This contribution provides a brief introduction to AC/RF superconductivity, with an emphasis on application to accelerators. The topics covered include the surface impedance of normal conductors and superconductors, the residual resistance, the field
dependence of the surface resistance, and the superheating field.
The Electron Cyclotron Resonance Ion Source (ECRIS) is nowadays the most effective device that can feed particle accelerators in a continuous and reliable way, providing high-current beams of low- and medium-charge-state ions and relatively intense c
urrents for highly charged ions. The ECRIS is an important tool for research with ion beams (in surface, atomic, and nuclear science) while, on the other hand, it implies plasma under extreme conditions and thus constitutes an object of scientific interest in itself. The fundamental aspect of the coupling between the electromagnetic wave and the plasma is hereinafter treated together with some variations to the classical ECR heating mechanism, with particular attention being paid to the frequency tuning effect and two-frequency heating. Considerations of electron and ion dynamics will be presented together with some recent observations connecting the beam shape with the frequency of the electromagnetic wave feeding the cavity. The future challenges of higher-charge states, high-charge breeding efficiency, and high absolute ionization efficiency also call for the exploration of new heating schemes and synergy between experiments and modelling. Some results concerning the investigation of innovative mechanisms of plasma ignition based on upper hybrid resonance will be described.
This chapter describes the basic principles, design features and characteristics of microwave discharge ion sources. A suitable source for the production of intense beams for high-power accelerators must satisfy the requirements of high brightness, s
tability and reliability. The 2.45 GHz off-resonance microwave discharge sources are ideal devices to generate the required beams, as they produce multimilliampere beams of protons, deuterons and singly charged ions. A description of different technical designs will be given, analysing their performance, with particular attention being paid to the quality of the beam, especially in terms of its emittance.
Electron beam ion sources (EBISs) are ion sources that work based on the principle of electron impact ionization, allowing the production of very highly charged ions. The ions produced can be extracted as a DC ion beam as well as ion pulses of differ
ent time structures. In comparison to most of the other known ion sources, EBISs feature ion beams with very good beam emittances and a low energy spread. Furthermore, EBISs are excellent sources of photons (X-rays, ultraviolet, extreme ultraviolet, visible light) from highly charged ions. This chapter gives an overview of EBIS physics, the principle of operation, and the known technical solutions. Using examples, the performance of EBISs as well as their applications in various fields of basic research, technology and medicine are discussed.
In polarized proton operation in the Relativistic Heavy Ion Collider (RHIC) coherent beam-beam modes are routinely observed with beam transfer function measurements. These modes can become unstable under external excitation or in the presence of impe
dance. This becomes even more relevant in the presence of head-on compensation, which reduces the beam-beam tune spread and hence Landau damping. We report on experiments and simulations carried out to understand the impact of coherent modes on operation with electron lenses.
In polarized proton operation, the performance of the Relativistic Heavy Ion Collider (RHIC) is limited by the head-on beam-beam effect. To overcome this limitation, two electron lenses are under commissioning. We give an overview of head-on beam-bea
m compensation in general and in the specific design for RHIC, which is based on electron lenses. The status of installation and commissioning are presented along with plans for the future.
During the proton-anti proton collider run several experiments were carried out in order to understand the effect of the beam-beam interaction on backgrounds and lifetimes. In this talk a selection of these experiments will be presented. From these e
xperiments, the importance of relative beam sizes and tune ripple could be demonstrated.
I give a theoretical overview of some basic properties of massive neutrinos in these lectures. Particular attention is paid to the origin of neutrino masses, the pattern of lepton flavor mixing, the feature of leptonic CP violation and the electromag
netic properties of massive neutrinos. I highlight the TeV seesaw mechanisms as a possible bridge between neutrino physics and collider physics in the era characterized by the Large Hadron Collider.
I review the basics of perturbative QCD, including infrared divergences and safety, collinear and $k_T$ factorization theorems, and various evolution equations and resummation techniques for single- and double-logarithmic corrections. I then elaborat
e its applications to studies of jet substructures and hadronic two-body heavy-quark decays.
This chapter provides an overview of the basic requirements for ion sources designed and operated in radioactive ion beam facilities. The facilities where these sources are operated exploit the isotope separation online (ISOL) technique, in which a t
arget is combined with an ion source to maximize the secondary beam intensity and chemical element selectivity. Three main classes of sources are operated, namely surface-type ion sources, arc discharge-type ion sources, and finally radio-frequency-heated plasma-type ion sources.
