Beam Dynamics Studies for the CLIC Main Linac

The implications of long-range wakefields on the beam quality are investigated through a detailed beam dynamics study. Injection offsets are considered and the resulting emittance dilution recorded, including systematic sources of error. These simulations have been conducted for damped and detuned structures (DDS) and for waveguide damped structures-both for the CLIC collider.Comment: 3 pages, 6 figures, IPAC1

The synthesis of optimal controls for linear problems with retarded controls

Synthesis of optimal controls for linear systems with retarded control

Alignment of the CLIC BDS

Aligning the CLIC Beam Delivery System faces two major challenges, the tight tolerances for the emittance preservation and its strong non-linear beam dynamics. For these reasons conventional beam-based alignment techniques, like dispersion free steering, are only partially successful and need to be followed by optimization algorithms based on other observables, like beam sizes

Evaluation of Psychometric and Linguistic Properties of the Italian Adolescent Pain Assessment Scales: A Systematic Review

Introduction: Adolescents’ pain experiences are complex and multidimensional, and evaluating pain only from a sensory and affective point of view may be in many instances limiting and inadequate; this is the reason why it is of paramount importance to identify the tools which can better assess the pain experienced by young patients. A person-oriented approach is highly encouraged, as it may better investigate the cognitive and behavioral development typical of this age group. The aim of this review paper is to describe the available tools which are able to adequately assess pain intensity in adolescents, in particular those validated in Italian. Methods: We conducted a systematic review using four databases: CINAHL, PsycINFO, PubMed and Cochrane, and selected all the articles published between January 1970 and November 2017. We selected all the papers reporting the validation process of pain assessment tools specifically tailored for adolescent patients (age range 10–18 years) and based on psychometric and linguistic parameters, and focused especially on the tools available in Italian and able to measure acute and chronic pain. Results: The results of our investigation have revealed the existence of 40 eligible tools, 17 of which are monodimensional and the remaining 23 multidimensional, more specifically tailored to assess both acute and chronic pain. Some of the instruments (26) were self-reports while others were classified as behavioral (13) and/or mixed. Only one tool turned out to be suitable for fragile adolescents, while six adopted a person-oriented approach that better emphasized the cognitive and behavioral process typical of the adolescent population. None of them has ever been validated in Italian. Conclusion: Valid and reliable psychometric tools specifically organized to provide a cultural and linguistic evaluation of the patient are indeed the most recommended instruments to assess the intensity of the pain experienced by the patient, as they may provide useful information to implement a health policy aimed at identifying the best assistance programs

Feedback Studies

Dynamic imperfections in future linear colliders can lead to a significant luminosity loss. We discuss different orbit feedback strategies in the main linac that can mitigate the emittance dilution and compare their efficiency. We also address the impact of ground motion in the beam delivery system and the potential cures

A primary electron beam facility at CERN

This paper describes the concept of a primary electron beam facility at CERN, to be used for dark gauge force and light dark matter searches. The electron beam is produced in three stages: A Linac accelerates electrons from a photo-cathode up to 3.5 GeV. This beam is injected into the Super Proton Synchrotron, SPS, and accelerated up to a maximum energy of 16 GeV. Finally, the accelerated beam is slowly extracted to an experiment, possibly followed by a fast dump of the remaining electrons to another beamline. The beam parameters are optimized using the requirements of the Light Dark Matter eXperiment (LDMX) as benchmark.Comment: 3 pages, 3 figure

Beam Dynamics Issues in the CLIC Long Transfer Line

Both the main and the drive beam of the CLIC project must be transported from the central production site to the head of the main linacs over more than twenty kilometers. Over such distances chromatic error may be substantial. With long distances and large beam currents, ion-induced detuning and instabilities and multi-bunch resistive wall effects must also be considered. These effects are quantified and simulated. Based on these results, a baseline design has been established

Recent Improvements in the Tracking Code Placet

The tracking code Placet has recently undergone several improvements. A redesign of its internal data structures and a new user interface based on the mathematical toolbox Octave considerably expanded its simulation capabilities. Several new lattice elements, optimization algorithms and physics processes were added to allow for more complete start-to-end simulations. Finally, the use of the AML language and the Universal Parser Library have extended its interfacing capability. A review of these new features is presented in this paper

EUPRAXIA@SPARC_LAB: Beam Dynamics studies for the X-band Linac

In the framework of the Eupraxia Design Study an advanced accelerator facility EUPRAXIA@SPARC_LAB has been proposed to be realized at Frascati (Italy) Laboratories of INFN. Two advanced acceleration schemes will be applied, namely an ultimate high gradient 1 GeV X-band linac together with a plasma acceleration stage to provide accelerating gradients of the GeV/m order. A FEL scheme is foreseen to produce X-ray beams within 3-10 nm range. A 500-TW Laser system is also foreseen for electron and ion production experiments and a Compton backscattering Interaction is planned together with extraction beamlines at intermediate electron beam energy for neutron beams and THz radiation production. The electron beam dynamics studies in the linac are here presented together with the preliminary machine layout.Comment: 5 pages, 3 figures, NIM-A proceedings of EAAC201

TRADITIONAL FINAL FOCUS SYSTEM FOR CLIC

Abstract A traditional Final Focus System based on dedicated chromaticity correction sections is presented as an alternative for CLIC Final Focus. The Scheme of the lattice is shown and tha luminosity bandwidth is calculated. A systematic tuning using Beam Based Alignment and sectupole knobs is perdormed. The complete comparison to the Local Chromaticity correction scheme is presented