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La Stevia rebaudiana est une herbe vivace à feuilles oblongues et crénelées et à saveur sucrée. Elle est originaire des zones d’altitudes du Brésil et du Paraguay. Elle a été introduite et est cultivée dans de nombreuses régions du globe, en particulier en Asie (Japon, Corée, Taïwan). Les feuilles renferment une série d’hétérosides formés à partir d’un(More)
Administrative Secretariat AT Department CERN CH 1211 Geneva 23 CERN is a large user of industrially procured cryogens essentially liquid helium and nitrogen. Recent contracts have been placed by the Organization for the delivery of quantities up to 280 tons of liquid helium over four years and up to 50000 tons of liquid nitrogen over three years. Main(More)
A transducer based on a virtual flow meter is proposed for monitoring helium distribution and consumption in cryogenic systems for particle accelerators. The virtual flow meter allows technical and economical constraints, preventing installation of physical instruments in all the needed measurement points, to be overcome. Virtual flow meter performance for(More)
The LHC will be equipped with about 8000 superconducting magnets of all types. The total current to be transported into the cryogenic enclosure amounts to some 3360 kA. In order to reduce the heat load into the liquid helium, CERN intends to use High Temperature Superconducting (HTS) material for leads having current ratings up to 13 kA. The resistive part(More)
The cryogenic system for the Large Hadron Collider accelerator is presently in its final phase of installation and commissioning at nominal operating temperatures. The refrigeration capacity for the LHC will be produced using eight large cryogenic plants installed on five technical sites and distributed around the 26.7-km circumference ring located in a(More)
  • T. Bager, Ch. Balle, +5 authors N. Vauthier
  • 2002
CERN is now setting up String 2 [1], a full-size prototype of a regular cell of the LHC arc. It is composed of two quadrupole, six dipole magnets, and a separate cryogenic distribution line (QRL) for the supply and recovery of the cryogen. An electrical feed box (DFB), with up to 38 High Temperature Superconducting (HTS) leads, powers the magnets. About 700(More)
This paper addresses the system identification and advanced control of a helium (He) liquifier supplying cooling power at liquid helium (LHe) temperatures (-269 ◦C). To study the dynamic response to heat load variation, a He liquifier simulation model is utilized. The main focus is to regulate the discharge pressure of the compressor station to guarantee(More)