Cryopump
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Completion of JT-60SA construction and contribution to ITER Open
Construction of the JT-60SA tokamak was completed on schedule in March 2020. Manufacture and assembly of all the main tokamak components satisfied technical requirements, including dimensional accuracy and functional performances. Developm…
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Commissioning of the JT-60SA helium refrigerator Open
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Design and feasibility of a pumping concept based on tritium direct recycling Open
In the DEMO Pre-Concept Design Phase, a novel fuel cycle architecture has been developed that aims at reducing the tritium inventory of the plant. In contrast to previous designs, the central role thereby is taken by an additional direct i…
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Observations of the Gas Stream from the Large Helical Device for the Design of an Exhaust Detritiation System Open
A small amount of tritium is produced by deuterium-deuterium reactions in the core plasma during deuterium plasma experiments conducted in the Large Helical Device (LHD). From the viewpoints of tritium safety handling and public acceptance…
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Design status of the ESS cryogenic moderator system Open
The Cryogenic Moderator System (CMS) has been designed to cool high-energy neutrons down to cold neutrons in two cryogenic hydrogen moderators (four ones in the future) by forced flow of subcooled liquid hydrogen at 17 K and 1.0 MPa. At 5 …
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Development of a large capacity cryopump equipped with a two-stage GM cryocooler Open
Cryopump, which involves the removal of gas by cryo-sorption, condensation and solidification onto cryo-panels, is an ideal form of ultra-high vacuum (UHV) pump due to its contamination-free operation and black hole pumping speed. The high…
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SOLPS-ITER modeling of Ar and N seeded discharges in ASDEX upgrade and ITER Open
In this paper SOLPS-ITER simulations of Ar and N seeded discharges are presented for H-mode conditions on ASDEX Upgrade and for burning plasmas on ITER. These discharges are additionally compared with Ne seeded cases for both tokamaks. It …
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Concept for the cryo distribution for the Wendelstein 7-X cryo vacuum pumps Open
After the completion of the third experimental campaign in 2018, actively cooled high heat flux divertors (10 pcs.) will be implemented within the stellarator fusion experiment Wendelstein 7-X (W7-X). A cryo vacuum pump will be installed i…
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Control Methodology and Test Modes During the Qualification Test of the ITER Cold Circulator Open
Supercritical helium cold circulators operating at unprecedented high mass flow rates are required to maintain the ITER magnet and cryopump system at operating conditions. The qualification test plan has been developed for the two cold cir…
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STG-CT: High-vacuum plume test facility for chemical thrusters Open
The STG-CT, operated by the DLR Institute for Aerodynamics and Flow Technology in Göttingen, is a vacuum facility specically designed to provide and maintain a space-like vacuum environment for researching plume flow and plume impingement …
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Experimental investigation on charcoal adsorption for cryogenic pump application Open
Fusion reactors are generating energy by nuclear fusion between deuterium and tritium. In order to evacuate the high gas throughputs from the plasma exhaust, large pumping speed systems are required. Within the European Fusion Programme, t…
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Final Acceptance Tests of Helium Refrigerator for Wendelstein 7-X Open
Following successful installation and commissioning, final acceptance tests were carried out on the helium refrigerator for Wendelstein 7-X.The tests were carried out for the normal operating modes i.e. peak power mode (3.4 K), standard mo…
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Design and Analysis of the Inlet Valve for the CFETR Torus Cryopump Open
The China Fusion Engineering Test Reactor (CFETR), a superconducting magnetic confinement tokamak fusion reactor, will develop a high-performance torus cryopump to pump torus plasma exhaust gas. The inlet valve is one of the key components…
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Cryosorption pumping of He by charcoal and a compound cryopump design for TSTA Open
This paper presents the studies of cryosorption pumping of He by charcoal at 4.2/sup 0/K and between 10 and 20/sup 0/K. We conclude that coconut charcoal at 4.2/sup 0/K is suitable for evacuating He from fusion reactors. A compound cryopum…
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Towards assessment of plasma edge transport in Neon seeded plasmas in disconnected double null configuration in EAST with SOLPS-ITER Open
Energy dissipation in the plasma edge is key for future tokamaks. The potential of neon as radiating seeding species in disconnected double null (DDN) configuration is assessed in EAST discharges in high confinement mode (H-mode). As the s…
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Development of highly efficient NEG pumping system for EBIS Open
