NIFS-117

FULL TEXT (PDF, 715 KB)


Author(s):

K. Itoh, H. Sanuki and S. -I. Itoh

Title:

Fast Ion Loss and Radial Electric Field in Wendelstein VII-L Stellarator

Date of publication:

Oct. 1991

Key words:

Stellarator, Fast lon Loss, Loss cone, Radial Electric Field, Charge Exchange Loss, Neoclassical Transport, Wendelstein VII-A

Abstract:

Theoretical model is developed to determine the radial electric field and the fast ion loss simultaneously in stellarators, and is applied to the Wendelstein VII-A stellarator. The predicted value of the radial electric field is more closer to experiments than the purely neoclassical calculation. The loss rate, which is determined simultaneously, is in the range of experimental observations. The partition of the injection energy by the bulk heating, direct orbit loss and shine through is estimated by using the self consistent electric field profile. The orbit loss become noticeable as the injection energy increases. The influence of the neutral particles is also studied . Neutral particles enhances the negative radial electric field, and reduces the direct orbit loss by the expense of the charge exchange loss. The impact of the increased radial electric field on the neoclassical ion thermal energy loss is compared to the direct loss of fast ions. The reduction of the neoclassical loss is much smaller than the orbit loss.

List of NIFS Report (1991)Return toContents Page Return toNIFS Homepage
footer
 National Institute for Fusion Science
Copyright: 1995-2007 National Institute for Fusion Science (NIFS)
Address: 322-6,Oroshi-cho, Toki, GIFU, 509-5292, Japan
Telephone:+81-572-58-2222