DIPAC2011 - List of Keywords (coupling)

Paper	Title	Other Keywords	Page
MOOC01	Overview of Recent Trends and Developments for BPM Systems	cavity, pick-up, monitoring, linac	18
	M. Wendt Fermilab, Batavia, USA
	Beam position monitoring (BPM) systems are the workhorse beam diagnostics for almost any kind of charged particle accelerator; linear, circular or transport-lines, operating with leptons, hadrons or heavy ions. The BPMs are essential for beam commissioning, accelerator fault analysis and trouble shooting, machine optics and lattice measurements, and finally for the accelerator optimization to achieve the ultimate beam quality. This presentation summarizes the efforts of the beam instrumentation community on recent developments and advances on BPM technologies, i.e. BPM pickup monitors and front-end electronics (analog and digital). Principles, examples, and state-of-the-art status on various BPM techniques are outlined, serving hadron and heavy ion machines, sync light synchrotron's, as well as electron linacs for FEL or HEP applications.
	Slides MOOC01 [4.123 MB]

MOPD13	Mode Selective Waveguide BPM	cavity, pick-up, simulation, impedance	65
	A. Lyapin JAI, Egham, Surrey, United Kingdom
	I propose a mode-selective waveguide Beam Position Monitor (BPM). It uses waveguide couplers arranged at the beampipe to create boundary conditions similar to those in slot-coupled cavity BPMs. This structure allows to couple to the differential waveguide mode co-propagating with the beam, and reject the usually much stronger monopole component of the field. As the full dynamic range of the processing electronics can be used for position measurements, and a waveguide is a native high-pass filter, such a BPM is expected to outperform stripline and button BPMs in terms of both spacial and time resolution. In this paper I give some details on the basic principle and the first simulation results and discuss possible ways of signal processing.
	Poster MOPD13 [3.052 MB]

MOPD24	A High-resolution Diode-based Orbit Measurement System – Prototype Results from the LHC	feedback, pick-up, vacuum, injection	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]

MOPD25	Diode Down-mixing of HOM Coupler Signals for Beam Position Determination in 1.3-GHz- and 3.9-GHz-Cavities at FLASH	HOM, cavity, polarization, dipole	101
	H.-W. Glock, H. Ecklebe, T. Flisgen Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany N. Baboi, P. Zhang DESY, Hamburg, Germany
	Funding: work supported by BMBF under contract 05K10HRC and by European Commission under the FP7 Research Infrastructures grant agreement No.227579 Beam excited signals available at the HOM coupler ports of superconducting accelerating cavities cover a wide frequency range and carry information about (amongst others) transverse beam position. Down-mixing these signals using detector diodes is a mean to measure with standard and non-specific oscilloscope technology the time dependency of the power leaving the HOM coupler. Experiments undertaken at the accelerator modules ACC1 and ACC39 at FLASH demonstrated the possibility to extract beam position data out of low-frequency signals sampled with such a setup. These experiments as part of an ongoing study are described together with mathematical details of the evaluation scheme.

TUPD13	CLIC Drive Beam Position Monitor	electron, damping, linac, luminosity	326
	S.R. Smith, A. Cappelletti, D. Gudkov, L. Søby, I. Syratchev CERN, Geneva, Switzerland S.R. Smith SLAC, Menlo Park, California, USA
	Funding: Work supported by Department of Energy contract DE-AC02-76SF00515 CLIC, an electron-positron linear collider proposed to probe the TeV energy scale, is based on a two-beam scheme where RF power to accelerate a high energy luminosity beam is extracted from a high current drive beam. The drive beam is efficiently generated in a long train at modest frequency and current then compressed in length and multiplied in frequency via bunch interleaving. The drive beam decelerator requires >40000 quadrupoles, each holding a beam position monitor (BPM). Though resolution requirements are modest (2 microns) these BPMs face several challenges. They must be compact and inexpensive. They must operate below waveguide cutoff to insure locality of position signals, ruling out processing at the natural 12 GHz bunch spacing frequency. Wakefields must be kept low. We find compact conventional stripline BPM with signals processed below 40 MHz can meet requirements. Choices of mechanical design, operating frequency, bandwidth, calibration, and processing algorithm are presented. Calculations of wakes and trapped modes and damping are discussed.

TUPD61	Multi Optical Transition Radiation System for ATF2	emittance, target, controls, extraction	446
	C. Blanch Gutierrez, J. Alabau-Gonzalvo, A. Faus-Golfe, J.J. García-Garrigós IFIC, Valencia, Spain J. Cruz, D.J. McCormick, G.R. White, M. Woodley SLAC, Menlo Park, California, USA
	Funding: FPA2010-21456-C02-00 In this paper we describe the calibration tests, software development and first measurements of a Multi Optical Transition Radiation System in the beam diagnostic section of the Extraction (EXT) line of ATF2, close to the multi wire scanner system. First 2D emittance measurements have been made with success and the system is being used normally for coupling correction. 4D emittance reconstruction algorithm is under improvement and implementation before a systematic measurement campaign and comparison with wire scanners is done. This will be a definitive test of the OTR as a beam emittance diagnostic device, which will give the ability to measure the beam emittance with high statistics, giving a low error and a good understanding of emittance jitter.

