Beam Diagnostic Requirements: an Overview: https://arxiv.org/abs/2005.08389
Beam diagnostics and instrumentation are an essential part of any kind of accelerator. There is a large variety of parameters to be measured for observation of particle beams with the precision required to tune, operate, and improve the machine. In the first part, the basic mechanisms of information transfer from the beam particles to the detector are described in order to derive suitable performance characteristics for the beam properties. However, depending on the type of accelerator, for the same parameter, the working principle of a monitor may strongly differ, and related to it also the requirements for accuracy. Therefore, in the second part, selected types of accelerators are described in order to illustrate specific diagnostics needs which must be taken into account before designing a related instrument.
Comments: 102 pages, contribution to the CAS - CERN Accelerator School: Beam Instrumentation, 2-15 June 2018, Tuusula, Finland
Introduction to Optics and Lasers for Beam Instrumentation: https://arxiv.org/abs/2007.11272
The versatility of optics enables the design of a wide range of elegant beam instrumentation. Multiple properties of particle beams can be precisely measured by various optical techniques, which include: direct sampling of optical radiation emitted from a charged particle beam; monitoring interactions with an optical probe such as a laserwire; and by electro-optic conversion of the beam signal with high-bandwidth fibre readout. Such methods are typically minimally-invasive and non-destructive, thus permitting diagnostics during accelerator operation without perturbation of the particle beam or risk of damage to the instrument. These proceedings summarise three CAS lectures that introduce the basic principles of optics relevant for instrumentation design, outline the key laser technologies and setups, and review the state-of-the-art in laser-based beam instrumentation.
Comments: 34 pages, contribution to the CAS - CERN Accelerator School: Beam Instrumentation, 2-15 June 2018, Tuusula, Finland
Diagnostics Examples from CTF3: https://arxiv.org/abs/2004.13368
After a short introduction of CLIC, the Compact Linear Collider, and its test facility CTF3 (CLIC Test Facility 3), this paper gives an overview and some examples of the diagnostics used at CTF3.
Comments: 10 pages, contribution to the CAS - CERN Accelerator School: Beam Instrumentation, 2-15 June 2018, Tuusula, Finland
Longitudinal Beam Dynamics -- Recap: https://arxiv.org/abs/2004.11908
This paper gives a very brief summary of longitudinal beam dynamics for both linear and circular accelerators. After discussing synchronism conditions in linacs, it focuses on particle motion in synchrotrons. It summarizes the equations of motion, discusses phase-space matching during beam transfer, and introduces the Hamiltonian of longitudinal motion.
Comments: 17 pages, contribution to the CAS - CERN Accelerator School: Beam Instrumentation, 2-15 June 2018, Tuusula, Finland. arXiv admin note: substantial text overlap with arXiv:1601.04901
Longitudinal Beam Dynamics: https://arxiv.org/abs/1601.04901
F. Tecker (CERN)
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.
Comments: 21 pages, contribution to the CAS - CERN Accelerator School: Advanced Accelerator Physics Course, Trondheim, Norway, 18-29 Aug 2013
Linear Imperfections: https://arxiv.org/abs/2004.14001
This lecture gives an overview of the impacts on linear machine optics of machine imperfections due to incorrect field settings and misalignments. The effects of imperfections in dipole, quadrupole, and sextupole magnets are presented, along with beam observables and correction techniques that may be used to restore the nominal machine parameters. The main concepts of orbit correction are discussed in detail, because the principles underlying those techniques can be used for other corrections.
Comments: 30 pages
Measuring Tune, Chromaticity and Coupling: https://arxiv.org/abs/2005.02753
This chapter takes a look at the ways tune, chromaticity and coupling can be measured in synchrotrons. After briefly introducing the importance of these parameters for machine operation, a broad overview of the various instrumentation and analysis techniques used in their determination will be given.
