Speaker
Dr
Petr Deichuli
(Budker Institute of Nuclear Physics)
Description
The significant part of any high-power neutral beam injector is the beam absorber, which serves also as a calorimeter. The power neutral beam injector operates in multimegawatt range and the peak-power densities normal to the beam axis can reach few tens kW/cm2, especially for injectors with beam focusing. With these parameters the main problem is the crisis of the heat transfer between the inner wall of the cooling channel and the cooling water, which limit allowable power density at calorimeter surface by the ~5-7 kW/cm2 [1]. The operation at a high power density requires the high water velocity and flow rate. In addition, it means a complicate water-cooling system and calorimeter construction.
In this paper, the calorimeter based on the tubes with narrow annular cooling channels and with spiral flow swirler described. This construction is technologically simple and has a higher heat transfer characteristic at a moderate flow rate and velocity in comparison with the typical design based on twisted tape in a cylindrical cooling channel as a flow swirler.
Simple methods of beam overlap with the location of pipes in one echelon offered. This method allow sufficiently simplify the calorimeter design.
The construction designed and tested in 2008 for 1.7 MW injector. The neutral power flow density at axis was 12-15 kW/cm2. About 2 thousand pulses were made during tests, the systems of 6 power injectors operates with such type calorimeters [2].
1. S.K.Combs, S.L.Milora, C.A.Foster, H.H.Haselton, M.M.Menon, C.C.Tsai. Compact inexpensive target design for steady-state heat removal in high-heat-flux fusion applications. Rev. Sci. Instrum., 56, 1526 (1985).
2. A.Sorokin, V.Belov, V.Davydenko, P.Deichuli, A.Ivanov, A.Podyminogin, I.Shikhovtsev, G.Shulzhenko, N.Stupishin, M.Tiunov. “Characterization of 1 MW, 40 keV, 1 s neutral beam for plasma heating”. Rev. Sci. Instrum. 81, 02B108 (2010)
Primary author
Dr
Petr Deichuli
(Budker Institute of Nuclear Physics)
Co-author
Mr
Vladimir Khrestolubov
(Budker Institute of Nuclear Physics)
