Paper 
Title 
Page 
TUOAA03 
Tests of Low Emittance Tuning Techniques at SLS and DAΦNE 
1065 

 S.M. Liuzzo, M.E. Biagini, P. Raimondi
INFN/LNF, Frascati (Roma), Italy
 M. Aiba
Paul Scherrer Institut, Villigen, Switzerland
 M. Böge
PSI, Villigen, Switzerland



The SuperB collider design is based on extremely low emittances, comparable to those of synchrotron light sources. A Low Emittance Tuning (LET) algorithm was developed for SuperB and has been tested last year at DIAMOND. This paper will report on the results of the application of LET to SLS (PSI) and DAΦNE (LNF) in order to compare and confirm the previous results. In this tests, the correction of orbit, dispersion and coupling is applied simultaneously to the detection of Beam Position Monitors tilts. The effect of beam based alignment at DAΦNE is also presented, together with an evaluation of the effects of other possible sources of emittance growth.



Slides TUOAA03 [4.313 MB]



TUPPC033 
Random Walk Optimization in Accelerators: Vertical Emittance Tuning at SLS 
1230 

 M. Aiba, M. Böge, N. Milas, A. Streun
Paul Scherrer Institut, Villigen, Switzerland



The operation of a high performance accelerator is realized only when several beam based corrections are implemented. These corrections are, however, limited by measurement errors as the correction approaches the ideal value. To overcome this limitation, we investigate the application of a random walk (RW) optimization specifically to minimize the vertical emittance at the SLS. A systematic minimization is performed by measuring linear coupling and spurious vertical dispersion and correcting them using 36 skew quadrupole correctors. On the other hand, the minimization can be performed by simply applying a multivariable optimization from the mathematics point of view, where the best combination of skew corrections is to be found. The measured vertical beam size is available as a stable target function of the minimization even at very low vertical emittance. Although RW and other algorithms are implemented into various accelerator computer codes, it is interesting to apply this concept to the real machine, where measurement errors are unavoidable and may prohibit systematic minimization based on a machine model. Possible applications of the technique in general are also discussed.



TUPPC034 
Preparation of SLS for IBS Measurements 
1233 

 N. Milas, M. Böge, A. Streun
PSI, Villigen, Switzerland
 M. Aiba, A. Lüdeke, A. Saa Hernandez
Paul Scherrer Institut, Villigen, Switzerland
 F. Antoniou, Y. Papaphilippou
CERN, Geneva, Switzerland



It is planned to use the SLS for testing damping ring issues related to linear colliders. One aspect is the study of IntraBeam Scattering (IBS) effects, which are a limiting factor for ultralow emittance rings. In this paper we present the setup and characterization of a new mode of operation in which the SLS runs at lower energy (1.57 GeV) with a natural emittance of 2.4 nm rad. This is much smaller than that at the nominal energy (2.41 GeV) and should make IBS effects more easily visible. In order to be able to observe IBS a careful setup is required: Optics measurement and correction as well as measurements of the bunch natural energy spread and the onset of turbulent bunch lengthening. Also, a detailed discussion on the available diagnostics and their limitations are shown and finally some preliminary results of beam emittance measurements, in all three planes, as a function of single bunch current are presented.



TUPPP065 
Progress Report on the SwissFEL Injector Test Facility 
1747 

 T. Schietinger, M. Aiba, S. Bettoni, B. Beutner, M. Csatari, K. Doshekenov, Y.C. Du, M.W. Guetg, C.P. Hauri, R. Ischebeck, F. Le Pimpec, N. Milas, G.L. Orlandi, M. Pedrozzi, P. Peier, E. Prat, S. Reiche, B. Smit, A. Trisorio, C. Vicario
Paul Scherrer Institut, Villigen, Switzerland



The SwissFEL injector test facility at the Paul Scherrer Institute is the principal test bed and demonstration plant for the SwissFEL project, which aims at realizing a hardXray Free Electron Laser by 2017. The RF photoinjector facility has been in operation since 2010 and has recently reached its design energy of 250 MeV. A newly installed movable magnetic chicane allows longitudinal bunch compression studies. We report on the first experience with the bunch compressor and present the latest results of projected and slice emittance measurements.



Poster TUPPP065 [1.801 MB]



TUPPR057 
Intrabeam Scattering Studies at the Swiss Light Source 
1951 

 F. Antoniou, Y. Papaphilippou
CERN, Geneva, Switzerland
 M. Aiba, M. Böge, N. Milas, A. Streun
Paul Scherrer Institut, Villigen, Switzerland
 T. Demma
INFN/LNF, Frascati (Roma), Italy



The target parameters of modern ultralow emittance rings are entering into a regime where intrabeam scattering (IBS) becomes important and, in the case of linear collider damping rings, even a limitation for the delivered emittances. The Swiss Light Source (SLS) storage ring, as it has achieved a vertical geometrical emittance of around 2 pm at 2.4 GeV, and it has the ability to run at even lower energies, and the availability of emittance monitoring diagnostics, is an ideal test bed for IBS studies. Simulations using the classical IBS theories and tracking codes are undertaken in order to explore the possibilities and limitations for IBS measurements at the SLS. In this respect, comparison between the theories and codes is first discussed. The dependence of the output emittances, taking into account the effect of IBS, with respect to energy, bunch charge and zero current vertical and longitudinal emittance is also studied, in order to define the regimes where the IBS effect can be significant. First measurement results from the SLS running at lower energies are finally presented.


