IBIC2013 - List of Keywords (beam-losses)

Paper	Title	Other Keywords	Page
MOPC05	Beam Diagnostics of SuperKEKB Damping Ring	KEKB, beam-position, extraction, injection	53
	H. Ikeda, A. Arinaga, J.W. Flanagan, H. Fukuma, H. Ishii, S. Kanaeda, K. Mori, M. Tejima, M. Tobiyama KEK, Ibaraki, Japan
	The KEKB accelerator ceased operation in 2010, and is being upgraded to SuperKEKB. Adopting low emittance and high current beams, the design luminosity is set at 40 times larger than that of KEKB. We are constructing a damping ring (DR) in order to achieve a low-emittance positron beam for injection. Turn-by-turn beam position monitors (BPMs), a transverse feedback system, a synchrotron radiation monitor (SRM), a DCCT, loss monitors using ion chambers, a bunch current monitor and a tune meter will be installed for beam diagnostics at the DR. An overview of the instrumentation of the DR will be presented in this paper.

MOPC43	Performance of Detectors using Diamond Sensors at the LHC and CMS	DIAMOND, LHC, luminosity, injection	174
	M. Hempel BTU, Cottbus, Germany T. Baer, A.E. Dabrowski CERN, Geneva, Switzerland E. Griesmayer ATI, Wien, Austria W. Lange, O. Novgorodova DESY Zeuthen, Zeuthen, Germany W. Lohmann DESY, Hamburg, Germany N.J. Odell NU, Evanston, USA D.P. Stickland PU, Princeton, New Jersey, USA
	Diamond detectors are used as beam loss and luminosity monitors for CMS and LHC. A time resolution in the nanosecond range allows to detect beam losses and luminosities of single bunches. The radiation hardness and negligible temperature dependence allow the usage of diamond sensors in high radiation fields without cooling. Two different diamond detector types are installed at LHC and CMS. One is based on pCVD diamonds and installed at different locations in the LHC tunnel for beam loss monitoring. Measurements of these detectors are used to perform a bunch-by-bunch beam loss analysis. They allow to disentangle the origin of beam losses. The second type uses sCVD diamonds and is located inside CMS for van-der-Meer scan, beam halo and online luminosity monitoring and around the LHC tunnel for beam loss observation. Results on the performance of these detectors will be presented and examples of the use for analyzing the beam conditions will be given. In order to persist the enhanced requirements of the LHC after the long shutdown, e.g. higher luminosity, an upgrade of the detectors is required. The concept of the new detectors will be presented and first results will be shown.
	Poster MOPC43 [0.721 MB]

MOPC44	A Gigabit Ethernet Link for an FPGA Based Beam Loss Measurement System	CERN, monitoring, instrumentation, LHC	178
	M. Kwiatkowski, M. Alsdorf, B. Dehning, W. Viganò, C. Zamantzas CERN, Geneva, Switzerland
	A new Beam Loss Measurement (BLM) system is under development at the European Organisation for Nuclear Research (CERN) within the LHC Injector Upgrade (LIU) project. The multi-channel system will measure the beam losses from various types of detectors with a high precision and wide dynamic range. Several modes of data acquisition are supported. The data rate in the single-channel mode is 16 Mbps and in the multi-channel mode 128 Mbps. The Gigabit Ethernet link is implemented in an FPGA, which allows both a high throughput and a quick validation of the digital data processing algorithms using standard PCs in the initial stages of the development. Both TCP and UDP protocols were explored. The implementation of the Ethernet link is flexible and proved to be highly reliable, leading to its planned use in other measurement systems developed at CERN. The implementation details of the Ethernet link and the results achieved will be described in this paper.
	Poster MOPC44 [0.833 MB]

MOPC45	A Prototype Readout System for the Diamond Beam Loss Monitors at LHC	DIAMOND, LHC, injection, proton	182
	E. Effinger, T. Baer, B. Dehning, R. Schmidt CERN, Geneva, Switzerland H. Frais-Kölbl FH WN, Wiener Neustadt, Austria E. Griesmayer ATI, Wien, Austria P. Kavrigin CIVIDEC Instrumentation, Wien, Austria
	Diamond Beam Loss Monitors are used at the LHC for the measurement of fast beam losses. Results from specimen LHC loss measurements are presented in this talk. The bunch-to-bunch loss measurements make full use of the fast signal response of the diamond detectors with 1 ns time resolution and 6.7 ns double pulse resolution. The data processing is done with a dedicated readout system, which was designed and optimized for particular applications with the diamond beam loss monitors. This FPGA-based system provides on-line, real-time, and dead-time-free data processing. Several examples are presented: the Time Loss Histogram with 1.6 ns binning provides beam loss measurements that are synchronized with the revolution period throughout the full operational LHC cycle. The Post Mortem Recorder with a sampling frequency of 1 GS/s allows beam-loss-based tune estimates for all bunches in parallel. Future applications and upgrades are discussed.
	Poster MOPC45 [0.778 MB]

MOPC46	Beam Loss Monitor System for Low-Energy Heavy-Ion FRIB Accelerators	ion, radiation, background, heavy-ion	186
	Z. Liu, T. Russo, R.C. Webber, Y. Yamazaki, Y. Zhang FRIB, East Lansing, Michigan, USA
	Funding: Work is supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 Radiation transport simulations reveal shortcomings in the use of ion chambers for the detection of beam losses in low-energy, heavy-ion accelerators like FRIB. Radiation cross-talk effects due to the specific FRIB paper-clip geometry complicate locating specific points of beam loss. We describe an economical and robust solution that complements ionization chambers. A specifically designed device, the halo monitor ring (HMR), is implemented upstream of each cryomodule to detect beam loss directly. Together with fast response neutron scintillators, the new integrated BLM system satisfies both machine protection and sensitivity requirements.
	Poster MOPC46 [1.014 MB]

