IFMIF/EVEDA lithium test loop: design and fabrication technology of target assembly as a key component

Abstract

The engineering validation and engineering design activity (EVEDA) for the International Fusion Materials Irradiation Facility (IFMIF) is proceeding as one of the ITER broader approach activities. In the concept of the IFMIF, two 40 MeV deuteron beams are injected into a liquid Li stream (Li target) flowing at a velocity of 15 m s −1. The EVEDA Li test loop (ELTL) is aimed at validating the hydraulic stability of the Li target at a velocity up to 20 m s −1 under a vacuum condition of 10 −3 Pa as the most important issue. Construction of the ELTL, which is the largest liquid metal loop possessing 5.0 m 3 Li for the fusion research ever, was completed in the O-arai Research & Development Center in the Japan Atomic Energy Agency on 22 November 2010. This paper presents the design and fabrication technology of a target assembly called integrated target assembly, in which the Li target is produced by a contraction nozzle along a concave channel. There are two concepts regarding the target assembly: the integrated target assembly and the bayonet target assembly. Both target assemblies are outlined in this paper, and then the newly proposed design of the integrated target assembly for the ELTL and its fabrication technology are given. The integrated target assembly was processed by a five-axis milling machine and the processing accuracy was measured by 3D measurement tools. Finally, methods applied for the validation of the stability of the Li target are introduced in this paper.

Nitrogen Hot Trap Design and Manufactures for Lithium Test Loop in IFMIF/EVEDA Project

“…On the other hand, the solubility of nitrogen and hydrogen in lithium is large even at around the melting point of lithium; therefore, both elements should be removed from the liquid lithium chemically with other traps, which are so called hot traps. The related recent activities of lithium purification studies were reported in the references [8][9][10][11][12][13][14][15][16][17][18], and the content of the lithium test facility of IFMIF have been reported in the references [8,9,[19][20][21][22][23][24][25][26][27].…”

Chemical reaction of lithium with room temperature atmosphere of various humidities

“…As a major Japanese activity for the Lithium Target Facility of the IFMIF, we designed and constructed the EVEDA lithium test loop, which is the largest liquid lithium test loop in the world, and started validating it in 2012 [3,4]. Along with the validation, we have been developing the technology for the safe handling of lithium since 2008.…”

Liquid Li based neutron source for BNCT and science application

“…Quest for more intense neutron source resulted in a combination of Li target and intense deutron or proton beams to avoid destruction of target itself by own generated neutrons. The facility of the internaitional fusion material irradiation facility (IFMIF) is now under development to generate 10 16-17 neutrons per second at 14MeV comtinuously [1,2]. In the early phase of the development, the solid target was abandoned, since the solid target sufferes strongest irradiation damage from own neutrons, and results in destruction before full irradiation on the test specimen is completed.…”