| 1. |
- Brosi, Miriam, et al.
(författare)
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Time-resolved measurement and simulation of a longitudinal single-bunch instability at the MAX IV 3 GeV ring
- 2023
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Ingår i: 14th International Particle Accelerator Conference. - 9783954502318 ; , s. 2685-2688
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The study and understanding of collective effects plays a vital role for fourth-generation light sources. These effects mostly need to be mitigated and controlled to achieve the design operational parameters. However, they can also be utilized to gain insights into the properties of the machine. While the 3 GeV storage ring at the MAX IV light source is running in multi-bunch mode during user operation. Single-bunch operation is available in dedicated machine study shifts, providing the possibility to study collective effects at higher bunch currents. In such a current range an instability has been observed in the longitudinal plane. Above the threshold current of the instability a dynamic deformation of the bunch profile and a strong increase in energy spread occurs. Dedicated measurements were conducted with multiple diagnostic tools such as time-resolved bunch profile measurements. First simulations of the observed effects were performed with a Vlasov-Fokker-Planck solver. This contribution presents measurement results and draws a comparison to the simulations.
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| 2. |
- Skripka, Galina, et al.
(författare)
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Simultaneous computation of intrabunch and interbunch collective beam motions in storage rings
- 2016
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 806, s. 221-230
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Tidskriftsartikel (refereegranskat)abstract
- We present the multibunch tracking code mbtrack developed to simulate, in 6-dimensional phase space, single- and multibunch collective instabilities driven by short- and long-range wakefields in storage rings. Multiple bunches, each composed of a large number of macroparticles, are tracked, allowing simulation of both intra- and interbunch motions. Besides analytical impedance models, the code allows employment of numerical wake potentials computed with electromagnetic (EM) field solvers. The corresponding impedances are fitted to a number of known analytical functions and the coefficients obtained in the fit are used as an input to the code. mbtrack performs a dynamic treatment of long-range resistive-wall and harmonic cavity fields, which are likely to be the two major factors impacting multibunch collective motions in many present and future ring-based light sources. Furthermore, it is capable of simulating beam-ion interactions as well as transverse bunch-by-bunch feedback. We describe the physical effects considered in the code and their implementation, which makes use of parallel processing to significantly shorten the computation time. mbtrack is benchmarked against other codes and applied to the MAX IV 3 GeV ring as an example, where the importance of the interplay of various physical effects as well as coupling among different degrees of freedom is demonstrated.
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| 3. |
- Tavares, Pedro F., et al.
(författare)
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Commissioning and first-year operational results of the MAX IV 3 GeV ring
- 2018
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Ingår i: Journal of Synchrotron Radiation. - 0909-0495. ; 25:5, s. 1291-1316
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Tidskriftsartikel (refereegranskat)abstract
- The MAX IV 3 GeV electron storage ring in Lund, Sweden, is the first of a new generation of light sources to make use of the multibend-achromat lattice (MBA) to achieve ultralow emitance and hence ultrahigh brightness and transverse coherence. The conceptual basis of the MAX IV 3 GeV ring project combines a robust lattice design with a number of innovative engineering choices: compact, multifunctional magnet blocks, narrow low-conductance NEG-coated copper vacuum chambers and a 100 MHz radio-frequency system with passively operated third-harmonic cavities for bunch lengthening. In this paper, commissioning and first-year operational results of the MAX IV 3 GeV ring are presented, highlighting those aspects that are believed to be most relevant for future MBA-based storage rings. The commissioning experience of the MAX IV 3 GeV ring offers in this way an opportunity for validation of concepts that are likely to be essential ingredients of future diffraction-limited light sources.
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