. A beam position monitor (BPM) upgrade at the KEK Accelerator Test Facility (ATF) damping ring has been accomplished, carried out by a KEK/FNAL/SLAC collaboration under the umbrella of the global ILC R&D effort. The upgrade consists of a high resolution, high reproducibility read-out system, based on analog and digital down-conversion techniques, digital signal processing, and also implements a new automatic gain error correction schema. The technical concept and realization as well as results of beam studies are presented.

MOPD23	Photon BPM Electronics Development at Taiwan Light Source	photon, feedback, controls, diagnostics	95
	P.C. Chiu, J. Chen, Y.K. Chen, K.T. Hsu, K.H. Hu, C.H. Kuo NSRRC, Hsinchu, Taiwan
	Photon BPMs are very useful for photon beam position and stability observation. There are several kinds of photon BPMs and electronics with different design installed at beamline front-ends at the Taiwan Light Source. To provide a better integration and efficient usage of the photon BPM, a commercial BPM electronics - Libera Photon was chosen for an integral solution and has showed at least one micron performance for several months of testing. In this report, the installation process and testing results of the photon BPM will be presented.
	Poster MOPD23 [0.595 MB]

MOPD24	A High-resolution Diode-based Orbit Measurement System – Prototype Results from the LHC	feedback, pick-up, vacuum, coupling	98
	M. Gasior, J. Olexa, R.J. Steinhagen CERN, Geneva, Switzerland
	The prototype of a high resolution beam position monitor (BPM) electronics based on diode peak detectors was tested with LHC beams. In this technique developed at CERN the short beam pulses from each BPM electrode are converted into slowly varying signals by compensated diode peak detectors. The slow signals can be digitised with a laboratory voltmeter or high resolution ADC. As presented in the paper, this technique allows resolutions in the order of 1 ppm of the BPM aperture to be achieved with a measurement rate in the Hz range. Ongoing developments and future prospects for the technique are also discussed.
	Poster MOPD24 [2.055 MB]

MOPD44	Self Testing Functionality of the LHC BLM System	high-voltage, monitoring, collider, diagnostics	152
	J. Emery, B. Dehning, E. Effinger, A. Nordt, C. Zamantzas CERN, Geneva, Switzerland
	Reliability concerns have driven the design of the LHC BLM system throughout its development, from the early conceptual stage right through the commissioning phase and up to the latest development of diagnostic tools. To protect the system against non-conformities, new ways of automatic checking have been developed and implemented. These checks are regularly and systematically executed by the LHC operation team to insure that the system status after each test is "as good as new". This checks the electrical part of the detectors (ionisation chamber or secondary emission monitor), their cable connections to the front-end electronics, the connections to the back-end electronics and their ability to request a beam abort. During the installation and in the early commissioning phase, these checks proved invaluable in finding non-conformities caused by unexpected failures. This paper will describe these checks in detail, commenting on the latest performance and the typical non-conformities detected. A statistical analysis of the LHC BLM system will also be presented to show the evolution of the various system parameters.
	Poster MOPD44 [2.068 MB]

MOPD59	A New Fast Acquisition Profile for the LHC and the SPS	radiation, optics, betatron, alignment	182
	S. Burger, A. Boccardi, E. Bravin, A. Rabiller, R.S. Sautier CERN, Geneva, Switzerland
	The beam profile is an important parameter for the tuning of particle accelerators. These profiles are often obtained by imaging optical transition radiation from a radiator on a CCD camera. This technique works well for slow acquisitions, but in some cases it is necessary to acquire profiles with higher rates where such standard cameras are no longer suitable. In our case the aim is to sample the profiles on a turn-by-turn basis which, for the CERN-SPS, corresponds to ~44 kHz. For this reason we have developed a fast detector based on a recent Hamamatsu linear CCD and an optical system using cylindrical lenses. The readout electronics is based on CERN developed, radiation tolerant components and the digital data is transmitted to an acquisition board outside of the tunnel by mean of optical fibres. This contribution describes the system and shows the performance obtained on a test bench.

MOPD62	Storage Ring Injector Diagnostics using Synchrotron Radiation	emittance, diagnostics, radiation, booster	191
	A.F.D. Morgan, C.A. Thomas Diamond, Oxfordshire, United Kingdom R. Bartolini JAI, Oxford, United Kingdom
	The state of the Diamond injector can be passively monitored using beam profile measurements of synchrotron radiation from bending magnets. This provides us with information on the characteristics of the beam injected into the storage ring. Using a numerical fit we are able to retrieve key parameters like beam position, size and tilt angle from every shot. This enables us to gather longer term trends to monitor for any changes during top-up operation in order to better understand any variability of the injector. We present here the study and the analysis performed with this diagnostic with the results from several months of operation.
	Poster MOPD62 [0.451 MB]

MOPD64	High Quality Measurements of Beam Lifetime, Instant-Partial-Beam Losses and Charge-Accumulation with the New ESRF BPM System	cavity, beam-losses, storage-ring, controls	194
	K.B. Scheidt, F. Ewald, B. Joly ESRF, Grenoble, France
	The BPM system of the ESRF Storage Ring, that was entirely replaced by 224 units of the Libera-Brilliance system in 2009, is now also being used for precise and fast measurements of the Beam Lifetime and so-called Instant-Partial-BeamLosses. This is possible by the use of the Sum signal of the four BPM buttons on each of the 224 BPM stations in the Ring. This paper will describe the strong advantages in terms of response time, but also the precautions and the limitations of this particular use. Results will show the ultimate attainable performances and a detailed comparison with that of three independent DC current transformers also installed in the Ring. The same Sum signal is also usable for precise measurement of Accumulated Charge during the injection process and results of this will also be presented.

