<?xml version="1.0" encoding="UTF-8"?>
<xml>
<records>
<record>
  <contributors>
    <authors>
      <author>Benda, V</author>
      <author>Sergo, V</author>
      <author>Vuillierme, B</author>
    </authors>
  </contributors>
  <titles>
    <title>Electrical heater for very-low pressure helium gas</title>
    <secondary-title/>
  </titles>
  <doi/>
  <pages/>
  <volume/>
  <number/>
  <dates>
    <year>1996</year>
    <pub-dates>
      <date>1996</date>
    </pub-dates>
  </dates>
  <abstract>Testing superconducting magnets for the Large Hadron Collider (LHC) in superfluid helium requires large-capacity refrigeration at 1.8K. At CERN, this is provided by a combination of a cold compressor and a set of warm vacuum pumps capable of handling up to 18g/s at 1 kPa suction pressure. The cold helium vapour, after the cold compressor, is warmed up from about 5K to ambient temperature in a 32 kW electrical heater. The device is designed to operate reliably at flow rates varying from 1 to 18g/s, inlet pressure of 1 kPa to 3 kPa, with pressure drop 100 Pa. Design and construction of the heater, completely realised at CERN, are presented, as well as measured performance. Some technological problems are discussed.</abstract>
</record>

<record>
  <contributors>
    <authors>
      <author>Lebrun, P</author>
      <author>Tavian, L</author>
      <author>Claudet, G</author>
    </authors>
  </contributors>
  <titles>
    <title>Development of large-capacity refrigeration at 1.8 K for the Large Hadron Collider at CERN</title>
    <secondary-title/>
  </titles>
  <doi/>
  <pages/>
  <volume/>
  <number/>
  <dates>
    <year>1996</year>
    <pub-dates>
      <date>1996</date>
    </pub-dates>
  </dates>
  <abstract>CERN, the European Laboratory for Particle Physics, is working towards the construction of the Large Hadron Collider (LHC), a high-energy, high-luminosity particle accelerator and collider [1] of 26.7 km circumference, due to start producing frontier physics, by bringing into collision intense proton and ion beams with centre-of-mass energies in the TeV-per-constituent range, at the beginning of the next century. The key technology for achieving this ambitious scientific goal at economically acceptable cost is the use of high-field superconducting magnets using Nb-Ti conductor operating in superfluid helium [2]. To maintain the some 25 km of bending and focusing magnets at their operating temperature of 1.9 K, the LHC cryogenic system will have to produce an unprecedented total refrigeration capacity of about 20 kW at 1.8 K, in eight cryogenic plants distributed around the machine circumference [3]. This has requested the undertaking of an industrial development programme, in the form of a collaboration between CERN and CEA, France, for investigating specific machinery, i.e. very-low pressure cryogenic heat exchangers, volumetric and hydrodynamic compressors, as well as practical and efficient thermodynamic cycles. We report on the aims lines of action and present progress of this ongoing programme.</abstract>
</record>


</records>
</xml>