MOPC47	Monte Carlo Simulations of Beam Losses in the Test Beam Line of CTF3	quadrupole, electron, CLIC, simulation	189
	E. Nebot Del Busto, S. Mallows, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom E. Branger Linköping University, Linköping, Sweden S. Döbert, E.B. Holzer, R.L. Lillestøl, S. Mallows, E. Nebot Del Busto CERN, Geneva, Switzerland R.L. Lillestøl University of Oslo, Oslo, Norway C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	The Test Beam Line (TBL) of the CLIC Test Facility 3 (CTF3) aims to validate the drive beam deceleration concept of CLIC, in which the RF power requested to boost particles to multi-TeV energies is obtained via deceleration of a high current and low energy drive beam (DB). Despite a TBL beam energy (150-80 MeV) significantly lower than the minimum nominal energy of the CLIC DB (250 MeV), the pulse time structure of the TBL provides the opportunity to measure beam losses with CLIC-like DB timing conditions. In this contribution, a simulation study on the detection of beam losses along the TBL for the commissioning of the recently installed beam loss monitoring system is presented. The most likely loss locations during stable beam conditions are studied by considering the beam envelope defined by the FODO lattice as well as the emittance growth due to the deceleration process. Moreover, the optimization of potential detector locations is discussed. Several factors are considered, namely: the distance to the beam, the shielding provided by the different elements of the line, the detector sensitivity and possible saturation effects of both the radiation detectors and electronics.

MOPF26	New Booster Tune Measurement System for TLS and TPS Prototype	booster, synchrotron, kicker, BPM	271
	P.C. Chiu, J. Chen, Y.-S. Cheng, K.T. Hsu, S.Y. Hsu, K.H. Hu, C.H. Kuo NSRRC, Hsinchu, Taiwan
	Taiwan Light Source (TLS) is a 1.5 GeV synchrotron based light source and its booster synchrotron was delivered in 1992. Initial booster tune measurement which adopted extraction kicker as beam excitation and use digital oscillator to extract tune was obsolete. Recently, the beam excitation device has been modified to provide more effective excitation strength and new BPM electronics is adopted to acquire tune for routine booster tune measurement. It also provides a chance to experience for the TPS project booster prototype with the similar infrastructure. Efforts will be summarized in the report.

MOPF28	Optics Non-Linear Components Measurement Using BPM Signals	optics, focusing, BPM, synchrotron	279
	M. Alhumaidi, A.M. Zoubir TU Darmstadt, Darmstadt, Germany
	The knowledge of linear and non-linear errors in circular accelerator optics is very crucial for controlling and compensating resonances and their consequent beam losses. This is indispensable, especially for high intensity machines. Fortunately, the relationship between the recorded beam offset signals at the BPMs is a manifestation of the accelerator optics, and can therefore be exploited in the determination of the optics linear and non-linear components. We propose a novel method for estimating lattice non-linear components located in-between the positions of two BPMs by analyzing the beam offset signals of a BPMs triple containing these two BPMs. Depending on the non-linear components in-between the locations of the BPMs triple, the relationship between the beam offsets follows a multivariate polynomial. After calculating the covariance matrix of the polynomial terms, the Generalized Total Least Squares method is used to find the model parameters, and thus the non-linear components. Finally, a bootstrap technique is used to determine confidence intervals of the estimated values. Results for synthetic data are shown.

MOPF31	Design and Performance of the Biased Drift Tube System in the BNL Electron Lens	RHIC, electron, vacuum, ion	291
	T.A. Miller, W. Fischer, D.M. Gassner, X. Gu, A.I. Pikin, S. Polizzo, P. Thieberger BNL, Upton, Long Island, New York, USA J. Barth Barth Electronics, Boulder City, USA
	Funding: Work supported by U.S. DOE under contract No DE-AC02-98CH10886 with the U.S. Department of Energy. The installation of the Electron Lenses in RHIC will be completed this year. Its design includes a series of drift tubes through which the electron beam copropagates, with the RHIC proton beams. These drift tubes are used to create an electric field gradient to sweep out ions that become trapped within the central magnetic field where the electron beam interacts with the proton beams. These isolated drift tubes are biased by high voltage power supplies. Without a path for the proton beam image currents, high voltages will develop on the drift tubes that can be detrimental to the electron beam and increase the RHIC machine impedance. This paper presents the design of the drift tubes, axial electric field gradient, and the custom high voltage RF bias tees that were designed to provide separate paths for the high frequency image currents and the DC high voltage bias over the same cables. The design and simulation of the bias tee is discussed, as well as RF signals from the proton beam current imaged on the drift tubes, as measured through the bias tees during the commissioning of the blue RHIC beam electron lens this past spring.
	Poster MOPF31 [31.237 MB]

TUPC16	Bunch-by-Bunch Feedback and Diagnostics at BESSY II	feedback, longitudinal, injection, kicker	399
	A. Schälicke, F. Falkenstern, R. Müller HZB, Berlin, Germany
	At the light source BESSY II new digital bunch-by-bunch feedback systems have been put into operation in January 2013, replacing the existing analog as well as the obsolete digital systems. From the first days of operation the new system successfully suppresses transverse and longitudinal beam instabilities in wide range of machine parameters. The system offers also many new diagnostics opportunities, these include the analysis of instability modes, measurement of the feedback loop gain, and determination of the transfer function. A method to systematically optimise the output amplifier response function with the help of shaper coefficients for the optimal bunch separation has been developed. In addition the analysis of the input data stream allows a passive determination of machine properties like betatron and synchrotron frequencies as well as the longitudinal phases for every bunch. The integration of external triggers permits the analysis of postmortem data, the characterisation of beam-loss events, and monitoring of the injection process. In this contribution first operational experience, the developed data analysis techniques and experimental data will be presented.
	Poster TUPC16 [56.767 MB]

