CAS Advanced Accelerator Physics, 6-18 November 2022, Sevrier, France

6 Nov 2022, 08:30 → 18 Nov 2022, 14:30 Europe/Zurich

Les Balcons du lac d'Annecy (France)

Frank Tecker (CERN)

 

The course will be of interest to physicists and engineers who wish to extend their knowledge of accelerator physics and technologies and expand their professional network. The program offers core lectures on accelerator physics in the mornings and a practical course with hands-on tuition in the afternoons. Participants will select one afternoon course from the three available.

A successful participation at this course requires some basic knowledge of accelerator physics or experience acquired through professional work.  As this course introduces advanced and contemporary concepts, knowledge of classical mechanics, electrodynamics, as well as mathematics for physics or engineering at the university entrance level is expected.

It is recommended that participants register as soon as possible, first come first served as there may be a limited number of participants due to limitations of the hotel facilities.

As usual we will accept GRANT applications. As big exception this year, it is not sure if we will be able to accept grants for people who will need a visa. The time between confirmation of the course and its beginning might be too short for the visa formalities.   

 

Sunday 6 November

1 Arrival day and registration

For the hotel, the rooms will be available from 17:00 on the arrival day.
The hotel reception will be open only until 20:00. They will prepare the room keys for you and we can give you the keys while our CAS registration desk (for your badge, etc.) is open on arrival on Sunday from 19:00 – 21:00. So please make sure that you arrive by 21:00 at the latest, otherwise you will not be able to get your room key for the night.
Further registrations can be done on Monday from 7:30 – 8:30 and in the morning coffee break.

20:00 Dinner

Monday 7 November

2 Opening

Speaker: Frank Tecker (CERN)

opening-advanced-r.pdf

opening-advanced-r.pptx

3 Recap Transverse Beam Dynamics I

The Advanced General CAS course is thought to be the continuation of the Introductory Course, which is held every year. Some of the students might not have had the chance to assist to this course and therefore on the first day a two hours recapitulation is foreseen. The main focus of this recapitulation is the theoretical description of particle motion in electromagnetic fields. Since the longitudinal motion is treated an an extra two hours recap, the main focus of this presentation is transverse beam motion, mathematical models, different accelerator types and collective effects.

Speaker: Hermann Schmickler

Recap_Intro_HS_2022.pdf

Recap_Intro_HS_2022.pptx

Recording

Video preview

10:30 Coffee break

4 Intro to RF measurement techniques I

RF measurement techniques are a vital part in today's accelerator design and engineering. In this lecture we cover the measurement of radio-frequency (RF) signals and the characterization of RF components, systems and subsystems deployed in particle accelerators, based on the use of modern measurement instruments, like the RF vector network analyzer (VNA) and the spectrum analyzer (SA). In addition, the handling of more general purpose instruments, like the oscilloscope and others will be covered in this course.

Speaker: Manfred Wendt (CERN)

Recording

Video preview

5 Intro to Beam Instrumentation and Diagnostics I

Beam instrumentation and diagnostics combines the disciplines of accelerator physics with mechanical, electronic and software engineering, making it an extremely interesting field in which to work. The aim of the beam instrumentation physicist or engineer is to design, build, maintain and improve the diagnostic equipment for the observation of particle beams with the precision required to tune, operate and improve the accelerators and their associated transfer lines. This introduction is intended to give an overview of the instrumentation in use in modern accelerators and how they can be used to diagnose problems or improve machine performance.

Speaker: Rhodri Jones (CERN)

CAS2022 - BI - Lecture 1 - RJ.pdf

CAS2022 - BI - Lecture 1 - RJ.pptx

Recording

Video preview

13:00 Lunch

6 Recap Transverse Beam Dynamics II

The Advanced General CAS course is thought to be the continuation of the Introductory Course, which is held every year. Some of the students might not have had the chance to assist to this course and therefore on the first day a two hours recapitulation is foreseen. The main focus of this recapitulation is the theoretical description of particle motion in electromagnetic fields. Since the longitudinal motion is treated an an extra two hours recap, the main focus of this presentation is transverse beam motion, mathematical models, different accelerator types and collective effects.

Speaker: Hermann Schmickler

Recording

Video preview

7 Intro to Optics Design

This lecture provides an overview of the principles and methodologies involved in linear optics design. It aims to introduce key concepts such as the matrix formalism for linear optics, the use of symplectic matrices in particle evolution, the Courant-Snyder invariant. It also covers the concept of beam emittance and matching conditions for ensemble of particles. The material delves into using xsuite, a general-purpose tracking code, for simulating beam dynamics and optimizing lattice design for large-scale projects like the LHC. The goal is to equip readers with the foundational tools needed for both theoretical understanding and practical application in linear optics and accelerator design.

