DIII-D RESEARCH OPPORTUNITIES FORUM FOR THE 2013 EXPERIMENTAL CAMPAIGN Review | Direct submission with log-in | Request submission without log-in
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Title	110: Electron Heat Transport in E-Dominated Heating of ITER-like H-Mode Discharges with Modulated ECH
Name:	Stephanie Diem sjdiem@wisc.edu	Affiliation:	University of Wisconsin
Research Area:	Turbulence & Transport	Presentation time:	Requested
Co-Author(s):	P.M. Ryan, M. Murakami, J.M. Park, J.C. Hosea, R.J. Perkins, G. Taylor	ITPA Joint Experiment :	No
Description:	This experiment will modulate the ECH power to study the heating deposition and electron transport in ITER relevant discharges on DIII-D. EC modulation at frequency ~5 Hz has been chosen to study the CD efficiency and q0 evolution using break-in-slope and Fourier transform analyses. This frequency was chosen to avoid characteristic ELM and sawtooth frequencies (7-10 Hz).	ITER IO Urgent Research Task :	No
Experimental Approach/Plan:	All discharges should be run with no beta feedback on NBI power so that the NBI power remains constant. Run plan: 1. Begin with Q-H mode target discharge 150840 (dominant electron heating discharge). Density should be lower than the baseline discharge so that 2nd harmonic ECE is not cut off. The beams should be balanced to minimize the applied torque. 2. Apply modulated radial launch EC heating at a rate of 5 Hz. 3. Increase density to that of original discharge, 150840 and then repeat the modulated radial launch EC heating at rate of 5 Hz. This will require 3rd harmonic ECE monitoring of Te. 4. Reduce counter and increase co-current NBI to increase torque/plasma rotation and run modulated EC heating at 5 Hz for low-density conditions of [1]. 5. Repeat 5 with high-density conditions of [4]. 6. Choose the conditions of [1]-[6] that demonstrate the best heating and increases in stored energy. Replace the radial ECH injection with equivalent amount of tangentially injected counter-ECCD and repeat modulation experiments to evaluate the change in q0.
Background:	The direct electron heating comparison made between FW and ECW in 2012 showed that both techniques had difficulty in consistently and efficiently heating the core plasma for the ITER Baseline Scenario. Understanding the EC power deposition and electron heat transport is important both to evaluate a proposed ITER operation scenario that uses net counter-ECCD to control q0, and to improve our ongoing analysis of FW heating of IBS plasmas. The target discharge proposed in this experiment is close to the target discharges in ROF proposals 118 and 257. Combining these proposals would simply require repeating several discharges during the shot development and scans in proposals 118 and 257 while adding ECH and ECCD modulation.
Resource Requirements:	Machine time: 2 days of machine time Number of gyrotrons: 6 Number of neutral beam sources: 2, plus beam blips for MSE
Diagnostic Requirements:	ECE, 3HECE, CHERS, MSE, UCLA reflectometor, ORNL reflectometor
Analysis Requirements:	TRANSP, CURRAY
Other Requirements:	Also submitted to Inductive Scenarios - please discuss placement with that group