Analysis and experiment of the hypervapotron mock-up for the EAST upgrade
During the EAST upgrade, the peak heat flux applied on the first wall components will be 2 MW/m2, which requires powerful cooling concept to decrease the component temperature, in order to simplify the material requirement and armor/heat sink module design. Hypervapotron is a promising method for high heat transfer coefficient, which bases on sub cooling boiling phenomenon, and has the potential to support the demand in several years (up to 20 MW/m2 with strong armor), and is chosen to be a candidate. The design contains a copper heat sink and uses water as coolant, a series of CFD analyses are performed to optimize the design, and a mock-up based on this optimization is assembled on a high heat flux test facility which employs electromagnetic induction heating and high speed photography; during the experiment under the required working conditions, the flowing status and thermal parameters are recorded. The analysis and experiment confirm the performance of the hypervapotron concept and the feasibility of the use in the EAST upgrade project.
High heat flux removal from a single-side heated monoblock using flow boiling
Abstract The robust design of one-side-heated plasma-facing components and other high heat flux components is dependent on knowing the local distribution of inside wall heat flux in the flow channels. The local inside wall heat flux can be obtained from selectively chosen local plasma-facing component wall temperatures close to the inside boundary of the flow channel. To this end, three-dimensional thermal measurements for a one-side-heated monoblock were made and show: (1) the three-dimensional variation of the wall temperature close to both the heated and fluid/solid surface boundaries, (2) the resultant effects of mass velocity on the three-dimensional wall temperature/outside heat flux relationship, and (3) the occurrence of local critical heat flux and local post-critical heat flux. The monoblock has a 180.0 mm heated length, has a 10.0 mm inside diameter, and has a square cross-section with 30.0 mm nominal outside surfaces.
5.63 and 5.80 MeV levels of Ne20; de-excitation branching
Abstract The ratio Г γ /Г for the 5.63 and 5.80 MeV levels of Ne 20 has been determined to be 0.077 (±0.008) and −4 , respectively, by using the C 12 (C 12 , α)Ne 20 reaction and determining the fraction of the events in which the alpha-particle and the Ne 20 recoil are present in coincidence at the kinematically correct angles. In both cases these results in themselves are shown to imply radiative E1 transition (5.63→1.63 and 5.80→0, respectively) probabilities ⪡5 × 10 −5 Weisskopf units. When taken together with the life-time for the 5.63 MeV level measured by Evans et al . values of Г( E1 ) ≲ 5 × 10 −6 and Г α ≈ 6% of the particle estimate are obtained for this state.