Charles Karney: Publication 79/85, Takenaga(2001)

H. Takenaga, A. Sakasai, H. Kubo, N. Asakura, M. J. Schaffer, T. W. Petrie, M. A. Mahdavi, D. R. Baker, S. L. Allen, G. D. Porter, T. D. Rognlien, M. E. Rensink, D. P. Stotler, and C. F. F. Karney.
Study of particle pumping characteristics for different pumping geometries in JT-60U and DIII-D divertors.
Nucl. Fusion, 41(12):1777–1787, December 2001.
Reprint: nf01
DOI: 10.1088/0029-5515/41/12/305
BibTeX Entry

Particle pumping characteristics were compared between pumping from the inner side private flux region (IPP) and pumping from both sides of the private flux region (BPP) in the JT-60U W shaped divertor, and between JT-60U IPP and pumping in the DIII-D lower baffled divertor. The pumping flux for BPP is smaller than that for IPP by about a factor of 2 with weak in-out asymmetry of recycling neutral flux and by a factor of 3.5–6.5 with strong in-out asymmetry. The reduction of the pumping flux for BPP is consistent with Monte Carlo simulations, where backflow at the outer pumping slot is observed due to in-out recycling asymmetry. The pumping flux in DIII-D at I_p = 0.8 MA and B_T = 1.6 T is comparable to or smaller than that for JT-60U IPP at I_p = 1.0 MA, B_T = 3.8 T and I_p = 1.5 MA, B_T = 3.5 T in the same density regime. In the DIII-D divertor with pumping from the private flux region, the pumping flux decreases with increasing in-out asymmetry. The pumping flux normalized by the integrated D_α emission over the whole plasma exhibits a similar dependence on the distance between the pumping slot and the strike point in JT-60U IPP and the DIII-D lower divertor with pumping through the outer divertor plasma region.