Status of activities on the lithium target in the key element technology phase in IFMIF

Nakamura, Hiroo; Burgazzi, L.*; Cevolani, S.*; Dell'Ocro, G.*; Fazio, C.*; Giusti, D.*; Horiike, Hiroshi*; Ida, Mizuho*; Kakui, Hideo*; Loginov, N.*; Matsui, Hideki*; Muroga, Takeo*; Nakamura, Hideo  ; Riccardi, B.*; Takeuchi, Hiroshi; Tanaka, Satoru*

This paper describes the latest design of the IFMIF liquid Li target system reflecting the KEP results. Future prospects will be also summarized. To handle an averaged heat flux of 1 GW/m2 under a continuous 10 MW D beam deposition, a high-speed Li flow of 20 m/s, a double reducer nozzle and a concaved flow are applied to the target design. Hydraulic characteristics of the Li target design have been validated in a water jet experiment. To obtain a control scenario of the Li loop in an accident of the D beam trip, a transient analysis has been done. To control tritium and impurities in Li, a cold trap and two kinds of hot trap are adopted in Li purification loop. To maintain reliable continuous operation, various diagnostics are attached to the target assembly. To exchange the target assembly and back wall, a remote handling system with a multi axis arm and welding/cutting tool are designed. As an option, design of a replaceable back wall with a mechanical seal is being in progress. In a next phase of IFMIF beyond 2004, a Li test loop will be constructed for engineering validation.