Benda, V
Bézaguet, Alain-Arthur
Casas-Cubillos, J
Claudet, S
Erdt, W K
Lebrun, P
Riddone, G
Sergo, V
Serio, L
Tavian, L
Vullierme, B
Van Weelderen, R
Wagner, U
Conceptual design of the cryogenic system for the Large Hadron Collider (LHC)
http://preprints.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=CERN-LHC-PROJECT-REPORT-12;
https://accelconf.web.cern.ch/e96/abstracts/leb4165.pdf;
https://accelconf.web.cern.ch/e96/PAPERS/ORALS/THO04A.PDF;
http://cds.cern.ch/record/310033/files/lhc-project-report-12.pdf;
http://cds.cern.ch/record/310033/files/lhc-project-report-12.ps.gz;
Imported from Invenio.
Bottura, L
Faus-Golfe, A
Walckiers, L
Wolf, R
Field quality of the main dipole magnets for the LHC accelerator
http://preprints.cern.ch/cgi-bin/setlink?base=preprint&categ=.&id=CERN-LHC-PROJECT-REPORT-17;
https://accelconf.web.cern.ch/e96/abstracts/bot2176.pdf;
https://accelconf.web.cern.ch/e96/PAPERS/MOPG/MOP010G.PDF;
http://cds.cern.ch/record/315772/files/lhc-project-report-17.pdf;
http://cds.cern.ch/record/315772/files/lhc-project-report-17.ps.gz;
Imported from Invenio.
Ostojic, R
Taylor, T M
Amplitude dependent tune spread and field errors of superconducting low-$\beta$ quadrupoles
http://preprints.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=LHC-PROJECT-REPORT-24;
https://accelconf.web.cern.ch/e96/abstracts/ost2243.pdf;
https://accelconf.web.cern.ch/e96/PAPERS/MOPG/MOP018G.PDF;
http://cds.cern.ch/record/310752/files/lhc-project-report-24.pdf;
http://cds.cern.ch/record/310752/files/lhc-project-report-24.ps.gz;
Imported from Invenio.
Andreyev, N I
Artoos, K
Bottura, L
Kirby, G A
Leroy, D
Oberli, L R
Ostler, J M
Perini, D
Poncet, Alain
Rodríguez-Mateos, F
Russenschuck, Stephan
Siambanis, T
Siegel, N
Siemko, A
Tommasini, D
Trinquart, G
Vanenkov, I
Veness, R J M
Walckiers, L
Weterings, W
The 1 m long single aperture dipole coil test program for LHC
https://accelconf.web.cern.ch/e96/PAPERS/MOPG/MOP027G.PDF;
https://accelconf.web.cern.ch/e96/abstracts/sie3434.pdf;
http://preprints.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=LHC-PROJECT-REPORT-25;
http://cds.cern.ch/record/310753/files/lhc-project-report-25.pdf;
http://cds.cern.ch/record/310753/files/lhc-project-report-25.ps.gz;
http://cds.cern.ch/record/310753/files/lhc-project-report-255.LHCprojrep255_cover.ps.gz;
Imported from Invenio.
Berland, V
Hagedorn, Dietrich
Rodríguez-Mateos, F
Gerstenberg, H
Annealing of superconducting magnet protection diodes for the LHC after irradiation at liquid helium temperatures
http://preprints.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=LHC-PROJECT-REPORT-26;
https://accelconf.web.cern.ch/e96/abstracts/hag3433.pdf;
https://accelconf.web.cern.ch/e96/PAPERS/MOPG/MOP015G.PDF;
http://cds.cern.ch/record/310755/files/lhc-project-report-26.pdf;
http://cds.cern.ch/record/310755/files/lhc-project-report-26.ps.gz;
Imported from Invenio.
Salminen, J
Ijspeert, Albert
Puntambekar, A
Superconducting Sextupole Corrector Magnet for the LHC Main Dipoles
Each LHC main dipole will be equipped with small sextupole corrector ma g nets with a field strength of 1970 x2 T/m2 and a magnetic length of 100 mm designed to correct the sextupole field errors. The paper presents a cosine-q type of design where much emphasis has been put on the cost reduction because these magnets have to be made in large series of some 2500 pieces. We describe the design of a two-layer coil which can be wound automatically. The winding starts in the middle of the wire with the only joggle, the layer jump, which is housed in a corresponding groove in the end of the central island. The two layers are wound simultaneously turning in opposite directions to find their position without the need of local tooling. The coil ends are closely packed and need no end spacers. The 18 pole perturbation introduced by the ends is corrected by the position of the coil block in the straight part. The yoke is made of iron laminations of the "Scissors type" which transmit the pre-stress from the outer aluminium shrink ring to the coil. This allows the iron to be close to the coil for field enhancement and also boosts the pre-stress in the coil due to the cool down contractions. The paper describes the experience with the magnet construction and gives the first test results.
eng
1996
http://preprints.cern.ch/cgi-bin/setlink?base=preprint&categ=.&id=CERN-LHC-PROJECT-REPORT-27;
https://accelconf.web.cern.ch/e96/abstracts/sal1268.pdf;
https://accelconf.web.cern.ch/e96/PAPERS/MOPG/MOP024G.PDF;
http://cds.cern.ch/record/307557/files/lhc-project-report-27.pdf;
http://cds.cern.ch/record/307557/files/lhc-project-report-27.ps.gz;
Imported from Invenio.
