Overview of physics results from the ADITYA-U tokamak and future experiments
Authors: Tanna R.L. , Ghosh J. , Jadeja K.A. , Kumar Rohit , Aich Suman , Patel K.M. , Raj Harshita , Singh Kaushlender , Dolui Suman , Shah Kajal , Patel S. , Yadava Nandini , Macwan Tanmay , Kanik A. , Kumar Ankit , Hegde Bharat , Kumawat Ashok , Kundu A. , Joshi R. , Sharma Deepti , Patel Ankit , Pradhan L. , Galodiya K. , Pandya Shwetang , Banerjee Soumitra , Hoque Sk Injamul , Komal  , Chowdhuri M.B. , Manchanda R. , Ramaiya N. , Dey Ritu , Shukla G. , Modi D. , Sharma Vishal , Gauttam Aman , Makwana M.N. , Shah Kunal , Gupta S. , Nair Supriya , Purohit S. , Nagora U.C. , Adhiya A. , Patel Kiran , Asudani Kumudni , Jha S.K. , Kumawat D. , Pandya Santosh , S. Varsha , Edappala Praveenlal , Arambhadiya B. , Shah Minsha , Gautam Pramila , Raulji V. , Shukla Praveena , Kumar Abhijeet , Patel Mitesh , Rajpal R. , Bhandarkar M. , Mansuri Imran , Mahajan Kirti , Mishra K. , Kumar Sunil , Shukla B.K. , Kumar Jagabandhu , Sharma P.K. , Aggarwal Snehlata , Ajay Kumar , Gupta M.K. , Pathak S.K. , Chattopadhyay P.K. , Raju D. , Dutta S. , Pahari S. , Bisai N. , Chauhan Chetna , Saxena Y.C. , Sen A. , Pal R. , Chaturvedi S. 
Published: April 2024

Abstract
The ADITYA upgrade (ADITYA-U), a medium-sized

(

R
0

=
75

cm

,

a
=
25

cm

)

conventional tokamak facility in India, has been consistently producing experiments findings by using circular and shaped-plasmas. Recognizing the plasma parameters aligning closely with the design parameters of circular limited plasmas, ADITYA-U shifted its focus toward exploring the operational regime for experimentation on saw-tooth and MHD phenomena. Moreover, ADITYA-U has made consistent advancements toward conducting preliminary plasma shaping experiments through the activation of top and bottom divertor coils utilizing hydrogen as well as deuterium fuels. Confinement is improved by a factor of ∼1.5 in

D
2

plasmas when compared to H
2 plasmas of ADITYA-U. Further, ADITYA-U operations emphasize preventing disruptions and runaway electrons (REs) to ensure safe operations for future fusion devices. Significant suppression of REs has been achieved in ADITYA-U with the application of pulsed localized vertical magnetic field (LVF) perturbation, thereby establishing the technique’s independence from the tokamak device. The successful RE mitigation requires a critical threshold of LVF pulse magnitude, which is approximately 1% of the toroidal magnetic field, and a minimum duration of ∼5 ms. Apart from this, several novel findings have been achieved in the ADITYA-U experiments, including the modification of sawtooth duration through gas-puff, the emergence of MHD-induced geodesic acoustic mode-like oscillations, the propagation of fast heat pulses induced by MHD activity, the control of RE dynamics through Gas-puffs, the propagation of pinch-driven cold-pulses, the transport and core accumulations of argon impurities, the mass dependency of plasma toroidal rotation and the detection of ‘RICE’ scaling, as well as the characterization of edge plasma using wall conditioning methods, such as glow discharge cleaning using a combination of Ar-H
2 mixture, localized wall cleaning by electron cyclotron resonant plasma, and the development of machine learning-based disruption predictions, will be discussed in this paper.