TUPD70	Conceptual Design of a High Sensitive Versatile Schottky Sensor for the Collector Ring at FAIR	cavity, antiproton, impedance, storage-ring	470
	M. Hansli, R. Jakoby, A. Penirschke TU Darmstadt, Darmstadt, Germany W. Ackermann, T. Weiland TEMF, TU Darmstadt, Darmstadt, Germany W. Kaufmann GSI, Darmstadt, Germany
	Funding: Funded by the Federal Ministry of Education and Research (BMBF): 06DA90351 The FAIR (Facility for Antiproton and Ion Research) accelerator complex includes the Collector Ring CR, i.e. a dedicated storage ring for secondary particles, rare isotopes and antiprotons. The CR features three different modes of operation: pre-cooling of antiprotons at 3 GeV, pre-cooling of rare isotope beams at 740 MeV/u and an isochronous mode for mass measurements. For beam optimizations in all three modes a sensitive Schottky setup is required to monitor very low beam intensities down to single particles. In this paper the conceptual design of a longitudinal Schottky sensor based on a pillbox cavity with adjustable coupling and frequency tuning is presented. The basic measurement principles are depicted and a possible realization is discussed with emphasize on the special requirements of the CR operational modes. Full-wave simulations of the proposed sensor cavity allow for further optimizations.
	Poster TUPD70 [1.247 MB]

WEOC01	Beam Charge Measurements	vacuum, impedance, pick-up, linac	564
	D. Belohrad CERN, Geneva, Switzerland
	The measurement of beam charge is fundamental to all particle accelerators. There exist many methods to achieve this, which can broadly be classified into two categories: intercepting measurements, which are destructive for the beam and result in absorption of a significant amount of energy; non-intercepting measurements using electric or magnetic field coupling. In both categories one can find instruments that process the beam signals with high dynamic range, both in amplitude and time. The aim of this article is to present the current state of beam charge measurement technology. Various measurement methods will be described with their uses, advantages, and achievable resolution and accuracy discussed. The technological problems related to their fabrication will also be addressed.
	Slides WEOC01 [5.738 MB]

Paper

Title

Other Keywords

Page

MOOC01

Overview of Recent Trends and Developments for BPM Systems

cavity, pick-up, monitoring, linac

18

M. Wendt
Fermilab, Batavia, USA

Beam position monitoring (BPM) systems are the workhorse beam diagnostics for almost any kind of charged particle accelerator; linear, circular or transport-lines, operating with leptons, hadrons or heavy ions. The BPMs are essential for beam commissioning, accelerator fault analysis and trouble shooting, machine optics and lattice measurements, and finally for the accelerator optimization to achieve the ultimate beam quality. This presentation summarizes the efforts of the beam instrumentation community on recent developments and advances on BPM technologies, i.e. BPM pickup monitors and front-end electronics (analog and digital). Principles, examples, and state-of-the-art status on various BPM techniques are outlined, serving hadron and heavy ion machines, sync light synchrotron's, as well as electron linacs for FEL or HEP applications.

Slides MOOC01 [4.123 MB]

MOPD13

Mode Selective Waveguide BPM

cavity, pick-up, simulation, impedance

65

A. Lyapin
JAI, Egham, Surrey, United Kingdom

I propose a mode-selective waveguide Beam Position Monitor (BPM). It uses waveguide couplers arranged at the beampipe to create boundary conditions similar to those in slot-coupled cavity BPMs. This structure allows to couple to the differential waveguide mode co-propagating with the beam, and reject the usually much stronger monopole component of the field. As the full dynamic range of the processing electronics can be used for position measurements, and a waveguide is a native high-pass filter, such a BPM is expected to outperform stripline and button BPMs in terms of both spacial and time resolution. In this paper I give some details on the basic principle and the first simulation results and discuss possible ways of signal processing.

Poster MOPD13 [3.052 MB]

MOPD24

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

feedback, pick-up, vacuum, injection

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]

MOPD25

Diode Down-mixing of HOM Coupler Signals for Beam Position Determination in 1.3-GHz- and 3.9-GHz-Cavities at FLASH

HOM, cavity, polarization, dipole

101

H.-W. Glock, H. Ecklebe, T. Flisgen
Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
N. Baboi, P. Zhang
DESY, Hamburg, Germany

Funding: work supported by BMBF under contract 05K10HRC and by European Commission under the FP7 Research Infrastructures grant agreement No.227579
Beam excited signals available at the HOM coupler ports of superconducting accelerating cavities cover a wide frequency range and carry information about (amongst others) transverse beam position. Down-mixing these signals using detector diodes is a mean to measure with standard and non-specific oscilloscope technology the time dependency of the power leaving the HOM coupler. Experiments undertaken at the accelerator modules ACC1 and ACC39 at FLASH demonstrated the possibility to extract beam position data out of low-frequency signals sampled with such a setup. These experiments as part of an ongoing study are described together with mathematical details of the evaluation scheme.