TUPC46	Beam Loss Monitoring Study for SIS100@FAIR	ion, simulation, GSI, SIS	485
	V.S. Lavrik, L.H.J. Bozyk, O.K. Kester, A. Reiter GSI, Darmstadt, Germany O.K. Kester, V.S. Lavrik IAP, Frankfurt am Main, Germany
	FAIR, the facility for antiproton and ion research, is a multi-disciplinary accelerator facility which will extend the existing GSI complex in Darmstadt, Germany. In the FAIR start version, the new synchrotron SIS100 will provide proton or heavy ion beams for a variety of experiments. The GSI synchrotron SIS18 will operate as injector for SIS100. The current study focuses on beam loss measurements for SIS18 and SIS100. The aim of this study is to find quantitative methods to measure beam losses around the machine, mainly SIS100, on an absolute scale. The contribution will present results of two pilot experiments carried out in the high-energy beam lines and at the SIS18 with Uranium ions in the energy range up to 900 MeV/u. In the first experiment the Uranium beam was totally stopped in a Copper target and the particle shower measured with LHC-type ionization chambers. In the second experiment, the beam was slowly excited in the SIS18 synchrotron to create controlled losses on a scraper which were monitored by the DC current transformer and beam loss monitors. Experimental data are compared against the predictions of Fluka simulations.
	Poster TUPC46 [5.404 MB]

TUPC47	Simulation for Radiation Field Caused by Beam Loss of C-ADS Injector II	proton, photon, electron, radiation	489
	G. Ren, W. Li, Y. Li USTC/NSRL, Hefei, Anhui, People's Republic of China M. Zeng Tsinghua University, Beijing, People's Republic of China
	CADS is a Chinese ADS(Accelerator Driven Sub-critical System) project. Its injector is a high current, full superconducting proton accelerator. For such a facility, a BLM system is necessary, especially in low energy segments. This paper presents some basic simulation for 10MeV proton by Monte Carlo program FLUKA, as well as the distributions we got about different secondary particles in three aspects: angular, energy spectrum and current. These results are helpful to select the detector type and its location, determine its dynamic range matching different requirements for both fast and slow beam loss. This paper also analyzes the major impact of the background, such as superconducting cavity X radiation and radiation caused by material activation. This work is meaningful in BLM system research.

WECL3	The LUPIN Detector: Supporting Least Intrusive Beam Monitoring Technique Through Neutron Detection	radiation, monitoring, proton, synchrotron	648
	G.P. Manessi, M. Silari CERN, Geneva, Switzerland M. Caresana Politecnico/Milano, Milano, Italy M. Ferrarini CNAO Foundation, Milan, Italy G.P. Manessi, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom G.P. Manessi, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom
	The Long interval, Ultra-wide dynamic Pile-up free Neutron rem counter (LUPIN) is a novel detector initially developed for radiation protection purposes, specifically conceived for applications in pulsed neutron fields. The detector has a measurement capability varying over many orders of neutron burst intensity, from a single neutron up to thousands of interactions for each burst, without showing any saturation effect. Whilst LUPIN has been developed for applications in the radiation protection fields, its unique properties make it also well suited to support other beam instrumentation. In this contribution, the design of LUPIN is presented in detail and its main characteristics are summarized. Its potential use as beam loss monitor and complementary detector for non-invasive beam monitoring purposes (e.g. to complement a monitor based on proton beam “halo” detection) in medical accelerators is then examined. In the context of its application as a beam loss monitor for hadrontherapy accelerators, results of measurements performed at the Italian National Centre of Hadrontherapy (CNAO) are presented and analyzed.
	Slides WECL3 [1.431 MB]

WEPC43	Update on Beam Loss Monitoring at CTF3 for CLIC	CLIC, DIAMOND, photon, quadrupole	787
	L.J. Devlin, S. Mallows, C.P. Welsch, E.N. del Busto Cockcroft Institute, Warrington, Cheshire, United Kingdom E. Branger Linköping University, Linköping, Sweden L.J. Devlin, S. Mallows, C.P. Welsch, E.N. del Busto The University of Liverpool, Liverpool, United Kingdom E. Effinger, E.B. Holzer, S. Mallows, E.N. del Busto CERN, Geneva, Switzerland
	Funding: Work supported by STFC Cockcroft Institute Core Grant No. ST/G008248/1 The primary role of the beam loss monitoring (BLM) system for the compact linear collider (CLIC) study is to work within the machine protection system. Due to the size of the CLIC facility, a BLM that covers large distances along the beamline is highly desirable, in particular for the CLIC drive beam decelerators, which would alternatively require some ~40,000 localised monitors. Therefore, an optical fiber BLM system is currently under investigation which can cover large sections of beamline at a time. A multimode fiber has been installed along the Test Beam Line at the CLIC test facility (CTF3) where the detection principle is based on the production of Cherenkov photons within the fiber resulting from beam loss and their subsequent transport along the fiber where they are then detected at the fiber ends using silicon photomultipliers. Several additional monitors including ACEMs, PEP-II and diamond detectors have also been installed. In this contribution the first results from the BLMs are presented, comparisons of the signals from each BLM are made and the possible achievable longitudinal resolution from the fiber BLM signal considering various loss patterns is discussed.

WEPC44	Operation of Silicon, Diamond and Liquid Helium Detectors in the Range of Room Temperature to 1.9 Kelvin and After an Irradiation Dose of Several Mega Gray	DIAMOND, proton, LHC, CERN	791
	C. Kurfuerst, M.R. Bartosik, B. Dehning, T. Eisel, M. Sapinski CERN, Geneva, Switzerland V. Eremin IOFFE, St. Petersburg, Russia
	At the triplet magnets close to the interaction regions of the LHC, the current Beam Loss Monitoring system is sensitive to the debris from the collision points. For future beams with higher energy and intensity, the expected increase in luminosity and associated increase of the debris from interaction products is expected to compete with any quench-provoking beam losses from the primary proton beams. In order to distinguish between the two, it is proposed to locate the detectors as close as possible to the superconducting coil. The detectors therefore have to be located inside the cold mass of the superconducting magnets in superfluid helium at 1.9 K. Past measurements have shown that in a liquid helium chamber, diamond and silicon detectors are promising candidates for cryogenic beam loss monitors. This contribution will show the results from new high irradiation beam measurements at both room temperature and 1.9 Kelvin to reveal the radiation tolerance of these different detectors.

