Fast-ion radial diffusivity evaluated from vertical neutral particle measurements following short pulse beam injection into a TFTR ohmic plasma

Abstract

NOTICEThis report was prepared as an accountof work sponsoredby an agency of the United Stat._sGovernment. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibilityfor the accuracy, completeness, or usefulness of any information,apparatus, product,or processdisclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial produce, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarilyconstitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Neutral Particle Measurements and other DiagnosticsTwo vertically-viewing, mass-resolved, charge-exchange neutral Prior to neutral beam injection, the time-= averaged noise ratios, Sn(E), were determined by Sn(E)=F(E,t)/Fn(t) , where F(E,t) was the count rate including noise. During this period, no significant neutral particle flux was detected in the detector channels for energies above 25; keV. Under the assumption that Sn(E) is constant throughout a discharge, , the noise-corrected neutral flux during beam injection was evaluated by Experimental ResultsFnc(E,t) = F(E,t) -Sn(E)Fn(t) and the error was defined as Sn(E)Fn(t)/I Fnc(E,t) I. In