Karppinen, M
Russenschuck, Stephan
Ijspeert, Albert
Automated Design of a Correction Dipole Magnet for LHC
A correction dipole magnet, with a horizontal dipole nested inside a vertical dipole has been designed and optimized linking together different electromagnetic software and CAD/CAM systems. The necessary interfaces have recently been established in the program ROXIE which has been developed at CERN for the automatic generation and optimization of superconducting coil geometries. The program provides, in addition to a mathematical optimization chest, interfaces to commercial electromagnetic and structural software packages, CAD/CAM and databases. The results from electromagnetic calculations with different programs have been compared. Some modelling considerations to reduce the computation time are also given.
eng
1996
http://preprints.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=CERN-LHC-PROJECT-REPORT-29;
https://accelconf.web.cern.ch/e96/abstracts/kar1508.pdf;
https://accelconf.web.cern.ch/e96/PAPERS/THPG/THP025G.PDF;
http://cds.cern.ch/record/307558/files/lhc-project-report-29.pdf;
http://cds.cern.ch/record/307558/files/lhc-project-report-29.ps.gz;
http://cds.cern.ch/record/307558/files/lhc-project-report-297_cov.pdf;
Imported from Invenio.
Bézaguet, Alain-Arthur
Brahy, D
Casas-Cubillos, J
Coull, L
Cruikshank, P
Dahlerup-Petersen, K
Faugeras, Paul E
Flemsæter, B
Guinaudeau, H
Hagedorn, Dietrich
Hilbert, B
Krainz, G
Kos, N
Lavielle, D
Lebrun, P
Leo, G
Mathewson, A G
Missiaen, D
Momal, F
Parma, Vittorio
Quesnel, Jean Pierre
Richter, D
Riddone, G
Rijllart, A
Rodríguez-Mateos, F
Rohmig, P
Saban, R I
Schmidt, R
Serio, L
Skiadelli, M
Suraci, A
Tavian, L
Walckiers, L
Wallén, E
Van Weelderen, R
Williams, L
McInturff, A
The LHC test string: first operational experience
CERN operates the first version of the LHC Test String which consists of one quadrupole and three 10-m twin aperture dipole magnets. An experimental programme aiming at the validation of the LHC systems started in February 1995. During this programme the string has been powered 100 times 35 of which at 12.4 kA or above. The experiments have yielded a number of results some of which, like quench recovery for cryogenics, have modified the design of subsystems of LHC. Others, like controlled helium leaks in the cold bore and quench propagation bewteen magnets, have given a better understanding on the evolution of the phenomena inside a string of superconducting magnets cooled at superfluid helium temperatures. Following the experimental programme, the string will be powered up and powered down in one hour cycles as a fatigue test of the structure thus simulating 20 years of operation of LHC.
eng
1996
http://preprints.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=CERN-LHC-PROJECT-REPORT-32;
https://accelconf.web.cern.ch/e96/abstracts/sab2197.pdf;
https://accelconf.web.cern.ch/e96/PAPERS/ORALS/WEO07A.PDF;
http://cds.cern.ch/record/307374/files/lhc-project-report-32.pdf;
http://cds.cern.ch/record/307374/files/lhc-project-report-32.ps.gz;
http://cds.cern.ch/record/307374/files/WEO07A.PDF;
Imported from Invenio.
Bartolini, R
Faus-Golfe, A
Giovannozzi, Massimo
Todesco, Ezio
Scandale, Walter
Early indicators of long term stability in hadron colliders
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 the variation of the instantaneous non-linear tunes. A threshold is associated to each indicator, by which a simple and automated procedure can be defined to select chaotic from regular trajectories. The methods are checked against long-term tracking for a linear lattice with a sextupole (Hénon map). The results show that rather precise long-term dynamic aperture estimates can be worked out using short-term tracking data. The method is successfully applied to identify the dynamic aperture of the CERN LHC in realistic situations.
eng
1996
http://preprints.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=LHC-PROJECT-REPORT-041;
https://accelconf.web.cern.ch/e96/abstracts/sca1881c.pdf;
https://accelconf.web.cern.ch/e96/PAPERS/ORALS/TUO01A.PDF;
http://cds.cern.ch/record/309214/files/lhc-project-report-041.pdf;
http://cds.cern.ch/record/309214/files/lhc-project-report-041.ps.gz;
Imported from Invenio.