WEPC45	Beam Loss Monitoring at the European Spallation Source	ESS, LHC, XFEL, simulation	795
	L. Tchelidze, H. Hassanzadegan, A. Jansson, M. Jarosz ESS, Lund, Sweden
	At the European Spallation Source proton linear accelerator will generate 5 MW protons to be delivered to a target. This high power accelerator will require significant amount of beam instrumentation, among which the beam loss monitoring system is one of the most important for operation. An LHC type ionization chamber will be used with ~54 uC/Gy sensitivity. At most 1.5 mGy/sec radiation levels are expected close to the beam pipe during normal operation, resulting in up to 80 nA current signal in detectors. Loss monitor electronics is designed to be able to measure currents as little as 1% of the expected current up to as much as 1% of the total beam loss, thus ~800 pA – few mA. In order to study beam loss pattern along the accelerator a coherent model of the whole machine is created for the purposes of Monte Carlo particle transport simulations. Data obtained using the model will be stored in a database together with the initial beam loss conditions. The contents of the database will then be processed using custom neural network algorithms to optimize number and position of the loss monitors and to provide reference on the beam loss localization during operation of the machine.
	Poster WEPC45 [1.784 MB]

WEPF26	Test Bench Experiments for Energy Measurement and Beam Loss of ESS-Bilbao	rfq, ion, ESS, diagnostics	876
	S. Varnasseri, I. Arredondo, D. Belver, P. Echevarria, M. Eguiraun ESS Bilbao, Zamudio, Spain
	Various test benches have been developed at ESS-Bilbao in order to characterize different beam diagnostics and control systems prior to their installation on various parts of the accelerator. One test bench includes time-of-flight (TOF) characterization for energy measurement using fast current transformers (FCT). Using FCTs for the TOF measurement would allow us to measure accurately the delay between two successive bunched or un-bunched beam pulses of low energy ions. The other test bench includes a beam loss monitoring and interlock system using ACCTs, cRIO and PXI chassis with some acquisition modules and optical fiber link which represent a complete system of beam loss detection, interlock logic and trigger signal transmission. Having an integration on the ACCT output also allows us to measure the beam charge at the location of monitoring. In the test benches the functionality of hardware and software, the logic and required signal specifications like rise time, jitters and delays are measured. An overview of test benches and their measurement results are reported in this paper.
	Poster WEPF26 [1.120 MB]

WEPF29	The LHC Fast Beam Current Change Monitor	LHC, injection, CERN, FIR	887
	D. Belohrad, J.M. Belleman, L.K. Jensen, M. Krupa, A. Topaloudis CERN, Geneva, Switzerland
	The modularity of the Large Hadron Collider’s (LHC) machine protection system (MPS) allows for the integration of several beam diagnostic instruments. These instruments have not necessarily been designed to have protection functionality, but MPS can still use them to increase the redundancy and reliability of the machine. The LHC fast beam current change monitor (FBCCM) is an example. It is based on analogue signals from fast beam current transformers (FBCT) used nominally to measure the LHC bunch intensities. The FBCCM calculates the magnitude of the beam signal provided by the FBCT, looks for a change over specific time intervals, and triggers a beam dump interlock if losses exceed an energy-dependent threshold. The first prototype of the FBCCM was installed in the LHC during the 2012-2013 run. The aim of this article is to present the FBCCM system and the results obtained, analyse its current performance and provide an outlook for the final system which is expected to be operational after the long LHC shutdown.

WEPF30	System Overview and Preliminary Test Results of the ESS Beam Current Monitor System	ESS, linac, controls, monitoring	891
	H. Hassanzadegan, A. Jansson ESS, Lund, Sweden K. Strniša Cosylab, Ljubljana, Slovenia
	The ESS Linac will include in total 21 Beam Current Monitors, mostly of ACCT type, to measure the average current over the 2.86 ms beam pulse, the pulse charge and the pulse profile. It is also planned to use a few Fast Current Transformers to check the performance of the fast beam choppers with a rise time as short as 10 ns. In addition to the absolute current measurement, the BCM system needs to measure the differential beam current and act on the Machine Interlock System if the difference exceeds some thresholds. The differential current measurement is particularly important in the low energy part of the Linac, where Beam Loss Monitors cannot reliably detect beam losses. This paper gives an overview of the ESS BCM system and presents some preliminary test results with a commercial ACCT and MTCA.4 electronics.
	Poster WEPF30 [6.267 MB]

THAL2	A New Differential and Errant Beam Current Monitor for the SNS Accelerator	SCL, SNS, linac, target	921
	W. Blokland ORNL, Oak Ridge, Tennessee, USA C.C. Peters ORNL RAD, Oak Ridge, Tennessee, USA
	Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725 A new Differential and errant Beam Current Monitor (DBCM) is being implemented for the Spallation Neutron Source's Medium Energy Beam Transport (MEBT) and Super Conducting linac (SCL) accelerator sections. This new current monitor will abort the beam when the difference between two toroidal pickups exceeds a threshold. The MEBT DBCM will protect the MEBT chopper target while the SCL DBCM will abort beam to minimize fast beam losses in the SCL cavities. The new DBCM will also record instances of errant beam such as beam drop-outs to assist in further optimization of the SNS Accelerator. A software Errant Beam Monitor was implemented on the regular BCM hardware to study errant beam pulses. The new system will take over this functionality and will also be able to abort beam on pulse to pulse variations. as it is based on the FlexRIO hardware programmed in LabVIEW FPGA and can abort beam in 5 us. This paper describes the development, implementation, and initial test results of the DBCM as well as errant beam examples.
	Slides THAL2 [9.413 MB]

