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The Linear Accelerator Shortage Index (LSI) is a practical tool for prioritising the deployment of linear accelerators (LINACs) in various regions within a country. The LSI reflects the ratio of LINAC demand to current availability. The aim of this study was to use the LSI to predict global LINAC needs and classify countries according to the degree of radiotherapy shortage (LINAC shortage grade). In this cross-sectional, population-based study of globally representative, country-level data, we sourced regional LINAC distribution, numbers of radiotherapy centres, and cancer incidence data for 181 countries from the Directory of Radiotherapy Centers and Global Cancer Observatory 2022 databases. Current gross domestic product and gross national income per capita in US dollars were obtained from the World Bank. We calculated an LSI for each country to assess the relative demand and supply of radiotherapy by dividing LINAC use by 450 and multiplying by 100. An LSI of 100 or less indicates no shortage (450 or fewer patients per LINAC), whereas an LSI greater than 100 signals a shortage, with higher values indicating more severe deficits. We categorised countries by LINAC shortage grade: grade 0 (LSI ≤100, no shortage), grade 1 (LSI 101–130, low need), grade 2 (LSI 131–300, high need), grade 3 (LSI >300, excessive need), or grade 4 (no existing LINACs). We estimated LINAC requirements until 2045 using the LSI and Global Cancer Observatory data. We determined future investment costs according to the LSI for each country. As of the data cutoff on Sept 15, 2024, the global median LSI was 130 (IQR 96–319), suggesting a shortage of 30% in radiotherapy capacity. Significant disparities in median LSI were observed across income levels: low-income countries had a median LSI of 1523 (528–2247), lower-middle-income countries 399 (183–685), upper-middle-income countries 133 (104–198), and high-income countries 96 (83–127; p<0·0001). The distribution of countries across LINAC shortage grades was 40 (22%) of 181 as grade 0, 32 (18%) as grade 1, 35 (19%) as grade 2, 38 (21%) as grade 3, and 36 (20%) as grade 4 (no LINACs). Most LINAC shortage grade 4 countries were low income (12 [33%]) or lower-middle income (16 [44%]). The median number of new LINACs needed per country by 2045 was estimated at 6 (1–13) for grade 0, 21 (4–102) for grade 1, 22 (8–80) for grade 2, 52 (26–113) for grade 3, and three (2–14) for grade 4. To meet these demands, also including the replacement of obsolete devices, an estimated 30 470 LINACs will be needed by 2045. The median total investment required for new and replacement machines and radiotherapy centres to meet the 2045 demand is projected at US$162 million (49–369) for grade 0, $216 million (54–772) for grade 1, $143 million (64–580) for grade 2, $238 million (126–561) for grade 3, and $16 million (9–59) for grade 4. A significant change in LINAC shortage grade composition between 2020 and 2045 is predicted, with distribution of 40 (22%) versus seven (4%) for grade 0, 32 (18%) versus 23 (13%) for grade 1, 35 (19%) versus 63 (35%) for grade 2, 38 (21%) versus 52 (29%) for grade 3, and 38 (20%) versus 38 (20%) for grade 4 (p<0·0001). The LSI and LINAC shortage grade systems are effective for evaluating, monitoring, and forecasting global LINAC needs. The LSI and LINAC shortage grade highlight the substantial disparities in radiotherapy availability and underscore the urgent need for investment in radiotherapy capacity building, particularly in many low-income and middle-income countries. None.

Hands-On Accelerator Physics Using MATLAB®, Second Edition, provides a broad introduction into the physics and the technology of particle accelerators from synchrotron light sources to high-energy colliders. It covers the design of beam optics, magnets, and radio-frequency systems, followed by a discussion of beam instrumentation and correction algorithms. Later chapters deal with the interaction of beams with targets, the emission of synchrotron radiation, and intensity limitations. Chapters discussing running and future accelerators round up the presentation. Theoretical concepts and the design of key components are explained with the help of MATLAB code. Practical topics, such as beam size measurements, magnet construction and measurements, and radio-frequency measurements are explored in student labs that do not require access to an accelerator. This unique approach provides a look at what goes on \"\"under the hood\"\" inside modern accelerators and presents readers with the tools to perform their independent investigations on the computer or in student labs. This book will be of interest to graduate students, post-graduate researchers studying accelerator physics, as well as engineers entering the field. The second edition features a new chapter on future accelerators and several new sections on polarization, neutrino beams, testing of superconducting cavities, and matching in longitudinal phase space, among others. The MATLAB code was updated to be consistent with the recent release of R2024a. All code is available from the book’s GitHub site at https://github.com/volkziem/HandsOnAccelerators2nd. Key features: Provides a broad introduction into physics of particle accelerators from synchrotron light sources to high-energy colliders. Discusses technical subsystems, including magnets, radio-frequency engineering, instrumentation and diagnostics, correction of imperfections, control, vacuum, and cryogenics. Illustrates key concepts with sample code in MATLAB.

