DLSR design and plans: an international overview
01 Sep 2014-Journal of Synchrotron Radiation (International Union of Crystallography)-Vol. 21, Iss: 5, pp 843-855
TL;DR: A review of fourth-generation ring design concepts and plans in the world is presented and it is suggested that future larger-circumference rings, possibly housed in >2-km tunnels made available by decommissioned high-energy physics accelerators, could have sub-10-pm-rad emittances, providing very high coherence for >10-keV X-rays.
Abstract: It has been known for decades that the emittance of multi-GeV storage rings can be reduced to very small values using multi-bend achromat (MBA) lattices. However, a practical design of a ring having emittance approaching the diffraction limit for multi-keV photons, i.e. a diffraction-limited storage ring (DLSR), with a circumference of order 1 km or less was not possible before the development of small-aperture vacuum systems and other accelerator technology, together with an evolution in the understanding and accurate simulation of non-linear beam dynamics, had taken place. The 3-GeV MAX IV project in Sweden has initiated a new era of MBA storage ring light source design, i.e. a fourth generation, with the Sirius project in Brazil now following suit, each having an order of magnitude smaller horizontal emittance than third-generation machines. The ESRF, APS and SPring-8 are all exploring 6-GeV MBA lattice conversions in the imminent future while China is considering a similar-energy green-field machine. Other lower-energy facilities, including the ALS, SLS, Soleil, Diamond and others, are studying the possibility of such conversions. Future larger-circumference rings, possibly housed in >2-km tunnels made available by decommissioned high-energy physics accelerators, could have sub-10-pm-rad emittances, providing very high coherence for >10-keV X-rays. A review of fourth-generation ring design concepts and plans in the world is presented.
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TL;DR: This article summarizes the contributions in this special issue on Diffraction-Limited Storage Rings and analyses the progress in accelerator technology enabling a significant increase in brightness and coherent fraction of the X-ray light provided by storage rings.
Abstract: This article summarizes the contributions in this special issue on Diffraction-Limited Storage Rings. It analyses the progress in accelerator technology enabling a significant increase in brightness and coherent fraction of the X-ray light provided by storage rings. With MAX IV and Sirius there are two facilities under construction that already exploit these advantages. Several other projects are in the design stage and these will probably enhance the performance further. To translate the progress in light source quality into new science requires similar progress in aspects such as optics, beamline technology, detectors and data analysis. The quality of new science will be limited by the weakest component in this value chain. Breakthroughs can be expected in high-resolution imaging, microscopy and spectroscopy. These techniques are relevant for many fields of science; for example, for the fundamental understanding of the properties of correlated electron materials, the development and characterization of materials for data and energy storage, environmental applications and bio-medicine.
227 citations
Cites background from "DLSR design and plans: an internati..."
...Today’s third-generation synchrotron radiation sources have an extreme asymmetry in the geometrical source size ( x, y) (Hettel, 2014)....
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...This also eases the problem of making strong magnet lenses (quadrupoles, sextupoles, octupoles) (Hettel, 2014), since the number of Ampère-turns can be kept low and room-temperature technology can be used without saturation of the magnet poles (Johansson et al., 2014)....
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...This is achieved by building the ring from a large number of focusing cells (Hettel, 2014; Einfeld et al., 2014)....
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...In fact, the horizontal emittance "0, which determines the average spectral brightness Bavgð Þ and the coherent fraction fcohð Þ, scales inversely with the third power of the number of bending magnets Nd: "0 N 3d (Hettel, 2014)....
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...The lower horizontal emittance poses less stringent requirements on the horizontal field profile of undulators (Hettel, 2014)....
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TL;DR: This review is focused on free-electron lasers (FELs) in the hard to soft x-ray regime and provides newcomers to the area with insights into: the basic physics of FELs, the qualities of the radiation they produce, the challenges of transmitting that radiation to end users and the diversity of current scientific applications.