Paper

Title

Other Keywords

Page

MOPC05

Beam Diagnostics of SuperKEKB Damping Ring

KEKB, beam-position, extraction, injection

53

H. Ikeda, A. Arinaga, J.W. Flanagan, H. Fukuma, H. Ishii, S. Kanaeda, K. Mori, M. Tejima, M. Tobiyama
KEK, Ibaraki, Japan

The KEKB accelerator ceased operation in 2010, and is being upgraded to SuperKEKB. Adopting low emittance and high current beams, the design luminosity is set at 40 times larger than that of KEKB. We are constructing a damping ring (DR) in order to achieve a low-emittance positron beam for injection. Turn-by-turn beam position monitors (BPMs), a transverse feedback system, a synchrotron radiation monitor (SRM), a DCCT, loss monitors using ion chambers, a bunch current monitor and a tune meter will be installed for beam diagnostics at the DR. An overview of the instrumentation of the DR will be presented in this paper.

MOPC43

Performance of Detectors using Diamond Sensors at the LHC and CMS

DIAMOND, LHC, luminosity, injection

174

M. Hempel
BTU, Cottbus, Germany
T. Baer, A.E. Dabrowski
CERN, Geneva, Switzerland
E. Griesmayer
ATI, Wien, Austria
W. Lange, O. Novgorodova
DESY Zeuthen, Zeuthen, Germany
W. Lohmann
DESY, Hamburg, Germany
N.J. Odell
NU, Evanston, USA
D.P. Stickland
PU, Princeton, New Jersey, USA

Diamond detectors are used as beam loss and luminosity monitors for CMS and LHC. A time resolution in the nanosecond range allows to detect beam losses and luminosities of single bunches. The radiation hardness and negligible temperature dependence allow the usage of diamond sensors in high radiation fields without cooling. Two different diamond detector types are installed at LHC and CMS. One is based on pCVD diamonds and installed at different locations in the LHC tunnel for beam loss monitoring. Measurements of these detectors are used to perform a bunch-by-bunch beam loss analysis. They allow to disentangle the origin of beam losses. The second type uses sCVD diamonds and is located inside CMS for van-der-Meer scan, beam halo and online luminosity monitoring and around the LHC tunnel for beam loss observation. Results on the performance of these detectors will be presented and examples of the use for analyzing the beam conditions will be given. In order to persist the enhanced requirements of the LHC after the long shutdown, e.g. higher luminosity, an upgrade of the detectors is required. The concept of the new detectors will be presented and first results will be shown.

Poster MOPC43 [0.721 MB]

MOPC44

A Gigabit Ethernet Link for an FPGA Based Beam Loss Measurement System

CERN, monitoring, instrumentation, LHC

178

M. Kwiatkowski, M. Alsdorf, B. Dehning, W. Viganò, C. Zamantzas
CERN, Geneva, Switzerland

A new Beam Loss Measurement (BLM) system is under development at the European Organisation for Nuclear Research (CERN) within the LHC Injector Upgrade (LIU) project. The multi-channel system will measure the beam losses from various types of detectors with a high precision and wide dynamic range. Several modes of data acquisition are supported. The data rate in the single-channel mode is 16 Mbps and in the multi-channel mode 128 Mbps. The Gigabit Ethernet link is implemented in an FPGA, which allows both a high throughput and a quick validation of the digital data processing algorithms using standard PCs in the initial stages of the development. Both TCP and UDP protocols were explored. The implementation of the Ethernet link is flexible and proved to be highly reliable, leading to its planned use in other measurement systems developed at CERN. The implementation details of the Ethernet link and the results achieved will be described in this paper.

Poster MOPC44 [0.833 MB]

MOPC45

A Prototype Readout System for the Diamond Beam Loss Monitors at LHC

DIAMOND, LHC, injection, proton

182

E. Effinger, T. Baer, B. Dehning, R. Schmidt
CERN, Geneva, Switzerland
H. Frais-Kölbl
FH WN, Wiener Neustadt, Austria
E. Griesmayer
ATI, Wien, Austria
P. Kavrigin
CIVIDEC Instrumentation, Wien, Austria

Diamond Beam Loss Monitors are used at the LHC for the measurement of fast beam losses. Results from specimen LHC loss measurements are presented in this talk. The bunch-to-bunch loss measurements make full use of the fast signal response of the diamond detectors with 1 ns time resolution and 6.7 ns double pulse resolution. The data processing is done with a dedicated readout system, which was designed and optimized for particular applications with the diamond beam loss monitors. This FPGA-based system provides on-line, real-time, and dead-time-free data processing. Several examples are presented: the Time Loss Histogram with 1.6 ns binning provides beam loss measurements that are synchronized with the revolution period throughout the full operational LHC cycle. The Post Mortem Recorder with a sampling frequency of 1 GS/s allows beam-loss-based tune estimates for all bunches in parallel. Future applications and upgrades are discussed.

Poster MOPC45 [0.778 MB]

MOPC46

Beam Loss Monitor System for Low-Energy Heavy-Ion FRIB Accelerators

ion, radiation, background, heavy-ion

186

Z. Liu, T. Russo, R.C. Webber, Y. Yamazaki, Y. Zhang
FRIB, East Lansing, Michigan, USA

Funding: Work is supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
Radiation transport simulations reveal shortcomings in the use of ion chambers for the detection of beam losses in low-energy, heavy-ion accelerators like FRIB. Radiation cross-talk effects due to the specific FRIB paper-clip geometry complicate locating specific points of beam loss. We describe an economical and robust solution that complements ionization chambers. A specifically designed device, the halo monitor ring (HMR), is implemented upstream of each cryomodule to detect beam loss directly. Together with fast response neutron scintillators, the new integrated BLM system satisfies both machine protection and sensitivity requirements.

