Wildner, E, Broggi, F, Cerutti, F, Ferrari, A, Mereghetti, A, Todesco, E
Recent studies show that the energy deposition for the LHC Phase I luminosity upgrade, aiming at a peak luminosity 2.5×10**34 cm**-2s**-1, can be handled by appropriate shielding. The Phase II...
First field test of FiDeL: The magnetic field description for the LHC (2009)
Bottura, L, Buzio, M, Catalan-Lasheras, N, Deniau, L, Di Castro, M, Fartoukh, S, ...
The start-up of the LHC has provided the first field test for the concept, functionality and accuracy of FiDeL, the Field Description for the LHC. FiDeL provides a parametric model of the transfer...
Electromagnetic efficiency of block design in superconducting dipoles (2009)
Semi-analytical scaling laws have been derived for the electromagnetic design of superconducting dipoles based on sector coils approximation. Here we discuss the different features of block coils...
Open midplane designs based on sector coils in superconducting dipoles (2009)
This paper presents a study of the effects of opening up the midplane in conventional sector coil dipoles, also known as cosè-designs. The open midplane design is a candidate for the higher...
Borgnolutti, F, Caspi, S, Ferracin, P, Kashikhin, V V, Sabbi, G, Velev, G, ...
The random part of the integral field harmonics in a series of superconducting magnets has been used in the past to identify the reproducibility of the coil positioning. Using a magnetic model and a...
Parametric Analysis of Forces and Stresses in Superconducting Quadrupole Sector Windings (2009)
Fessia, P, Regis, F, Todesco, E
We first present a review of the existing analytical equations for electromagnetic forces and stress in a sector coil quadrupole, evaluating their extent of application in function of the coil...
Electromagnetic Design of the 120 mm Aperture Quadrupole for the LHC Phase One Upgrade (2009)
Borgnolutti, F, Fessia, P, Todesco, E
The phase I of the LHC upgrade aims at increasing the luminosity by a factor 2-3 with respect to the nominal luminosity of 10**34 cm**-2s**-1. Part of this increase is obtained through a reduction of...
Report of the Task Force on the Incident of 19th September 2008 at the LHC (2009)
Bajko, M, Bertinelli, F, Catalan-Lasheras, N, Claudet, S, Cruikshank, P, Dahlerup-Petersen, K, ...
This report summarizes the findings and recommendations of the AT department Task Force established to investigate the 19th September 2008 incident which occurred in sector 3-4 of the LHC. It...
Tollestrup, Alvin V, Todesco, E
Superconducting magnets have played a key role in advancing the energy reach of proton synchrotrons and enabling them to play a major role in defining the Standard Model. The problems encountered and...
Parametric Analysis of Forces and Stresses in Superconducting Quadrupole Sector Windings (2008)
Fessia, P, Regis, F, Todesco, E
We first present a review of the existing analytical equations for electromagnetic forces and stress in a sector coil quadrupole, evaluating their extent of application in function of the coil...
WISE: A Simulation of the LHC Optics including Magnet Geometrical Data (2008)
Hagen, P, Giovannozzi, M, Koutchouk, Jean-Pierre, Risselada, Thys, Schmidt, F, Todesco, E, ...
The beam dynamics in the LHC require a tight control of the field quality and geometry of its magnets. At the EPAC06 we presented the simulation tool WISE which generates magnetic field errors to be...
Parametric Study of Energy Deposition in the LHC Inner Triplet for the Phase 1 Upgrade (2008)
Wildner, E, Borgnolutti, F, Cerutti, F, Mauri, M, Mereghetti, A, Todesco, E
To be able to make a global parametric analysis and to have some basic understanding of the influence of critical parameters, scaling laws may be of help. For the design of the LHC insertion regions...
Scaling Laws for Magnetic Energy in Superconducting Quadrupoles (2008)
Borgnolutti, F, Todesco, E, Mailfert, A
The stored energy in superconducting magnets is one of the main ingredients needed for the quench calculation and for designing quench protections. Here we propose an analytical formula based on the...