The use of particle accelerators as photon sources has enabled advances in science and technology 1 . Currently the workhorses of such sources are storage-ring-based synchrotron radiation facilities 2 – 4 and linear-accelerator-based free-electron lasers 5 – 14 . Synchrotron radiation facilities deliver photons with high repetition rates but relatively low power, owing to their temporally incoherent nature. Free-electron lasers produce radiation with high peak brightness, but their repetition rate is limited by the driving sources. The steady-state microbunching 15 – 22 (SSMB) mechanism has been proposed to generate high-repetition, high-power radiation at wavelengths ranging from the terahertz scale to the extreme ultraviolet. This is accomplished by using microbunching-enabled multiparticle coherent enhancement of the radiation in an electron storage ring on a steady-state turn-by-turn basis. A crucial step in unveiling the potential of SSMB as a future photon source is the demonstration of its mechanism in a real machine. Here we report an experimental demonstration of the SSMB mechanism. We show that electron bunches stored in a quasi-isochronous ring can yield sub-micrometre microbunching and coherent radiation, one complete revolution after energy modulation induced by a 1,064-nanometre-wavelength laser. Our results verify that the optical phases of electrons can be correlated turn by turn at a precision of sub-laser wavelengths. On the basis of this phase correlation, we expect that SSMB will be realized by applying a phase-locked laser that interacts with the electrons turn by turn. This demonstration represents a milestone towards the implementation of an SSMB-based high-repetition, high-power photon source. The mechanism of steady-state electron microbunching is demonstrated, providing a basis that will enable its full implementation in electron storage rings to generate high-repetition, high-power coherent radiation.

Awarded one of BookAuthority's best new Particle Physics books in 2019! Hands-On Accelerator Physics Using MATLAB® provides an introduction into the design and operational issues of a wide range of particle accelerators, from ion-implanters to the Large Hadron Collider at CERN. Many aspects from the design of beam optical systems and magnets, to the subsystems for acceleration, beam diagnostics, and vacuum are covered. Beam dynamics topics ranging from the beam-beam interaction to free-electron lasers are discussed. Theoretical concepts and the design of key components are explained with the help of MATLAB® code. Practical topics, such as beam size measurements, magnet construction and measurements, and radio-frequency measurements are explored in student labs without requiring access to an accelerator. This unique approach provides a look at what goes on 'under the hood' inside modern accelerators and presents readers with the tools to perform their independent investigations on the computer or in student labs. This book will be of interest to graduate students, postgraduate researchers studying accelerator physics, as well as engineers entering the field. Features: Provides insights into both synchrotron light sources and colliders Discusses technical subsystems, including magnets, radio-frequency engineering, instrumentation and diagnostics, correction of imperfections, control, and cryogenics Accompanied by MATLAB® code, including a 3D-modeler to visualize the accelerators, and additional appendices which are available on the CRC Press website MATLAB live-scripts to accompany the book can be found here: https://ziemann.web.cern.ch/ziemann/mybooks/mlx/ Chapter 1. Introduction and History. Chapter 2. Reference System. Chapter 3. Transverse Beam Optics. Chapter 4. Magnets. Chapter 5. Longitudinal Dynamics and Acceleration. Chapter 6. Radio-Frequency Systems. Chapter 7. Instrumentation and Diagnostics. Chapter 8. Imperfections and their Corrections. Chapter 9. Targets and Luminosity. Chapter 10. Synchrotron Radiation and Free-Electron Lasers. Chapter 11. Non-Linear Dynamics. Chapter 12 . Collective Effects. Chapter 13. Accelerator Subsystems. Chapter 14. Examples of Accelerators. Volker Ziemann obtained his PhD in accelerator physics from Dortmund University in 1990. After post-doctoral positions in Stanford at SLAC and in Geneva at CERN, where he worked on the design of the LHC, in 1995 he moved to Uppsala where he worked at the electron-cooler storage ring CELSIUS. In 2005 he moved to the physics department where he has since taught physics. He was responsible for several accelerator physics projects at CERN, DESY and XFEL. In 2014 he received the Thuréus prize from the Royal Society of Sciences in Uppsala.

High-dimensional optimization is a critical challenge for operating large-scale scientific facilities. We apply a physics-informed Gaussian process (GP) optimizer to tune a complex system. Typical GP models learn from past observations to make predictions, but this reduces their applicability to systems where there is limited relevant archive data. Instead, here we use a fast approximate model from physics simulations to design the GP model. The GP is then employed to make inferences from sequential online observations in order to optimize the system. Simulation and experimental studies were carried out to demonstrate the method for online control of a storage ring. Our method is a simple prescription to construct a custom GP model, including correlations between the high-dimensional input space, while encoding the physical response of a system. The ability to inform the machine-learning model with physics, without relying on the availability and range of prior data, may have wide applications in science.