Comments: 19 pages
Video Cameras used in Beam Instrumentation -- an Overview: https://arxiv.org/abs/2005.04977
B. Walasek-Hoehne, K. Hoehne, R. Singh
Imaging systems have been an integral part of many beam monitors since the early days of accelerator diagnostics. The main application remains the observation of scintillating screens during commissioning, alignment and routine operation with the beam. Recorded images are often further analyzed to characterize the beam distribution for machine optimization. This report provides an overview of imaging technologies and market trends of today. The image sensor, like TV tubes and solid state sensors (CCD, CMOS and CID), with particular focus on the aspects important for beam instrumentation will be discussed. Digital image acquisition as well as camera interfaces and radiation effects will be also presented.
Comments: 21 pages
Transverse emittance: https://arxiv.org/abs/2005.05770
This chapter defines the concept of transverse emittance and describes the techniques most frequently used to measure it.
Comments: 14 pages
Transverse Beam Profiles: https://arxiv.org/abs/2005.07400
The performance and safe operation of a particle accelerator is closely connected to the transverse emittance of the beams it produces. For this reason many techniques have been developed over the years for monitoring the transverse distribution of particles along accelerator chains or over machine cycles. The definition of beam profiles is explained and the different techniques available for the detection of the particle distributions are explored. Examples of concrete applications of these techniques are given.
Comments: 37 pages, 53 figures
Bunch Length Diagnostics: Current Status and Future Directions: https://arxiv.org/abs/2005.05715
Charged particle bunch length detection is one of the most challenging measurements in particle and accelerator physics, especially when the bunch length reduces below tens of femtoseconds. Since these measurements are most critical in high energy electron accelerators and devices with ultrashort electron bunches - such as the plasma wakefield and related accelerators - this discussion is limited to electron bunch detection, although the results clearly have significance for any ultra-relativistic particle bunches.
Comments: 13 pages
Analog to digital conversion in beam instrumentation systems: https://arxiv.org/abs/2005.06203
Analog to digital conversion is a very important part of almost all beam instrumentation systems. Ideally, in a properly designed system, the used analog to digital converter (ADC) should not limit the system performance. However, despite recent improvements in ADC technology, quite often this is not possible and the choice of the ADC influences significantly or even restricts the system performance. It is therefore very important to estimate the requirements for the analog to digital conversion at an early stage of the system design and evaluate whether one can find an adequate ADC fulfilling the system specification. In case of beam instrumentation systems requiring both, high time and amplitude resolution, it often happens that the system specification cannot be met with the available ADCs without applying special processing to the analog signals prior to their digitisation. In such cases the requirements for the ADC even influence the system architecture. This paper aims at helping the designer of a beam instrumentation system in the process of selecting an ADC, which in many cases is iterative, requiring a trade off between system performance, complexity and cost. Analog to digital conversion is widely and well described in the literature, therefore this paper focusses mostly on aspects related to beam instrumentation. The ADC fundamentals are limited to the content presented as an introduction during the CAS one-hour lecture corresponding to this paper.
Comments: 36 pages
Beam halo and bunch purity monitoring: https://arxiv.org/abs/2005.07027
Beam halo measurements imply measurements of beam profiles with a very high dynamic range; in transverse and also longitudinal planes. This lesson gives an overview of high dynamic range instruments for beam halo measurements. In addition halo definitions and quantifications in view of beam instrumentation are discussed.
Comments: 29 pages
Diagnostics Examples from Third-Generation Light Sources: https://arxiv.org/abs/2005.06762
This lesson discusses many examples of how the signals from the beam monitors are used to diagnose the beam in circular, third-generation synchrotron light sources. During the school, diagnostic examples in other machines (e.g. colliders, CTF3, linacs and free-electron lasers (FEL), and medical accelerators) were given in other lectures. This lesson assumes that the signal generation in the instrument itself is already known; the main focus lies on the dependence of the signals on various machine parameters and their interpretation to diagnose the machine parameters and conditions.