Poster MOPC46 [1.014 MB]

MOPC47

Monte Carlo Simulations of Beam Losses in the Test Beam Line of CTF3

quadrupole, electron, CLIC, simulation

189

E. Nebot Del Busto, S. Mallows, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
E. Branger
Linköping University, Linköping, Sweden
S. Döbert, E.B. Holzer, R.L. Lillestøl, S. Mallows, E. Nebot Del Busto
CERN, Geneva, Switzerland
R.L. Lillestøl
University of Oslo, Oslo, Norway
C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

The Test Beam Line (TBL) of the CLIC Test Facility 3 (CTF3) aims to validate the drive beam deceleration concept of CLIC, in which the RF power requested to boost particles to multi-TeV energies is obtained via deceleration of a high current and low energy drive beam (DB). Despite a TBL beam energy (150-80 MeV) significantly lower than the minimum nominal energy of the CLIC DB (250 MeV), the pulse time structure of the TBL provides the opportunity to measure beam losses with CLIC-like DB timing conditions. In this contribution, a simulation study on the detection of beam losses along the TBL for the commissioning of the recently installed beam loss monitoring system is presented. The most likely loss locations during stable beam conditions are studied by considering the beam envelope defined by the FODO lattice as well as the emittance growth due to the deceleration process. Moreover, the optimization of potential detector locations is discussed. Several factors are considered, namely: the distance to the beam, the shielding provided by the different elements of the line, the detector sensitivity and possible saturation effects of both the radiation detectors and electronics.

MOPF26

New Booster Tune Measurement System for TLS and TPS Prototype

booster, synchrotron, kicker, BPM

271

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

Taiwan Light Source (TLS) is a 1.5 GeV synchrotron based light source and its booster synchrotron was delivered in 1992. Initial booster tune measurement which adopted extraction kicker as beam excitation and use digital oscillator to extract tune was obsolete. Recently, the beam excitation device has been modified to provide more effective excitation strength and new BPM electronics is adopted to acquire tune for routine booster tune measurement. It also provides a chance to experience for the TPS project booster prototype with the similar infrastructure. Efforts will be summarized in the report.

MOPF28

Optics Non-Linear Components Measurement Using BPM Signals

optics, focusing, BPM, synchrotron

279

M. Alhumaidi, A.M. Zoubir
TU Darmstadt, Darmstadt, Germany

The knowledge of linear and non-linear errors in circular accelerator optics is very crucial for controlling and compensating resonances and their consequent beam losses. This is indispensable, especially for high intensity machines. Fortunately, the relationship between the recorded beam offset signals at the BPMs is a manifestation of the accelerator optics, and can therefore be exploited in the determination of the optics linear and non-linear components. We propose a novel method for estimating lattice non-linear components located in-between the positions of two BPMs by analyzing the beam offset signals of a BPMs triple containing these two BPMs. Depending on the non-linear components in-between the locations of the BPMs triple, the relationship between the beam offsets follows a multivariate polynomial. After calculating the covariance matrix of the polynomial terms, the Generalized Total Least Squares method is used to find the model parameters, and thus the non-linear components. Finally, a bootstrap technique is used to determine confidence intervals of the estimated values. Results for synthetic data are shown.

MOPF31

Design and Performance of the Biased Drift Tube System in the BNL Electron Lens

RHIC, electron, vacuum, ion

291

T.A. Miller, W. Fischer, D.M. Gassner, X. Gu, A.I. Pikin, S. Polizzo, P. Thieberger
BNL, Upton, Long Island, New York, USA
J. Barth
Barth Electronics, Boulder City, USA

Funding: Work supported by U.S. DOE under contract No DE-AC02-98CH10886 with the U.S. Department of Energy.
The installation of the Electron Lenses in RHIC will be completed this year. Its design includes a series of drift tubes through which the electron beam copropagates, with the RHIC proton beams. These drift tubes are used to create an electric field gradient to sweep out ions that become trapped within the central magnetic field where the electron beam interacts with the proton beams. These isolated drift tubes are biased by high voltage power supplies. Without a path for the proton beam image currents, high voltages will develop on the drift tubes that can be detrimental to the electron beam and increase the RHIC machine impedance. This paper presents the design of the drift tubes, axial electric field gradient, and the custom high voltage RF bias tees that were designed to provide separate paths for the high frequency image currents and the DC high voltage bias over the same cables. The design and simulation of the bias tee is discussed, as well as RF signals from the proton beam current imaged on the drift tubes, as measured through the bias tees during the commissioning of the blue RHIC beam electron lens this past spring.

Poster MOPF31 [31.237 MB]

TUPC16

Bunch-by-Bunch Feedback and Diagnostics at BESSY II

feedback, longitudinal, injection, kicker

399

A. Schälicke, F. Falkenstern, R. Müller
HZB, Berlin, Germany

At the light source BESSY II new digital bunch-by-bunch feedback systems have been put into operation in January 2013, replacing the existing analog as well as the obsolete digital systems. From the first days of operation the new system successfully suppresses transverse and longitudinal beam instabilities in wide range of machine parameters. The system offers also many new diagnostics opportunities, these include the analysis of instability modes, measurement of the feedback loop gain, and determination of the transfer function. A method to systematically optimise the output amplifier response function with the help of shaper coefficients for the optimal bunch separation has been developed. In addition the analysis of the input data stream allows a passive determination of machine properties like betatron and synchrotron frequencies as well as the longitudinal phases for every bunch. The integration of external triggers permits the analysis of postmortem data, the characterisation of beam-loss events, and monitoring of the injection process. In this contribution first operational experience, the developed data analysis techniques and experimental data will be presented.