Abstract: This review is focused on free-electron lasers (FELs) in the hard to soft x-ray regime. The aim is to provide newcomers to the area with insights into: the basic physics of FELs, the qualities of the radiation they produce, the challenges of transmitting that radiation to end users and the diversity of current scientific applications. Initial consideration is given to FEL theory in order to provide the foundation for discussion of FEL output properties and the technical challenges of short-wavelength FELs. This is followed by an overview of existing x-ray FEL facilities, future facilities and FEL frontiers. To provide a context for information in the above sections, a detailed comparison of the photon pulse characteristics of FEL sources with those of other sources of high brightness x-rays is made. A brief summary of FEL beamline design and photon diagnostics then precedes an overview of FEL scientific applications. Recent highlights are covered in sections on structural biology, atomic and molecular physics, photochemistry, non-linear spectroscopy, shock physics, solid density plasmas. A short industrial perspective is also included to emphasise potential in this area.
178 citations
Cites background from "DLSR design and plans: an internati..."
...A number of storage ring facilities are actively pursuing upgrades to the storage ring lattice arrangement to significantly reduce the electron beam emittance so that the emitted light is diffraction limited even at x-ray wavelengths [149]....
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TL;DR: An overview of the features and future prospects of X-ray FELs, including the working principles and properties, the operational status of different FEL facilities worldwide, the applications supported by such facilities, and the current developments and outlook for X-Ray FEL-based research are presented.
Abstract: Linear accelerator-based free-electron lasers (FELs) are the leading source of fully coherent X-rays with ultra-high peak powers and ultra-short pulse lengths. Current X-ray FEL facilities have proved their worth as useful tools for diverse scientific applications. In this paper, we present an overview of the features and future prospects of X-ray FELs, including the working principles and properties of X-ray FELs, the operational status of different FEL facilities worldwide, the applications supported by such facilities, and the current developments and outlook for X-ray FEL-based research.
65 citations
Cites background from "DLSR design and plans: an internati..."
...SR-based synchrotron radiation sources, which first appeared in the 1960s, have undergone three generations of development and evolution, and are currently moving toward the fourth generation, which aims to deliver diffraction-limited SRs with higher brightness and better transverse coherence.(3,4) Over the last decades, evolutionary increases in the brightness of SR sources have birthed a robust array of X-ray capabilities....
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...To increase X-ray brightness further, new storage ring lattices have been proposed at synchrotron radiation facilities, which are designed to reduce electron beam emittance to values close to the theoretical minimum for diffraction-limited light sources.(4) Modern storage ring facilities provide bright X-ray beams with a high degree of spatial coherence....
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TL;DR: Commissioning and first-year operational results of the MAX IV 3 GeV electron storage ring, the first synchrotron light source to make use of the multibend-achromat lattice to achieve ultralow emittance and high brightness, are presented.
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
63 citations
Cites background from "DLSR design and plans: an internati..."
...Introduction The MAX IV 3 GeV ring in Lund, Sweden (Tavares et al., 2014a), is the first of a new generation of synchrotron light sources (Hettel, 2014) which employ a multibend-achromat lattice (Einfeld & Plesko, 1993) to reach emittances in the few hundred pm rad range in a circumference of a few…...