MOPD68	Pickup Beam Measurement System at the VEPP-2000 Collider	collider, betatron, controls, positron	203
	Yu. A. Rogovsky, E.A. Bekhtenev BINP SB RAS, Novosibirsk, Russia
	This paper reviews the present state of electromagnetic beam position monitors (pickups) at VEPP-2000 collider. It includes descriptions of position monitors, typical interfaces for these monitors and their system characteristics (resolution, stability, bandwidth and problems or limitations) are discussed. The paper also reviews several types of diagnostic measurements using beam position monitors which are useful in improving accelerator operations.
	Poster MOPD68 [0.398 MB]

MOPD69	Tune Measurements with High Intensity Beams at SIS-18	acceleration, monitoring, emittance, diagnostics	206
	R. Singh, P. Forck, W. Kaufmann, P. Kowina GSI, Darmstadt, Germany R. Singh TEMF, TU Darmstadt, Darmstadt, Germany
	Funding: This work is supported by DITANET (novel DIagnostic Techniques for future particle Accelerators: A Marie Curie Initial Training NETwork), Project Number ITN-2008-215080 To achieve high current operation close to the space charge limit in a synchrotron, a precise tune measurement during a full accelerating cycle is required. A tune measurement system that was recently commissioned at GSI synchrotron SIS-18 allows for online evaluation of the actual tune. This system consists of three distinct parts; an exciter which provides power to excite coherent betatron oscillations of the beam. The BPM signals thus induced are digitized by fast ADCs at 125 MSa/s and then the post processing electronics integrates the data bunch by bunch to obtain one position value per bunch. Subsequently base band tune is determined by Fourier transformation of the position data. The tune variation during acceleration for various beam conditions was measured using this system and is discussed. A detailed investigation of the incoherent tune shift was conducted with Uranium ion beams at the injection energy of 11.6 MeV/u. The results show the influence of beam current on the tune spectrum. In addition, the effects of the measurement method on the beam emittance and beam losses are discussed.

MOPD73	Study of Beam Size Blowup due to Transverse Bunch Feedback Noise on e⁺e⁻ Collider	luminosity, feedback, simulation, beam-beam-effects	212
	M. Tobiyama, K. Ohmi KEK, Ibaraki, Japan
	Vertical beam size blowup with the gain of the transverse bunch feedback systems has been observed in KEKB B-factory rings. With the numerical simulation, large beam-beam effect enhances small oscillation induced by the broadband noise of the bunch feedback kick. To examine the simulation, beam response, effective beam size and the luminosity change with artificial external noise injected in the transverse feedback system have beem measuredn in KEKB LER ring during collision. The result has been compaired with the simulation including beam-beam effect and showed good agreement.
	Poster MOPD73 [0.296 MB]

MOPD76	The Petra III Fast Orbit Feedback System	feedback, instrumentation, controls, brilliance	221
	J. Klute, K. Balewski, H.T. Duhme, H. Tiessen, F. Wierzcholek DESY, Hamburg, Germany
	Orbit stability is a crucial and import issue of 3rd generation light sources. Ambient mechanical and electrical noise cause rather large orbit distortions which have to be counteracted by an orbit feedback. Extensive studies of the orbit distortions in PETRA III have shown that the frequencies of the ambient noise lie within a frequency range from about 0.01Hz to 100Hz. In this paper we describe the main components, their properties and the layout of PETRA III’s orbit feedback. Furthermore experimental results on short and long term stability will be presented. It will be shown that the required orbit stability of ±0.5 μm in the vertical plane can be maintained over 50 h.

MOPD79	An FPGA-based Turn-by-Turn Beam Position Monitoring System for Studying Multiple Bunch Beams in the ATF Damping Ring	extraction, damping, feedback, synchrotron	230
	G.B. Christian, D.R. Bett, B. Constance, M.R. Davis JAI, Oxford, United Kingdom R. Apsimon, P. Burrows, A. Gerbershagen, C. Perry Oxford University, Physics Department, Oxford, Oxon, United Kingdom J. Resta-López IFIC, Valencia, Spain
	Instabilities associated with beam-size blow-up have previously been observed with multi-bunch beam in the damping ring (DR) of the KEK Accelerator Test Facility (ATF). A system has been developed to monitor such instabilities, utilising an ATF stripline beam position monitor (BPM) in the DR, and BPM processor hardware designed for the FONT upstream feedback system in the ATF extraction line. The system is designed to record the horizontal and/or vertical positions of up to three bunches in the DR in single-bunch multi-train mode or the head bunch of up to three trains in multi-bunch mode, with a bunch spacing of 5.6 ns. The FPGA firmware and data acquisition software were modified to record turn-by-turn data for up to six channels and 1–3 bunches in the DR. The maximum memory configuration on the FPGA allows 131071 bunch-turn-channels of data to be recorded from a particular machine pulse, and the system has the capability to select only certain turns at a regular interval in which to record data, in order to zoom out and cover the entire period of the damping cycle at the ATF. An overview of the system and initial results will be presented.

