Study on free-surface flow of liquid Lithium, 1; Measurement of characteristics of surface oscillation using probe

Okita, Takafumi*; Suzuki, Sachiko*; Hoashi, Eiji*; Sugiura, Hirokazu*; Kanemura, Takuji; Kondo, Hiroo; Yamaoka, Nobuo*; Horiike, Hiroshi*

In the International Fusion Materials Irradiation Facility (IFMIF), a stable lithium (Li) target is required to maintain the integrity of the Li target itself and guarantee the desired neutron flux level. In this study, amplitudes of the free-surface waves were measured in an Osaka University Li loop with a contact-type liquid level sensor, and based on the measurement results, heat deposition rate from the deuteron beam to the flow channel (back wall) was calculated. Measurement results showed that at 175 mm downstream from the nozzle exit, maximum amplitudes at the velocity of more than 9 m/s were approximately 2 mm, which is larger than the IFMIF design specification value of 1 mm. However occurrence frequency of such large-amplitude waves were very low. Based on the amplitude measurement data, heat deposition rate from the deuteron beam to the flow channel was calculated to be less than 200 W in the simple model.