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References
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21 Mar 1997-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this article, a computer code called LOCO (Linear Optics from Closed Orbits) was developed to analyze the NSLS X-ray ring measured response matrix to determine: the gradients in all 56 quadrupole magnets; the calibration of the steering magnets and BPMs; the roll of the quadrupoles, steering magnets, and beam position monitors about the electron beam direction; the longitudinal magnetic centers of the orbit steering magnets; and the horizontal dispersion at the orbit steerable magnet; and transverse mis-alignment of the electron orbit in each
Abstract: The measured response matrix giving the change in orbit at beam position monitors (BPMs) with changes in steering magnet excitation can be used to accurately calibrate the linear optics in an electron storage ring [1–8]. A computer code called LOCO (Linear Optics from Closed Orbits) was developed to analyze the NSLS X-Ray Ring measured response matrix to determine: the gradients in all 56 quadrupole magnets; the calibration of the steering magnets and BPMs; the roll of the quadrupoles, steering magnets, and BPMs about the electron beam direction; the longitudinal magnetic centers of the orbit steering magnets; the horizontal dispersion at the orbit steering magnets; and the transverse mis-alignment of the electron orbit in each of the sextupoles. Random orbit measurement error from the BPMs propagated to give only 0.04% rms error in the determination of individual quadrupole gradients and 0.4 mrad rms error in the determination of individual quadrupole rolls. Small variations of a few parts in a thousand in the quadrupole gradients within an individual family were resolved. The optics derived by LOCO gave accurate predictions of the horizontal dispersion, the beta functions, and the horizontal and vertical emittances, and it gave good qualitative agreement with the measured vertical dispersion. The improved understanding of the X-Ray Ring has enabled us to increase the synchrotron radiation brightness. The LOCO code can also be used to find the quadrupole family gradients that best correct for gradient errors in quadrupoles, in sextupoles, and from synchrotron radiation insertion devices. In this way the design periodicity of a storage ring's optics can be restored. An example of periodicity restoration will be presented for the NSLS VUV Ring. LOCO has also produced useful results when applied to the ALS storage ring [8].
280 citations
"DLSR design and plans: an internati..." refers methods in this paper
...The methods have been benchmarked on real machines with beam-based lattice calibration tools [e.g. LOCO (Safranek, 1997)] and parameter measurement techniques....
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TL;DR: The design of the MAX IV 3 GeV ultralow-emittance storage ring is presented and the implementation of solutions to the technological challenges imposed by the compact multi-bend achromat lattice are described.
Abstract: The MAX IV facility, currently under construction in Lund, Sweden, features two electron storage rings operated at 3 GeV and 1.5 GeV and optimized for the hard X-ray and soft X-ray/VUV spectral ranges, respectively. A 3 GeV linear accelerator serves as a full-energy injector into both rings as well as a driver for a short-pulse facility, in which undulators produce X-ray pulses as short as 100 fs. The 3 GeV ring employs a multibend achromat (MBA) lattice to achieve, in a relatively short circumference of 528 m, a bare lattice emittance of 0.33 nm rad, which reduces to 0.2 nm rad as insertion devices are added. The engineering implementation of the MBA lattice raises several technological problems. The large number of strong magnets per achromat calls for a compact design featuring small-gap combined-function magnets grouped into cells and sharing a common iron yoke. The small apertures lead to a low-conductance vacuum chamber design that relies on the chamber itself as a distributed copper absorber for the heat deposited by synchrotron radiation, while non-evaporable getter (NEG) coating provides for reduced photodesorption yields and distributed pumping. Finally, a low main frequency (100 MHz) is chosen for the RF system yielding long bunches, which are further elongated by passively operated third-harmonic Landau cavities, thus alleviating collective effects, both coherent (e.g. resistive wall instabilities) and incoherent (intrabeam scattering). In this paper, we focus on the MAX IV 3 GeV ring and present the lattice design as well as the engineering solutions to the challenges inherent to such a design. As the first realisation of a light source based on the MBA concept, the MAX IV 3 GeV ring offers an opportunity for validation of concepts that are likely to be essential ingredients of future diffraction-limited light sources.
163 citations
"DLSR design and plans: an internati..." refers background in this paper
...…test mode with 158-nm-rad emittance in 2013 to test low-" accelerator physics issues (A. Kling, DESY, private communication). detail in this issue (Tavares et al., 2014), the MAX IV design has made a pioneering step in marrying technological developments in small-aperture NEG-coated vacuum…...
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01 Apr 1999-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this article, a technique for producing high average intensity X-ray radiation from a storage ring for studies of the ultrafast phenomena on a subpicosecond time scale is proposed.
