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Magnetic measurements are used for studying the full-scale magnet system assembled with the cryostat for the J-PARC neutrino proton beam line. The beam simulation has shown that the measured values of magnetic field are sufficient for the primary proton beam transport.

The development and testing of the first full-scale prototype magnet system assembled with the cryostat for the Japan Proton Accelerator Research Complex (J-PARC) proton beam line of neutrino experiment are discussed. Findings reveal the successful cooling of the magnets to 4.5 K by forced flow supercritical helium and excitation up to the current of 7345 A.

The article studies the fabrication and testing of three superconducting combined function magnets for the Japan Proton Accelerator Research Complex (J-PARC) neutrino beam line. Findings reveal the observation of excellent excitation and quench performances in the magnets.

Superconducting combined function magnets would be utilized for the 50 GeV - 750 kw proton beam line for the J-PARC neutrino experiment and an R&D program is launched at KEK. A single layer coil is proposed to reduce the fabrication cost and the coil arrangement in the 2-D cross-section results in left-right asymmetry.

A neutrino oscillation experiment using the J-PARC 50 GeV proton beam is planned by designing a superconducting magnet system. A system with 28 combined function magnets is proposed to simplify the system and optimize the cost.

KEK has developed a super-conducting low-beta quadrupole magnet, MQXA, as a part of the collaboration program between CERN and KEK for the LHC. The magnetic field behavior of the 13 MQXA magnets from the viewpoint of accelerator operation is described.

A superconducting magnet system for the J-PARC neutrino beam line has been under construction since 2004. The system consists of 14 doublet cryostats; each contains 2 combined function magnets (SCFM). The SCFM uses two single layer left/right asymmetric coils that produce a dipole field of 2.6 T and quadrupole of 19 T/m. The SCFMs had been developed by 2004, mass-produced since 2005, and completed by summer 2008. The system is being installed since Feb. 2008 till the end of 2008. The paper summarizes the system overview including cryogenics and safety peripheries. The paper also reports the production and installation status. [ABSTRACT FROM AUTHOR]

Fabrication and cold tests of 32 superconducting combined function magnets including 4 backup magnets for the J-PARC neutrino have been completed. All the magnets reached 7700 A, 105% of maximum operation current, without any spontaneous quenches. Quench protection performance was also confirmed to be safe. In the field measurement during cold tests, all the magnets showed sufficient field quality to fulfill the specification. Reproducibility of the field quality was evaluated to be about the same order of that observed in ordinary cos - θ magnets, indicating good manufacturing reproducibility. [ABSTRACT FROM AUTHOR]

A magnetic field measurement under a warm condition for a prototype of superconducting combined function magnet (SCFM) in a J-PARC was performed. In this measurement, the magnet was aligned on an alignment-line defined by a laser beam by referring alignment markers on the magnet shell and laser beam position markers on the alignment-line. Each process of alignment and measurement was performed within ±0.05 mm accuracy. To identify the precise magnetic field distribution in the SCFM, we developed a position-monitoring system of a magnetic sensor (rotating coil), which consisted of a laser also used as the alignment-line and a position-sensitive detector mounted on the rotating coil. By using this position monitor, we identified displacements of the rotating coil to ±0.06 ham accuracy. Finally, we succeeded to identify the measured positions of the magnetic field in the prototype SCFM within the required tolerance of ±0.3 mm. [ABSTRACT FROM AUTHOR]

Superconducting combined function magnets are adopted for the 50 GeV, 750 kW proton beam line for the J-PARC neutrino experiment, and two full-scale prototype magnets have been developed successfully at KEK. In the cold tests, both prototypes were excited up to 7700 A without spontaneous quenches. The measured field quality of the both prototypes agreed well with the design field, indicating that the fabrication process has no major problem. The heater quench tests of the first prototype, however, showed that the magnet was not self-protected. Consequently, the design was revised and quench protection heaters were adopted. In quench heater tests of the second prototype magnet using small sheet heaters, the fundamental characteristics of the quench protection heaters were studied. [ABSTRACT FROM AUTHOR]

The J-PARC Neutrino Experiment, the construction of which starts in JFY 2004, will use a superconducting magnet system for its primary proton beam line. The system, which bends the 50 GeV 0.75 MW proton beam by about 80 degrees, consists of 28 superconducting combined function magnets. The magnets utilize single layer left/right asymmetric coils that generate a dipole field of 2.6 T and a quadrupole field of 18.6 T/m with the operation current of about 7.35 kA. The system also contains a few conduction cooled superconducting corrector magnets that serve as vertical and horizontal steering magnets. All the magnets are designed to provide a physical beam aperture of 130 mm in order to achieve a large beam acceptance. Extensive care is also required to achieve safe operation with the high power proton beam. The paper summarizes the system design as well as some safety analysis results. [ABSTRACT FROM AUTHOR]

Superconducting combined function magnets will be utilized for the 50 GeV, 750 kW proton beam line for the J-PARC neutrino experiment and an R&D program has been launched at KEK. The magnet is designed to provide a combined function of a dipole field of 2.6 T with a quadrupole field of 19 T/m in a coil aperture of 173.4 mm. Critical magnet components including glass-fiber reinforced phenolic plastic spacers have been successfully developed. The mechanical design has been verified by a 100 mm long short-cut model, and coils have been wound for the first full-length prototype. [ABSTRACT FROM AUTHOR]

Discusses the fabrication of a Large Hadron Collider interaction region superconducting magnet MQXA. Magnetic field measurements; Production of field gradients; Field quality; Requirements of the accelerator beam optics.