Core-ion temperature measurement of the ADITYA tokamak using passive charge exchange neutral particle energy analyzer
- Institute for Plasma Research, Bhat, Gandhinagar 382 428, Gujarat (India)
Core-ion temperature measurements have been carried out by the energy analysis of passive charge exchange (CX) neutrals escaping out of the ADITYA tokamak plasma (minor radius, a= 25 cm and major radius, R= 75 cm) using a 45 Degree-Sign parallel plate electrostatic energy analyzer. The neutral particle analyzer (NPA) uses a gas cell configuration for re-ionizing the CX-neutrals and channel electron multipliers (CEMs) as detectors. Energy calibration of the NPA has been carried out using ion-source and {Delta}E/E of high-energy channel has been found to be {approx}10%. Low signal to noise ratio (SNR) due to VUV reflections on the CEMs was identified during the operation of the NPA with ADITYA plasma discharges. This problem was rectified by upgrading the system by incorporating the additional components and arrangements to suppress VUV radiations and improve its VUV rejection capabilities. The noise rejection capability of the NPA was experimentally confirmed using a standard UV-source and also during the plasma discharges to get an adequate SNR (>30) at the energy channels. Core-ion temperature T{sub i}(0) during flattop of the plasma current has been measured to be up to 150 eV during ohmically heated plasma discharges which is nearly 40% of the average core-electron temperature (typically T{sub e}(0) {approx} 400 eV). The present paper describes the principle of tokamak ion temperature measurement, NPA's design, development, and calibration along with the modifications carried out for minimizing the interference of plasma radiations in the CX-spectrum. Performance of the NPA during plasma discharges and experimental results on the measurement of ion-temperature have also been reported here.
- OSTI ID:
- 22105405
- Journal Information:
- Review of Scientific Instruments, Vol. 84, Issue 2; Other Information: (c) 2013 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
- Country of Publication:
- United States
- Language:
- English
Similar Records
Measurement of spatial and temporal behavior of H{sub α} emission from Aditya tokamak using a diagnostic based on a photomultiplier tube array
Investigation of atomic and molecular processes in Hα emission through modelling of measured Hα emissivity profile using DEGAS2 in the ADITYA tokamak
Related Subjects
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
ADITYA TOKAMAK
CHARGE EXCHANGE
ELECTRON MULTIPLIERS
ELECTRON TEMPERATURE
ENERGY ANALYSIS
EV RANGE
FAR ULTRAVIOLET RADIATION
ION TEMPERATURE
NEUTRAL PARTICLE ANALYZERS
NEUTRAL PARTICLES
PLASMA
PLASMA DIAGNOSTICS
SIGNAL-TO-NOISE RATIO
TEMPERATURE MEASUREMENT