Numerical study on pressure wave propagation in a mercury loop

Kogawa, Hiroyuki  ; Hasegawa, Shoichi   ; Futakawa, Masatoshi  ; Riemer, B.*; Wendel, M.*; Haines, J.*

In beam test was carried out at the LANSCE-WNR to investigate pressure wave mitigation in mercury targets for the MW-class spallation neutron sources under international collaboration between SNS and JSNS. A mercury loop with micro bubble generator was used for the target. The loop target consists of the rectangular pipe which was made of stainless steel. The total length of the loop is about 2 m. Strain sensors were set on many points of loop to measure the strain on the pipe wall caused by the pressure wave. The maximum strain at 350 mm apart from the proton bombarded point appeared after 5.5 ms after the proton bombardment. The wave propagation velocity was slower than the stress wave and the pressure wave propagation velocities and became 65 m/s in the IBBTL. Numerical analysis result shows that the maximum strain at 350 mm apart from the proton bombarded point appeared at 5.5 ms after proton bombardment as well as the experimental due to interaction between liquid and solid.