Speaker: Guido Sterbini (CERN)

Introduction_to_Optics_Design.pdf

Recording

Video preview

16:30 Coffee break

8 1 slide 1 minute

1S1M_Advanced_Sevrier2022.pptx

18:00 Welcome Drink

19:30 Dinner

Tuesday 8 November

9 Lattice Cells

This lecture presents an analysis of lattice cell design, with a particular focus on the FODO topology and its various applications in particle accelerator optics. The design methodology explores the stability conditions, phase advances, and chromaticity of the FODO lattice under both theoretical and practical constraints. Additionally, the optics of the CERN accelerators are presented, demonstrating the principles in practical scenarios.

Speaker: Guido Sterbini (CERN)

Lattice Design.pdf

Recording

Video preview

10 Accelerator issues overview

This lecture summarises the status and the recent advances on muon collider facility design. The challenges in producing intense proton beams, using them to make pions and muons and subsequent cooling, acceleration and collision are described.

Speaker: Frank Tecker (CERN)

Issues-overview.pdf

Issues-overview.pptx

Recording

Video preview

10:30 Coffee break

11 Intro to RF measurement techniques II

RF measurement techniques are a vital part in today's accelerator design and engineering. In this lecture we cover the measurement of radio-frequency (RF) signals and the characterisation of RF components, systems and subsystems deployed in particle accelerators, based on the use of modern measurement instruments, like the RF vector network analyser (VNA) and the spectrum analyzer (SA). In addition, the handling of more general purpose instruments, like the oscilloscope and others will be covered in this course.

Speaker: Manfred Wendt (CERN)

Recording

RFmeasTechCAS2022.pdf

RFmeasTechCAS2022.pptx

Video preview

12 Intro to Beam Instrumentation and Diagnostics II

Beam instrumentation and diagnostics combines the disciplines of accelerator physics with mechanical, electronic and software engineering, making it an extremely interesting field in which to work. The aim of the beam instrumentation physicist or engineer is to design, build, maintain and improve the diagnostic equipment for the observation of particle beams with the precision required to tune, operate and improve the accelerators and their associated transfer lines. This introduction is intended to give an overview of the instrumentation in use in modern accelerators and how they can be used to diagnose problems or improve machine performance.

Speaker: Rhodri Jones (CERN)

CAS2022 - BI - Lecture 2 - RJ.pdf

CAS2022 - BI - Lecture 2 - RJ.pptx

Recording

Video preview

13:00 Lunch

13 Insertions & Dispersion Suppressors

This lecture presents a comprehensive exploration of the design principles for low-beta insertions and dispersion suppressors in particle colliders. The primary focus is on optimizing beam optics to enhance collider performance, particularly in high-luminosity environments. Both sections emphasize theoretical models, practical implementation, and the comparative advantages of alternative topological configurations.

Speaker: Guido Sterbini (CERN)

Dispersion Suppressors

Insertion Matching

LHC_Squeeze.pdf

Recording

Video preview

14 BI

Speakers: Dr Marek Gasior (CERN), Rhodri Jones (CERN), Thibaut Lefevre (CERN)

Beam_Instrumenation_Simulator_Installer.exe

BISS homodyne experiment.mat

CAS_Annecy_BPM-Course_students.pdf

Homodyne Experiment.pdf

Homodyne Experiment.pptx

15 Optics

Speakers: Davide Gamba (CERN), Guido Sterbini (CERN), Hannes Bartosik (CERN)

16 RF

Speakers: Christine Vollinger (CERN), Manfred Wendt (CERN)

16:30 Coffee break

17 BI

Speakers: Dr Marek Gasior (CERN), Rhodri Jones (CERN), Thibaut Lefevre (CERN)

18 Optics

Speakers: Davide Gamba (CERN), Guido Sterbini (CERN), Hannes Bartosik (CERN)

19 RF

Speakers: Christine Vollinger (CERN), Manfred Wendt (CERN)

19:30 Dinner

Wednesday 9 November

20 Recap Longitudinal Beam Dynamics I

The course gives a summary of longitudinal beam dynamics for both linear and circular accelerators. After discussing different types of acceleration methods and synchronism conditions, it focuses on the particle motion in synchrotrons.

Speaker: Frank Tecker (CERN)

Longitudinal-Sevrier-2022.pdf

Longitudinal-Sevrier-2022.pptx

Recording

21 Space charge in linear machines

Space charge forces are those generated directly by the charge distribution within th bunch. In this lecture we introduce, from basic principles, the main concepts of beam focusing and transport in high brightness linacs and injectors under the effects of space charge forces using the beam envelope equation as a convenient mathematical tool. Matching conditions suitable for preserving beam quality are derived from the model for significant beam dynamics regimes.

Speaker: Massimo Ferrario

CAS_Annecy_SC_Linac.pdf

Recording

Video preview

10:30 Coffee break

22 Recap Longitudinal Beam Dynamics II

The course gives a summary of longitudinal beam dynamics for both linear and circular accelerators. After discussing different types of acceleration methods and synchronism conditions, it focuses on the particle motion in synchrotrons.