Kirby, G A
Ostojic, R
Strait, J B
Milward, S R
Nobes, S
Smith, K D
Street, A J
Townsend, M C
Treadgold, J R
Wiatrzyk, J M
Progress in the Development of the 1 m Model of the 70 mm Aperture Quadrupole for the LHC Low-$\beta$ Insertions
IEEE Trans. Appl. Supercond.
594-597
7
Within the LHC magnet development program Oxford Instruments has built a one metre model of the 70 mm aperture low-beta quadrupole. The magnet features a four layer coil wound from two 8.2 mm wide graded NbTi cables, and is designed for 250 T/m at 1.9 K. The magnet has previously been tested between 4.5 K and 2.3 K. In this paper we review the magnet rebuild and the subsequent tests. Results on magnet training at 4.3 K and 1.9 K are presented along with the results related to quench protection studies.
eng
1996
http://preprints.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=LHC-PROJECT-REPORT-42;
http://preprints.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=LHC-PROJECT-REPORT-68;
https://accelconf.web.cern.ch/e96/abstracts/tre2157.pdf;
https://accelconf.web.cern.ch/e96/PAPERS/MOPG/MOP103G.PDF;
http://cds.cern.ch/record/308010/files/lhc-project-report-42.pdf;
http://cds.cern.ch/record/308010/files/lhc-project-report-42.ps.gz;
http://cds.cern.ch/record/308010/files/lhc-project-report-68.pdf;
http://cds.cern.ch/record/308010/files/lhc-project-report-68.ps.gz;
Imported from Invenio.
Strait, J B
Mokhov, N V
Optimization of the LHC Interaction Region With Respect to Beam-Induced Energy Deposition
Energy deposition in the superconducting magnets by particles from p-p collisions is a significant challenge for the design of the LHC high luminosity insertions. We have studied the dependence of the energy deposition on the apertures and strengths of insertion magnets and on the placement of absorbers in front of and within the quadrupoles. Monte Carlo simulations were made using the code DTUJET to generate 7 x 7 TeV p-p events and the code MARS to follow hadronic and electromagnetic cascades induced in the insertion components. The 3D geometry and magnetic field descriptions of the LHC-4.1 lattice were used. With a quadrupole coil aperture 70 mm, absorbers can be placed within the magnet bore which reduce the peak power density, at full luminosity, below 0.5 mW/g, a level that should allow the magnets to operate at their design field. The total heat load can be removed by a cooling system similar to that used in the main magnets.
eng
1996
http://preprints.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=LHC-PROJECT-REPORT-43;
http://fnalpubs.fnal.gov/archive/1996/conf/Conf-96-136.html;
https://accelconf.web.cern.ch/e96/PAPERS/THPG/THP028G.PDF;
http://cds.cern.ch/record/308011/files/lhc-project-report-43.pdf;
http://cds.cern.ch/record/308011/files/lhc-project-report-43.ps.gz;
Imported from Invenio.
Ijspeert, Albert
Salminen, J
Superconducting Coil Compression by Scissor Laminations
A new system of coil compression has been designed which uses iron laminations to transfer the pressure from an outer shrink ring to the coil. The laminations are simple circular discs around the coil with the peculiarity that the rim is slightly eccentric as compared to the coil. Successive laminations are mounted with different angular orientations to oppose their eccentricities. The shrink ring pushed these discs inwards against the coil creating compression by a scissor movement. Tests on mechanical models of single as well as multiple aperture magnets have shown it to work as expected. The system has already successfully been applied to several corrector magnets for LHC. The advantages are low cost (suppression of the usual collars), increased coil compression in particular from cooling down, and field enhancement from having the iron close to the coil.
eng
1996
http://preprints.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=LHC-PROJECT-REPORT-47;
https://accelconf.web.cern.ch/e96/abstracts/ijs1954.pdf;
https://accelconf.web.cern.ch/e96/PAPERS/MOPG/MOP016G.PDF;
http://cds.cern.ch/record/308369/files/lhc-project-report-47.pdf;
http://cds.cern.ch/record/308369/files/lhc-project-report-47.ps.gz;
Imported from Invenio.
