Cryogenic Performance of a Superconducting Magnet System for the J-Parc Neutrino Beam Line

Abstract

A neutrino experiment facility using the J-PARC proton beam has been constructed at Tokai campus of KEK. In this project, a 150 m superconducting magnet system is installed in an arc section of the primary proton beam line. The magnet system consists of 28 superconducting magnets. The cold mass of a magnet is 6 tons. The refrigerator and the magnets are connected by a transfer tube with the total length of 90 m. Forced flow supercritical Helium with the mass flow rate of 300 g/sec, the inlet temperature of 4.5 K and inlet pressure of 400 kPa is supplied to the magnets through the transfer tube. A pair of superconducting busbars are also installed in the transfer tube. Total cold mass of the magnet system including the transfer tube and other instruments is about 204 tons. This paper describes the cryogenic performance of the superconducting magnet system.

Cryogenic System for J-Parc Neutrino Superconducting Magnet Beam Line—design, Construction and Performance Test

“…Measured heat load in the magnet and the transfer tubes is 230 W [10], which is within the estimation including contingency of 20 %. Measured heat load in the magnet and the transfer tubes is 230 W [10], which is within the estimation including contingency of 20 %.…”

“…The neutrino-oscillation experiment uses an artificial neutrino beam being directed towards the Super-Kamiokande detector located 295 km west of J-PARC. This beam line has a bending section with a radius of 105 m, where a superconducting magnet system with a dipole field of 2.6 T and quadrupole field of 19.6 T/m at the nominal current of 7345 A to transport 50 GeV protons has been designed, manufactured and installed [3][4][5][6][7][8][9][10]. This beam line has a bending section with a radius of 105 m, where a superconducting magnet system with a dipole field of 2.6 T and quadrupole field of 19.6 T/m at the nominal current of 7345 A to transport 50 GeV protons has been designed, manufactured and installed [3][4][5][6][7][8][9][10].…”

“…Measured cryogenic characteristics in the magnet part are presented in the same conference, CEC 2009, in detail [10]. The plant engineering design started by a main contract with Taiyo-Nippon Sanso Co. (TNSC) in 2006, and the construction was completed by December 2008.…”

Commissioning Results of Superconducting Magnet System for the Neutrino Beam Line

“…The cryogenic performance of the system has been already reported in [6], [7]. The system was stopped and warmed up to about 100 K for the government inspection, and cooled down again for the beam commissioning.…”

Construction of Superconducting Magnet System for the J-PARC Neutrino Beam Line

“…The helium transfer tube (TRT) with a length of 100 m connects the refrigerator on the ground and the magnets in the beam line tunnel 11 m below the ground, and supplies SHe to the magnets. Detailed reports on the development, production, and testing of the superconducting magnet system for the J-PARC neutrino beam line can be found in [4]- [17].…”