PPT Slide

Is there a Penalty in Backing Off 10% from Full Beta Limit ?

• All CD efficiencies have been evaluated for equilibria at full beta limit.

• At 90% beta limit, _ 0.9 x _N,limit ( Ip / a Bo ), one anticipates a drop

in BS fraction, which may lead to higher CD power and lower _B.

• To assess this possible penalty, multiply p(_) by 0.9, adjust profiles to obtain

maximum BS alignment, calculate CD power and compare with 100% p(_) case.

• Results for one design point are:

_N,limit = 6.0, = 16 keV, Zeff = 2.0, Ip = 19 MA, Bo = 8 T

_N/_N,limit To/ Ibs/Ip Pic (MW) PLH (MW) _B

1.0 1.764 0.944 7.5 59.6 5.80

0.9 1.632 0.905 20.4 66.4 4.02

• Backing off from _-limit by 10% results in 30% reduction in _B for this point,

and a higher proportion of ICRF power for on-axis CD.

There is a penalty in the form of higher CD power.

Previous slide

Next slide

Back to first slide

View graphic version