HT-7 Soft x-ray PHA diagnostics in the HT-7 and the EAST Z.Y.Chen, Y.J.Shi,B.Lv,B.N.Wan, L.Q.Hu, S.Y.Lin Q.S.Hu, S.X.Liu, Institute of Plasma Physics,Chinese Academy of Sciences P.O.Box 1126, Hefei,Anhui, P.R.China ASIPP

HT-7 2 Content Aims of PHA and qualifications of its detector Virtues of Silicon Drift Detector (SDD) Layout of PHA in the HT-7 Preliminary experimental results PHA diagnostics for EAST Summary

HT-7 3 PHA diagnostic aims in the HT-7 Te profile with high spatial resolution High time resolution of Te Investigating the concentration of heavy impurities  1. Compact assembly Spatial multi-channel configuration  2. High input count rate Considerable time resolution  3. High energy resolution Impurities concentration measurement Qualifications of soft x-ray PHA detector Qualifications of detector

HT-7 4 Virtues of SDD detector for PHA High count rate count rate up to 200kHZ (0.5  sec shaping time) High energy resolution FWHM<160eV -10 ºC) High quantum efficiency suitable for soft X-ray detecting in range of 1~20keV Integrated FET lower noise, high SNR, no microphony Compact setup work at -10 ~ -20 ºC, cooled by peltier element SDD very suitable spatial multi-channel PHA setup in tokamaks active surface: 5mm² 280µm thick Silicon crystal with 8  m Be foil in the entrance

HT-7 5 High detecting efficiency with 8  m Be foil in the energy range of 1~20keV Performance of SDD Calibration spectra of SDD The energy resolution is about (0.5  sec shaping time, -10 ºC )

HT-7 6 Layout of SDD_PHA in HT-7 tokamak Vertical 15-channel (V-PHA) Measuring range: + 21 cm Spatial resolution : 3 cm Horizontal 6 channels (H-PHA) Measuring range: 0~+24 cm Spatial resolution : 4.8 cm

HT-7 7 SDD for PHA in HT-7  Isolated SDD With preamplifier, shaper, and peltier cooler in a housing Five preamplifiers were not operational in last experiment, now they work.  15-channel SDD linear array

HT-7 8 Arrangement of vertical SDD_PHA Interchangeable Be foils for each sight line Interchangeable pinholes and Be foils in the focus

HT-7 9 Vertical PHA Setup Horizontal PHA Setup Unfortunately, the SDD measured 24cm was not operational in last experiment

HT-7 10 Experimental Results from H-PHA(1) Ip=120 kA n e0 =1.43 × m -3 Central Te with 100ms time resolution X-ray spectra obtained along five chords With horizontal PHA (350~450ms) Te profile of ohmic discharge, it is close to the parabola form of : 0.91 × (1-(r/a) 2 ) 2.3 Waveforms of OH discharge

HT-7 11 Experimental Results from H-PHA(2) Ip=120kA n e0 =1.35 × m -3 LHW~400kW (0.1 s to 5 s ) IBW~200kW(0.2 s to 5.1 s ) Central Te with 250ms time resolution Waveforms of high performance long-pulse discharge Te increased considerably in half plasma minor radius during wave heated phase Profile was much flat in central region and had a large gradient at 0.52a, showing an ITB-like structure Profile at 2.75s in wave heated long pulse discharge by 250ms collecting time

HT-7 12 Experimental Results from V-PHA Waveforms of LHCD discharge Ip=154kA n e0 =1.1 × m -3 LHW: ~275kW The concentration of iron in core plasma range is about 0.08% The blue curve is OH phase, the red curve is wave heated phase X-ray spectra from V-PHA 200ms collecting time

HT-7 13 PHA diagnostics for EAST Arrangement of PHA in the EAST Vertical 15-channel PHA for full section measurement Horizontal 6-channel PHA for upper half section measurement Spatial resolution: 6cm Time resolution: <100ms

HT-7 14 Summary 1. The use of SDD has allowed the design of compact spatial multi-channel soft x-ray PHA 2. The level of count rate improved the time resolution in Te measurement 3. The high energy resolution is suitable for investigating heavy impurities 4. The experimental results from SDD_PHA are satisfying 5. Further study on the metallic impurities by SDD_PHA is the next target

HT-7 15 Thank you

HT-7 16 Appendix The redesign of horizontal PHA sketch map: pinholes Be foils Arrangement of detector Gate valve