Speaker: Frank Tecker (CERN)

Recording

23 Space charge in circular machines

Space charge forces are those generated directly by the charge distribution, with the inclusion of the image charges and currents due to the interaction of the beam with a perfectly conducting smooth pipe. Space charge forces are responsible of several unwanted phenomena related to beam dynamics, such as energy loss, shift of the synchronous phase and frequency, shift of the betatron frequencies, and instabilities. We will discuss in this lecture the main feature of space charge effects in high energy storage rings.

Speaker: Massimo Ferrario

CAS_Annecy_SC_Ring.pdf

Recording

13:00 Lunch

24 Beam loading

Radio-frequency (RF) systems in particle accelerators are usually designed to transfer energy to the beam or to define its longitudinal structure. However, charged particles passing through an RF cavity induce a voltage which acts back on themselves and on subsequent particles. The additional contribution of the beam to the cavity voltage moreover changes the effective properties of the RF system and is generally referred to as beam loading. The fundamental theorem of beam loading is introduced to derive the effect of a single bunch passage through an RF cavity. The choice of the cavity parameters, notably shunt impedance divided by quality factor, plays an important role to reduce the beam induced voltage. Extending the single bunch case to the periodic passage of bunches allows to calculate the steady state cavity detuning due to beam loading for a continuous bunch pattern. Special emphasis is given to the partially filled ring, with gaps in the filling pattern, which is the most common case of transient beam loading in electron and hadron synchrotrons.

Speaker: Heiko Damerau (CERN)

BeamLoading_corr.pdf

BeamLoading_corr.pptx

Recording

Video preview

25 C1/C2/C3

16:30 Coffee break

26 C1/C2/C3

Seminar

19:30 Dinner

Thursday 10 November

27 Instabilities in Linacs

When a charged particle travels across the vacuum chamber of an accelerator, it induces electromagnetic fields, which are left mainly behind the generating particle. These electromagnetic fields act back on the beam and influence its motion. Such an interaction of the beam with its surroundings results in beam energy losses, alters the shape of the bunches, and shifts the betatron and synchrotron frequencies. At high beam current the fields can even lead to instabilities thus limiting the performance of the accelerator in terms of beam quality and current intensity. We discuss in this lecture the general features of the electromagnetic fields, introducing the concepts of wake fields and giving few simple examples of them in cylindrical geometry. We then show the effect of the wake fields on the dynamics of a beam in a LINAC, dealing in particular with the beam breakup instability and the way to cure it.

Speaker: Massimo Ferrario

L3_Wake_Annecy.pdf

Recording

28 Collimation

Modern accelerators cannot operate high intensity hadron beams without adequate beam collimation systems that are designed to dispose safely and efficiently of unavoidable losses in each phase of the beam operation. This is in particular the case for hadron colliders that rely on super-conducting magnets to push beam energy and current, like the Large Hadron Collider (LHC). In this case, the tiny energy amounts sufficient to spoil the super-conducting state is several orders of magnitude below the total stored beam energy, calling for very efficient beam collimation. Uncontrolled beam losses also risk to damage permanently accelerator equipment, which must be avoided to ensure a high-availability operation. In this contribution, the design of a multi-stage collimation system is reviewed, discussing typical target specifications, design criteria and performance. Modern tools used to study and characterize collimation systems are briefly introduced. The LHC collimation system is presented as a case study, covering also its technical implementation and collimation operational aspects.

Speaker: Stefano Redaelli (CERN)

Recording

SRedaelli_CAS_2022-11-10.pdf

10:30 Coffee break

29 Overview of Wakefield Accelerator

Recent years have seen spectacular progress in the development of innovative acceleration methods that are not based on traditional RF accelerating structures. These novel developments are at the interface of laser, plasma and accelerator physics and may potentially lead to much more compact and cost effective accelerator facilities. While primarily focusing on the ability to accelerate charged particles with much larger gradients than traditional RF, these new techniques have yet to demonstrate comparable performances to RF in terms of both beam parameters and reproducibility. In this lecture will review the most promising developments in new acceleration methods and it will present the status of ongoing projects including the European EuPRAXIA project.

Speaker: Massimo Ferrario

L4_PWFA_Annecy.pdf

Recording

30 Collimation + technical implementation

Modern accelerators cannot operate high intensity hadron beams without adequate beam collimation systems that are designed to dispose safely and efficiently of unavoidable losses in each phase of the beam operation. This is in particular the case for hadron colliders that rely on super-conducting magnets to push beam energy and current, like the Large Hadron Collider (LHC). In this case, the tiny energy amounts sufficient to spoil the super-conducting state is several orders of magnitude below the total stored beam energy, calling for very efficient beam collimation. Uncontrolled beam losses also risk to damage permanently accelerator equipment, which must be avoided to ensure a high-availability operation. In this contribution, the design of a multi-stage collimation system is reviewed, discussing typical target specifications, design criteria and performance. Modern tools used to study and characterize collimation systems are briefly introduced. The LHC collimation system is presented as a case study, covering also its technical implementation and collimation operational aspects.