Poster TUPC16 [56.767 MB]

TUPC46

Beam Loss Monitoring Study for SIS100@FAIR

ion, simulation, GSI, SIS

485

V.S. Lavrik, L.H.J. Bozyk, O.K. Kester, A. Reiter
GSI, Darmstadt, Germany
O.K. Kester, V.S. Lavrik
IAP, Frankfurt am Main, Germany

FAIR, the facility for antiproton and ion research, is a multi-disciplinary accelerator facility which will extend the existing GSI complex in Darmstadt, Germany. In the FAIR start version, the new synchrotron SIS100 will provide proton or heavy ion beams for a variety of experiments. The GSI synchrotron SIS18 will operate as injector for SIS100. The current study focuses on beam loss measurements for SIS18 and SIS100. The aim of this study is to find quantitative methods to measure beam losses around the machine, mainly SIS100, on an absolute scale. The contribution will present results of two pilot experiments carried out in the high-energy beam lines and at the SIS18 with Uranium ions in the energy range up to 900 MeV/u. In the first experiment the Uranium beam was totally stopped in a Copper target and the particle shower measured with LHC-type ionization chambers. In the second experiment, the beam was slowly excited in the SIS18 synchrotron to create controlled losses on a scraper which were monitored by the DC current transformer and beam loss monitors. Experimental data are compared against the predictions of Fluka simulations.

Poster TUPC46 [5.404 MB]

TUPC47

Simulation for Radiation Field Caused by Beam Loss of C-ADS Injector II

proton, photon, electron, radiation

489

G. Ren, W. Li, Y. Li
USTC/NSRL, Hefei, Anhui, People's Republic of China
M. Zeng
Tsinghua University, Beijing, People's Republic of China

CADS is a Chinese ADS(Accelerator Driven Sub-critical System) project. Its injector is a high current, full superconducting proton accelerator. For such a facility, a BLM system is necessary, especially in low energy segments. This paper presents some basic simulation for 10MeV proton by Monte Carlo program FLUKA, as well as the distributions we got about different secondary particles in three aspects: angular, energy spectrum and current. These results are helpful to select the detector type and its location, determine its dynamic range matching different requirements for both fast and slow beam loss. This paper also analyzes the major impact of the background, such as superconducting cavity X radiation and radiation caused by material activation. This work is meaningful in BLM system research.

WECL3

The LUPIN Detector: Supporting Least Intrusive Beam Monitoring Technique Through Neutron Detection

radiation, monitoring, proton, synchrotron

648

G.P. Manessi, M. Silari
CERN, Geneva, Switzerland
M. Caresana
Politecnico/Milano, Milano, Italy
M. Ferrarini
CNAO Foundation, Milan, Italy
G.P. Manessi, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
G.P. Manessi, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom

The Long interval, Ultra-wide dynamic Pile-up free Neutron rem counter (LUPIN) is a novel detector initially developed for radiation protection purposes, specifically conceived for applications in pulsed neutron fields. The detector has a measurement capability varying over many orders of neutron burst intensity, from a single neutron up to thousands of interactions for each burst, without showing any saturation effect. Whilst LUPIN has been developed for applications in the radiation protection fields, its unique properties make it also well suited to support other beam instrumentation. In this contribution, the design of LUPIN is presented in detail and its main characteristics are summarized. Its potential use as beam loss monitor and complementary detector for non-invasive beam monitoring purposes (e.g. to complement a monitor based on proton beam “halo” detection) in medical accelerators is then examined. In the context of its application as a beam loss monitor for hadrontherapy accelerators, results of measurements performed at the Italian National Centre of Hadrontherapy (CNAO) are presented and analyzed.

Slides WECL3 [1.431 MB]

WEPC43

Update on Beam Loss Monitoring at CTF3 for CLIC

CLIC, DIAMOND, photon, quadrupole

787

L.J. Devlin, S. Mallows, C.P. Welsch, E.N. del Busto
Cockcroft Institute, Warrington, Cheshire, United Kingdom
E. Branger
Linköping University, Linköping, Sweden
L.J. Devlin, S. Mallows, C.P. Welsch, E.N. del Busto
The University of Liverpool, Liverpool, United Kingdom
E. Effinger, E.B. Holzer, S. Mallows, E.N. del Busto
CERN, Geneva, Switzerland

Funding: Work supported by STFC Cockcroft Institute Core Grant No. ST/G008248/1
The primary role of the beam loss monitoring (BLM) system for the compact linear collider (CLIC) study is to work within the machine protection system. Due to the size of the CLIC facility, a BLM that covers large distances along the beamline is highly desirable, in particular for the CLIC drive beam decelerators, which would alternatively require some ~40,000 localised monitors. Therefore, an optical fiber BLM system is currently under investigation which can cover large sections of beamline at a time. A multimode fiber has been installed along the Test Beam Line at the CLIC test facility (CTF3) where the detection principle is based on the production of Cherenkov photons within the fiber resulting from beam loss and their subsequent transport along the fiber where they are then detected at the fiber ends using silicon photomultipliers. Several additional monitors including ACEMs, PEP-II and diamond detectors have also been installed. In this contribution the first results from the BLMs are presented, comparisons of the signals from each BLM are made and the possible achievable longitudinal resolution from the fiber BLM signal considering various loss patterns is discussed.

WEPC44

Operation of Silicon, Diamond and Liquid Helium Detectors in the Range of Room Temperature to 1.9 Kelvin and After an Irradiation Dose of Several Mega Gray

DIAMOND, proton, LHC, CERN

791

C. Kurfuerst, M.R. Bartosik, B. Dehning, T. Eisel, M. Sapinski
CERN, Geneva, Switzerland
V. Eremin
IOFFE, St. Petersburg, Russia

At the triplet magnets close to the interaction regions of the LHC, the current Beam Loss Monitoring system is sensitive to the debris from the collision points. For future beams with higher energy and intensity, the expected increase in luminosity and associated increase of the debris from interaction products is expected to compete with any quench-provoking beam losses from the primary proton beams. In order to distinguish between the two, it is proposed to locate the detectors as close as possible to the superconducting coil. The detectors therefore have to be located inside the cold mass of the superconducting magnets in superfluid helium at 1.9 K. Past measurements have shown that in a liquid helium chamber, diamond and silicon detectors are promising candidates for cryogenic beam loss monitors. This contribution will show the results from new high irradiation beam measurements at both room temperature and 1.9 Kelvin to reveal the radiation tolerance of these different detectors.

