Abstracts Brochure - CERN

WEPLS — Poster Session 28-Jun-06 16:00 - 18:00
The Dependence of the Field Decay on the Powering History of the LHC Superconducting
Dipole Magnets
The decay amplitude of the allowed multipoles
in the LHC dipoles is expected to perturb
the beam stability during the injection
phase and is strongly dependent on the pow-
N.J. Sammut, L. Bottura, S. Sanfilippo (CERN) J. Micallef (University
of Malta, Faculty of Engineering)
ering history of the magnet. The effect is particularly large for the pre-cycle nominal flat-top current and duration.
With possible prospects of having different genres of cycles during the LHC operation, the powering history effect
must be taken into account in the Field Description Model for the LHC (FIDEL) and must hence be corrected for
during machine operation. This paper presents the results of the modelling of this phenomenon. We also discuss
the statistic of magnetic measurements required to guarantee that the current history effect is predicted within the
specified accuracy.
Performance of the LHC Arc Superconducting Quadrupoles towards the End of their Series
Fabrication
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 is presented
in this paper. These data cover the
T. Tortschanoff, P. Hagen, M. Modena, L. Rossi, S. Sanfilippo, K. M.
Schirm, E. Todesco, E.Y. Wildner (CERN) R. Burgmer, H.-U. Klein,
D. Krischel, B. Schellong, P. Schmidt (ACCEL) M. Durante, A. Payn,
F. Simon (CEA)
fabrication and the efficiency in the use of the main components, the geometrical measurements and the achieved
dimensional precision, the warm magnetic measurements in the factory and the performance at cold conditions,
especially the training behaviour. The scrap rate of the NbTi/Cu conductor as well as that of other components
turned out to be acceptably low and the quench performance measured was in general very good. Most quadrupoles
measured so far exceeded the operating field gradient with one or no quench. The multipole content at cold was
measured for a limited numbers of quadrupoles as far as needed for verifying the warm-to-cold correlation. From the
point of view of field quality, all quadrupoles could be accepted for the machine and the measures taken to overcome
the problem of a too high permeability of a batch of collars are discussed.
Design, Performance and Series Production of the LHC Superconducting Trim Quadrupoles
for the Large Hadron Collider
The Large Hadron Collider (LHC) will be
equipped with several thousands of superconducting
corrector magnets. Among the
largest ones are the superconducting trim
quadrupoles (MQTL). These are twin-aperture
magnets with a nominal gradient of 120
M. Karppinen, C. Boyer, J.-M. Castro, J. Mazet, G. Mugnai, V. Remondino,
W. Venturini Delsolaro, R. Wolf (CERN) G. Gaggero, L.
Loche, M. Tassisto (ANSALDO Energia, Magnet & Special Product
Division) P. Khare, A. Puntambekar (RRCAT)
T/m at 1.9 K and a magnetic length of 1.3 m, with a mass of about 1800 kg. Sixty MQTL are required for the LHC,
36 operating at 1.9 K in the dispersion suppressors and 24 operating at 4.5 K in the cleaning insertions. The paper
describes the design features, and reports the measured quench performance and magnetic field quality. The MQTL
363
WEPLS104
WEPLS105
WEPLS106