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In the framework of development programs for future European Space Agency (ESA) missions aimed at Mars exploration, a breadboard propulsion system has been developed at Commissariat à l’Energie Atomique (CEA-INAC/SBT). The objective is to design a system that can produce a thrust sufficient to move the whole device on the planet surface. In order to reduce the cost and the mass launched, the system uses the particular properties of the planet atmosphere which contains 98% of carbon dioxide (CO2). First the CO2 atmospheric gas is collected in a very high density storage tank using a cryopumping process (condensation of gas at around 140 K). Then an applied heat load allows generation of a continuous high pressure and high flow rate CO2 discharge, which will be used to feed the future nozzles of the system. The present system is designed to study the cryopumping process in a 0.6 liter collection tank and the discharge through an exhaust line. The design principles are presented, and the breadboard is described. Some preliminary results are then presented and discussed. As an example, the presented design allows the collection of 220 g of solid CO2 during a one shot 3 hr cryopumping process. This amount has been increased to 440 g by performing several thermal cycles. The discharge is achieved with 10 g/s maximum flow rate at 5 MPa maximum. [ABSTRACT FROM AUTHOR]

A new high voltage platform has been installed at the ORNL Multicharged Ion Research Facility (MIRF) to extend the energy range of multicharged ions available for experiments studying their collisional interactions with electrons, atoms, molecules, and solid surfaces. For the production of the multiply charged ions, a new all-permanent magnet ECRIS has been designed and fabricated at CEA/Grenoble. After a brief overview of the basic features of the new platform, and associated beam transporta detailed description of the new ion source design and performance is provided, together with some typical Ar, Xe, and O beam intensities obtained during source commissioning prior to shipment to ORNL. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

A new ion source to be installed on a compact high voltage platform is under study. The purpose of this machine is to deliver very high charge states, which requires long ion lifetimes and then a large plasma volume. On the other hand, to deliver intense beams, the highest frequency compatible with the magnetic confinement has been chosen. Due to the room available for this source, the magnetic system is chosen hybrid: radial field is created by permanent magnets, while axial field is produced by 4K superconducting coils placed in a cryostat filled with LHe. This article gives the major parameters of this ion source, with a special emphasis on the magnetic system and its cryogenic features. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

The ion injector chain for the LHC has to be adapted and modified to reach the design beam parameters. Up to now an ECR4 delivered the ion beam for the SPS fixed target physics programme. This source will be replaced by a higher intensity source to produce the Pb27+ ion current required to fill the Low Energy Ion Ring (LEIR). The new ion source will be based on the Grenoble Test Source which was itself based on empirical scaling laws derived from the Framework 5 “Innovative ECRIS” collaboration. This paper will describe the design principle, the commissioning timetable and the present status of the source development. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

The ITER cryogenic system includes provision for cooling the eight cryo-sorption pumps that maintain vacuum conditions within the tokamak plasma vacuum vessel. The eight pumps are operated such that at any given instant four pumps pump the plasma vessel and four pumps are undergoing four sequential stages of regeneration, each having a duration of 150 s. The regeneration includes a cold helium exhaust stage, warm-up from 4.5 K to 80–100 K, desorption and pump-out of released gases and cool-down from 80–100 K to 4.5 K. Thus after every 150 s of operation one of the four pumps is taken off-line for regeneration and another just-regenerated pump is restored to the set of four pumps that provide the nominal pumping. This paper presents the current design status of the cryogenic subsystems for cooling and heating the cryopumps during pumping and fast regeneration and details of the fluid-dynamic numerical analysis of the cryopumps (Vincenta code) used to study the transient behaviour of helium flow in the cryo-sorption panels during regeneration. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]