WEPC45

Beam Loss Monitoring at the European Spallation Source

ESS, LHC, XFEL, simulation

795

L. Tchelidze, H. Hassanzadegan, A. Jansson, M. Jarosz
ESS, Lund, Sweden

At the European Spallation Source proton linear accelerator will generate 5 MW protons to be delivered to a target. This high power accelerator will require significant amount of beam instrumentation, among which the beam loss monitoring system is one of the most important for operation. An LHC type ionization chamber will be used with ~54 uC/Gy sensitivity. At most 1.5 mGy/sec radiation levels are expected close to the beam pipe during normal operation, resulting in up to 80 nA current signal in detectors. Loss monitor electronics is designed to be able to measure currents as little as 1% of the expected current up to as much as 1% of the total beam loss, thus ~800 pA – few mA. In order to study beam loss pattern along the accelerator a coherent model of the whole machine is created for the purposes of Monte Carlo particle transport simulations. Data obtained using the model will be stored in a database together with the initial beam loss conditions. The contents of the database will then be processed using custom neural network algorithms to optimize number and position of the loss monitors and to provide reference on the beam loss localization during operation of the machine.

Poster WEPC45 [1.784 MB]

WEPF26

Test Bench Experiments for Energy Measurement and Beam Loss of ESS-Bilbao

rfq, ion, ESS, diagnostics

876

S. Varnasseri, I. Arredondo, D. Belver, P. Echevarria, M. Eguiraun
ESS Bilbao, Zamudio, Spain

Various test benches have been developed at ESS-Bilbao in order to characterize different beam diagnostics and control systems prior to their installation on various parts of the accelerator. One test bench includes time-of-flight (TOF) characterization for energy measurement using fast current transformers (FCT). Using FCTs for the TOF measurement would allow us to measure accurately the delay between two successive bunched or un-bunched beam pulses of low energy ions. The other test bench includes a beam loss monitoring and interlock system using ACCTs, cRIO and PXI chassis with some acquisition modules and optical fiber link which represent a complete system of beam loss detection, interlock logic and trigger signal transmission. Having an integration on the ACCT output also allows us to measure the beam charge at the location of monitoring. In the test benches the functionality of hardware and software, the logic and required signal specifications like rise time, jitters and delays are measured. An overview of test benches and their measurement results are reported in this paper.

Poster WEPF26 [1.120 MB]

WEPF29

The LHC Fast Beam Current Change Monitor

LHC, injection, CERN, FIR

887

D. Belohrad, J.M. Belleman, L.K. Jensen, M. Krupa, A. Topaloudis
CERN, Geneva, Switzerland

The modularity of the Large Hadron Collider’s (LHC) machine protection system (MPS) allows for the integration of several beam diagnostic instruments. These instruments have not necessarily been designed to have protection functionality, but MPS can still use them to increase the redundancy and reliability of the machine. The LHC fast beam current change monitor (FBCCM) is an example. It is based on analogue signals from fast beam current transformers (FBCT) used nominally to measure the LHC bunch intensities. The FBCCM calculates the magnitude of the beam signal provided by the FBCT, looks for a change over specific time intervals, and triggers a beam dump interlock if losses exceed an energy-dependent threshold. The first prototype of the FBCCM was installed in the LHC during the 2012-2013 run. The aim of this article is to present the FBCCM system and the results obtained, analyse its current performance and provide an outlook for the final system which is expected to be operational after the long LHC shutdown.

WEPF30

System Overview and Preliminary Test Results of the ESS Beam Current Monitor System

ESS, linac, controls, monitoring

891

H. Hassanzadegan, A. Jansson
ESS, Lund, Sweden
K. Strniša
Cosylab, Ljubljana, Slovenia

The ESS Linac will include in total 21 Beam Current Monitors, mostly of ACCT type, to measure the average current over the 2.86 ms beam pulse, the pulse charge and the pulse profile. It is also planned to use a few Fast Current Transformers to check the performance of the fast beam choppers with a rise time as short as 10 ns. In addition to the absolute current measurement, the BCM system needs to measure the differential beam current and act on the Machine Interlock System if the difference exceeds some thresholds. The differential current measurement is particularly important in the low energy part of the Linac, where Beam Loss Monitors cannot reliably detect beam losses. This paper gives an overview of the ESS BCM system and presents some preliminary test results with a commercial ACCT and MTCA.4 electronics.

Poster WEPF30 [6.267 MB]

THAL2

A New Differential and Errant Beam Current Monitor for the SNS Accelerator

SCL, SNS, linac, target

921

W. Blokland
ORNL, Oak Ridge, Tennessee, USA
C.C. Peters
ORNL RAD, Oak Ridge, Tennessee, USA

Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725
A new Differential and errant Beam Current Monitor (DBCM) is being implemented for the Spallation Neutron Source's Medium Energy Beam Transport (MEBT) and Super Conducting linac (SCL) accelerator sections. This new current monitor will abort the beam when the difference between two toroidal pickups exceeds a threshold. The MEBT DBCM will protect the MEBT chopper target while the SCL DBCM will abort beam to minimize fast beam losses in the SCL cavities. The new DBCM will also record instances of errant beam such as beam drop-outs to assist in further optimization of the SNS Accelerator. A software Errant Beam Monitor was implemented on the regular BCM hardware to study errant beam pulses. The new system will take over this functionality and will also be able to abort beam on pulse to pulse variations. as it is based on the FlexRIO hardware programmed in LabVIEW FPGA and can abort beam in 5 us. This paper describes the development, implementation, and initial test results of the DBCM as well as errant beam examples.

Slides THAL2 [9.413 MB]