A5029977777- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Gyrotron and Vacuum Electronics Research
- Electromagnetic Simulation and Numerical Methods
- Magnetic confinement fusion research
- Superconducting Materials and Applications
- Particle Detector Development and Performance
- Particle physics theoretical and experimental studies
- Advanced optical system design
- Semiconductor Quantum Structures and Devices
- Laser-Plasma Interactions and Diagnostics
- Engineering Applied Research
- Silicon and Solar Cell Technologies
- Radio Frequency Integrated Circuit Design
- Microwave Engineering and Waveguides
- Semiconductor materials and devices
- Distributed and Parallel Computing Systems
- Lightning and Electromagnetic Phenomena
- Advanced X-ray Imaging Techniques
MAX IV Laboratory
2018-2024
Lund University
2018-2024
Synchrotron soleil
2015-2017
Royal Holloway University of London
2011-2016
European Organization for Nuclear Research
2014
The MAX IV 3 GeV electron storage ring in Lund, Sweden, is the first of a new generation light sources to make use multibend-achromat lattice (MBA) achieve ultralow emitance and hence ultrahigh brightness transverse coherence. conceptual basis project combines robust design with number innovative engineering choices: compact, multifunctional magnet blocks, narrow low-conductance NEG-coated copper vacuum chambers 100 MHz radio-frequency system passively operated third-harmonic cavities for...
The ongoing trend towards synchrotron light storage rings with ultralow emittance lattices leads to greater challenges achieve beam stability, sufficient Touschek lifetime, low heating of machine components, and conservation the at high bunch charge. One solution meet these is lengthen electron bunches harmonic cavities. Many upgrade proposals therefore include cavities enhance performance. This also case for MAX IV 3 GeV ring, which employs passive third up five times lengthening....
A small vacuum chamber aperture is a present trend in the design of future synchrotron light sources. This leads to large resistive-wall impedance that can drive coupled-bunch instabilities. Another use passively driven cavities at harmonic main radio frequency lengthen electron bunches order increase Touschek lifetime and reduce emittance blowup due intrabeam scattering. In some cases, may be tuned fulfill flat potential condition. With this condition met, it has been predicted simulation...
In synchrotrons, nonuniform fill patterns, which give rise to beam phase transients and a spread in synchrotron tune between bunches, have been observed damp longitudinal coupled-bunch instabilities driven by higher-order modes rf cavities. The are especially large the presence of Landau cavities, used commonly storage-ring light sources particularly new generation diffraction-limited storage rings. A method has recently devised predict transient including complex form factors for different...
The Compact Linear Collider (CLIC) requires beam position monitors (BPMs) with 50 nm spatial resolution for alignment of the line elements in main linac and delivery system. Furthermore, BPMs must be able to make multiple independent measurements within a single 156 ns long bunch train. A prototype cavity BPM CLIC has been manufactured tested on probe at 3rd Test Facility (CTF3) CERN. transverse is determined from electromagnetic resonant modes excited by two cavities pickup, reference...
Wakefields are an important factor in accelerator design, and a real concern when preserving the low beam emittance modern machines. Charge dependent size growth has been observed at Accelerator Test Facility (ATF2), test for future linear collider delivery systems. Part of explanation this is wakefields. In paper we present numerical calculations wakefields produced by several types geometrical discontinuities line as well tracking simulations to estimate induced effects. We also discuss...
The MAX IV 3 GeV storage ring operates with beam of high current and ultralow emittance. These parameters in combination the small effective aperture enhance possible collective instabilities. Three passive harmonic cavities are installed to introduce bunch lengthening tune spread, leading decoupling spectrum from machine impedance mitigating instabilities by Landau damping respectively. In this paper we present first results commissioning third ring. additional cavity potential...
At the 3 GeV ring of MAX IV Laboratory, a fourth generation ring-based synchrotron light source, an asymmetric influence sign amplitude-dependent tune shift (ADTS) on transverse mode-coupling instability (TMCI) has been observed. Measurements instability, in dedicated single-bunch experiments at low chromaticity, revealed significant dependence dynamics above threshold ADTS. While for negative ADTS crossing does not lead to loss beam current, positive results 40% or more current threshold....
Landau cavities used to lengthen the bunches in storage rings necessarily constitute a significant impedance. Because of particular phase field required for bunch lengthening, they are often detuned quite considerably from resonance, more so than main cavities. As result, their impedance can excite first coupled-bunch mode such that it becomes unstable. This phenomenon has previously been predicted [M. Venturini, ] and characterized simulations [T. He, but experimental observation is yet be...
At the 3 GeV ring of MAX IV Laboratory, a fourth-generation ring-based synchrotron light source, an asymmetric influence sign amplitude-dependent tune shift (ADTS) on transverse mode-coupling instability has been observed. Measurements instability, in dedicated single-bunch experiments at low chromaticity, revealed significant dependence dynamics above threshold ADTS. While for negative ADTS, crossing does not lead to loss beam current, positive results 40% or more current threshold. In...
In previous publications, the effect of inhomogeneous beam loading Landau cavities due to a nonuniform fill pattern in storage ring has been studied with aim predicting resulting longitudinal profiles bunches and their time offsets relative main rf [T. Olsson et al., Phys. Rev. Accel. Beams 21, 120701 (2018)]. This work was extended treat dipolar coupled-bunch modes driven by beam-excited higher-order [F. J. Cullinan 23, 074402 (2020)]. These are interest because they can become unstable,...
Six UK institutes are engaged in a collaborative R&D programme with CERN aimed at demonstrating key aspects of technology feasibility for the Compact Linear Collider (CLIC). We give an overview and status of: 1) Drive-beam components: quadrupole magnets beam phase feed-forward prototype. 2) Beam instrumentation: stripline cavity position monitors, electro-optical longitudinal bunch profile monitor, laserwire diffraction transition radiation monitors transverse beam-size determination. 3)...
Each long SOLEIL beamline, ANATOMIX and Nanoscopium, takes a photon beam from an in-vacuum undulator with minimum gap of 5.5 mm. The canted radiation sources are installed in straight section the storage ring. first closure both undulators led to severe damage downstream 2011. reason for this incident has been investigated clearly identified. A long-term project enabled us find technical solution simultaneous operation undulators. special angle fast interlock was designed dedicated absorber...
Longitudinal coupled-bunch instabilities are driven by monopole higher-order modes (HOMs) in the active and passive radio-frequency (rf) cavities at MAX IV 3 GeV electron storage ring. By combining different beam rf-based techniques, we have performed a systematic survey of properties these resonant as function cavity temperatures fundamental mode frequency. This information was then used to setup HOM model that allowed us infer optimized temperature ranges for cavities. An important feature...
Many current and future synchrotron light sources employ harmonic cavities to lengthen the electron bunches in order reduce emittance dilution caused by intrabeam scattering. In some cases, may be tuned fulfill flat potential condition. For this condition, a large increase threshold currents of transverse coupled-bunch instabilities has been predicted recently, physical content behind stabilisation better understood. With mind, an investigation is made into effectiveness for different...
At nonzero chromaticity, the threshold current due to transverse coupled bunch instabilities in an electron storage ring is defined by intrabunch head-tail motion of higher than zeroth order. Multibunch tracking simulations predict that this can be increased several times its original value through introduction lengthening harmonic cavities. One previously suggested explanation narrower spectra elongated bunches but reliable estimates for currents are not obtainable anything other rigid beam...