MOPD87	The LHC Beam Presence Flag System	controls, impedance, monitoring, feedback	251
	M. Gasior, T.B. Bogey CERN, Geneva, Switzerland
	Before injecting any high intensity bunches into the LHC a circulating low intensity pilot bunch must be present to confirm the correct settings of the main machine parameters. For the 2010 LHC run the detection of this pilot beam was done with the beam current transformer system. To increase redundancy of this important safety function a dedicated beam presence flag system was designed, built and tested with beam to be used operationally in the 2011 run. In this system signals from four electrodes of a beam position monitor (BPM) are processed with separate channels, resulting in a quadruple system redundancy for either beam. Each system channel consists of an analogue front-end converting the BPM signals into two logic states, which are then transmitted optically to the machine protection and interlock systems. For safety reasons the system does not have any remote control or adjustable elements and its only inputs are the beam signals. This paper describes the new LHC beam presence flag system, in particular the analogue front-end based on diode peak detectors.
	Poster MOPD87 [8.200 MB]

MOPD88	Electron Beam Ion Sources, Ion Optical Elements and Beam Diagnostics for Particle Accelerators	ion, emittance, electron, ion-source	254
	F. Ullmann, V.P. Ovsyannikov, M. Schmidt DREEBIT GmbH, Dresden, Germany G. Zschornack Technische Universität Dresden, Institut für Angewandte Physik, Dresden, Germany
	Electron Beam Ion Sources (EBISs) provide highly charged ions (HCIs) for a variety of investigations and applications, amongst others as injection source for particle accelerators. EBISs feature a lot of advantages which qualify them for accelerator injection, and which partly compensate their comparatively low number of particles. DREEBIT GmbH provides a family of compact EBISs based on permanent magnets. A more sophisticated version is based on cryogen-free superconducting magnets providing a higher ion output. Its compact design makes them transportable, low in operational costs, and guarantee easy handling. We present latest improvements and measurements proving the feasibility of producing beams of HCIs with convenient beam properties such as low transversal and longitudinal emittance. In addition we present a variety of ion optical elements and ion beam diagnostics. The DREEBIT Wien filter allows for the charge mass separation. The DREEBIT Pepper-pot Emittance Meter allows for emittance measurements of beams of a wide range of particle intensity. Other beam diagnostics are provided, such as Beam Imaging System, Retarding Field Analyzer and different kinds of Faraday cups.

TUOA02	Diagnostics during the ALBA Storage Ring Commissioning	diagnostics, synchrotron, kicker, storage-ring	280
	U. Iriso, M. Alvarez, F.F.B. Fernandez, A. Olmos, F. Pérez CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
	The ALBA Storage Ring is a 3GeV 3rd Generation Synchrotron Light Source whose 1st phase commissioning took place in Spring 2011. The machine is equipped with 123 BPMs, striplines, several fluorescent screens, FCT and DCCT, 128 BLMs, and two front ends strictly used for electron beam diagnostics (pinhole and streak camera). This paper presents an overview of the Diagnostics elements installed in the machine and our experience during the commissioning.
	Slides TUOA02 [5.476 MB]

TUPD03	Beam Profile Measurement during Top-up Injection with a Pulsed Sextupole Magnet	kicker, simulation, quadrupole, dipole	305
	R. Takai, K. Harada, T. Honda, Y. Kobayashi, S. Nagahashi, N. Nakamura, T. Obina, A. Ueda KEK, Ibaraki, Japan H. Takaki ISSP/SRL, Chiba, Japan
	A beam injection scheme using a pulsed multipole magnet is suitable for the top-up injection because a disturbance to the stored beam is much smaller than that of the conventional scheme using several kicker magnets. At the Photon Factory storage ring, the top-up injection with a pulsed sextupole magnet (PSM) has been used for the user operation since January 2011. In order to ascertain the effect of the PSM injection, we measured turn-by-turn stored beam profiles following the injection kick by using a fast-gated camera. As a result, it was demonstrated that the PSM injection dramatically decreases not only the coherent dipole oscillation but also the beam profile modulation, as expected from the beam tracking simulation.

TUPD12	The LHC Beam Position System: Performance during 2010 and Outlook for 2011	pick-up, feedback, closed-orbit, vacuum	323
	E. Calvo Giraldo, J.L. Gonzalez, L.K. Jensen, O.R. Jones, T. Lefèvre, J.-J. Savioz, R.J. Steinhagen, J. Wenninger CERN, Geneva, Switzerland
	This paper presents the performance of the LHC Beam Position System during 2010. The system proved to meet most specifications, was highly reliable and continuously provided 25Hz real-time orbit data with micron level resolution to the automatic global orbit feedback system. However, several issues were observed and they will be discussed in detail, such as the dependence on bunch intensity and the effect of surface electronics temperature variations on the measured position.

TUPD19	Initial Tests of New Electron and Photon Beam Position Monitor Electronics at the Advanced Photon Source	photon, brilliance, electron, controls	344
	P. Leban I-Tech, Solkan, Slovenia G. Decker ANL, Argonne, USA
	Funding: Use of the APS, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by ANL, was supported by the U.S. DOE under Contract No. DE-AC02-06CH11357 Measurements were done at the Advanced Photon Source (APS) with Libera Brilliance+, connected to the small-aperture insertion device vacuum chamber pickup electrodes near the beamline 35-ID source point. A photoemission-based photon beam position monitor located 16.35 meters downstream of the center of the ID straight section was also monitored using Libera Photon electronics in horizontal/vertical configuration. Top-up injection transients were recorded simultaneously on both units, providing details about the electron and photon beam motions before, during, and after injection in the storage ring and beamline front end. FFT spectra from the APS-developed BSP-100 broadband BPM data acquisition electronics were compared with the Libera instruments. This article discusses the calibration procedure for electron and photon beam position monitors along with results of these measurements.