Borgnolutti, F, Brüning, Oliver Simon, Dorda, U, Fartoukh, S, Giovannozzi, M, Herr, Werner, ...
In the framework of the studies for the upgrade of the insertions of the CERN Large Hadron Collider, four optical layouts were proposed with the aim of reducing the beta-function at the collision...
Magnetic Performance of the Main Superconducting Magnets for the LHC (2008)
Sanfilippo, S, Sammut, N, Bottura, L, Di Castro, M, Basu, A, Koutchouk, JP, ...
The field strength and homogeneity of all the LHC superconducting magnets were measured as a part of the production control and qualification process that has taken place during the past four years....
130 mm Aperture Quadrupoles for the LHC Luminosity Upgrade (2008)
Todesco, E, Borgnolutti, F, Mailfert, A
Several studies for the LHC luminosity upgrade pointed out the need for low-beta quadrupoles with apertures larger than the present baseline (70 mm). In this paper we focus on the design issues of a...
Koutchouk, Jean-Pierre, Assmann, Ralph Wolfgang, Métral, E, Todesco, E, Zimmermann, F, De Maria, R, ...
A significant reduction of b* requires a new beam crossing scheme to overcome the consequence of the luminosity loss factor. We define in this paper the parameters of a possible solution taking...
Todesco, E, Bellesia, B, Koutchouk, Jean-Pierre, Santoni, C
Random components of field harmonics in superconducting quadrupoles are usually estimated by computing the effect of a random positioning of the coil blocks with an r.m.s. of 0.05 mm. Here, we review...
A generic four-dimensional model representing the nonlinear betatronic oscillations of a single particle in a magnetic lattice for hadrons is considered. The classification of the different...
W. Scandale, R. Bartolini, P. Ferracin, P. Fessia, E. Todesco
The stability of the geometry of the superconducting coils is essential to the field homogeneity of the LHC dipole magnets. Mechanical stresses during coil assembly, thermal stresses during cool-down...
M. Giovannozzi, W. Scandale, E. Todesco
Abstract. A phenomenological picture of the mechanisms that lead to longterm particle loss is outlined, using numerical simulations. The Lyapunov exponent and the variation of the nonlinear tunes...
THE USE OF MAPPINGS FOR STABILITY PROBLEMS IN BEAM DYNAMICS (2007)
A review of some stability problems in single-particle dynamics of circular accelerators when the nonlinearities are not negligible is given. The betatron motion is modelized through the discrete...
SOME NUMERICAL AND ANALYTICAL TOOLS FOR THE ANALYSIS OF 4D BETATRONIC MOTION (2007)
Abstract. We review the formalism of 4D symplectic mappings to analyse the betatronic motion in a circular hadron collider; different methods for the evaluation of the nonlinear frequencies are...
M. Giovannozzi, R. Grassi, W. Scandale, E. Todesco
Abstract. The problem of defining an efficient procedure to sort the magnets in a circular accelerator is considered. Using a simplified model of the LHC, we analyze the effects of random errors on...
Evaluation of Nonlinear Resonances in 4D symplectic mappings (2007)
E. Todesco, M. Gemmi, M. Giovannozzi
We discuss the evaluation of the stability, position and width of resonances in four-dimensional symplectic mappings. The approach presented in this paper is based on the computation of the resonant...
Symplectic mappings that describe the 4D betatronic motion in a magnetic lattice are considered. We define the dynamic aperture in terms of the connected volume in phase space of initial conditions...
The recent approval of the Large Hadron Collider (LHC) project [1] has raised new interest in nonlinear beam dynamics. The very intense magnetic field (about 8 Tesla) necessary to keep particles of 7...
Scaling Laws for Dynamic Aperture due to (2007)
Chromatic Sextupoles, E. Todesco, W. Sc
Scaling laws for the dynamic aperture due to chromatic sextupoles are investigated. The problem is addressed in a simplified lattice model containing 4N identical cells and one linear betatron phase...
Sorting Strategies For The Lhc Based On Normal Forms (2007)
W. Scandale, M. Giovannozzi, R. Grassi, E. Todesco
Sorting strategies for superconducting dipoles are discussed, in view of maximizing the dynamic aperture in hadron colliders like the CERN LHC. Quality factors based on the perturbative tools of...
