Alexey Burov
(Fermi National Accelerator Lab. (US))
16/01/2014, 09:00
(Review)
Main theoretical aspects of beam transverse instabilities in low-emittance rings are successively considered. First, coherent tune shifts are found with the nested head-tail method for arbitrary longitudinal distribution and single and coupled bunches, and with a feedback damper taken into account. Then, the transverse nonlinearity is included, and Landau damping is analyzed by means...
Eirini Koukovini Platia
(Ecole Polytechnique Federale de Lausanne (CH))
16/01/2014, 10:15
Single bunch instability thresholds and the associated coherent tune shifts have been evaluated in the transverse plane for the damping rings (DR) of the Compact Linear Collider (CLIC). A multi-kick version of the HEADTAIL code was used to study the instability thresholds in the case where different impedance contributions are taken into account such as the broad-band resonator model in...
Henrique de Oliveira Caiafa DUARTE
(LNLS)
16/01/2014, 11:30
For the future 3rd Generation Brazilian Light Source, Sirius, an evaluation of several electromagnetic simulation software was done, motivated by the small ~3 mm Sirius bunch length. User interface was analyzed on CST, ACE3P and GdfidL and their numerical errors were compared with ECHO code. Impedance optimization of some components will be shown as well.
Thomas Guenzel
(CELLS/ALBA)
16/01/2014, 11:50
In the framework of a collaboration between the CLIC project at CERN and CELLS a 1.7m long prototype stripline will be tested in the ALBA storage ring. The power loss of the stripline flanged to the ALBA vacuum pipe is computed under consideration of an external load connected to the feedthroughs. Although the total power loss at 400mA is still significant (78W), the external load consumes 58W...
Galina SKRIPKA
(Univ. of Lund)
16/01/2014, 12:30
In order to maintain the high quality of the beam it is crucial to study the effect of the wake fields on the bunches. The linear accelerators often require extreme stability of the beam parameters such as emittance and energy spread. Using the scheme recently proposed by B. Podobedov and G. Stupakov the short-range wake fields are investigated with MAX IV linac as an example. MAX IV linac...
Alexei BLEDNYKH
(NSLS-II)
16/01/2014, 13:45
To estimate the vertical impedance of more complex geometry as an In-Vacuum Undulator we cross-checked first the results for simple geometries.
Axially symmetric tapered structure and rectangular structures are under discussion. Comparison of analytical results with numerically obtained data
using different EM Field Solvers. Two types of the In-Vacuum Undulator have been analyzed, the...
Carolina BELVER AGUILAR
(CERN)
16/01/2014, 14:05
The Compact Linear Collider (CLIC) aims for electron-positron collisions with high luminosity at a nominal centre-of-mass energy of 3 TeV. Pre-Damping Rings (PDRs) and Damping Rings (DRs) are required for reducing the emittance of the electron and positron beams before it is injected into the booster linac. Several stripline kicker systems will be used to inject and extract the beam from the...
Fanouria Antoniou
(National Technical Univ. of Athens (GR))
16/01/2014, 15:05
Suntao Wang
(Cornell University)
16/01/2014, 15:25
Low emittance electron and positron storage rings with an energy of a few GeV are important tools for scientific research. This will be increasingly true in coming years for next generation colliders such as CLIC and ILC, and for light sources as they approach 'ultimate storage ring' conditions. CESR-TA is a research program at Cornell University aimed at better understanding the physics of...
Dr
Roberto Cimino
(LNF-INFN)
16/01/2014, 16:40
Electron cloud is an ubiquitous effect in positively charted particle accelerators and has been observed to induce unwanted detrimental effects on beam quality, stability, vacuum etc. In this presentation a short review of the present understanding of the mitigation strategies adopted so far will be given with particular emphasis to the ongoing research on new materials and material coatings...
Giovanni Iadarola
(CERN - University of Naples Federico II)
16/01/2014, 17:00
The formation of an Electron Cloud (EC) in the vacuum chambers could significantly limit the performances of the positron damping ring of the Compact Linear Collider (CLIC). Depending on the Secondary Electron Yield (SEY) of the inner surface of the vacuum chambers, electrons generated by photoemission due to synchrotron radiation, can multiply through beam induced multipacting and accumulate...
Ryutaro Nagaoka
(Synchrotron SOLEIL)
16/01/2014, 17:40
In this talk we shall review a series of observations, experimental analyses and simulations made at SOLEIL on beam instabilities which are now identified as fast beam-ion instability arising from local outgassing. Peculiarity of these phenomena is that despite being ion instability, uniform beam filling is preferred to avoid the instability. An explanation is given, also suggesting that the...
Nicolo Biancacci
(Universita e INFN, Roma I (IT))
17/01/2014, 09:45
The beam coupling impedance leads to limitations in beam brightness and needs accurate quantification and continuous monitoring
in order to detect and mitigate high impedance sources. In the CERN hadron accelerators, kickers and collimators
are expected to be major contributors to the total imaginary part of the machine transverse impedance. In order to detect
other sources, beam based...
Pascale BRUNELLE
(Synchrotron SOLEIL)
17/01/2014, 10:05
In third generation synchrotron light sources such as SOLEIL, the large number of small gap insertion devices imposes vertical limitations of the vacuum chamber aperture. The former induce an incoherent transverse wake field due to the resistive-wall effect in flat chambers and lead to betatron tune variation with stored current and an optical function symmetry break. Since at SOLEIL, the...
Takeshi Nakamura
(Japan Synchrotron Radiation Research Institute)
17/01/2014, 11:25
The hybrid filling composed of singlets with high bunch current and bunch trains with low bunch current is in user operation at SPring-8, by simultaneously suppressing single-bunch instabilities of singlet and multi-bunch instabilities of trains by the Spring-8 bunch-by-bunch feedback system. To overcome the high contrast of the bunch current between singlets and trains, a bunch current...
Kevin LI
(cern)
17/01/2014, 12:05
Anke-Susanne Mueller
(Max-Planck-Gesellschaft (DE))
17/01/2014, 13:55
In the past year, several new additions to the beam diagnostics facilities available at the ANKA storage ring have opened new windows to the study of the CSR instability. A detection system consisting of an ultra-fast superconducting THz detector and data acquisition system, for example, was used to investigate correlations visible on the CSR bursting pattern and to study the interactions...
Markus Ries
(Helmholtz-Zentrum Berlin)
17/01/2014, 14:35
The Metrology Light Source (MLS) of the Physikalisch-Technische Bundesanstalt (PTB) is able to vary the zero current bunch length over more than two orders of magnitude. Bunch length manipulation can be achieved by adjusting momentum compaction factor, RF-cavity voltage as well as electron energy. The MLS is able to control the three leading orders of the momentum compaction factor and is...
Dr
Riccardo Bartolini
(Diamond Light Source and John Adams Institute)
17/01/2014, 15:15
Boris PODOBEDOV
(Broohaven National Laboratory),
John BYRD
17/01/2014, 16:15
Anke-Susanne Mueller
(Max-Planck-Gesellschaft (DE)),
Guenther Rehm
(Diamond Light Source)
17/01/2014, 16:40
Emanuel Karantzoulis
(Elettra -Sincrotrone Trieste),
Theo DEMMA
(LAL),
Yannis Papaphilippou
(CERN)
17/01/2014, 17:00
Giovanni Rumolo
(CERN), Dr
Roberto Cimino
(LNF-INFN)
17/01/2014, 17:20
Anke-Susanne Mueller
(Max-Planck-Gesellschaft (DE)),
Karl BANE
(SLAC National Accelerator Laboratory),
Peter KUSKE
(BESSY II)
17/01/2014, 17:40
