IBIC2013 - List of Authors (Soby, L.)

Paper

Title

Page

Beam Position Monitors R&D for keV Ion Beams

78

S. Naveed, A.A. Nosych, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
S. Naveed, A.A. Nosych, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
A.A. Nosych, L. Søby
CERN, Geneva, Switzerland

Funding: Work supported by the EU within the DITANET and oPAC projects under contracts 215080 and 289485, HGF and GSI under contract VH-NG-328 and STFC under the Cockcroft Institute core grant ST/G008248/1.
Beams of cooled antiprotons at keV energies shall be provided by the Ultra-low energy Storage Ring (USR) at the Facility for Low energy Antiproton and Ion Research (FLAIR) and the Extra Low ENergy Antiproton ring (ELENA) at CERN's Antiproton Decelerator (AD) facility. Both storage rings put challenging demands on the beam position monitoring system as their capacitive pick-ups should be capable of determining the beam position of beams at low intensities and low velocities, close to the noise level of state-of-the-art electronics. In this contribution we describe the design and anticipated performance of BPMs for low-energy ion beams on the examples of the USR and ELENA orbit measurement systems. We also present the particular challenges encountered in the numerical simulation of pickup response at very low beta values and describe an experimental setup realized at the Cockcroft Institute for BPM callibration. Finally, we provide an outlook on how the implementation of faster algorithms for the simulation of BPM characteristics could potentially help speed up such studies considerably.

TUPC12

Status of the Stripline Beam Position Monitor Development for the CLIC Drive Beam

384

A. Benot-Morell, L. Søby, M. Wendt
CERN, Geneva, Switzerland
A. Benot-Morell, A. Faus-Golfe
IFIC, Valencia, Spain
J.M. Nappa, S. Vilalte
IN2P3-LAPP, Annecy-le-Vieux, France
S.R. Smith
SLAC, Menlo Park, California, USA

Funding: MINECO contract FPA2010-21456-C02-01, SEIC-2010-00028, U.S. Department of Energy contract DE-AC02-76SF00515
In collaboration with SLAC, LAPP and IFIC, a first prototype of a strip-line Beam Position Monitor (BPM) for the CLIC Drive Beam and its associated readout electronics has been successfully tested in the CLIC Test Facility linac (CTF3) at CERN. In addition, a modified prototype with downstream terminated strip-lines is under development to better suppress any unwanted RF signal interference. This paper presents the results of the beam tests, the most relevant design aspects for the modified strip-line BPM version and its expected performance.

Poster TUPC12 [1.729 MB]

TUPC19

First Beam Tests of a Prototype Cavity Beam Position Monitor for the CLIC Main Beam

411

F.J. Cullinan, S.T. Boogert, A. Lyapin, J.R. Towler
JAI, Egham, Surrey, United Kingdom
W. Farabolini, T. Lefèvre, L. Søby, M. Wendt
CERN, Geneva, Switzerland

Beam position monitors (BPMs) throughout the CLIC (Compact Linear Collider) main linac and beam delivery system must routinely operate at 50 nm resolution and be able to make multiple position measurements within a single 156 ns long bunch train. A prototype cavity beam position monitor, designed to demonstrate this performance, has been tested on the probe beamline of CTF3 (the CLIC Test Facility). Sensitivity measurements of the dipole mode position cavity and of the monopole mode reference cavity have been made. The characteristics of signals from short and long bunch trains and the dominant systematic effects have also been studied.

TUPC20

Technologies and R&D for a High Resolution Cavity BPM for the CLIC Main Beam

415

J.R. Towler, T. Lefèvre, L. Søby, M. Wendt
CERN, Geneva, Switzerland
S.T. Boogert, F.J. Cullinan, A. Lyapin
JAI, Egham, Surrey, United Kingdom

The Main Beam (MB) LINAC of the Compact Linear Collider (CLIC) requires a beam orbit measurement system with a high spatial (50 nm) and high temporal (50 ns) resolution to resolve the beam position within the 156 ns long bunch train, traveling on an energy-chirped, minimum dispersive trajectory. A 15 GHz prototype cavity BPM has been commissioned in the probe beam-line of the CTF3 CLIC Test Facility. The performance and technical details of this prototype installation are discussed in this paper, including the 15 GHz analog down-converter, the data acquisition and the control electronics and software. An R&D outlook is given for the next steps, which requires a system of 3 cavity BPMs to investigate the full resolution potential.

WEPF28

Longitudinal Beam Diagnostic from a Distributed Electrostatic Pick-Up in CERN’s ELENA Ring

883

M.E. Angoletta, F. Caspers, S. Federmann, J.C. Molendijk, P.J. Pascal Jean, F. Pedersen, J. Sanchez-Quesada, L. Søby, M.A. Timmins
CERN, Geneva, Switzerland

The CERN Extra Low ENergy Antiproton (ELENA) Ring is a new synchrotron that will be commissioned in 2016 to further decelerate the antiprotons coming from CERN’s Antiproton Decelerator (AD). Required longitudinal diagnostics include the intensity measurement for bunched and debunched beam and the measurement of Dp/p for a debunched beam to assess the electron cooling performance. A novel method for the calculation of these parameters is proposed for ELENA, where signals from the twenty electrostatic pick-ups (PU) used for orbit measurements will be combined to improve the signal-to-noise ratio. This requires that the signals be digitally down-converted, rotated and digitally summed so that the many electrostatic PUs will function as a single, distributed PU from to the processing system viewpoint. This method includes some challenges and will not be used as the baseline longitudinal diagnostics for the initial ELENA operation. This paper gives an overview of the hardware and digital signal processing involved, as well as of the challenges that will have to be faced.

