H-MODE POWER THRESHOLD DATABASE FOR ITER

The ITER Threshold Database, which at present comprises data from nine divertor tokamaks, is described. The main results are presented and d iscussed. The properties and dependences of the power threshold in ind ividual devices are reviewed. In particular, the analysis shows a rath er general linear dependence on magnetic field, but a non-monotonic de nsity dependence that varies from device to device. Investigation of t he combined database suggests that the threshold dependence P-thres ap proximate to 0.3<(n)over barB(T)R(2.5) shows reasonable agreement with the data. This expression yields P-thres approximate to 150 MW at a d ensity of 0.3 x 10(20) m(-3) for ITER. Other expressions with weaker s ize dependence. and therefore lower threshold power for ITER, are also discussed. Their agreement with the present data is poorer than that of the above expression. In addition, the database is investigated by statistical discriminant analysis. The edge data included at present a re described and discussed. Finally, there is a discussion of the impl ications of the results for ITER.