3,387 research outputs found
Lattice Design in High-energy Particle Accelerators
This lecture gives an introduction into the design of high-energy storage
ring lattices. Applying the formalism that has been established in transverse
beam optics, the basic principles of the development of a magnet lattice are
explained and the characteristics of the resulting magnet structure are
discussed. The periodic assembly of a storage ring cell with its boundary
conditions concerning stability and scaling of the beam optics parameters is
addressed as well as special lattice insertions such asdrifts, mini beta
sections, dispersion suppressors, etc. In addition to the exact calculations
that are indispensable for a rigorous treatment of the matter, scaling rules
are shown and simple rules of thumb are included that enable the lattice
designer to do the first estimates and get the basic numbers 'on the back of an
envelope'.Comment: 40 pages, contribution to the CAS - CERN Accelerator School: Advanced
Accelerator Physics Course, Trondheim, Norway, 18-29 Aug 2013. arXiv admin
note: substantial text overlap with arXiv:1303.651
Introduction to Transverse Beam Dynamics
In this chapter we give an introduction to the transverse dynamics of the
particles in a synchrotron or storage ring. The emphasis is more on qualitative
understanding rather than on mathematical correctness, and a number of
simulations are used to demonstrate the physical behaviour of the particles.
Starting from the basic principles of how to design the geometry of the ring,
we review the transverse motion of the particles, motivate the equation of
motion, and show the solutions for typical storage ring elements. Following the
usual treatment in the literature, we present a second way to describe the
particle beam, using the concept of the emittance of the particle ensemble and
the beta function, which reflects the overall focusing properties of the ring.
The adiabatic shrinking due to Liouville's theorem is discussed as well as
dispersive effects in the most simple case.Comment: 19 pages, contribution to the CAS-CERN Accelerator School: Ion
Sources, Senec, Slovakia, 29 May - 8 June 2012, edited by R. Bailey,
CERN-2013-00
Higher-order Modes and Heating
This chapter gives a basic introduction to the problem of wake fields created
in the beam-surrounding environment and the resulting heating effects of
machine components. The concepts are introduced and scaling rules derived that
are exemplified by several observations from operation of the LHC and other
machines.Comment: 14 pages, contribution to the CAS-CERN Accelerator School:
Superconductivity for Accelerators, Erice, Italy, 24 April - 4 May 2013,
edited by R. Baile
Introduction to Longitudinal Beam Dynamics
This chapter gives an overview of the longitudinal dynamics of the particles
in an accelerator and, closely related to that, the issue of synchronization
between the particles and the accelerating field. Beginning with the trivial
case of electrostatic accelerators, the synchronization condition is explained
for a number of driven accelerators like Alvarez linacs, cyclotrons and finally
synchrotrons and storage rings, where it plays a crucial role. In the case of
the latter, the principle of phase focusing is motivated qualitatively as well
as on a mathematically more correct level and the problem of operation below
and above the transition energy is discussed. Throughout, the main emphasis is
more on physical understanding rather than on a mathematically rigorous
treatment.Comment: 15 pages, contribution to the CAS-CERN Accelerator School: Ion
Sources, Senec, Slovakia, 29 May - 8 June 2012, edited by R. Bailey,
CERN-2013-00
First Evaluation of Dynamic Aperture at Injection for FCC-hh
In the Hadron machine option, proposed in the context of the Future Circular
Colliders (FCC) study, the dipole field quality is expected to play an
important role, as in the LHC. A preliminary evaluation of the field quality of
dipoles, based on the NbSn technology, has been provided by the magnet
group. The effect of these field imperfections on the dynamic aperture, using
the present lattice design, is presented and first tolerances on the b and
b multipole components are evaluated
Simulation of the Pion Decay Channel of a Neutrino Factory
In the pion decay channel of a neutrino factory the particles are transported in a solenoidal magnetic field, a 1.8 T constant field in the CERN reference scenario. Increasing the field strength decreases the transverse emittance of the decay muons. To define a lower limit on the achievable u emittance, the reference scenario is compared with a study case where pions decay in a field of 20 T. This simulation shows that in any realistic scenario the u emittance will only reduced by less than 21 in each transverse plane as compared to the reference scenario, and at the expense of an increase in longitudinal emittance
State Complexity of Reversals of Deterministic Finite Automata with Output
We investigate the worst-case state complexity of reversals of deterministic
finite automata with output (DFAOs). In these automata, each state is assigned
some output value, rather than simply being labelled final or non-final. This
directly generalizes the well-studied problem of determining the worst-case
state complexity of reversals of ordinary deterministic finite automata. If a
DFAO has states and possible output values, there is a known upper
bound of for the state complexity of reversal. We show this bound can be
reached with a ternary input alphabet. We conjecture it cannot be reached with
a binary input alphabet except when , and give a lower bound for the
case . We prove that the state complexity of reversal depends
solely on the transition monoid of the DFAO and the mapping that assigns output
values to states.Comment: 18 pages, 3 tables. Added missing affiliation/funding informatio
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