Giotto: A Code For The Nonlinear Analysis Of Area-Preserving Mappings (2007)
G. Servizi, D. Bortolotti, E. Todesco, M. Giovannozzi, M. N. Vrahatis
Introduction In the study of dynamical systems of low dimensionality the geometry of the orbits is a crucial aspect, and the real time visualization obtained through workstations allows one to detect...
Local Analysis Of Formal Stability And Existence Of Fixed Points In 4D Symplectic Mappings (2007)
Symplectic mappings in a four-dimensional phase space are analysed; in the neighbourhood of an elliptic fixed point whose eigenvalues are close to satisfy a double resonance condition, the...
Long Term Estimates For Sorting Strategies Of The Lhc Dipoles (2007)
Scandale Bartolini, W. Sc, R. Bartolini, M. Giovannozzi, E. Todesco
Sorting strategies are investigated in view of improving the dynamic aperture of the CERN-LHC. Local and quasi-local compensation of the random field shape imperfections are discussed and applied to...
Sorting Approach To Magnetic Random Errors (2007)
Giovannozzi Grassi, R. Grassi, W. Sc, E. Todesco
The problem of defining effective sorting strategies for the random errors of a magnetic lattice is analyzed. The final goal is to define a way of sorting the magnets in order to maximize the dynamic...
Scandale Bartolini, W. Sc, R. Bartolini, P. Ferracin, P. Fessia, E. Todesco
The stability of the geometry of the superconducting coils is essential to the field homogeneity of the LHC dipole magnets. Mechanical stresses during coil assembly, thermal stresses during cool-down...
Scandale Todesco Cern, W. Sc, E. Todesco
The problem of long-term losses in hadron colliders such as the Large Hadron Collider (LHC) is considered. A previous formula that provides the reduction of dynamic aperture with the number of turns...
Sissa Via Beirut, L. Billi, E. Todesco, G. Turchetti
The analysis of the singularity structure of some series arising in the conjugation theory of holomorphic maps is performed using the Pad'e Approximants. The validity of P.A. is checked for...
Approximation Of Linearizable Mappings Of (c,0) Through Resonant Diffeomorphisms (2007)
this paper is to investigate the transition from resonant orbits, which have the flower structure with 2kq petals, to nonresonant orbits, which are diffeomorphic to circles. The considered model is a...
Nero: A Code For Evaluation Of Nonlinear Resonances In 4d Symplectic Mappings (2007)
Todesco Gemmi Dipartimento, E. Todesco
A code to evaluate the stability, the position and the width of nonlinear resonances in four-dimensional symplectic mappings is described. NERO is based on the computation of the resonant...
Long Term Estimates For Sorting Strategies Of The Lhc Dipoles (2007)
Scandale Bartolini, W. Sc, R. Bartolini, M. Giovannozzi, E. Todesco
Sorting strategies are investigated in view of improving the dynamic aperture of the CERN-LHC. Local and quasi-local compensation of the random field shape imperfections are discussed and applied to...
Multipolar correction for LHC: an analytical approach with normal forms (2007)
W. Scandale, F. Schmidt, E. Todesco
We briefly review the formalism of symplectic maps for nonlinear betatron oscillations [1] and the theory of non resonant normal forms [2];[3] in two dimensions. We then develop a technique for...
Evaluation Of Dynamic Aperture In The Presence Of Phase Space Distortions (2007)
We study symplectic mappings which occur in the modelization of the 4D betatronic motion in a magnetic lattice and define the dynamic aperture in terms of the connected volume in phase space of...
Sorting Strategies For The Lhc Dipoles (2007)
R. Bartolini, W. Scandale, M. Giovannozzi, E. Todesco
this paper are either the tuneshift or the strength of a certain resonance. The first step of the sorting procedure is the analysis of the correlation of various QF with the DA. A QF is retained if...