TUPD30	Bunch Length Measurement using Coherent Cherenkov Radiation	electron, laser, gun, linac	368
	K. Kan, T. Kondoh, T. Kozawa, K. Norizawa, A. Ogata, J. Yang, Y. Yoshida ISIR, Osaka, Japan
	Ultra-short electron bunches on the order of 100 fs or less can be used in the study of ultrafast reactions and phenomena in time-resolved pump-probe experiments involving the application of techniques such as pulse radiolysis. Such electron bunches are also useful for electro-magnetic (EM) radiation production, where the frequency of EM radiation depends on the electron bunch length. In this presentation, Coherent Cherenkov Radiation (CCR), which is a method of THz radiation emitted from relativistic electron bunches, was studied for a diagnostic of electron bunch length. A picosecond electron bunch generated by a photocahode radio frequency (RF) gun was used. CCR can emit narrow-band THz wave with a dielectric-lined waveguide structure. The intensity and frequency of CCR were measured by a Michelson interferometer and a 4.2K liquid-He cooled bolometer.

TUPD40	Analysis of the Post-mortem Events at the TLS	SRF, diagnostics, power-supply, dipole	392
	K.H. Hu, Y.-T. Chang, J. Chen, P.C. Chiu, K.T. Hsu, C.H. Kuo, Y.-H. Lin, Y.R. Pan NSRRC, Hsinchu, Taiwan
	Analyzing the reasons of various trip events are basis to improve reliability of a accelerator system. Understand the mechanisms caused trip of the machine will be very helpful to decide what the adequate measures to improve availability. To identify the causes of trips at Taiwan Light Source (TLS), various diagnostics tool were employed. These diagnostic tools can capture beam trips, interlock signals of superconducting RF system, quench and interlock signals of the superconducting insertion device, waveform of the injection kickers, and instability signals of the stored beam for post-mortem analysis. Various functionalities of trip diagnostic are supported. Available tools and experiences will be summarized in this report.

TUPD67	Injection Efficiency Diagnostic at TLS Storage Ring	storage-ring, booster, diagnostics, septum	461
	P.C. Chiu, J. Chen, Y.K. Chen, K.T. Hsu, K.H. Hu, C.H. Kuo NSRRC, Hsinchu, Taiwan
	TLS is now running at 360 mA top-up mode. In the normal situation, it takes few minutes for injection from zero current to 360 mA. When the working point is drifted too much at machine start, however, injection efficiency become worsen and it is necessary to adjust some machine parameters such as quadrupole strength, transport line correctors or booster dipole to improve efficiency. The current reading at 10 Hz time resolution which is the same with injection cycle seems too rough to estimate efficiency therefore a new diagnostic tool based on BPM sum reading is developed to provide 10 kHz waveform display every second. Operators could utilize it to estimate efficiency more precise, quickly and easier.
	Poster TUPD67 [0.842 MB]

TUPD74	The Bunch by Bunch Feedback System in J-PARC Main Ring	feedback, kicker, proton, acceleration	482
	Y. Kurimoto, Y.H. Chin, T. Obina, M. Tobiyama, T. Toyama KEK, Ibaraki, Japan Y. Shobuda JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	We report the current status of the bunch by bunch feedback system for the J-PARC Main Ring. The J-PARC Main Ring is the synchrotron accelerating protons from 3 GeV to 30 GeV. It is normally operating at the intensity of 135 kW. The bunch by bunch feedback system have been developed and used for the normal operation of J-PARC Main Ring. The system aims to reduce the coherent transverse oscillation due to the instabilities or injection errors. It consists of a beam position monitor, a stripline kicker and a signal processing electronics. We've observed the injection error leading to the head-tail oscillation and succeed in damping such kind of oscillations and reducing the beam loss significantly.
	Poster TUPD74 [1.107 MB]

WEOD02	LHC Beam Diagnostics - the Users Point of View	luminosity, proton, ion, instrumentation	580
	J. Wenninger CERN, Geneva, Switzerland
	The LHC started up with beam in November 2009, and within less then on year its luminosity reached 2·10³² cm^-2s⁻¹ at 3.5 TeV in October 2010. A few weeks later, in November 2010, lead ion collisions were established within little over 2 days. The fast progress and successes of the LHC commissioning and early operation would not have been possible without the excellent performance of its beam instrumentation. All essential instruments worked from the first day or were commissioned in a very short time, providing rapid diagnostics for the beam parameters. Tune and orbit feedbacks that rely on high quality measurements were used early on to achieve smooth operation with minimal beam losses. This presentation will address the performance of the LHC beam instrumentation, in particular the very large beam position and beam loss monitoring systems, both composed of many thousand channels. Present limitations and future improvements will also be discussed.
	Slides WEOD02 [11.950 MB]

Paper

Title

Other Keywords

Page

MOPD06

Capabilities and Performance of the LHC Schottky Monitors

pick-up, emittance, impedance, proton

44

M. Favier, T.B. Bogey, F. Caspers, O.R. Jones
CERN, Geneva, Switzerland
J. Cai, E.S.M. McCrory, R.J. Pasquinelli
Fermilab, Batavia, USA
A. Jansson
ESS, Lund, Sweden

The LHC Schottky system has been under commissioning since summer 2010. This non destructive observation relies on a slotted waveguide structure resonating at 4.8GHz. Four monitors, one for each plane of the two counter-rotating LHC beams, are used to measure the transverse Schottky sidebands Electronic gating allows selective bunch-by-bunch measurements, while a triple down-mixing scheme combined with heavy filtering gives an instantaneous dynamic range of over 100dB within a 20kHz bandwidth. Observations of both proton and lead ion Schottky spectra will be discussed along with a comparison of predicted and measured performance.