Coull, L
Hagedorn, Dietrich
Krainz, G
Rodríguez-Mateos, F
Schmidt, R
Electrodynamic behaviour of the LHC superconducting magnet string during a discharge
A string of three dipole magnets and one quadrupole magnet, representing a half cell of the future LHC collider, has been assembled and tested at CERN. In order to avoid high temperatures in the magnets and high voltages between coils and ground in case of a quench, a reliable magnet protection system is necessary. The magnets are by-passed by protection diodes which are located in the cold mass. In case of a quench most of the stored magnetic energy is dissipated in the resistive parts of the magnets. Many natural and heater provoked quenches have been performed during the two experimental runs of the string at 1.9 K. This paper describes the electrodynamic behaviour during a fast discharge (i.e. after a quench) of the magnet string configuration. A simulation program was developed to evaluate parameters which cannot be directly measured, such as the current sharing between magnets and diodes, as well as the dissipated energy. The simulation program gives also the possibility for worst-case calculations, for example non-uniform magnet quench characteristics and protection heater delays.
eng
1996
http://preprints.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=LHC-PROJECT-REPORT-61;
https://accelconf.web.cern.ch/e96/abstracts/kra2212.pdf;
https://accelconf.web.cern.ch/e96/PAPERS/MOPG/MOP017G.PDF;
http://cds.cern.ch/record/314682/files/lhc-project-report-61.pdf;
Imported from Invenio.
Coull, L
Hagedorn, Dietrich
Krainz, G
Rodríguez-Mateos, F
Schmidt, R
Quench propagation tests on the LHC superconducting magnet string
The installation and testing of a series connection of superconducting magnets (three 10 m long dipoles and one 3 m long quadrupole) has been a necessary step in the verification of the viability of the Large Hadron Collider at CERN. In the LHC machine, if one of the lattice dipoles or quadrupoles quenches, the current will be by-passed through cold diodes and the whole magnet chain will be de-excited by opening dump switches. In such a scenario it is very important to know whether the quench propagates from the initially quenching magnet to adjacent ones. A series of experiments have been performed with the LHC Test String powered at different current levels and at different de-excitation rates in order to understand possible mechanisms for such a propagation, and the time delays involved. Results of the tests and implications regarding the LHC machine operation are described in this paper.
eng
1996
http://preprints.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=LHC-PROJECT-REPORT-70;
https://accelconf.web.cern.ch/e96/abstracts/rod2214.pdf;
https://accelconf.web.cern.ch/e96/PAPERS/MOPG/MOP023G.PDF;
http://cds.cern.ch/record/315078/files/lhc-project-report-70.pdf;
Imported from Invenio.
Lepeule, P
Menot, C
Veness, R J M
Design and implementation of synchrotron radiation masks for LEP2
Estimates of photon flux for LEP2 have predicted unacceptable background levels within the detectors of the four LEP experiments. As part of the solution to this problem, synchrotron radiation masks have been installed within the experimental vacuum Chambers close to the interaction points. The photon flux calculations and specification for the masks have been laid-out by von Holtey et.al. [1]. This paper describes the design of the masks and outlines the principal technical issues overcome for their installation and alignment.
eng
1996
http://preprints.cern.ch/cgi-bin/setlink?base=preprint&categ=.&id=CERN-LHC-96-008;
https://accelconf.web.cern.ch/e96/abstracts/ven4106.pdf;
https://accelconf.web.cern.ch/e96/PAPERS/MOPL/MOP035L.PDF;
http://cds.cern.ch/record/307861/files/lhc-96-008.pdf;
http://cds.cern.ch/record/307861/files/lhc-96-008.ps.gz;
http://cds.cern.ch/record/307861/files/lhc-96-008.tif;
Imported from Invenio.
Hagedorn, Dietrich
Rodríguez-Mateos, F
Schmidt, R
Protection of LHC superconducting corrector magnets
The protection of superconducting magnets in case of a quench has to be considered already in the design phase for the proton-proton collider LHC. The protection of main dipole and quadrupole magnets, based on cold diodes and quench heaters, is reported elsewhere [1]. In this paper the protection of other magnets is discussed. In the arcs some of the magnets are connected in series: sextupole magnets to correct the lattice chromaticity, small sextupole and decapole magnets to correct systematic field errors of the dipoles and octupole magnets. The magnets in the arcs to correct horizontal and vertical closed orbit excursions are powered individually. In the insertions other superconducting magnets will be used: quadrupole magnets for the low-beta insertions, orbit corrector magnets, etc. Some magnets will be constructed with sufficient copper stabilization to safely absorb the energy. For other magnets different methods of protection after the detection of a quench in the circuit are envisaged.
eng
1996
http://preprints.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=LHC-PROJECT-REPORT-63;
https://accelconf.web.cern.ch/e96/abstracts/sch2017.pdf;
https://accelconf.web.cern.ch/e96/PAPERS/MOPG/MOP025G.PDF;
http://cds.cern.ch/record/314683/files/lhc-project-report-63.pdf;
http://cds.cern.ch/record/314683/files/lhc-project-report-63.ps.gz;
Imported from Invenio.