Speaker: Stefano Redaelli (CERN)

Recording

Video preview

13:00 Lunch

31 Free for BI/Optics

3 Screen Emittance readme_2022.pdf

3 Screen Emittance readme_2022.pptx

CAS_BI_2022.pdf

Interferometer_readme_2022.pdf

Interferometer_readme_2022.pptx

Introduction to readout_2022.pdf

Introduction to readout_2022.pptx

Pepperpot readme_2022.pdf

Pepperpot readme_2022.pptx

QP Scan readme_2022.pdf

QP Scan readme_2022.pptx

32 RF

Speaker: Manfred Wendt (CERN)

CAS2022_ExercisesRFnumerical.pdf

CAS2022_RF_Hands-on_Experiments_wCover.pdf

CAS2022_SolutionsRFnumerical_Smith.pdf

CAS2022Theory_wCover.pdf

diplexer.pdf

NVA_mw.pdf

SmithChart_Color_CorrRulers.pdf

33 RF

19:30 Dinner

Friday 11 November

34 Recap Synchrotron Radiation

Synchrotron radiation affects the motion of particles in storage rings in various ways. In the absence of radiation, particle motion is symplectic, and the beam emittances are conserved. In this lecture, it is shown that the inclusion of radiation effects in a classical approximation leads to emittance damping: expressions for the longitudinal and transverse damping times are derived. Then, it is shown that quantum radiation effects lead to excitation of the beam emittances. General expressions for the equilibrium longitudinal and horizontal (natural) emittances in a synchrotron storage ring are derived.

Speaker: Andy Wolski (University of Liverpool)

LowEmittanceMachines1.pdf

Recording

35 Wakefields and Impedances

In beam dynamics, low intensity particle beams can be satisfactorily modelled using the single particle approach, in which it is sufficient to describe the motion of particles through the external electromagnetic fields, while neglecting all other types of interactions. Conversely, the evolution of high intensity particle beams must be described including not only the externally applied electromagnetic fields but also the mutual interactions between beam particles as well as the interactions of beam particles with their surrounding environment. All the perturbations to the motion induced by the additional driving terms associated to these interactions are known as collective effects. The powerful tools of the kinetic theory in plasma physics and self-consistent multi-particle simulations including the beam-induced fields are needed to model the dynamics of particle beams in this regime.

Speaker: Giovanni Rumolo (CERN)

Recording

Sevrier_Introduction_v01.pdf

Sevrier_Introduction_v01.pptx

10:30 Coffee break

36 Low emittance lattices

The impact of lattice design on the natural emittance in an electron storage ring is discussed. The general expressions for the equilibrium longitudinal and horizontal emittances in a storage ring are applied to the specific cases of storage rings constructed from FODO cells, double-bend achromats, multi-bend achromats and theoretical minimum emittance lattices. Finally, the effects of betatron coupling and vertical dispersion (generated by magnet alignment and lattice tuning errors) on the vertical emittance are described briefly.

Speaker: Andy Wolski (University of Liverpool)

LowEmittanceMachines2.pdf

Recording

37 Beam Instabilities - Longitudinal

In beam dynamics, low intensity particle beams can be satisfactorily modelled using the single particle approach, in which it is sufficient to describe the motion of particles through the external electromagnetic fields, while neglecting all other types of interactions. Conversely, the evolution of high intensity particle beams must be described including not only the externally applied electromagnetic fields but also the mutual interactions between beam particles as well as the interactions of beam particles with their surrounding environment. All the perturbations to the motion induced by the additional driving terms associated to these interactions are known as collective effects. The powerful tools of the kinetic theory in plasma physics and self-consistent multi-particle simulations including the beam-induced fields are needed to model the dynamics of particle beams in this regime.
Beside the beam's own space charge, collective effects are typically triggered by the direct electromagnetic interaction of the beam with the external chamber and equipment, described through wake fields and beam-coupling impedances, and the interaction of the beam with electron or ion clouds generated in the vacuum chamber through vacuum or surface processes. They manifest themselves as macroscopic responses of the particle beams to intensity dependent excitations, resulting in observables such as coherent tune shifts, coherent instabilities or emittance growth.
Collective effects are important because they define the machine and beam parameter space, outside of which instabilities or incoherent processes cause intolerable beam quality degradation. For example, the intensity threshold due to impedance represents the upper limit to the number of particles that can circulate in an accelerator or storage ring.

Speaker: Giovanni Rumolo (CERN)

Recording

Sevrier_Longitudinal_v01.pdf

Sevrier_Longitudinal_v01.pptx

13:00 Lunch

38 RF Feedbacks

Feedback systems are commonly applied to stabilise charged particle beams in accelerators. In the longitudinal plane radio-frequency (RF) feedback reduces the beam induced voltage in an RF system, or it allows to damp bunch oscillations. While local feedback decreases the cavity impedance at the origin, global feedback cures the consequence when the source driving the instability is not identified or cannot be removed. The general stability criterion for bandwidth-limited RF feedback is derived and defines the maximum gain due to loop delay. Profiting from the periodicity of bunches passing through an RF system in a circular accelerator, this electrical stability limit can be overcome with 1-turn delay or narrow-band multi-harmonic feedback. For a multi-bunch beam in a synchrotron, global feedback systems can either stabilise the beam bunch-by-bunch in the time domain, or mode-by-mode in the frequency domain. Examples for RF feedback implementations are compared, and criteria to choose the appropriate architecture for a given application are established.