Abstract: A technique is proposed for producing high average intensity X-ray radiation from a storage ring for studies of the ultrafast phenomena on a subpicosecond time scale. Two RF cavity accelerating structures excited in the E 110 mode can be installed in a storage ring to create vertical displacements of electrons correlated with their longitudinal position in the bunch. The magnitude of these displacements can be sufficient for the X-ray radiation of the electron bunch between accelerating structures to be viewed as produced by a large number of independent sources, each of a subpicosecond duration.
110 citations
TL;DR: The Delta undulator as mentioned in this paper is a short undulator magnet prototype whose features make optimum use of the unique conditions expected in synchrotron radiation sources and is 30 cm long.
Abstract: In anticipation of a new era of synchrotron radiation sources based on energy recovery linac techniques, we designed, built, and tested a short undulator magnet prototype whose features make optimum use of the unique conditions expected in these facilities. The prototype has pure permanent magnet (PPM) structure with 24 mm period, 5 mm diameter round gap, and is 30 cm long. In comparison with conventional undulator magnets it has the following: (i) full x-ray polarization control.---It may generate varying linear polarized as well as left and right circular polarized x rays with photon flux much higher than existing Apple-II--type devices. (ii) 40% stronger magnetic field in linear and approximately 2 times stronger in circular polarization modes. This advantage translates into higher x-ray flux. (iii) Compactness.---The prototype can be enclosed in a $\ensuremath{\sim}20\text{ }\text{ }\mathrm{cm}$ diameter cylindrical vacuum vessel. These advantages were achieved through a number of unconventional approaches. Among them is control of the magnetic field strength via longitudinal motion of the magnet arrays. The moving mechanism is also used for x-ray polarization control. The compactness is achieved using a recently developed permanent magnet soldering technique for fastening PM blocks. We call this device a ``Delta'' undulator after the shape of its PM blocks. The presented article describes the design study, various aspects of the construction, and presents some test results.
94 citations
"DLSR design and plans: an internati..." refers background in this paper
...…injected beam losses are reduced, the horizontal good-field region of magnets can be reduced, and highperformance insertion devices having small horizontal as well as vertical apertures [e.g. helical, Delta-type (Temnykh, 2008) or possibly RF undulators (Yeddulla et al., 2011)] can be accommodated....
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...As noted previously, the round beams and on-axis injection would support the use of highperformance insertion devices having small horizontal as well as vertical gaps, including helical and Delta-type undulators....
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...Because the lattice does not have to accommodate the many-millimeter oscillation amplitudes of the incoming beam, injected beam losses are reduced, the horizontal good-field region of magnets can be reduced, and highperformance insertion devices having small horizontal as well as vertical apertures [e.g. helical, Delta-type (Temnykh, 2008) or possibly RF undulators (Yeddulla et al., 2011)] can be accommodated....
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TL;DR: The first proposed lattice for a ‘diffraction-limited light source’ is reported and this approach has now more or less been used for the MAX IV project.
Abstract: By the beginning of 1990, three third-generation synchrotron light sources had been successfully commissioned in Grenoble, Berkeley and Trieste (ESRF, ALS and ELETTRA). Each of these new machines reached their target specifications without any significant problems. In parallel, already at that time discussions were underway regarding the next generation, the `diffraction-limited light source (DLSR)', which featured sub-nm rad electron beam emittance, photon beam brilliance exceeding 1022 and the potential to emit coherent radiation. Also, at about that time, a first design for a 3 GeV DLSR was developed, based on a modified multiple-bend achromat (MBA) design leading to a lattice with normalized emittance of ∊x = 0.5 nm rad. The novel feature of the MBA lattice was the use of seven vertically focusing bend magnets with different bending angles throughout the achromat cell to keep the radiation integrals and resulting beam emittance low. The baseline design called for a 400 m ring circumference with 12 straight sections of 6 m length. The dynamic aperture behaviour of the DLSR lattice was estimated to produce > 5 h beam lifetime at 100 mA stored beam current.
76 citations