IBIC2015 - List of Authors (Rehm, G.)

Paper	Title	Page
MOPB064	Initial Work on the Design of a Longitudinal Bunch-by-Bunch Feedback Kicker at Diamond	197
	A.F.D. Morgan, G. Rehm DLS, Oxfordshire, United Kingdom
	In 2017 it is planned to install some additional normal conducting cavities into the Diamond storage ring. There is some concern that higher order modes in these devices could cause longitudinal instabilities in the beam. In order to deal with this potential problem we have started work on designing a longitudinal bunch-by-bunch feedback system. This paper will concentrate on the design and simulation of the kicker cavity, which is of the overloaded cavity type.
	Poster MOPB064 [0.440 MB]
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MOPB065	Considerations and Improved Workflow for Simulation of Dissipated Power from Wake Losses	202
	A.F.D. Morgan, G. Rehm DLS, Oxfordshire, United Kingdom
	At Diamond quite some effort has gone into simulating and understanding the dissipation of energy into structures induced by wake losses. Due to changes in the core simulation code we use, it is now possible to extract the dissipated energy information directly from the simulation rather than inferring it from other parts of the simulation output which was, by necessity, our previous method. Various modeled geometries will be used to illustrate the improved approach. Also, we will discuss the considerations needed when constructing the model geometries in order to get the most representative results from the simulation.
	Poster MOPB065 [0.436 MB]
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MOPB066	Streak Camera PSF Optimisation and Dual Sweep Calibration for Sub-ps Bunch Length Measurement	206
	L.M. Bobb, A.F.D. Morgan, G. Rehm DLS, Oxfordshire, United Kingdom
	Streak cameras are commonly used for bunch length measurement. In normal beam modes, bunch lengths are on the order of 10 ps. For the study of microbunch instabilities, a low alpha single bunch mode is implemented with bunch lengths approaching 1 ps and beam current in the tens of microamps. In order to reliably measure such a short bunch at low beam currents, the input optics for the streak camera must be optimised for sufficient incident light intensity and high resolution in both sweep directions. This is achieved through the use of reflective input optics in which a pinhole is imaged to provide a small circular Point Spread Function. Furthermore to precisely measure the bunch length, the calibration of the dual sweep must be known. Here we describe a calibration method using electrical delays to incorporate calibration information within streak camera images.
	Poster MOPB066 [1.970 MB]
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TUPB046	Integration of the Diamond Transverse Multibunch Feedback System at ALBA	414
	A. Olmos, U. Iriso, J. Moldes, F. Pérez ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain M.G. Abbott, G. Rehm, I.S. Uzun DLS, Oxfordshire, United Kingdom
	A Transverse Multi-Bunch Feedback system (TMBF) has been commissioned at the ALBA storage ring for stabilization of the beam instabilities. The system is based on the Libera Bunch-By-Bunch electronics, controlled using a specific software developed at Diamond Light Source. This system refurbishes the existing FPGA code to include several features for machine studies, like fast and precise tune measurements using a Phase Locked Loop, sequences of grow-damp experiments that allow measuring damping rates on a mode-by-mode basis, and precise bunch cleaning. We describe the TMBF system and the integration of the control software into the ALBA machine. Finally we show examples of beam stabilization and machine studies using this system.
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Paper

Title

Page

Initial Work on the Design of a Longitudinal Bunch-by-Bunch Feedback Kicker at Diamond

197

A.F.D. Morgan, G. Rehm
DLS, Oxfordshire, United Kingdom

In 2017 it is planned to install some additional normal conducting cavities into the Diamond storage ring. There is some concern that higher order modes in these devices could cause longitudinal instabilities in the beam. In order to deal with this potential problem we have started work on designing a longitudinal bunch-by-bunch feedback system. This paper will concentrate on the design and simulation of the kicker cavity, which is of the overloaded cavity type.

Poster MOPB064 [0.440 MB]

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reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

MOPB065

Considerations and Improved Workflow for Simulation of Dissipated Power from Wake Losses

202

A.F.D. Morgan, G. Rehm
DLS, Oxfordshire, United Kingdom

At Diamond quite some effort has gone into simulating and understanding the dissipation of energy into structures induced by wake losses. Due to changes in the core simulation code we use, it is now possible to extract the dissipated energy information directly from the simulation rather than inferring it from other parts of the simulation output which was, by necessity, our previous method. Various modeled geometries will be used to illustrate the improved approach. Also, we will discuss the considerations needed when constructing the model geometries in order to get the most representative results from the simulation.

Poster MOPB065 [0.436 MB]

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MOPB066

Streak Camera PSF Optimisation and Dual Sweep Calibration for Sub-ps Bunch Length Measurement

206

L.M. Bobb, A.F.D. Morgan, G. Rehm
DLS, Oxfordshire, United Kingdom

Streak cameras are commonly used for bunch length measurement. In normal beam modes, bunch lengths are on the order of 10 ps. For the study of microbunch instabilities, a low alpha single bunch mode is implemented with bunch lengths approaching 1 ps and beam current in the tens of microamps. In order to reliably measure such a short bunch at low beam currents, the input optics for the streak camera must be optimised for sufficient incident light intensity and high resolution in both sweep directions. This is achieved through the use of reflective input optics in which a pinhole is imaged to provide a small circular Point Spread Function. Furthermore to precisely measure the bunch length, the calibration of the dual sweep must be known. Here we describe a calibration method using electrical delays to incorporate calibration information within streak camera images.

Poster MOPB066 [1.970 MB]

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reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

TUPB046

Integration of the Diamond Transverse Multibunch Feedback System at ALBA

414

A. Olmos, U. Iriso, J. Moldes, F. Pérez
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
M.G. Abbott, G. Rehm, I.S. Uzun
DLS, Oxfordshire, United Kingdom

A Transverse Multi-Bunch Feedback system (TMBF) has been commissioned at the ALBA storage ring for stabilization of the beam instabilities. The system is based on the Libera Bunch-By-Bunch electronics, controlled using a specific software developed at Diamond Light Source. This system refurbishes the existing FPGA code to include several features for machine studies, like fast and precise tune measurements using a Phase Locked Loop, sequences of grow-damp experiments that allow measuring damping rates on a mode-by-mode basis, and precise bunch cleaning. We describe the TMBF system and the integration of the control software into the ALBA machine. Finally we show examples of beam stabilization and machine studies using this system.

Export •

reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)