Paper	Title	Page
MOPC14	Beam Position Monitors R&D for keV Ion Beams	78
	S. Naveed, A.A. Nosych, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom S. Naveed, A.A. Nosych, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom A.A. Nosych, L. Søby CERN, Geneva, Switzerland
	Funding: Work supported by the EU within the DITANET and oPAC projects under contracts 215080 and 289485, HGF and GSI under contract VH-NG-328 and STFC under the Cockcroft Institute core grant ST/G008248/1. Beams of cooled antiprotons at keV energies shall be provided by the Ultra-low energy Storage Ring (USR) at the Facility for Low energy Antiproton and Ion Research (FLAIR) and the Extra Low ENergy Antiproton ring (ELENA) at CERN's Antiproton Decelerator (AD) facility. Both storage rings put challenging demands on the beam position monitoring system as their capacitive pick-ups should be capable of determining the beam position of beams at low intensities and low velocities, close to the noise level of state-of-the-art electronics. In this contribution we describe the design and anticipated performance of BPMs for low-energy ion beams on the examples of the USR and ELENA orbit measurement systems. We also present the particular challenges encountered in the numerical simulation of pickup response at very low beta values and describe an experimental setup realized at the Cockcroft Institute for BPM callibration. Finally, we provide an outlook on how the implementation of faster algorithms for the simulation of BPM characteristics could potentially help speed up such studies considerably.

TUPC12	Status of the Stripline Beam Position Monitor Development for the CLIC Drive Beam	384
	A. Benot-Morell, L. Søby, M. Wendt CERN, Geneva, Switzerland A. Benot-Morell, A. Faus-Golfe IFIC, Valencia, Spain J.M. Nappa, S. Vilalte IN2P3-LAPP, Annecy-le-Vieux, France S.R. Smith SLAC, Menlo Park, California, USA
	Funding: MINECO contract FPA2010-21456-C02-01, SEIC-2010-00028, U.S. Department of Energy contract DE-AC02-76SF00515 In collaboration with SLAC, LAPP and IFIC, a first prototype of a strip-line Beam Position Monitor (BPM) for the CLIC Drive Beam and its associated readout electronics has been successfully tested in the CLIC Test Facility linac (CTF3) at CERN. In addition, a modified prototype with downstream terminated strip-lines is under development to better suppress any unwanted RF signal interference. This paper presents the results of the beam tests, the most relevant design aspects for the modified strip-line BPM version and its expected performance.
	Poster TUPC12 [1.729 MB]

TUPC19	First Beam Tests of a Prototype Cavity Beam Position Monitor for the CLIC Main Beam	411
	F.J. Cullinan, S.T. Boogert, A. Lyapin, J.R. Towler JAI, Egham, Surrey, United Kingdom W. Farabolini, T. Lefèvre, L. Søby, M. Wendt CERN, Geneva, Switzerland
	Beam position monitors (BPMs) throughout the CLIC (Compact Linear Collider) main linac and beam delivery system must routinely operate at 50 nm resolution and be able to make multiple position measurements within a single 156 ns long bunch train. A prototype cavity beam position monitor, designed to demonstrate this performance, has been tested on the probe beamline of CTF3 (the CLIC Test Facility). Sensitivity measurements of the dipole mode position cavity and of the monopole mode reference cavity have been made. The characteristics of signals from short and long bunch trains and the dominant systematic effects have also been studied.

TUPC20	Technologies and R&D for a High Resolution Cavity BPM for the CLIC Main Beam	415
	J.R. Towler, T. Lefèvre, L. Søby, M. Wendt CERN, Geneva, Switzerland S.T. Boogert, F.J. Cullinan, A. Lyapin JAI, Egham, Surrey, United Kingdom
	The Main Beam (MB) LINAC of the Compact Linear Collider (CLIC) requires a beam orbit measurement system with a high spatial (50 nm) and high temporal (50 ns) resolution to resolve the beam position within the 156 ns long bunch train, traveling on an energy-chirped, minimum dispersive trajectory. A 15 GHz prototype cavity BPM has been commissioned in the probe beam-line of the CTF3 CLIC Test Facility. The performance and technical details of this prototype installation are discussed in this paper, including the 15 GHz analog down-converter, the data acquisition and the control electronics and software. An R&D outlook is given for the next steps, which requires a system of 3 cavity BPMs to investigate the full resolution potential.

WEPF28	Longitudinal Beam Diagnostic from a Distributed Electrostatic Pick-Up in CERN’s ELENA Ring	883
	M.E. Angoletta, F. Caspers, S. Federmann, J.C. Molendijk, P.J. Pascal Jean, F. Pedersen, J. Sanchez-Quesada, L. Søby, M.A. Timmins CERN, Geneva, Switzerland
	The CERN Extra Low ENergy Antiproton (ELENA) Ring is a new synchrotron that will be commissioned in 2016 to further decelerate the antiprotons coming from CERN’s Antiproton Decelerator (AD). Required longitudinal diagnostics include the intensity measurement for bunched and debunched beam and the measurement of Dp/p for a debunched beam to assess the electron cooling performance. A novel method for the calculation of these parameters is proposed for ELENA, where signals from the twenty electrostatic pick-ups (PU) used for orbit measurements will be combined to improve the signal-to-noise ratio. This requires that the signals be digitally down-converted, rotated and digitally summed so that the many electrostatic PUs will function as a single, distributed PU from to the processing system viewpoint. This method includes some challenges and will not be used as the baseline longitudinal diagnostics for the initial ELENA operation. This paper gives an overview of the hardware and digital signal processing involved, as well as of the challenges that will have to be faced.