Poster MOPD06 [3.484 MB]

MOPD07

Newly Installed Beam Diagnostics at the Australian Synchrotron

booster, synchrotron, diagnostics, linac

47

E.D. van Garderen, M.J. Boland, G. LeBlanc, B. Mountford, A. Rhyder, A. C. Starritt, A. Walsh, K. Zingre
ASCo, Clayton, Victoria, Australia

The Australian Synchrotron (AS) is aiming at implementing Top-Up operations in 2012. To reduce costs only one of the two klystrons in the linac will be used. The electron beam in the linac will only be accelerated to 80 MeV, instead of 100 MeV achieved currently. The injection system will need to be recommissioned. The beam position monitors in the booster have been upgraded and YAG:Ce screens have been added to the booster-to-storage ring (BTS) transfer line. In addition the injection efficiency will be optimized and monitored. For this purpose another Fast Current Transformer has also been installed at the end of the BTS.

MOPD11

High Resolution BPM Upgrade for the ATF Damping Ring at KEK

damping, closed-orbit, controls, diagnostics

59

N. Eddy, C.I. Briegel, B.J. Fellenz, E. Gianfelice-Wendt, P.S. Prieto, R. Rechenmacher, A. Semenov, D.C. Voy, M. Wendt, D.H. Zhang
Fermilab, Batavia, USA
N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan

Funding: Work is supported by the joint high energy physics research program of Japan-USA, and by FNAL, operated by Fermi Research Alliance LLC under contract #DE-AC02-07CH11359 with the US Dept. of Energy.
A beam position monitor (BPM) upgrade at the KEK Accelerator Test Facility (ATF) damping ring has been accomplished, carried out by a KEK/FNAL/SLAC collaboration under the umbrella of the global ILC R&D effort. The upgrade consists of a high resolution, high reproducibility read-out system, based on analog and digital down-conversion techniques, digital signal processing, and also implements a new automatic gain error correction schema. The technical concept and realization as well as results of beam studies are presented.

MOPD23

Photon BPM Electronics Development at Taiwan Light Source

photon, feedback, controls, diagnostics

95

P.C. Chiu, J. Chen, Y.K. Chen, K.T. Hsu, K.H. Hu, C.H. Kuo
NSRRC, Hsinchu, Taiwan

Photon BPMs are very useful for photon beam position and stability observation. There are several kinds of photon BPMs and electronics with different design installed at beamline front-ends at the Taiwan Light Source. To provide a better integration and efficient usage of the photon BPM, a commercial BPM electronics - Libera Photon was chosen for an integral solution and has showed at least one micron performance for several months of testing. In this report, the installation process and testing results of the photon BPM will be presented.

Poster MOPD23 [0.595 MB]

MOPD24

A High-resolution Diode-based Orbit Measurement System – Prototype Results from the LHC

feedback, pick-up, vacuum, coupling

98

M. Gasior, J. Olexa, R.J. Steinhagen
CERN, Geneva, Switzerland

The prototype of a high resolution beam position monitor (BPM) electronics based on diode peak detectors was tested with LHC beams. In this technique developed at CERN the short beam pulses from each BPM electrode are converted into slowly varying signals by compensated diode peak detectors. The slow signals can be digitised with a laboratory voltmeter or high resolution ADC. As presented in the paper, this technique allows resolutions in the order of 1 ppm of the BPM aperture to be achieved with a measurement rate in the Hz range. Ongoing developments and future prospects for the technique are also discussed.

Poster MOPD24 [2.055 MB]

MOPD44

Self Testing Functionality of the LHC BLM System

high-voltage, monitoring, collider, diagnostics

152

J. Emery, B. Dehning, E. Effinger, A. Nordt, C. Zamantzas
CERN, Geneva, Switzerland

Reliability concerns have driven the design of the LHC BLM system throughout its development, from the early conceptual stage right through the commissioning phase and up to the latest development of diagnostic tools. To protect the system against non-conformities, new ways of automatic checking have been developed and implemented. These checks are regularly and systematically executed by the LHC operation team to insure that the system status after each test is "as good as new". This checks the electrical part of the detectors (ionisation chamber or secondary emission monitor), their cable connections to the front-end electronics, the connections to the back-end electronics and their ability to request a beam abort. During the installation and in the early commissioning phase, these checks proved invaluable in finding non-conformities caused by unexpected failures. This paper will describe these checks in detail, commenting on the latest performance and the typical non-conformities detected. A statistical analysis of the LHC BLM system will also be presented to show the evolution of the various system parameters.

Poster MOPD44 [2.068 MB]

MOPD59

A New Fast Acquisition Profile for the LHC and the SPS

radiation, optics, betatron, alignment

182

S. Burger, A. Boccardi, E. Bravin, A. Rabiller, R.S. Sautier
CERN, Geneva, Switzerland

The beam profile is an important parameter for the tuning of particle accelerators. These profiles are often obtained by imaging optical transition radiation from a radiator on a CCD camera. This technique works well for slow acquisitions, but in some cases it is necessary to acquire profiles with higher rates where such standard cameras are no longer suitable. In our case the aim is to sample the profiles on a turn-by-turn basis which, for the CERN-SPS, corresponds to ~44 kHz. For this reason we have developed a fast detector based on a recent Hamamatsu linear CCD and an optical system using cylindrical lenses. The readout electronics is based on CERN developed, radiation tolerant components and the digital data is transmitted to an acquisition board outside of the tunnel by mean of optical fibres. This contribution describes the system and shows the performance obtained on a test bench.

MOPD62

Storage Ring Injector Diagnostics using Synchrotron Radiation

emittance, diagnostics, radiation, booster

191

A.F.D. Morgan, C.A. Thomas
Diamond, Oxfordshire, United Kingdom
R. Bartolini
JAI, Oxford, United Kingdom

The state of the Diamond injector can be passively monitored using beam profile measurements of synchrotron radiation from bending magnets. This provides us with information on the characteristics of the beam injected into the storage ring. Using a numerical fit we are able to retrieve key parameters like beam position, size and tilt angle from every shot. This enables us to gather longer term trends to monitor for any changes during top-up operation in order to better understand any variability of the injector. We present here the study and the analysis performed with this diagnostic with the results from several months of operation.