Early Indicators Of Long Term Stability In Hadron Colliders (2007)
E. Todesco, R. Bartolini, A. Faus-Golfe, M. Giovannozzi, W. Scandale
Early indicators of long-term stability, based on short-term tracking data, are considered in hadron colliders, such as the CERN-LHC. Two early indicators are analysed: the Lyapunov coefficient and...
Inverse Logarithm Decay Of Long-Term Dynamic Aperture In Hadron Colliders (2007)
M. Giovannozzi, W. Scandale, E. Todesco
The long-term behaviour of the non-linear single-particle dynamics is considered for the 4D Henon map. The dynamic aperture is defined as the average of the particle loss boundary over several ratios...
Nero: A Code For Evaluation Of Nonlinear Resonances In 4d Symplectic Mappings (2007)
A code to evaluate the stability, the position and the width of nonlinear resonances in four-dimensional symplectic mappings is described. NERO is based on the computation of the resonant...
GIOTTO: an interactive program for the analysis of 2D area preserving mappings (2007)
A. Bazzani, D. Bortolotti, M. Giovannozzi, G. Servizi, E. Todesco, G. Turchetti
A description of an interactive program for the visualization of the orbits of an area preserving mapping is given. The code includes zooming and coloring facilities, and advanced analytical and...
Sorting Strategies For The Lhc Based On Normal Forms (2007)
Giovannozzi Grassi, R. Grassi, W. Sc, E. Todesco
Sorting strategies for superconducting dipoles are discussed, in view of maximizing the dynamic aperture in hadron colliders like the CERN LHC. Quality factors based on the perturbative tools of...
Mathematical Aspects And Physical Applications Of The Tuneshift Correction (2007)
We review the problem of the tuneshift correction of symplectic maps and its applications to accelerator physics. The normal form techniques used to compute the correcting terms are outlined both in...
Scandale Todesco, W. Sc, E. Todesco
The problem of long-term losses in hadron colliders such as the Large Hadron Collider (LHC) is considered. A previous formula that provides the reduction of dynamic aperture with the number of turns...
Precise Measurement Of The Betatron Tune (2007)
R. Bartolini, Bartolini Giovannozzi, W. Scandale, A. Bazzani, E. Todesco
this paper we review these methods, and the analytical estimates of the frequency error as a function of the sample size. Furthermore, we evaluate numerically the influence of noise in the...
Todesco, E, Bellesia, B, Koutchouk, Jean-Pierre
A possible scenario for the luminosity upgrade of the Large Hadron Collider is based on large aperture quadrupoles to lower b* in the interaction regions. Here we analyze the measurements relative to...
Status Report on the Superconducting Dipole Magnet Production for the LHC (2007)
Bajko, M, Bertinelli, F, Bellesia, B, Fessia, P, Hagen, P, Koutchouk, Jean-Pierre, ...
In August 2006, about 95 % of the production of the 1232 LHC superconducting dipole cold masses, whose coils are wound with Cu/Nb-Ti cables, is completed. One of the 3 manufacturers, having produced...
A Solution for Phase-one Upgrade of the LHC Low-beta Quadrupoles Based on Nb-Ti (2007)
Koutchouk, Jean-Pierre, Rossi, L, Todesco, E
We discuss the possibilities of upgrading the LHC triplet quadrupoles by significantly increasing their aperture (and length), using the Nb-Ti cable of the main dipoles. The goal of this first phase...
Electromagnetic Design of Superconducting Quadrupoles (2006)
We study how the critical gradient depends on the coil lay-out in a superconducting quadrupole for particle accelerators. We show that the results relative to a simple sector coil are well...
Savary, F, Bajko, M, Beauquis, J, Emelianenko, N, Fessia, P, Hagen, P, ...
The LHC accelerator, under construction at CERN, is characterized by the use on a large scale of high field superconducting dipoles: the 27-km ring requires 1232 15-m long dipole magnets designed for...
Tortschanoff, Theodor, Burgmer, R, Durante, M, Hagen, P, Klein, U, Krischel, D, ...
The fabrication of the 408 main arc quadrupole magnets and their cold masses will come to an end in summer 2006. A rich collection of measurement and test data has been accumulated and their analysis...