Comments: 22 pages
Beam Loss Monitors: https://arxiv.org/abs/2005.06522
This lecture covers the fundamental aspects of the measurement of beam losses including their use for beam diagnostic and safety issues. The detailed functionality and detection principle of various common beam loss monitors are also presented, with a focus on their intrinsic sensitivity.
Comments: 39 pages
Analog electronics for beam instrumentation: https://arxiv.org/abs/2005.07422
The task of analog front-end electronics in beam instrumentation is to optimize the useful information content of the signal delivered by an instrument. It must suppress signal components that do not contribute to the measured quantity. It must filter to put bounds on bandwidth and possibly dynamic range, to relax the demands made of subsequent processing stages. It must minimize noise, reject interference and match the signal to transmission media and digital acquisition equipment. Since the circuitry must often operate in radio-active areas, the accent is on passive electronics.
Comments: 27 pages, 60 figures
Timing and Synchronization: https://arxiv.org/abs/2005.07444
Several modern accelerator facilities require the synchronization of equipment, which is distributed over large distances, down to the femto-second scale. This document describes the resulting problems, gives a basic description of concepts for the solution, shows several solution presently in use and finishes with a linear model to compute the resulting phase-noise of a synchronization system.
Comments: 54 pages, 60 figures
Diagnostics Examples from lepton-linacs and FELs: https://arxiv.org/abs/2005.07469
There is a big gap between the charming principles ideas and the real implementation of a diagnostic. In this lecture we review some details that make the difference between a good and bad measurement, highlighting also the relation between the measured quantities and the real ones.
Comments: 17 pages, 21 figures
Diagnostic Needs for Wakefield Accelerator Experiments: https://arxiv.org/abs/2005.08376
Wakefield accelerators are under development in many laboratories worldwide. They bring the promise of a high accelerating gradient, orders of magnitude higher than current machines. The reduction in the overall length of the accelerators will pave the way to a wider use of such machines, for industrial, medical, research, and educational purposes. At the same time, all the equipment must be reduced as well, to keep the dimensions of the machine as small as possible. The two main challenges of the diagnostics for plasma accelerated electron beams are the ability to measure the 6D phase space properties with single shot techniques and the compactness to meet the requirements of a `table-top' facility.
Comments: 11 pages
Medical Applications -- Instrumentation and Diagnostics: https://arxiv.org/abs/2005.08729
This CAS talk describes the role of beam instrumentation and diagnostics in particle therapy accelerators. It presents an extended view on instrumentation, feedbacks, detector technology, quality assurance (QA) and their interdependencies. Furthermore, some basics, examples and challenges in near future concerning diagnostics and instrumentation techniques used in particle therapy are reported.
Comments: 12 pages, 17 figures
RF Measurement Techniques: https://arxiv.org/abs/2005.09106
For the characterization of components, systems and signals in the range of microwave and radio-frequencies (RF) specific equipment and dedicated measurement instruments are used. In this article the fundamentals of RF signal processing and measurement techniques are discussed. It gives complementary background information for the introduction to RF Measurement Techniques and the Practical RF Course, which are part of the Advanced Accelerator Physics training program of the CERN Accelerator School (CAS) and have also been presented at the CAS 2018 Special Topic Course in Beam Instrumentation.
Comments: 54 pages
BPM Systems: A brief Introduction to Beam Position Monitoring: https://arxiv.org/abs/2005.14081
This introduction on beam position monitors (BPM) summarizes the fundamental parts of the tutorial presented at the CAS 2018 on beam instrumentation. The focus is on the signal detection and normalization, and on the principle of operation of commonly used broadband pickups, i.e.\ button and stripline BPMs. Other BPM types, such as split-plane and cavity BPMs are also discussed, as well as the detection of low-β beams. Finally, a note on BPM signal processing techniques is given.
Comments: 40 pages
Beam Diagnostics EXamples from High Energy Colliders
This chapter takes a look at how beam diagnostic systems can be used to commission, optimise and solve issues on high energy colliders.
Comments: 18 pages, 41 figures