title: Design of a correlation electron cyclotron emission diagnostic for Alcator C-Mod.
abstract: A correlation electron cyclotron emission (CECE) diagnostic has been installed in Alcator C-Mod. In order to measure electron temperature fluctuations, this diagnostic uses a spectral decorrelation technique. Constraints obtained with nonlinear gyrokinetic simulations guided the design of the optical system and receiver. The CECE diagnostic is designed to measure temperature fluctuations which have k(θ) ≤ 4.8 cm(-1) (k(θ)ρ(s) < 0.5) using a well-focused beam pattern. Because the CECE diagnostic is a dedicated turbulence diagnostic, the optical system is also flexible, which allows for various collimating lenses and antenna to be used. The system overview and the demonstration of its operability as designed are presented in this paper.
authors.affiliation: Plasma Science and Fusion Center, MIT, Cambridge, Massachusetts 02139, USA. sck83@mit.edu
authors.forename: C
authors.initials: C
authors.lastname: Sung
authors.forename: A E
authors.initials: AE
authors.lastname: White
authors.forename: J H
authors.initials: JH
authors.lastname: Irby
authors.forename: R
authors.initials: R
authors.lastname: Leccacorvi
authors.forename: R
authors.initials: R
authors.lastname: Vieira
authors.forename: C Y
authors.initials: CY
authors.lastname: Oi
authors.forename: W A
authors.initials: WA
authors.lastname: Peebles
authors.forename: X
authors.initials: X
authors.lastname: Nguyen