Speaker: Heiko Damerau (CERN)

Recording

RFFeedbacks.pdf

RFFeedbacks.pptx

39 C1/C2/C3

16:30 Coffee break

40 C1/C2/C3

19:30 Dinner

Saturday 12 November

41 Beam Instabilities - Transverse

In beam dynamics, low intensity particle beams can be satisfactorily modelled using the single particle approach, in which it is sufficient to describe the motion of particles through the external electromagnetic fields, while neglecting all other types of interactions. Conversely, the evolution of high intensity particle beams must be described including not only the externally applied electromagnetic fields but also the mutual interactions between beam particles as well as the interactions of beam particles with their surrounding environment. All the perturbations to the motion induced by the additional driving terms associated to these interactions are known as collective effects. The powerful tools of the kinetic theory in plasma physics and self-consistent multi-particle simulations including the beam-induced fields are needed to model the dynamics of particle beams in this regime.

Speaker: Kevin Shing Bruce Li (CERN)

Recording

Sevrier_Transverse_v01.pdf

Sevrier_Transverse_v01.pptx

42 Insertion devices - Radiation

This lecture reviews the synchrotron radiation properties generated by different sources, such as bending magnets, undulators and wigglers. It provides an explanation as to why magnets with centimetre periods generate electromagnetic output at nanometre scale because of relativistic effects. The differences between undulators, which rely on interference, and other sources, which are less subtle, are compared with numerical examples being provided.

Speaker: Prof. Jim Clarke

Clarke_IDs_Radiation_2022.pdf

Clarke_IDs_Radiation_2022.pptx

Recording

10:30 Coffee break

43 Electron Cloud and instabilities

Beside the beam's own space charge, collective effects are typically triggered by the direct electromagnetic interaction of the beam with the external chamber and equipment, described through wake fields and beam-coupling impedances, and the interaction of the beam with electron or ion clouds generated in the vacuum chamber through vacuum or surface processes. They manifest themselves as macroscopic responses of the particle beams to intensity dependent excitations, resulting in observables such as coherent tune shifts, coherent instabilities or emittance growth.

Speaker: Kevin Shing Bruce Li (CERN)

Recording

Sevrier_ElectroCloud_v01.pdf

Sevrier_ElectroCloud_v01.pptx

44 Discussion on Instabilities

Speakers: Giovanni Rumolo (CERN), Kevin Shing Bruce Li (CERN)

13:00 Lunch

45 Insertion devices - Technology

This lecture reviews the options for building insertion device magnets. It highlights why permanent magnets are the most popular choice and explains how more complex magnetic field shapes, such as helical, can be generated with simple rectangular permanent magnet blocks. The use of iron is discussed to enhance the performance of insertion devices, as are the engineering challenges of building and adjusting these devices. Finally more exotic examples are discussed, including superconducting magnets and cryogenic permanent magnets.

Speaker: Prof. Jim Clarke

Clarke_IDs_Technology_2022.pdf

Clarke_IDs_Technology_2022.pptx

Recording

46 C1/C2/C3

16:30 Coffee break

47 C1/C2/C3

19:30 Dinner

Sunday 13 November

08:30 Excursion

13:00 Lunch

14:30 Murder party - https://annecy.takamaka.fr/fr/seminaire/p/murder-party-annecy

https://annecy.takamaka.fr/fr/seminaire/p/murder-party-annecy

19:30 Dinner

Monday 14 November

48 Optics calculations

This lecture provides hands-on guidance for performing optics calculations related to a simple synchrotron. It walks users through the steps needed to execute these calculations using the xsuite, a software for accelerator simulations. This resource is aimed at students and researchers interested in accelerator physics, particularly in understanding basic concept of resonances, chromatic correction, optimal tune and dynamic aperture.

