3rd IAEA Technical Meeting on Fusion Data Processing, Validation and Analysis from 27-31 May 2019 in Vienna, Austria

Spectroscopic and Langmuir probe Diagnostic Analysis of in GLAST-III Spherical

A. Qayyum, F. Deeba, M. U. Naseer, S. Hussain, and GLAST team National Tokamak Fusion Program 3329, Islamabad Outline • Initial Plasma Formation • GLAST-II • GLAST-III (upgrade) • Development of TLP • Plasma Characterization • Langmuir probe • Photodiode array • Ocean spectrometer

• Camera 2 ECR pre-ionization assisted startup (2.45 GHz, I kW) Vacuum Vessel = Pyrex Major radius = 15 cm Minor radius = 9 cm

IP = 5 kA

BT = 0.1 T

Pictorial illustration of GLAST-II

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3rd IAEA Technical Meeting on Fusion Data Processing, Validation and Analysis from 27-31 May 2019 in Vienna, Austria Optimization of compensation coils ECRH assisted plasma current in GLAST-II

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3rd IAEA Technical Meeting on Fusion Data Processing, Validation and Analysis from 27-31 May 2019 in Vienna, Austria Development and subsequent decay of plasma discharge

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3rd IAEA Technical Meeting on Fusion Data Processing, Validation and Analysis from 27-31 May 2019 in Vienna, Austria Langmuir probes •Triple probe

(b) Plasma

P2 P1 P3

g

e

n

i

b

t

o

a

r

o l

p I F

- + + - Vd2 Vd3 (fixed)

Oscilloscope Oscilloscope

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3rd IAEA Technical Meeting on Fusion Data Processing, Validation and Analysis from 27-31 May 2019 in Vienna, Austria ECR pre-ionization assisted startup (2.45 GHz, I kW) Vacuum vessel = Pyrex Major radius = 20 cm Minor radius = 10 cm IP = 5 kA BT = 0.2 T Available Diagnostics: Langmuir probe HR4000 Spectrometer Photodiodes (OPTODIODES) PMT array

A photographic image of GLAST-III with PD array and TLP system 7 3rd IAEA Technical Meeting on Fusion Data Processing, Validation and Analysis from 27-31 May 2019 in Vienna, Austria

GLAST-III, ECRH pre-ionization (MW+TF)

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0 -3 a a, 8x10 mbar 12 -3 b b, 6x10 mbar -3 e c, 4x10 mbar c 10 -3 -1 d d, 2x10 mbar -4 e, 9x10 mbar d 8 e

c

[eV]

[V]

e T

-2 6 floating

V -3 a, 8x10 mbar b 4 -3 b, 6x10 mbar -3 a -3 c, 4x10 mbar 2 -3 d, 2x10 mbar -4 e, 9x10 mbar 0

1 2 3 4 5 6 7 8 -4 t [ms] 1 2 3 4 5 6 7 8 t [ms] Plasma current formation (MW+TF+OH)

40 10 20 -4 2x10 mbar 0 9 -3 35 2 x 10 mbar Photodiode 16 8

30 -2 7 12

6 25 8

5 [V]

-4 [V] 20 4

4 Loop

[kA]

p

floating V

I 3 V

15 -6 0

2 Light emission (arb.u) emission Light 1 10 Floating probe -4 -8 0

5 -1 -8

-2 0 -10 -12 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 1.0 1.5 2.0 2.5 3.0 3.5 4.08 t[ms] t[ms) Effect of vertical field ECR pre-ionization assisted 9 10 11 12 Development of Plasma Diagnostics NATIONAL TOKAMAK FUSION PROGRAM Year 2011-13 2014-16 2016-18 2018-to date

Electrostatic Triple Probe Emissive Probe Fast Sweep Probe Rake Probe Probes

Development i) Probe head i) Emissive filament i) Cylindrical probe tip i) Multi-tip probe head ii) Biasing circuit ii) Resistive heating ii) Sweeping voltage ii) Biasing circuit ii) Measuring circuit circuit source iii) Measuring circuit ii) Measuring circuit ii) Measuring circuit

Achievement i) Floating potential Direct measurement i) Time-resolved (I-V) Radial profiles of ii) Electron temperature of plasma potential characteristics i) Floating potential iii) Electron density ii) Electron ii) Electron temperature Publication Temperature iii) Electron density Publications Plasma iii) Electron density Time-resolved Measurement of Plasma Measurements in Data has been recorded during ECR Parameters by Means of Triple Probe Pulse Discharge Publication assisted pre-ionization discharge in Rev. Sci. Instrum. 84 (2013) with Resistively A sweep Langmuir Probe metallic vessel Triple-probe diagnostic measurements Heated Emissive System for Temporal and analysis is in progress to in plasma of GLAST Spherical Tokamak Probe Measurements in Time- determine electron temperature Journal of Fusion Energy 35 (2016) 205 High Temperature, varying Plasmas and electron density for different 54 (2016) 905 Physics of Plasmas radial positions (submitted)

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3rd IAEA Technical Meeting on Fusion Data Processing, Validation and Analysis from 27-31 May 2019 in Vienna, Austria Development of Plasma Diagnostics

Year 2011-14 2014-16 2016-18 2018-to date

Emission USB 4000 Spectrometer HR2000+ Spectrometer HR 2000+ Spectrometer H-alpha Spectroscopy Spectroscopy BPX Photodiode BPX photodiode Photodiode array H-beta Spectroscopy (OPTODIODE )

Development i) Line of sight i) Positioning of optical fibers i) 8-channel line of sight i) Narrow band filters adjustment system ii) Mounting of photodiodes optical system ii) Photodiodes ii) Data acquisition system ii) Signal acquisition iii) PMT array

Achievement i) Discharge quality in Optimization of i) Movement of ECR layer Temporal profiles of GLAST-II pre-ionization and current ii) Plasma fluctuations i) H-beta ii) Identification of formation phases in GLAST-III iii) Stark broadening of H- ii) H-alpha Impurities in the alpha iii) Electron temperature by Line- discharge Publication ratio method Electrical and Optical Publication Publications Measurements in the Early A photodiode array and Data has been recorded during Initial Plasma Formation Discharge of GLAST- Langmuir probe for optimization of ECR assisted pre- in the GLAST-II Spherical III characterizing plasma in ionization discharge and analysis is Tokamak Plasma Sci. Technol. 19 (2017) GLAST-III tokamak device in progress to determine electron Journal of Fusion Energy 085103 Measurement, 125 (2018) temperature using line-ratio method 35 (2016) 529-537 56-62

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3rd IAEA Technical Meeting on Fusion Data Processing, Validation and Analysis from 27-31 May 2019 in Vienna, Austria 15 thanks

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