Development of Superconducting Tuning Quadrupole Corrector (MQT) Prototypes for the LHC

The main quadrupoles of the Large Hadron Collider (LHC) are connected in families of focusing and defocusing magnets. In order to make tuning corrections in the machine a number of quadrupole corrector magnets (designated MQT) are necessary. These 56 mm diameter aperture magnets have to be compact, with a maximum length of 395 mm and a coil radial thickness of 5 to 7.5 mm, while generating a minimum field gradient of 110 T/m. Two design options have been explored, both using the "counter-winding" system developed at CERN for the fabrication of low cost corrector coils. The first design, with the poles composed of two double-pancake coils, each counter-wound using a single wire, superposed to create 4-layer coils, was developed and built by ACCEL Instruments GmbH. A second design where single coils were counter-wound using a 3-wire ribbon to obtain 6-layer coils was developed at CERN. This paper describes the two designs and reports on the performance of the prototypes during testing

Further Development of the Sextupole and Decapole Spool Corrector Magnets for the LHC

In the Large Hadron Collider (LHC) the main dipoles will be equipped with sextupole (MCS) and decapole (MCD) spool correctors to meet the very high demands of field quality required for the satisfactory operation of the machine. Each decapole corrector will in addition have an octupole insert (MCO) and the assembly of the two is designated MCDO. These correctors are needed in relatively large quantities, i.e. 2464 MCS Sextupoles and 1232 MCDO Decapole-Octupole assemblies. Half the number of the required spool correctors will be made in India through a collaboration between CERN and CAT (Centre for Advanced Technology, Indore, India), the other half will be built by European industry. The paper describes final choices concerning design, materials, production techniques, and testing so as to assure economic magnet manufacture but while maintaining a homogenous magnetic quality that results in a robust product

Teachers concerns in the implementation of laptop computers: four case studies

Master of EducationThis study examines the concerns four teachers experience when confronted with technological innovation: the introduction of the laptop computer into their classroom. It attempts to define the factors which inhibit or encourage the move from an emphasis on personal concerns to ones which focus on the student as learner and finally lead to the teacher reflecting on their own practices and being able to share new knowledge with others. Through interview; observation and discussion this study explores these teachers' feelings and reactions to what is happening in their classrooms. The study is located in the social action of the teachers in their schools. It has chosen to emphasise the institutional factors in particular rather than looking to social uses the computer has been put to in classroom

13000 A current lead with 1.5 W heat load to 4.5 K for the Large Hadron Collider at CERN

Cryogenic Ltd. and ENEL S.p.A. have collaborated on the design and construction of prototype current leads for the Large Hadron Collider project at CERN, Geneva. The aim is to deliver a direct current of 13 kA into a 4.5 K liquid helium bath with a total heat load of less than 1.5 W. These hybrid leads transport the current via a resistive heat exchanger cooled by a separate source of helium gas in the high temperature region, and below 50 K via self-cooled high temperature superconductor. (8 refs)

13000 a current lead with 1.5 W heat load to 4.5 K for the Large Hadron Collider at CERN

Cryogenic Ltd. and ENEL S.p.A. have collaborated on the design and construction of prototype current leads for the Large Hadron Collider project at CERN, Geneva. The aim is to deliver a direct current of 13 kA into a 4.5 K liquid helium bath with a total heat load of less than 1.5 W. These hybrid leads transport the current via a resistive heat exchanger cooled by a separate source of helium gas in the high temperature region, and below 50 K via self-cooled high temperature superconductor. (6 refs)

13000 A current lead with 1.5 W heat load to 4.5 K for the large hadron collider at CERN

Cryogenic Ltd. and ENEL S.p.A. have collaborated on the design and construction of prototype current leads for the large hadron collider project at CERN, Geneva. This delivers a current of 13 kA into a 4.5 K liquid helium bath with a total heat load of 1.5 W. These leads transport the current via a resistive heat exchanger cooled by helium gas in the high-temperature region, and below 50 K via self-cooled high-temperature superconductor. (3 refs)

Status of the Production of the LHC Superconducting Corrector Magnets

The Large Hadron Collider (LHC) will be equipped with a large number (6400) of superconducting corrector magnets. These magnets are powerful, with typical peak fields of 3-4 T on the coils, but at the same time compact and of low cost. There are many types: sextupoles, octupoles and decapoles to correct the main dipole field, dipoles, quadrupoles, sextupoles and octupoles to condition the proton beams and several nested correctors from dipole to dodecapole in the inner triplets. The sizes vary from 6 kg, 110 mm long, nested decapole-octupole spool pieces to 1800 kg, 1.4m long, trim quadrupoles. The fabrication of the 11 different types of magnets is assured by 10 contracts placed at 6 firms, two of which are in India. A number of magnets are now in series production, others in their pre-series production. The paper describes the present state of the fabrication and the testing of these magnets