Speaker: Guido Sterbini (CERN)

Optics calculations

Recording

Video preview

49 ERL I

"Energy-Recovery-Linacs (ERLs) are an emerging field in accelerator R&D. They are needed for the sustainable operation of future high-power electron machines, e.g. the LHeC with an anticipated electron beam-power of 1 GW. The energy used for the beam's acceleration is recycled and re-used in an ERL. Higher beam currents are feasible while maintaining the RF power consumption at a comparable level. At the same time, the beam will be dumped at lower beam energies, typically below the neutron separation threshold. Less radiation is produced, and only a moderate dump cooling is needed. Since the postulation of the principle in 1965, many ERLs have been operated, and many more are foreseen and planned for the future. Especially the R&D for superconducting multi-turn ERLs is urgently needed to path the way to future high-power ERLs. An overview of the field and the latest developments, will be presented.
"

Speaker: Michaela Arnold

ERL-CAS_2022_Arnold_part-I.pdf

Recording

Video preview

10:30 Coffee break

50 FEL I

"The subject of this advanced course is a simplified treatment of the light amplification process in a free electron laser (FEL).
The first lecture deals with the so-called low gain FEL, where a “short” undulator is surrounded by an optical resonator. Starting with the calculation of the energy exchange between the electron beam and the radiation field, the ponderomotive phase is defined which remains constant when operating on resonance. The pendulum equations, linking this phase with the relative energy deviation from the resonance energy are derived and interpreted under the assumption that the radiation field will not change significantly during one pass through the undulator. Electron injection above resonance energy leads to an amplification of the radiation field. For low intensities, this is quantitatively described by the Madey theorem, which links the FEL gain curve with the spectrum of the spontaneous emission. For strong radiation, the gain curve will deviate significantly from the predictions of the Madey theorem and the gain will be reduced. Saturation and therewith stationary operation is achieved when the resonator losses are compensated by the FEL amplification.
The second lecture deals with an introduction to the dynamics of a high-gain FEL. Now dropping the assumption of a constant radiation field and assuming a slowly varying field amplitude and phase,  these variations are derived from a simplified one-dimensional treatment. The additional field equation supplements the pendulum equations extending them to a system of coupled differential equations. Further insight is gained by the definition of normalized parameters simplifying this system of coupled equations to a single cubic differential equation. The cubic equation is investigated in detail by solving it for two different cases: amplification starting from an existing radiation field and amplification starting from an initial density modulation. Both situations will finally lead to an exponential growth of the light intensity for a sufficiently long undulator and beam injection on resonance. Important parameters like the gain length and the Pierce parameter are introduced and explained in detail. Finally, the SASE process is presented and the properties of the generated radiation is discussed. State of-the-art methods for decreasing the spectral width of the generated radiation and increasing its longitudinal coherence are sketched briefly."

Speakers: Wolfgang Hillert, Wolfgang Hillert

FEL.pdf

Recording

Video preview

51 ERL II

Energy-Recovery-Linacs (ERLs) are an emerging field in accelerator R&D. They are needed for the sustainable operation of future high-power electron machines, e.g. the LHeC with an anticipated electron beam-power of 1 GW. The energy used for the beam's acceleration is recycled and re-used in an ERL. Higher beam currents are feasible while maintaining the RF power consumption at a comparable level. At the same time, the beam will be dumped at lower beam energies, typically below the neutron separation threshold. Less radiation is produced, and only a moderate dump cooling is needed. Since the postulation of the principle in 1965, many ERLs have been operated, and many more are foreseen and planned for the future. Especially the R&D for superconducting multi-turn ERLs is urgently needed to path the way to future high-power ERLs. An overview of the field and the latest developments, will be presented.

Speaker: Michaela Arnold

ERL-CAS_2022_Arnold_part-II.pdf

Recording

Video preview

13:00 Lunch

52 FEL II

The subject of this advanced course is a simplified treatment of the light amplification process in a free electron laser (FEL).
The first lecture deals with the so-called low gain FEL, where a “short” undulator is surrounded by an optical resonator. Starting with the calculation of the energy exchange between the electron beam and the radiation field, the ponderomotive phase is defined which remains constant when operating on resonance. The pendulum equations, linking this phase with the relative energy deviation from the resonance energy are derived and interpreted under the assumption that the radiation field will not change significantly during one pass through the undulator. Electron injection above resonance energy leads to an amplification of the radiation field. For low intensities, this is quantitatively described by the Madey theorem, which links the FEL gain curve with the spectrum of the spontaneous emission. For strong radiation, the gain curve will deviate significantly from the predictions of the Madey theorem and the gain will be reduced. Saturation and therewith stationary operation is achieved when the resonator losses are compensated by the FEL amplification.
The second lecture deals with an introduction to the dynamics of a high-gain FEL. Now dropping the assumption of a constant radiation field and assuming a slowly varying field amplitude and phase,  these variations are derived from a simplified one-dimensional treatment. The additional field equation supplements the pendulum equations extending them to a system of coupled differential equations. Further insight is gained by the definition of normalized parameters simplifying this system of coupled equations to a single cubic differential equation. The cubic equation is investigated in detail by solving it for two different cases: amplification starting from an existing radiation field and amplification starting from an initial density modulation. Both situations will finally lead to an exponential growth of the light intensity for a sufficiently long undulator and beam injection on resonance. Important parameters like the gain length and the Pierce parameter are introduced and explained in detail. Finally, the SASE process is presented and the properties of the generated radiation is discussed. State of-the-art methods for decreasing the spectral width of the generated radiation and increasing its longitudinal coherence are sketched briefly.