Poster MOPD62 [0.451 MB]

MOPD64

High Quality Measurements of Beam Lifetime, Instant-Partial-Beam Losses and Charge-Accumulation with the New ESRF BPM System

cavity, beam-losses, storage-ring, controls

194

K.B. Scheidt, F. Ewald, B. Joly
ESRF, Grenoble, France

The BPM system of the ESRF Storage Ring, that was entirely replaced by 224 units of the Libera-Brilliance system in 2009, is now also being used for precise and fast measurements of the Beam Lifetime and so-called Instant-Partial-BeamLosses. This is possible by the use of the Sum signal of the four BPM buttons on each of the 224 BPM stations in the Ring. This paper will describe the strong advantages in terms of response time, but also the precautions and the limitations of this particular use. Results will show the ultimate attainable performances and a detailed comparison with that of three independent DC current transformers also installed in the Ring. The same Sum signal is also usable for precise measurement of Accumulated Charge during the injection process and results of this will also be presented.

MOPD68

Pickup Beam Measurement System at the VEPP-2000 Collider

collider, betatron, controls, positron

203

Yu. A. Rogovsky, E.A. Bekhtenev
BINP SB RAS, Novosibirsk, Russia

This paper reviews the present state of electromagnetic beam position monitors (pickups) at VEPP-2000 collider. It includes descriptions of position monitors, typical interfaces for these monitors and their system characteristics (resolution, stability, bandwidth and problems or limitations) are discussed. The paper also reviews several types of diagnostic measurements using beam position monitors which are useful in improving accelerator operations.

Poster MOPD68 [0.398 MB]

MOPD69

Tune Measurements with High Intensity Beams at SIS-18

acceleration, monitoring, emittance, diagnostics

206

R. Singh, P. Forck, W. Kaufmann, P. Kowina
GSI, Darmstadt, Germany
R. Singh
TEMF, TU Darmstadt, Darmstadt, Germany

Funding: This work is supported by DITANET (novel DIagnostic Techniques for future particle Accelerators: A Marie Curie Initial Training NETwork), Project Number ITN-2008-215080
To achieve high current operation close to the space charge limit in a synchrotron, a precise tune measurement during a full accelerating cycle is required. A tune measurement system that was recently commissioned at GSI synchrotron SIS-18 allows for online evaluation of the actual tune. This system consists of three distinct parts; an exciter which provides power to excite coherent betatron oscillations of the beam. The BPM signals thus induced are digitized by fast ADCs at 125 MSa/s and then the post processing electronics integrates the data bunch by bunch to obtain one position value per bunch. Subsequently base band tune is determined by Fourier transformation of the position data. The tune variation during acceleration for various beam conditions was measured using this system and is discussed. A detailed investigation of the incoherent tune shift was conducted with Uranium ion beams at the injection energy of 11.6 MeV/u. The results show the influence of beam current on the tune spectrum. In addition, the effects of the measurement method on the beam emittance and beam losses are discussed.

MOPD73

Study of Beam Size Blowup due to Transverse Bunch Feedback Noise on e⁺e⁻ Collider

luminosity, feedback, simulation, beam-beam-effects

212

M. Tobiyama, K. Ohmi
KEK, Ibaraki, Japan

Vertical beam size blowup with the gain of the transverse bunch feedback systems has been observed in KEKB B-factory rings. With the numerical simulation, large beam-beam effect enhances small oscillation induced by the broadband noise of the bunch feedback kick. To examine the simulation, beam response, effective beam size and the luminosity change with artificial external noise injected in the transverse feedback system have beem measuredn in KEKB LER ring during collision. The result has been compaired with the simulation including beam-beam effect and showed good agreement.

Poster MOPD73 [0.296 MB]

MOPD76

The Petra III Fast Orbit Feedback System

feedback, instrumentation, controls, brilliance

221

J. Klute, K. Balewski, H.T. Duhme, H. Tiessen, F. Wierzcholek
DESY, Hamburg, Germany

Orbit stability is a crucial and import issue of 3rd generation light sources. Ambient mechanical and electrical noise cause rather large orbit distortions which have to be counteracted by an orbit feedback. Extensive studies of the orbit distortions in PETRA III have shown that the frequencies of the ambient noise lie within a frequency range from about 0.01Hz to 100Hz. In this paper we describe the main components, their properties and the layout of PETRA III’s orbit feedback. Furthermore experimental results on short and long term stability will be presented. It will be shown that the required orbit stability of ±0.5 μm in the vertical plane can be maintained over 50 h.

MOPD79

An FPGA-based Turn-by-Turn Beam Position Monitoring System for Studying Multiple Bunch Beams in the ATF Damping Ring

extraction, damping, feedback, synchrotron

230

G.B. Christian, D.R. Bett, B. Constance, M.R. Davis
JAI, Oxford, United Kingdom
R. Apsimon, P. Burrows, A. Gerbershagen, C. Perry
Oxford University, Physics Department, Oxford, Oxon, United Kingdom
J. Resta-López
IFIC, Valencia, Spain

Instabilities associated with beam-size blow-up have previously been observed with multi-bunch beam in the damping ring (DR) of the KEK Accelerator Test Facility (ATF). A system has been developed to monitor such instabilities, utilising an ATF stripline beam position monitor (BPM) in the DR, and BPM processor hardware designed for the FONT upstream feedback system in the ATF extraction line. The system is designed to record the horizontal and/or vertical positions of up to three bunches in the DR in single-bunch multi-train mode or the head bunch of up to three trains in multi-bunch mode, with a bunch spacing of 5.6 ns. The FPGA firmware and data acquisition software were modified to record turn-by-turn data for up to six channels and 1–3 bunches in the DR. The maximum memory configuration on the FPGA allows 131071 bunch-turn-channels of data to be recorded from a particular machine pulse, and the system has the capability to select only certain turns at a regular interval in which to record data, in order to zoom out and cover the entire period of the damping cycle at the ATF. An overview of the system and initial results will be presented.