TUPD13

CLIC Drive Beam Position Monitor

electron, damping, linac, luminosity

326

S.R. Smith, A. Cappelletti, D. Gudkov, L. Søby, I. Syratchev
CERN, Geneva, Switzerland
S.R. Smith
SLAC, Menlo Park, California, USA

Funding: Work supported by Department of Energy contract DE-AC02-76SF00515
CLIC, an electron-positron linear collider proposed to probe the TeV energy scale, is based on a two-beam scheme where RF power to accelerate a high energy luminosity beam is extracted from a high current drive beam. The drive beam is efficiently generated in a long train at modest frequency and current then compressed in length and multiplied in frequency via bunch interleaving. The drive beam decelerator requires >40000 quadrupoles, each holding a beam position monitor (BPM). Though resolution requirements are modest (2 microns) these BPMs face several challenges. They must be compact and inexpensive. They must operate below waveguide cutoff to insure locality of position signals, ruling out processing at the natural 12 GHz bunch spacing frequency. Wakefields must be kept low. We find compact conventional stripline BPM with signals processed below 40 MHz can meet requirements. Choices of mechanical design, operating frequency, bandwidth, calibration, and processing algorithm are presented. Calculations of wakes and trapped modes and damping are discussed.

TUPD61

Multi Optical Transition Radiation System for ATF2

emittance, target, controls, extraction

446

C. Blanch Gutierrez, J. Alabau-Gonzalvo, A. Faus-Golfe, J.J. García-Garrigós
IFIC, Valencia, Spain
J. Cruz, D.J. McCormick, G.R. White, M. Woodley
SLAC, Menlo Park, California, USA

Funding: FPA2010-21456-C02-00
In this paper we describe the calibration tests, software development and first measurements of a Multi Optical Transition Radiation System in the beam diagnostic section of the Extraction (EXT) line of ATF2, close to the multi wire scanner system. First 2D emittance measurements have been made with success and the system is being used normally for coupling correction. 4D emittance reconstruction algorithm is under improvement and implementation before a systematic measurement campaign and comparison with wire scanners is done. This will be a definitive test of the OTR as a beam emittance diagnostic device, which will give the ability to measure the beam emittance with high statistics, giving a low error and a good understanding of emittance jitter.

TUPD70

Conceptual Design of a High Sensitive Versatile Schottky Sensor for the Collector Ring at FAIR

cavity, antiproton, impedance, storage-ring

470

M. Hansli, R. Jakoby, A. Penirschke
TU Darmstadt, Darmstadt, Germany
W. Ackermann, T. Weiland
TEMF, TU Darmstadt, Darmstadt, Germany
W. Kaufmann
GSI, Darmstadt, Germany

Funding: Funded by the Federal Ministry of Education and Research (BMBF): 06DA90351
The FAIR (Facility for Antiproton and Ion Research) accelerator complex includes the Collector Ring CR, i.e. a dedicated storage ring for secondary particles, rare isotopes and antiprotons. The CR features three different modes of operation: pre-cooling of antiprotons at 3 GeV, pre-cooling of rare isotope beams at 740 MeV/u and an isochronous mode for mass measurements. For beam optimizations in all three modes a sensitive Schottky setup is required to monitor very low beam intensities down to single particles. In this paper the conceptual design of a longitudinal Schottky sensor based on a pillbox cavity with adjustable coupling and frequency tuning is presented. The basic measurement principles are depicted and a possible realization is discussed with emphasize on the special requirements of the CR operational modes. Full-wave simulations of the proposed sensor cavity allow for further optimizations.

Poster TUPD70 [1.247 MB]

WEOC01

Beam Charge Measurements

vacuum, impedance, pick-up, linac

564

D. Belohrad
CERN, Geneva, Switzerland

The measurement of beam charge is fundamental to all particle accelerators. There exist many methods to achieve this, which can broadly be classified into two categories: intercepting measurements, which are destructive for the beam and result in absorption of a significant amount of energy; non-intercepting measurements using electric or magnetic field coupling. In both categories one can find instruments that process the beam signals with high dynamic range, both in amplitude and time. The aim of this article is to present the current state of beam charge measurement technology. Various measurement methods will be described with their uses, advantages, and achievable resolution and accuracy discussed. The technological problems related to their fabrication will also be addressed.

Slides WEOC01 [5.738 MB]