Random Errors in Superconducting Dipoles (2006)
Bellesia, B, Santoni, C, Todesco, E
The magnetic field in a superconducting magnet is mainly determined by the position of the conductors. Hence, the main contribution to the random field errors comes from random displacement of the...
WISE: An Adaptative Simulation of the LHC Optics (2006)
Hagen, P, Giovannozzi, Massimo, Koutchouk, Jean-Pierre, Risselada, Thys, Sanfilippo, S, Todesco, E, ...
The beam dynamics in LHC requires a tight control of the field quality and geometry of the magnets. As the production advances, decisions have to be made on the acceptance of possible imperfections....
Bellesia, B, Molinari, G, Todesco, E
In this report the method for the localization of the electric shorts circuits in the main LHC dipoles using the magnetic measurements at room temperature is presented. The steps of the method are...
Accelerator Physics Code Web Repository (2006)
Zimmermann, Frank, Basset, R, Bellodi, G, Benedetto, E, Dorda, U, Giovannozzi, Massimo, ...
In the framework of the CARE HHH European Network, we have developed a web-based dynamic acceleratorphysics code repository. We describe the design, structure and contents of this repository,...
Impact of the First Powering Cycles on the LHC Superconducting Dipole Coil Geometry (2006)
Calvi, M, Todesco, E, Bottura, L, Sanfilippo, S, Siemko, A
The impact of the first powering cycles on the LHC superconducting dipoles coil geometry has been investigated. Dedicated magnetic measurements have been performed to estimate the changes in the...
Todesco, E, Bellesia, B, Hagen, P, Völlinger, C
More than two thirds of the dipoles of the Large Hadron Collider have been manufactured and their magnetic field has been measured at room temperature. In this paper we make a review of the trends...
Dependence of Magnetic Field Quality on Collar Supplier and Dimensions in the Main LHC Dipole (2006)
Bellesia, B, Bertinelli, F, Santoni, C, Todesco, E
In order to keep the electro-magnetic forces and to minimize conductor movements, the superconducting coils of the main Large Hadron Collider dipoles are held in place by means of austenitic steel...
The LHC Main Quadrupoles during Series Fabrication (2006)
Tortschanoff, Theodor, Burgmer, R, Durante, M, Hagen, P, Klein, U, Krischel, D, ...
By the end of August 2005 about 320 of the 400 main LHC quadrupole magnets have been fabricated and about 220 of them assembled into their cold masses, together with corrector magnets. About 130 of...
Magnetic measurements at room temperature have been used to monitor the production of the superconducting coils of the Large Hadron Collider main dipoles. They have made it possible to identify...
Long Term Stability of the LHC Superconducting Cryodipoles after Outdoor Storage (2006)
Seyvet, F, Arnau-Izquierdo, G, Bertarelli, A, Denis, O, El-Kallassi, P, Fernández-Cano, E D, ...
The main superconducting dipoles for the LHC are being stored outdoors for periods from a few weeks to several years after conditioning with dry nitrogen gas. Such a storage before installation in...
Bellesia, B, Molinari, G, Santoni, C, Scandale, Walter, Todesco, E
During the construction of the LHC main dipoles, 12 cases of short circuits between the cables of the superconducting coils have been detected. Some of them appeared only under the press, making...
Hagen, P, Bottura, L, Calvi, M, Sanfilippo, S, Schirm, K, Todesco, E, ...
The main issues concerning the field quality in the main quadrupoles of the Large Hadron Collider are presented. We show the trend plots for the focusing strength and multipoles at room temperature...
Bellesia, B., Molinari, G., Santoni, C., Scandale, W., Todesco, E.
During the construction of the LHC main dipoles, 12 cases of short circuits between the cables of the superconducting coils have been detected. Some of them appeared only under the press, making...
Dependence of Magnetic Field Quality on Collar Supplier and Dimensions in the Main LHC Dipole (2005)
Bellesia, B., Bertinelli, F., Santoni, C., Todesco, E.