MOPD87

The LHC Beam Presence Flag System

controls, impedance, monitoring, feedback

251

M. Gasior, T.B. Bogey
CERN, Geneva, Switzerland

Before injecting any high intensity bunches into the LHC a circulating low intensity pilot bunch must be present to confirm the correct settings of the main machine parameters. For the 2010 LHC run the detection of this pilot beam was done with the beam current transformer system. To increase redundancy of this important safety function a dedicated beam presence flag system was designed, built and tested with beam to be used operationally in the 2011 run. In this system signals from four electrodes of a beam position monitor (BPM) are processed with separate channels, resulting in a quadruple system redundancy for either beam. Each system channel consists of an analogue front-end converting the BPM signals into two logic states, which are then transmitted optically to the machine protection and interlock systems. For safety reasons the system does not have any remote control or adjustable elements and its only inputs are the beam signals. This paper describes the new LHC beam presence flag system, in particular the analogue front-end based on diode peak detectors.

Poster MOPD87 [8.200 MB]

MOPD88

Electron Beam Ion Sources, Ion Optical Elements and Beam Diagnostics for Particle Accelerators

ion, emittance, electron, ion-source

254

F. Ullmann, V.P. Ovsyannikov, M. Schmidt
DREEBIT GmbH, Dresden, Germany
G. Zschornack
Technische Universität Dresden, Institut für Angewandte Physik, Dresden, Germany

Electron Beam Ion Sources (EBISs) provide highly charged ions (HCIs) for a variety of investigations and applications, amongst others as injection source for particle accelerators. EBISs feature a lot of advantages which qualify them for accelerator injection, and which partly compensate their comparatively low number of particles. DREEBIT GmbH provides a family of compact EBISs based on permanent magnets. A more sophisticated version is based on cryogen-free superconducting magnets providing a higher ion output. Its compact design makes them transportable, low in operational costs, and guarantee easy handling. We present latest improvements and measurements proving the feasibility of producing beams of HCIs with convenient beam properties such as low transversal and longitudinal emittance. In addition we present a variety of ion optical elements and ion beam diagnostics. The DREEBIT Wien filter allows for the charge mass separation. The DREEBIT Pepper-pot Emittance Meter allows for emittance measurements of beams of a wide range of particle intensity. Other beam diagnostics are provided, such as Beam Imaging System, Retarding Field Analyzer and different kinds of Faraday cups.

TUOA02

Diagnostics during the ALBA Storage Ring Commissioning

diagnostics, synchrotron, kicker, storage-ring

280

U. Iriso, M. Alvarez, F.F.B. Fernandez, A. Olmos, F. Pérez
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

The ALBA Storage Ring is a 3GeV 3rd Generation Synchrotron Light Source whose 1st phase commissioning took place in Spring 2011. The machine is equipped with 123 BPMs, striplines, several fluorescent screens, FCT and DCCT, 128 BLMs, and two front ends strictly used for electron beam diagnostics (pinhole and streak camera). This paper presents an overview of the Diagnostics elements installed in the machine and our experience during the commissioning.

Slides TUOA02 [5.476 MB]

TUPD03

Beam Profile Measurement during Top-up Injection with a Pulsed Sextupole Magnet

kicker, simulation, quadrupole, dipole

305

R. Takai, K. Harada, T. Honda, Y. Kobayashi, S. Nagahashi, N. Nakamura, T. Obina, A. Ueda
KEK, Ibaraki, Japan
H. Takaki
ISSP/SRL, Chiba, Japan

A beam injection scheme using a pulsed multipole magnet is suitable for the top-up injection because a disturbance to the stored beam is much smaller than that of the conventional scheme using several kicker magnets. At the Photon Factory storage ring, the top-up injection with a pulsed sextupole magnet (PSM) has been used for the user operation since January 2011. In order to ascertain the effect of the PSM injection, we measured turn-by-turn stored beam profiles following the injection kick by using a fast-gated camera. As a result, it was demonstrated that the PSM injection dramatically decreases not only the coherent dipole oscillation but also the beam profile modulation, as expected from the beam tracking simulation.

TUPD12

The LHC Beam Position System: Performance during 2010 and Outlook for 2011

pick-up, feedback, closed-orbit, vacuum

323

E. Calvo Giraldo, J.L. Gonzalez, L.K. Jensen, O.R. Jones, T. Lefèvre, J.-J. Savioz, R.J. Steinhagen, J. Wenninger
CERN, Geneva, Switzerland

This paper presents the performance of the LHC Beam Position System during 2010. The system proved to meet most specifications, was highly reliable and continuously provided 25Hz real-time orbit data with micron level resolution to the automatic global orbit feedback system. However, several issues were observed and they will be discussed in detail, such as the dependence on bunch intensity and the effect of surface electronics temperature variations on the measured position.

