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Novel high-gradient accelerators have demonstrated acceleration of electrons and positrons with electric field strengths of 1 to > 100 GeV/m. This is about 10 to 1000 times higher than achieved in RF-based accelerators, and as such they have the potential to overcome the limitations associated with RF cavities. Plasma-based accelerators have produced multi-GeV bunches with parameters approaching those suitable for a linear collider. A significant reduction in size and, perhaps, cost of future accelerators can therefore in principle be envisaged., CERN Yellow Reports: Monographs, Vol. 1 (2022): European Strategy for Particle Physics - Accelerator R&D Roadmap

CERN Yellow Reports: Monographs, Vol. 1 (2022): European Strategy for Particle Physics - Accelerator R&D Roadmap; Geneva : CERN Yellow Reports: Monographs 53 pp. (2022). doi:10.23731/CYRM-2022-001.91, Novel high-gradient accelerators have demonstrated acceleration of electrons and positrons with electric field strengths of 1 to > 100 GeV/m. This is about 10 to 1000 times higher than achieved in RF-based accelerators, and as such they have the potential to overcome the limitations associated with RF cavities. Plasma-based accelerators have produced multi-GeV bunches with parameters approaching those suitable for a linear collider. These accelerators offer the prospect of near term, compact and cost-effective particle physics experiments that provide new physics possibilities supporting precision studies and the search for new particles. The expert panel has defined a long term R&D roadmap towards a compact collider with attractive intermediate experiments and studies. A delivery plan for the required R&D has been developed and includes work packages, deliverables, a minimal plan, connections to ongoing projects and an aspirational plan., Published by CERN Yellow Reports: Monographs, Geneva

8th International Beam Instrumentation Conference, IBIC2019, Malmö, Sweden, 8 Sep 2019 - 12 Sep 2019; JACoW Publishing, Geneva, Switzerland 7 pp. (2019). doi:10.18429/JACOW-IBIC2019-TUBO01, Scintillation screens made of various inorganic materials are widely used for transverse beam profile diagnostics at all kinds of accelerators. The monitor principle is based on the particles¿ energy loss and its conversion to visible light. The resulting light spot is a direct image of the two-dimensional beam distribution. For large beam sizes standard optical techniques can be applied, while for small beam sizes dedicated optical arrangements have to be used to prevent for image deformations. In the modern linac based light sources scintillator usage serves as an alternative way to overcome limitations related to coherent OTR emission. Radiation damages and intensity based saturation effects, in dependence of the screen material, have to be modelled. In this talk, an introduction to the scintillation mechanism in inorganic materials will be given including practical demands and limitations. An overview on actual applications at hadron and electron accelerators will be discussed as summary of the Joint ARIES-ADA Workshop on ¿Scintillation Screens and Optical Technology for transverse Profile Measurements¿ held in Kraków, Poland., Published by JACoW Publishing, Geneva, Switzerland

Accelerator Research and Innovation for European Science and Society, ARIES, is an initiative funded by the European Union. The activity comprises three major categories: Joint Research Activities; Transnational Ac- cess; Network Activities. One of 17 activities is a network related to Advanced Diagnostics at Accelerators, ADA with the task of strengthening collaborations between international laboratories and for coordinated R&D in beam diagnostics. This is performed by organizing Topi- cal Workshops on actual developments and supporting interchange of experts between different labs. Since the start of the project in May 2017 four Topical Workshops were organized, each with 30-45 participants. Future workshops will address actual topics.

THz streaking with split ring resonators (SRR) promise ultra-high (sub-femtosecond) temporal resolution even for relativistic electron bunches. A proof-of-principle experiment in collaboration between the University of Bern, the Paul Scherrer Institute (PSI) and the Karlsruhe Institute of Technology (KIT) is currently prepared at the FLUTE facility (Ferninfrarot Linac und Test Experiment) at KIT. Most of the critical components have been designed, tested and set-up in the 7 MeV diagnostics part of FLUTE. In this contribution we will present an update on the experimental set-up and report on SRR configurations which have been optimized for highest THz deflection, while simultaneously accounting for the restrictions of the manufacturing process. Test measurements characterizing the SRR samples and the THz source, which has been matched to the FLUTE gun laser, will also be presented., Proceedings of the 6th Int. Beam Instrumentation Conf., IBIC2017, Grand Rapids, MI, USA

High-brightness electron bunches with small transverse emittance are required to drive X-ray free-electron lasers (FELs). For the measurement of the transverse emittance, the quadrupole scan and multi-screen methods are the two most common procedures. By employing a transverse deflecting structure, the measurement of the slice emittance becomes feasible. The quadrupole scan is more flexible in freely choosing the data points during the scan, while the multi-screen method allows on-line emittance measurements utilising off-axis screens in combination with fast kicker magnets. The latter is especially the case for high-repetition multi-bunch FELs, such as the European XFEL, which offer the possibility of on-line diagnostics. In this paper, we present comparative measurements of projected and slice emittance applying these two methods at the SwissFEL Injector Test Facility and discuss the implementation of on-line diagnostics at the European XFEL.

The accurate, non-destructive measurements of FEL pulse length and arrival time relative to an experimental laser are necessary for operators and users alike. The FEL operators can get a better understanding of their machine and the optics of an FEL by examining the pulse length changes of the photons coming to the user stations, and the users can use the arrival time and pulse length information to better understand their data. PSI has created the pulse arrival and length monitor (PALM) based on the THz-streak camera concept for measurement at x-ray FELs, meant to be used at the upcoming SwissFEL facility. The first results from the experimental beamtime at SACLA will be presented, showcasing the accuracy and reliability of the device. Further plans for improvement and eventual integration into SwissFEL will also be presented.

SwissFEL will be a hard x-ray fourth generation light source to be built at Paul Scherrer Institut (PSI), Switzerland. In SwissFEL the electron bunches will be produced with a length of 3ps and will then be compressed by a factor of more than 1000 down to a few fs in order to generate ultra short x-ray pulses. Therefore reliable, accurate and noninvasive longitudinal diagnostic is essential after each compressing stage. In order to meet the requirements of this machine, new monitors have to be developed. We will present recent results of setups that measure electro-magnetic radiation, namely edge, synchrotron and diffraction radiation, emitted by the electron bunches (far field, spectral domain). These monitors are tested in the SwissFEL Injector Test Facility. A state of the art S-band Transverse Deflecting Cavity together with a Screen Monitor is used for calibration.

This report contains a comprehensive technical description of a new international research infrastructure, the European X-Ray Free-Electron Laser (XFEL) Facility. It was written between October 2005 and June 2006 and provides a realistic cost estimate and a compelling assessment of the scientific pay-off. The report has been prepared with the contribution of hundreds of people from many laboratories in Europe and even beyond. Their contributions have been harmonised and merged by many editors, and the whole effort has been coordinated by the European Project Team, generously supported and hosted by the Deutsches Elektronen-Synchrotron (DESY) laboratory.