Particle accelerators and storage rings have been transformative instruments of discovery, and, for many applications, innovations in particle-beam cooling have been a principal driver of that success 1 . Stochastic cooling (SC), one of the most important conceptual and technological advances in this area 2 – 6 , cools a beam through granular sampling and correction of its phase-space structure, thus bearing resemblance to a ‘Maxwell’s demon’. The extension of SC from the microwave regime up to optical frequencies and bandwidths has long been pursued, as it could increase the achievable cooling rates by three to four orders of magnitude and provide a powerful tool for future accelerators. First proposed nearly 30 years ago, optical stochastic cooling (OSC) replaces the conventional microwave elements of SC with optical-frequency analogues and is, in principle, compatible with any species of charged-particle beam 7 , 8 . Here we describe a demonstration of OSC in a proof-of-principle experiment at the Fermi National Accelerator Laboratory’s Integrable Optics Test Accelerator 9 , 10 . The experiment used 100-MeV electrons and a non-amplified configuration of OSC with a radiation wavelength of 950 nm, and achieved strong, simultaneous cooling of the beam in all degrees of freedom. This realization of SC at optical frequencies serves as a foundation for more advanced experiments with high-gain optical amplification, and advances opportunities for future operational OSC systems with potential benefit to a broad user community in the accelerator-based sciences. Stochastic cooling at optical frequencies is demonstrated in an experiment at the Fermi National Accelerator Laboratory’s Integrable Optics Test Accelerator, substantially increasing the bandwidth of stochastic cooling compared with conventional systems.

Tuning particle accelerators is a challenging and time-consuming task that can be automated and carried out efficiently using suitable optimization algorithms, such as model-based Bayesian optimization techniques. One of the major advantages of Bayesian algorithms is the ability to incorporate prior information about beam physics and historical behavior into the model used to make control decisions. In this work, we examine incorporating prior accelerator physics information into Bayesian optimization algorithms by utilizing fast executing, neural network models trained on simulated or historical datasets as prior mean functions in Gaussian process models. We show that in ideal cases, this technique substantially increases convergence speed to optimal solutions in high-dimensional tuning parameter spaces. Additionally, we demonstrate that even in non-ideal cases, where prior models of beam dynamics do not exactly match experimental conditions, the use of this technique can still enhance convergence speed. Finally, we demonstrate how these methods can be used to improve optimization in practical applications, such as transferring information gained from beam dynamics simulations to online control of the LCLS injector, and transferring knowledge gained from experimental measurements across different operating modes, such as accelerating different ion species at the ATLAS heavy ion accelerator.

This book provides a comprehensive treatment of intensity dependent particle beam instabilities in accelerating rings. Written for researchers, the material is also suitable for use as a textbook in an advanced graduate course for students studying accelerator physics.The presentation starts with a brief review of the basic concept of wake potentials and coupling impedances in the vacuum chamber followed by a discussion on static and dynamic solutions of their effects on the particle beams. Special emphasis is placed separately on proton and electron machines. Other special topics of interest covered include Landau damping, Balakin-Novokhatsky-Smirnov damping, Sacherer's integral equations, Landau cavity, saw-tooth instability, Robinson stability criteria, beam loading, transition crossing, two-stream instabilities, and collective instability issues of isochronous rings. After the formulation of an instability, readers are provided a thorough description of one or more experimental observations together with a discussion of the cures for the instability.Although the book is theory oriented, the use of mathematics has been minimized. The presentation is intended to be rigorous and self-contained with nearly all the formulas and equations derived.

This study aims to provide a technological comparison of possible alternatives for supervision and control system implementations to support the design of the IFMIF-DONES (International Fusion Materials Irradiation Facility DEMO Oriented Neutron Source) plant and its CODAC (Control, Data Access and Communication) System. A methodology to compare and assess open control frameworks such as EPICS (Experimental Physics and Industrial Control System), versus industrial solutions from different vendors, is presented. The hypothesis to be investigated is that license cost should not be taken as the primary decision factor for choosing the framework, even when considering open-source software as an alternative. The key elements addressed for each solution include reliability, scalability, load balancing, resilience, the costs associated with risks, development effort, future upgrade planning, and maintenance. To ground the analysis, this work examines the essential supervision and control requirements for the IFMIF-DONES particle accelerator, focusing specifically on the top-level services of the central CODAC system. Finally, the study presents illustrative results and provides recommendations for future design activities.