Speakers: Wolfgang Hillert, Wolfgang Hillert

Recording

Video preview

53 C1/C2/C3

16:30 Coffee break

54 C1/C2/C3

19:30 Dinner

Tuesday 15 November

55 Landau Damping I

Charged particle beams naturally exhibit self-enhanced oscillations, or coherent instabilities, driven by the interaction between the particles in the beam through collective forces such as electromagnetic wake fields, space-charge, beam-beam, ions or electron clouds. Highlighting the fundamental difference between the collective motion and the one of individual particles, we discuss how a spread in velocities or oscillation frequencies in an ensemble of particles leads to a damping of collective oscillations through the mechanism of Landau damping. We then illustrate the Liouville theorem from which we derive the strength of Landau damping in a simplified configuration using the Van Kampen approach. Based on this model we define the concept of stability diagrams.

Speaker: Xavier Buffat (CERN)

2022_CAS_LandauDamping.pdf

Recording

Video preview

56 Non Linear Dynamics - Methods and Tools I

The goal of this lecture is to present the contemporary methods and numerical tools of non-linear dynamical systems in order to analyse the motion in particle accelerators.
After a short introduction to non-linear effects and their impact to beam performance, the lecture will briefly review elements of classical mechanics, essential for the study of non-linear dynamics, including the Lagrangian and Hamiltonian formalism, canonical transformation and simplicity. Starting from the relativistic Hamiltonian for E/M fields, elements of canonical perturbation theory will be presented, showing its limitation, for particle accelerators. In this respect, concepts of linear and non-linear beam transport will be introduced, represented by matrices or more generally maps. The Lie formalism will be employed in order to elaborate and analyse these maps through non-linear normal form construction. An introduction to Truncated Power Series through differential Algebra will be also given, as it is essential for constructing 1-term maps. Finally, elements of symplectic integration will be reviewed.

Speaker: Yannis Papaphilippou (CERN)

nonlinear_CAS2022a.pdf

nonlinear_CAS2022a.pptx

Recording

Video preview

10:30 Coffee break

57 Muon Colliders I

A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy is being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon collider facility design. The challenges in producing intense proton beams, using them to make pions and muons and subsequent cooling, acceleration and collision are described.

Speaker: Chris Rogers

2022-11-04_rogers-cas-muon-collider-p1-v3.pdf

Recording

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58 Landau Damping II

We illustrate how Landau damping manifests itself in synchrotrons with a few applied cases covering longitudinal and transverse instabilities of bunched or coasting beams. We consider notably the impact of non-linear collective forces such as space-charge or beam-beam interactions. Various means of enhancing Landau damping using dedicated RF cavities, magnets or electron lenses are discussed.

Speaker: Xavier Buffat (CERN)

2022_CAS_LandauDamping_2.pdf

Recording

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13:00 Lunch

59 Muon Colliders II

A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy is being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon collider facility design. The challenges in producing intense proton beams, using them to make pions and muons and subsequent cooling, acceleration and collision are described.

Speaker: Chris Rogers

2022-11-04_rogers-cas-muon-collider-p2-v3.pdf

Recording

Video preview

60 BI

Speakers: Dr Marek Gasior (CERN), Rhodri Jones (CERN), Thibaut Lefevre (CERN)

61 Optics

Speakers: Davide Gamba (CERN), Guido Sterbini (CERN), Hannes Bartosik (CERN)

16:30 Coffee break

62 BI

Speakers: Dr Marek Gasior (CERN), Rhodri Jones (CERN), Thibaut Lefevre (CERN)

63 Optics

Speakers: Davide Gamba (CERN), Guido Sterbini (CERN), Hannes Bartosik (CERN)

19:30 Dinner

21:00 Cinema evening

Wednesday 16 November

64 Free

13:00 Lunch

65 Non Linear Dynamics - Methods and Tools II

The goal of this lecture is to present the contemporary methods and numerical tools of non-linear dynamical systems in order to analyse the motion in particle accelerators.
After a short introduction to non-linear effects and their impact to beam performance, the lecture will briefly review elements of classical mechanics, essential for the study of non-linear dynamics, including the Lagrangian and Hamiltonian formalism, canonical transformation and simplicity. Starting from the relativistic Hamiltonian for E/M fields, elements of canonical perturbation theory will be presented, showing its limitation, for particle accelerators. In this respect, concepts of linear and non-linear beam transport will be introduced, represented by matrices or more generally maps. The Lie formalism will be employed in order to elaborate and analyse these maps through non-linear normal form construction. An introduction to Truncated Power Series through differential Algebra will be also given, as it is essential for constructing 1-term maps. Finally, elements of symplectic integration will be reviewed.

Speaker: Yannis Papaphilippou (CERN)

Recording

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66 Beam-Beam effects

Particle colliders are one of the main drivers for discoveries in particle physics. Their performance is usually limited by the strong electromagnetic interactions of the two beams, so-called beam-beam interactions. Due to its non-linear and dynamical nature, this force introduces severe limitations by generating collective instabilities or distorting the single particle trajectories leading to a reduction of the beam lifetime and/or a growth of the emittances. In this lecture, we illustrate the mechanisms through which these degradations of the beam quality occur as well as basic models to describe them. We thus obtain an understanding of the fundamental properties of modern colliders.

