title: A novel multi-channel quadrature Doppler backward scattering reflectometer on the HL-2A tokamak.
abstract: A novel 16-channel fixed frequency Doppler backward scattering (DBS) reflectometer system has been developed on the HL-2A tokamak. This system is based on the filter-based feedback loop microwave source (FFLMS) technique, which has lower phase noise and lower power variation compared with present tunable frequency generation and comb frequency array generation techniques [J. C. Hillesheim et al. Rev. Sci. Instrum. 80, 083507 (2009) and W. A. Peebles et al. Rev. Sci. Instrum. 81, 10D902 (2010)]. The 16-channel DBS system is comprised of four × four-frequency microwave transmitters and direct quadrature demodulation receivers. The working frequencies are 17-24 GHz and 31-38 GHz with the frequency interval of 1 GHz. They are designed to measure the localized intermediate wave-number (k⊥ρ ∼ 1-2, k⊥∼ 2-9 cm-1) density fluctuations and the poloidal rotation velocity profile of turbulence. The details of the system design and laboratory tests are presented. Preliminary results of Doppler spectra measured by the multi-channel DBS reflectometer systems are obtained. The plasma rotation and turbulence distribution during supersonic molecular beam injection are analyzed.
authors.affiliation: Southwestern Institute of Physics, Chengdu 610041, China.
authors.forename: Zhongbing
authors.initials: Z
authors.lastname: Shi
authors.affiliation: Southwestern Institute of Physics, Chengdu 610041, China.
authors.forename: Wulu
authors.initials: W
authors.lastname: Zhong
authors.affiliation: Southwestern Institute of Physics, Chengdu 610041, China.
authors.forename: Min
authors.initials: M
authors.lastname: Jiang
authors.affiliation: Southwestern Institute of Physics, Chengdu 610041, China.
authors.forename: Zengchen
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Southwestern Institute of Physics, Chengdu 610041, China.
authors.forename: Boyu
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Southwestern Institute of Physics, Chengdu 610041, China.
authors.forename: Peiwan
authors.initials: P
authors.lastname: Shi
authors.affiliation: Southwestern Institute of Physics, Chengdu 610041, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.affiliation: Southwestern Institute of Physics, Chengdu 610041, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Wen
authors.affiliation: Southwestern Institute of Physics, Chengdu 610041, China.
authors.forename: Chengyuan
authors.initials: C
authors.lastname: Chen
authors.affiliation: Southwestern Institute of Physics, Chengdu 610041, China.
authors.forename: Bingzhong
authors.initials: B
authors.lastname: Fu
authors.affiliation: Southwestern Institute of Physics, Chengdu 610041, China.
authors.forename: Zetian
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Southwestern Institute of Physics, Chengdu 610041, China.
authors.forename: Xuantong
authors.initials: X
authors.lastname: Ding
authors.affiliation: Southwestern Institute of Physics, Chengdu 610041, China.
authors.forename: Qingwei
authors.initials: Q
authors.lastname: Yang
authors.affiliation: Southwestern Institute of Physics, Chengdu 610041, China.
authors.forename: Xuru
authors.initials: X
authors.lastname: Duan