TUPD19

Initial Tests of New Electron and Photon Beam Position Monitor Electronics at the Advanced Photon Source

photon, brilliance, electron, controls

344

P. Leban
I-Tech, Solkan, Slovenia
G. Decker
ANL, Argonne, USA

Funding: Use of the APS, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by ANL, was supported by the U.S. DOE under Contract No. DE-AC02-06CH11357
Measurements were done at the Advanced Photon Source (APS) with Libera Brilliance+, connected to the small-aperture insertion device vacuum chamber pickup electrodes near the beamline 35-ID source point. A photoemission-based photon beam position monitor located 16.35 meters downstream of the center of the ID straight section was also monitored using Libera Photon electronics in horizontal/vertical configuration. Top-up injection transients were recorded simultaneously on both units, providing details about the electron and photon beam motions before, during, and after injection in the storage ring and beamline front end. FFT spectra from the APS-developed BSP-100 broadband BPM data acquisition electronics were compared with the Libera instruments. This article discusses the calibration procedure for electron and photon beam position monitors along with results of these measurements.

TUPD30

Bunch Length Measurement using Coherent Cherenkov Radiation

electron, laser, gun, linac

368

K. Kan, T. Kondoh, T. Kozawa, K. Norizawa, A. Ogata, J. Yang, Y. Yoshida
ISIR, Osaka, Japan

Ultra-short electron bunches on the order of 100 fs or less can be used in the study of ultrafast reactions and phenomena in time-resolved pump-probe experiments involving the application of techniques such as pulse radiolysis. Such electron bunches are also useful for electro-magnetic (EM) radiation production, where the frequency of EM radiation depends on the electron bunch length. In this presentation, Coherent Cherenkov Radiation (CCR), which is a method of THz radiation emitted from relativistic electron bunches, was studied for a diagnostic of electron bunch length. A picosecond electron bunch generated by a photocahode radio frequency (RF) gun was used. CCR can emit narrow-band THz wave with a dielectric-lined waveguide structure. The intensity and frequency of CCR were measured by a Michelson interferometer and a 4.2K liquid-He cooled bolometer.

TUPD40

Analysis of the Post-mortem Events at the TLS

SRF, diagnostics, power-supply, dipole

392

K.H. Hu, Y.-T. Chang, J. Chen, P.C. Chiu, K.T. Hsu, C.H. Kuo, Y.-H. Lin, Y.R. Pan
NSRRC, Hsinchu, Taiwan

Analyzing the reasons of various trip events are basis to improve reliability of a accelerator system. Understand the mechanisms caused trip of the machine will be very helpful to decide what the adequate measures to improve availability. To identify the causes of trips at Taiwan Light Source (TLS), various diagnostics tool were employed. These diagnostic tools can capture beam trips, interlock signals of superconducting RF system, quench and interlock signals of the superconducting insertion device, waveform of the injection kickers, and instability signals of the stored beam for post-mortem analysis. Various functionalities of trip diagnostic are supported. Available tools and experiences will be summarized in this report.

TUPD67

Injection Efficiency Diagnostic at TLS Storage Ring

storage-ring, booster, diagnostics, septum

461

P.C. Chiu, J. Chen, Y.K. Chen, K.T. Hsu, K.H. Hu, C.H. Kuo
NSRRC, Hsinchu, Taiwan

TLS is now running at 360 mA top-up mode. In the normal situation, it takes few minutes for injection from zero current to 360 mA. When the working point is drifted too much at machine start, however, injection efficiency become worsen and it is necessary to adjust some machine parameters such as quadrupole strength, transport line correctors or booster dipole to improve efficiency. The current reading at 10 Hz time resolution which is the same with injection cycle seems too rough to estimate efficiency therefore a new diagnostic tool based on BPM sum reading is developed to provide 10 kHz waveform display every second. Operators could utilize it to estimate efficiency more precise, quickly and easier.

Poster TUPD67 [0.842 MB]

TUPD74

The Bunch by Bunch Feedback System in J-PARC Main Ring

feedback, kicker, proton, acceleration

482

Y. Kurimoto, Y.H. Chin, T. Obina, M. Tobiyama, T. Toyama
KEK, Ibaraki, Japan
Y. Shobuda
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

We report the current status of the bunch by bunch feedback system for the J-PARC Main Ring. The J-PARC Main Ring is the synchrotron accelerating protons from 3 GeV to 30 GeV. It is normally operating at the intensity of 135 kW. The bunch by bunch feedback system have been developed and used for the normal operation of J-PARC Main Ring. The system aims to reduce the coherent transverse oscillation due to the instabilities or injection errors. It consists of a beam position monitor, a stripline kicker and a signal processing electronics. We've observed the injection error leading to the head-tail oscillation and succeed in damping such kind of oscillations and reducing the beam loss significantly.

Poster TUPD74 [1.107 MB]

WEOD02

LHC Beam Diagnostics - the Users Point of View

luminosity, proton, ion, instrumentation

580

J. Wenninger
CERN, Geneva, Switzerland

The LHC started up with beam in November 2009, and within less then on year its luminosity reached 2·10³² cm^-2s⁻¹ at 3.5 TeV in October 2010. A few weeks later, in November 2010, lead ion collisions were established within little over 2 days. The fast progress and successes of the LHC commissioning and early operation would not have been possible without the excellent performance of its beam instrumentation. All essential instruments worked from the first day or were commissioned in a very short time, providing rapid diagnostics for the beam parameters. Tune and orbit feedbacks that rely on high quality measurements were used early on to achieve smooth operation with minimal beam losses. This presentation will address the performance of the LHC beam instrumentation, in particular the very large beam position and beam loss monitoring systems, both composed of many thousand channels. Present limitations and future improvements will also be discussed.

Slides WEOD02 [11.950 MB]