Ultrahigh vacuum inside the ion trap volume is crucial for stable and reliable operation of an Electron Beam Ion Source (EBIS). We have developed and tested a compact linear pumping system based on the ZAO Non-Evaporable Getter (NEG) modul…
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Performance studies of Cryocooler based cryosorption pumps with indigenous activated carbons for fusion applications Open
Cryosorption pumps are the only solution for pumping helium and hydrogen in fusion systems, due to their high pumping speeds and suitability in harsh environments. Their development requires the right Activated Carbons (ACs) and suitable a…
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The Cryostat and Subsystems Development at ITER Open
ITER is a large experimental tokamak being built to research fusion power. The ITER cryostat is a multifunctional system which provides vacuum insulation for the superconducting magnets operating at 4.5 K and for the thermal shield operati…
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Pumping speed offered by activated carbon at liquid helium temperatures by sorbents adhered to indigenously developed hydroformed cryopanel Open
Towards the aim of developing a pump with large pumping speed of the order of 1 L/(s-cm2) or above for gases like hydrogen and helium through physical adsorption, development of activated carbon based sorbents like granules, spheres, flock…
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Suppression of Vibration Induced by Reciprocal Motion of Displacer in Cryopump with an Active Dynamic Vibration Absorber Open
An active dynamic vibration absorber is introduced to a cyropump system achieving ultra-high vacuum and extremely low temperature environments for fine observation and high-accuracy measurement. In a cryopump, a so-called displacer moves r…
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High-speed pumping system characteristics of 2 MW neutral beam injector based on Ti gettering Open
The 15 kV, 2 MW neutral beam injector (NBI) was developed for C-2U magnetic trap experiments. Important part of the NBI is efficient pumping system which provided a good vacuum condition during beam pulse. The pressure rise during the NBI …
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Study of Cavitation Characteristics of a Cryogenic Pump by Computational Fluid Dynamic Methods Open
This article is devoted to the study of cavitation characteristics of a centrifugal cryogenic pump. Hydrodynamic simulation of the fluid flow in the wet part of the pump was carried out in order to determine the output parameters of the pu…
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Experimental and CFD analyses of a thermal radiation shield dimple plate for cryogenic pump application Open
Large customized cryogenic pumps are used in fusion reactors to evacuate the plasma exhaust from the torus. Cryopumps usually consist of an active pumping surface area cooled below 5 K and shielded from direct outer thermal radiation by pl…
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Study of the Effective Torus Exhaust High Vacuum Pumping System Performance in the Inner Tritium Plant Loop of EU-DEMO Open
The requirement for a reduction of the tritium inventory of the European demonstration fusion reactor (EU-DEMO) has led to the active research and development of a continuously working pumping process termed "KALPUREX." This process forese…
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Operations of the Helium Subcooling System for the LHD Helical Coils during Ten Plasma Experimental Campaigns Open
The Large Helical Device has a helium subcooling system with two cold compressors for helical coils to enhance the magnetic fields and improve the cryogenic stability of the coils by lowering the coil temperature. The system was installed …
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Thermal mode of ultracold neutron source at WWR-M reactor Open
The paper presents the results on creation of a source of ultracold neutrons in the National Research Center “Kurchatov Institute” — PNPI. The source has three temperature zones: a helium chamber with superfluid helium at the temperature of…
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Numerical simulation of filling and evacuating process of impurity gas in target capsule of inertial confinement fusion Open
Cryogenic target is one of the key components of inertial confinement fusion. The removal degree and efficiency of impurity gas in cryogenic target are of great significance to the on-line preparation of ice layer for cryogenic target fuel…
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Overall behaviour of PFC integrated SST-1 vacuum system Open
As a part of phase-I up-gradation of Steady-state Superconducting Tokamak (SST-1), Graphite Plasma Facing Components (PFCs) have been integrated inside SST-1 vacuum vessel as a first wall (FW) during Nov 14 and May 2015. The SST-1 FW has a…
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Role of Outgassing of ITER Vacuum Vessel In-Wall Shielding Materials in Leak Detection of ITER Vacuum Vessel Open
ITER Vacuum Vessel is a torus-shaped, double wall structure. The space between the double walls of the VV is filled with In-Wall Shielding Blocks (IWS) and Water. The main purpose of IWS is to provide neutron shielding during ITER plasma o…
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Cryogenic viscous pump analysis based on hemisphere model Open
Cryogenic viscous pump (CVP) is also known as fore pump that are mainly designed for the separation of hydrogen isotopes from the helium during the process of regeneration of cryo- pumps. This model will determine the amount of hydrogen wh…