In order to keep the electro-magnetic forces and to minimize conductor movements, the superconducting coils of the main Large Hadron Collider dipoles are held in place by means of austenitic steel...
Bellesia, B., Bottura, L., Granata, V., Le Naour, S., Oberli, L., Sanfilippo, S., ...
The production of more than 60% of superconducting cables for the main dipoles of the Large Hadron Collider has been completed. The results of the measurements of cable magnetization and the...
Bellesia, B., Molinari, G., Santoni, C., Scandale, W., Todesco, E.
During the construction of the LHC main dipoles, 12 cases of short circuits between the cables of the superconducting coils have been detected. Some of them appeared only under the press, making...
Dependence of Magnetic Field Quality on Collar Supplier and Dimensions in the Main LHC Dipole (2005)
Bellesia, B., Bertinelli, F., Santoni, C., Todesco, E.
In order to keep the electro-magnetic forces and to minimize conductor movements, the superconducting coils of the main Large Hadron Collider dipoles are held in place by means of austenitic steel...
Bellesia, B., Bottura, L., Granata, V., Le Naour, S., Oberli, L., Sanfilippo, S., ...
The production of more than 60% of superconducting cables for the main dipoles of the Large Hadron Collider has been completed. The results of the measurements of cable magnetization and the...
Bellesia, B., Molinari, G., Santoni, C., Scandale, W., Todesco, E.
During the construction of the LHC main dipoles, 12 cases of short circuits between the cables of the superconducting coils have been detected. Some of them appeared only under the press, making...
Dependence of Magnetic Field Quality on Collar Supplier and Dimensions in the Main LHC Dipole (2005)
Bellesia, B., Bertinelli, F., Santoni, C., Todesco, E.
In order to keep the electro-magnetic forces and to minimize conductor movements, the superconducting coils of the main Large Hadron Collider dipoles are held in place by means of austenitic steel...
Bellesia, B., Bottura, L., Granata, V., Le Naour, S., Oberli, L., Sanfilippo, S., ...
The production of more than 60% of superconducting cables for the main dipoles of the Large Hadron Collider has been completed. The results of the measurements of cable magnetization and the...
Dynamic Aperture Estimates And Phase Space Distortions In Nonlinear Betatronic Motion (1997)
Symplectic mappings which modelize the 4D betatronic motion in a magnetic lattice are considered. We define the dynamic aperture in terms of the connected volume in phase space of initial conditions...
Stability And Geometry Of Third-Order Resonances In Four-Dimensional Symplectic Mappings (1997)
Four-dimensional Symplectic, M. Gemmi, E. Todesco
We analyze four-dimensional symplectic mappings in the neighbourhood of an elliptic fixed point whose eigenvalues are close to satisfy a third-order resonance. Using the perturbative tools of...
Prediction Of Long-Term Stability In Large Hadron Colliders (1996)
M. Giovannozzi, W. Scandale, E. Todesco
Short-term tracking data are used to compute early indicators of long-term stability in large hadron colliders. A phenomenological picture of the mechanisms that lead to long-term particle loss is...
Non Resonant Limit For Sequences Of Resonant Orbits: The Case Of Holomorphic Maps (1995)
Introduction The resonant structures for hamiltonian systems have been intensively investigated: in fact, they are the bridge between the ordered quasi periodic orbits (i.e. KAM tori), and the...
A Program To Compute Birkhoff Normal Forms Of Symplectic Maps In ... (1995)
A. Bazzani, M. Giovannozzi, E. Todesco
this article we describe a program to calculate the Birkhoff normal forms for symplectic maps of lR
A. Bazzani, M. Giovannozzi, G. Servizi, E. Todesco, G. Turchetti
The geometrical and dynamical properties of area preserving maps in the neighborhood of an elliptic fixed point are analyzed in the framework of resonant normal forms. The interpolating flow is not...
Compensation of the tune shift in the LHC, using the normal forms techniques (1989)
W. Scandale, E. Todesco, F. Schmidt
The formalism of symplectic maps for the motion of a single particle in a lattice for hadrons is reviewed; the perturbative techniques for maps, based on the normal form theory, are outlined and the...