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Design and Implementation of RF Kickers in MAX IV

Olsson, David LU (2017)
Abstract
The MAX IV facility in Lund, Sweden, consists of two storage rings for production of synchrotron radiation, and a full-energy LINAC for top-up injections. The LINAC also delivers short high-intensity electron bunches to a short pulse facility. MAX IV was inaugurated in June 2016, and the larger 3 GeV ring has been delivering light to users since November 2016. In this thesis, the design and implementation of RF kickers for different systems in MAX IV are presented.

The first system is the chopper which is located in the so called thermionic pre-injector that delivers the electron pulses to the main LINAC during ring injections. The electron source is here a thermionic S-band RF gun. All electrons that enter the chopper can not be... (More)
The MAX IV facility in Lund, Sweden, consists of two storage rings for production of synchrotron radiation, and a full-energy LINAC for top-up injections. The LINAC also delivers short high-intensity electron bunches to a short pulse facility. MAX IV was inaugurated in June 2016, and the larger 3 GeV ring has been delivering light to users since November 2016. In this thesis, the design and implementation of RF kickers for different systems in MAX IV are presented.

The first system is the chopper which is located in the so called thermionic pre-injector that delivers the electron pulses to the main LINAC during ring injections. The electron source is here a thermionic S-band RF gun. All electrons that enter the chopper can not be captured by the rings during injection. These undesired electrons are deflected and dumped by the chopper before they reach the first accelerating structure in the LINAC. The RF kickers in the chopper system are two planar striplines.

The second system is the bunch-by-bunch feedback system in the 3 GeV ring. The system is mainly used to suppress coupled-bunch mode instabilities. These instabilities drive coherent oscillations of the electron bunches. The oscillations have a degrading effect on the beam quality since they increase the effective emittance and the energy spread. By sampling the beam motion, the bunch-by-bunch feedback system suppresses the oscillations by corrective kicks to the bunches in all three planes via RF kickers. The system is also a comprehensive diagnostic tool that can be used to characterize many different parameters of the ring. This far, two striplines have been operating as RF kickers in the three planes. A waveguide overloaded cavity kicker has been designed, and this device will operate as a dedicated kicker in the longitudinal plane after the 2017 summer shut-down.

The third system is a diagnostic stripline with switching networks that is mainly used for betatron tune measurements in the two MAX IV storage rings and in the SOLARIS storage ring. This stripline can be used for many different applications. (Less)
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author
supervisor
opponent
  • doctor Craievich, Paolo, Paul Scherrer Institute, Switzerland
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Accelerator cavities, Beam choppers, Bunch-by-bunch feedback, RF kickers, Striplines
edition
1
pages
215 pages
publisher
MAX-lab, Lund University
defense location
Lecture hall: 1406, building E, Ole Römers väg 3, Faculty of Engineering LTH, Lund University, Lund
defense date
2017-10-12 10:15
ISBN
978-91-7753-349-8
978-91-7753-350-4
language
English
LU publication?
yes
id
79fd33b7-9557-417a-bb52-1e938d7286d6
date added to LUP
2017-09-06 22:02:06
date last changed
2017-09-11 11:14:06
@phdthesis{79fd33b7-9557-417a-bb52-1e938d7286d6,
  abstract     = {The MAX IV facility in Lund, Sweden, consists of two storage rings for production of synchrotron radiation, and a full-energy LINAC for top-up injections. The LINAC also delivers short high-intensity electron bunches to a short pulse facility. MAX IV was inaugurated in June 2016, and the larger 3 GeV ring has been delivering light to users since November 2016. In this thesis, the design and implementation of RF kickers for different systems in MAX IV are presented. <br/><br/>The first system is the chopper which is located in the so called thermionic pre-injector that delivers the electron pulses to the main LINAC during ring injections. The electron source is here a thermionic S-band RF gun. All electrons that enter the chopper can not be captured by the rings during injection. These undesired electrons are deflected and dumped by the chopper before they reach the first accelerating structure in the LINAC. The RF kickers in the chopper system are two planar striplines.<br/><br/>The second system is the bunch-by-bunch feedback system in the 3 GeV ring. The system is mainly used to suppress coupled-bunch mode instabilities. These instabilities drive coherent oscillations of the electron bunches. The oscillations have a degrading effect on the beam quality since they increase the effective emittance and the energy spread. By sampling the beam motion, the bunch-by-bunch feedback system suppresses the oscillations by corrective kicks to the bunches in all three planes via RF kickers. The system is also a comprehensive diagnostic tool that can be used to characterize many different parameters of the ring. This far, two striplines have been operating as RF kickers in the three planes. A waveguide overloaded cavity kicker has been designed, and this device will operate as a dedicated kicker in the longitudinal plane after the 2017 summer shut-down.  <br/><br/>The third system is a diagnostic stripline with switching networks that is mainly used for betatron tune measurements in the two MAX IV storage rings and in the SOLARIS storage ring. This stripline can be used for many different applications.},
  author       = {Olsson, David},
  isbn         = {978-91-7753-349-8},
  keyword      = {Accelerator cavities, Beam choppers, Bunch-by-bunch feedback, RF kickers, Striplines},
  language     = {eng},
  month        = {09},
  pages        = {215},
  publisher    = {MAX-lab, Lund University},
  school       = {Lund University},
  title        = {Design and Implementation of RF Kickers in MAX IV},
  year         = {2017},
}