TY - CONF

T1 - Performance measurements of the collective Thomson scattering receiver at ASDEX Upgrade

A1 - Furtula,Vedran

A1 - Leipold,Frank

A1 - Salewski,Mirko

A1 - Michelsen,Poul

A1 - Korsholm,Søren Bang

A1 - Meo,Fernando

A1 - Moseev,Dmitry

A1 - Nielsen,Stefan Kragh

A1 - Stejner Pedersen,Morten

A1 - Johansen,Tom Keinicke

AU - Furtula,Vedran

AU - Leipold,Frank

AU - Salewski,Mirko

AU - Michelsen,Poul

AU - Korsholm,Søren Bang

AU - Meo,Fernando

AU - Moseev,Dmitry

AU - Nielsen,Stefan Kragh

AU - Stejner Pedersen,Morten

AU - Johansen,Tom Keinicke

PB - Institute of Physics Publishing

PY - 2012

Y1 - 2012

N2 - The fast-ion collective Thomson scattering (CTS) receiver at ASDEX Upgrade can detect spectral power densities of a few eV in the millimeter-wave range against the electron cyclotron emission (ECE) background on the order of 100 eV under presence of gyrotron stray radiation that is several orders of magnitude stronger than the signal to be detected. The receiver heterodynes the frequencies of scattered radiation (100–110 GHz) to intermediate frequencies (IF) (4.5–14.5 GHz). The IF signal is divided into 50 IF channels tightly spaced in frequency space which are terminated by square-law Schottky detector diodes. The performance of the entire receiver is determined by the main receiver components operating at mm-wave frequencies (notch-, bandpass- and lowpass filters, a voltage-controlled variable attenuator, and an isolator), a mixer, and the IF components (amplifiers, band-pass filters, and detector diodes). We discuss here the design of the entire receiver, focussing on its performance as a unit. The receiver has been disassembled, and the performance of its individual components has been characterized. Based on these individual component measurements we predict the spectral response of the receiver assembled as a unit. The measured spectral response of the assembled receiver is in reasonable agreement with this prediction.

AB - The fast-ion collective Thomson scattering (CTS) receiver at ASDEX Upgrade can detect spectral power densities of a few eV in the millimeter-wave range against the electron cyclotron emission (ECE) background on the order of 100 eV under presence of gyrotron stray radiation that is several orders of magnitude stronger than the signal to be detected. The receiver heterodynes the frequencies of scattered radiation (100–110 GHz) to intermediate frequencies (IF) (4.5–14.5 GHz). The IF signal is divided into 50 IF channels tightly spaced in frequency space which are terminated by square-law Schottky detector diodes. The performance of the entire receiver is determined by the main receiver components operating at mm-wave frequencies (notch-, bandpass- and lowpass filters, a voltage-controlled variable attenuator, and an isolator), a mixer, and the IF components (amplifiers, band-pass filters, and detector diodes). We discuss here the design of the entire receiver, focussing on its performance as a unit. The receiver has been disassembled, and the performance of its individual components has been characterized. Based on these individual component measurements we predict the spectral response of the receiver assembled as a unit. The measured spectral response of the assembled receiver is in reasonable agreement with this prediction.

KW - Plasma diagnostics - interferometry, spectroscopy and imaging

KW - Nuclear instruments and methods for hot plasma diagnostics

KW - Microwave radiometers

U2 - 10.1088/1748-0221/7/02/C02039

DO - 10.1088/1748-0221/7/02/C02039

JO - Journal of Instrumentation

JF - Journal of Instrumentation

SN - 1748-0221

IS - 02

VL - 7

SP - C02039

ER -