6 citations · 45 across the 21 of their papers we have counts for
23 papers
Status of Higher Order Mode Beam Position Monitors in 3.9 GHz Superconducting Accelerating Cavities at FLASH
P. Zhang, N. Baboi, T. Flisgen +3
Higher order mode (HOM) beam position monitors (BPM) are being developed for the 3.9 GHz third harmonic superconducting accelerating cavities at FLASH. The transverse beam position…
Beam Coupling Impedance of the LHC TCTP Collimators
Hugo Day, Fritz Caspers, Alessandro Dallocchio +5
As part of an upgrade to the LHC collimation system, 8 TCTP and 1 TCSG collimators are proposed to replace existing collimators in the collimation system. In an effort to review al…
Evaluation of the Beam Coupling Impedance of New Beam Screen Designs for the LHC Injection Kicker Magnets
Hugo Day, Michael Barnes, Fritz Caspers +3
During the 2011 run of the LHC there was a significant measured temperature increase in the LHC Injection Kicker Magnets (MKI) during operation with 50ns bunch spacing. This was du…
Higher order mode spectra and the dependence of localized dipole modes on the transverse beam position in third harmonic superconducting cavities at FLASH
Pei Zhang, Nicoleta Baboi, Roger M. Jones
An electron beam entering an accelerating cavity excites a wakefield. This wakefield can be decomposed into a series of multi-poles or modes. The dominant component of the transver…
Higher Order Modes for Beam Diagnostics in Third Harmonic 3.9 GHz Accelerating Module
N. Baboi, N. Eddy, T. Flisgen +4
An international team is currently investigating the best way to use Higher Order Modes (HOM) for beam diagnostics in 3.9 GHz cavities. HOMs are excited by charged particles when p…
Eigenmode Simulations of Third Harmonic Superconducting Accelerating Cavities for FLASH and the European XFEL
Pei Zhang, Nicoleta Baboi, Roger M. Jones
The third harmonic nine-cell cavity (3.9 GHz) for FLASH and the European XFEL has been investigated using simulations performed with the computer code CST Microwave Studio. The ban…
Measurement of the dynamic response of the CERN DC spark system and preliminary estimates of the breakdown turn-on time
Nicholas Shipman, Sergio Calatroni, Roger M. Jones +1
The new High Repetition Rate (HRR) CERN DC Spark System has been used to investigate the current and voltage time structure of a breakdown. Simulations indicate that vacuum breakdo…
Simulations of higher order modes in the ACC39 module of FLASH
I. R. R. Shinton, R. M. Jones, Z. Li +1
This study is focused on the development of a HOM-based BPM system for the ACC39 module currently installed and in operation at FLASH. A similar system is anticipated to be install…
Enhanced coupling design of a detuned damped structure for clic
A. D'Elia, R. M. Jones, A. Grudiev +3
The key feature of the improved coupling design in the Damped Detuned Structure (DDS) is focused on the four manifolds. Rectangular geometry slots and rectangular manifolds are use…
Comparison of the current LHC Collimators and the SLAC Phase 2 Collimator Impedances
Hugo Day, Fritz Caspers, Elias Metral +2
One of the key sources of transverse impedance in the LHC has been the secondary graphite collimators that sit close to the beam at all energies. This limits the stable bunch inten…
Coaxial Wire Measurements of Ferrite Kicker Magnets
Hugo Day, Michael Barnes, Fritz Caspers +4
Fast kicker magnets are used to inject beam into and eject beam out of the CERN accelerator rings. These kickers are generally transmission line type magnets with a rectangular sha…
Simulations of Coaxial Wire Measurements of the Impedance of Asymmetric Structures
Hugo Day, Fritz Caspers, Elias Metral +1
Coaxial wire measurements have provided a simple and effective way to measure the beam coupling impedance of accelerator structures for a number of years. It has been known how to…
Higher Order Modes in Coupled Cavities of the Flash Module ACC39
I. R. R. Shinton, R. M. Jones, Z. Li +1
We analyse the higher order modes (HOM's) in the 3.9GHz bunch shaping cavities installed in the FLASH facility at DESY. A suite of finite element computer codes (including HFSS and…
Comparative Wakefield Analysis of a First Prototype of a DDS Structure for CLIC Main Linac
A. D'Elia, R. M. Jones, V. F. Khan +2
A Damped Detuned Structure (DDS) for CLIC main linac has been proposed as an alternative to the present baseline design which is based on heavy damping. A first prototype, CLIC_DDS…
Study of Beam Diagnostics with Trapped Modes in Third Harmonic Superconducting Cavities at FLASH
P. Zhang, N. Baboi, R. M. Jones +1
Off-axis beams passing through an accelerating cavity excite dipole modes among other higher order modes (HOMs). These modes have linear dependence on the transverse beam offset fr…
First Beam Spectra of SC Third Harmonic Cavity at FLASH
P. Zhang, N. Baboi, T. Flisgen +5
Third harmonic superconducting cavities have been designed and fabricated by FNAL to minimise the energy spread along bunches in the FLASH facility at DESY. A module, consisting of…
Beam Dynamics Investigation of the 101.28 MHz IH Structure as Injector for the HIE-ISOLDE SC Linac
M. A. Fraser, M. Pasini, R. M. Jones +1
The first phase of the HIE-ISOLDE project at CERN consists of a superconducting (SC) linac upgrade in order to increase the energy of post-accelerated radioactive ion beams from 2.…
Gallium Arsenide preparation and QE Lifetime Studies using the ALICE Photocathode Preparation Facility
N. Chanlek, R. M. Jones, J. D. Herbert +3
In recent years, Gallium Arsenide (GaAs) type photocathodes have become widely used as electron sources in modern Energy Recovery Linac based light sources such as the Accelerators…
Status of COLDDIAG: A Cold Vacuum Chamber for Diagnostics
S. Gerstl, T. Baumbach, S. Casalbuoni +19
One of the still open issues for the development of superconducting insertion devices is the understanding of the beam heat load. With the aim of measuring the beam heat load to a…
Recent Progress on a Manifold Damped and Detuned Structure for CLIC
V. F. Khan, A. D'Elia, A. Grudiev +3
A damped detuned structure for the main X-band linacs of CLIC is being investigated as an alternative design to the present baseline heavily damped structure. In our earlier design…
High Gradient Superconducting Cavity with Low Surface EM Fields and Well-Suppressed HOMS for the ILC
N. Juntong, R. M. Jones
We present an optimized geometry for a 1.3 GHz superconducting cavity in which the surface electromagnetic fields have been minimized and the bandwidth of the fundamental mode has…
Higher Order Modes in Third Harmonic Cavities for XFEL/FLASH
I. R. R. Shinton, N. Baboi, N. Eddy +7
We analyse higher order modes in the 3.9 GHz bunch shaping cavities recently installed in the FLASH facility at DESY. We report on recent experimental results on the frequency spec…
Beam dynamics and wake-field simulations for the CLIC main linacs
V. Khan, R. M. Jones
The CLIC linear collider aims at accelerating multiple bunches of electrons and positrons and colliding them at a centre of mass energy of 3 TeV. These bunches will be accelerated…