Speaker: Xavier Buffat (CERN)

2022_CAS_BeamBeam.pdf

Recording

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16:30 Coffee break

67 Non Linear Dynamics - Phenomenology I

This lecture will review concepts for representing non-linear particle motion starting from analysing dynamics on phase space through fixed point identification. After introducing 1-turn (Poincaré) maps, the motion close to a resonance will be reviewed and its role on the onset of chaotic motion, leading to particle diffusion. Finally, methods for analysing and detecting chaotic motion will be presented, through direct particle tracking and the concept of dynamic aperture estimation. Other methods will be briefly introduced, including Lyapunov exponent and Frequency map analysis. Several examples of the application of these methods in design studies and improvements in the performance of operating hadron and lepton synchrotrons, storage rings, and colliders will finally be given.

Speaker: Yannis Papaphilippou (CERN)

nonlinear_CAS2022b.pdf

nonlinear_CAS2022b.pptx

Recording

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68 High Brightness Beam Diagnostics

This lecture gives an overview of the beam instrumentation and diagnostics for high charge, low emittance beams. It covers the techniques that are commonly used for non-relativistic and ultra-relativistic beams, Hadrons and Leptons. A special emphasis is given to non-invasive beam diagnostics which can be used on high charge density beams without being damaged.

Speaker: Thibaut Lefevre (CERN)

CAS22_high_brightness_BI.pdf

CAS22_high_brightness_BI.pptx

Recording

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19:30 Dinner

Thursday 17 November

69 HL-LHC I

The contribution recalls the HL-LHC design parameter and upgrade goals. The main remaining challenges and potential performance limitations that became visible with the re-start of the third operational run of the LHC after the second long shutdown (LS2) are recalled. This includes the beam performance in the injector complex following the LHC Injector upgrade, the e-cloud build-up and related heat load in the LHC arcs, the effect of dust particles in the vacuum chambers and radiation effects to electronics on machine availability as well as the status of magnet training for the LHC dipoles. The goals and planning of the IT String as one of the important intermediate milestones of the HL-LCH upgrade are presented along with the status of the global project planning and the current performance ramp-up scenario following the deployment of the project in LS3.

Speaker: Markus Zerlauth (CERN)

CAS_November_2022-HL-LHC-V4.0.pdf

CAS_November_2022-HL-LHC-V4.0.pptx

HL-LHC-CAS-Part1-V1.pdf

HL-LHC-CAS-Part1-V1.pptx

Recording

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70 HL-LHC II

The contribution recalls the HL-LHC design parameter and upgrade goals. The main remaining challenges and potential performance limitations that became visible with the re-start of the third operational run of the LHC after the second long shutdown (LS2) are recalled. This includes the beam performance in the injector complex following the LHC Injector upgrade, the e-cloud build-up and related heat load in the LHC arcs, the effect of dust particles in the vacuum chambers and radiation effects to electronics on machine availability as well as the status of magnet training for the LHC dipoles. The goals and planning of the IT String as one of the important intermediate milestones of the HL-LCH upgrade are presented along with the status of the global project planning and the current performance ramp-up scenario following the deployment of the project in LS3.

Speaker: Oliver Bruning (CERN)

Recording

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10:30 Coffee break

71 Non Linear Dynamics - Phenomenology II

This lecture will review concepts for representing non-linear particle motion starting from analysing dynamics on phase space through fixed point identification. After introducing 1-turn (Poincaré) maps, the motion close to a resonance will be reviewed and its role on the onset of chaotic motion, leading to particle diffusion. Finally, methods for analysing and detecting chaotic motion will be presented, through direct particle tracking and the concept of dynamic aperture estimation. Other methods will be briefly introduced, including Lyapunov exponent and Frequency map analysis. Several examples of the application of these methods in design studies and improvements in the performance of operating hadron and lepton synchrotrons, storage rings, and colliders will finally be given.

Speaker: Yannis Papaphilippou (CERN)

Recording

Video preview

72 Discussion on Non Linear Dynamics

Speaker: Yannis Papaphilippou (CERN)

13:00 Lunch

73 Longitudinal beam diagnostics

This lecture presents an overview of the different techniques that are commonly used to measure short bunches of charged particles. This includes direct detection of short bunches using optical methods, laser-based detection scheme, Bunch spectrum measurement using coherent radiation and beam manipulation using radiofrequency techniques

Speaker: Thibaut Lefevre (CERN)

CAS22_longitudinal_BI.pdf

CAS22_longitudinal_BI.pptx

Recording

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15:30 Coffee break

74 RF show

Recording

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75 Closing

Speaker: Frank Tecker (CERN)

closing-advanced2022.pdf

closing-advanced2022.pptx

19:30 Gala Dinner

Friday 18 November

76 Departure Day