Overview of physics results from the ADITYA-U tokamak and future experiments
R.L. Tanna, Joydeep Ghosh, K.A. Jadeja, Rohit Kumar, Suman Aich, Kiran Patel, Harshita Raj, Kaushlender Singh, Suman Dolui, Kajal Shah, Sharvil Patel, Nandini Yadava, Tanmay Macwan, Abha Kanik, Ankit Kumar, Bharat Hegde, Ashok Kumar Kumawat, A. Kundu, Ramesh Joshi, Deepti Sharma, Ankit R. Patel, Lagnajeet Pradhan, Kalpesh Galodiya, Shwetang N. Pandya, Soumitra Banerjee, SK Injamul Hoque, Komal, M.B. Chowdhuri, R. Manchanda, N. Ramaiya, R. Dey, Gopal Shukla, Dipti A. Modi, Vishal Sharma, Aman Gauttam, M.N. Makwana, Kunal Shah, Shubham Gupta, Supriya A. Nair, Shishir Purohit, Umesh Nagora, Asha Adhiya, Kiran Patel, Kumudni Asudani, Sameer Jha, Devilal Kumawat, Santosh P. Pandya, S. Varsha, Praveenlal Edappala, B. Arambhadiya, Minsha Shah, Pramila Gautam, Vismay Raulji, P. K. Shukla, Abhijeet Kumar, Mitesh Patel, Rachana Rajpal, M. Bhandarkar, Imran Mansuri, K. Mahajan, K. Mishra, Sunil Kumar, B.K. Shukla, Jagabandhu Kumar, P. K. Sharma, Snehlata Aggarwal, Kumar Ajay, Manoj Kumar Gupta, S. K. Pathak, P. K. Chattopadhyay, D. Raju, Srimonti Dutta, S. Pahari, N. Bisai, Chetna C. Chauhan, Y. C. Saxena, Abhijit Sen, R. Pal, Shashank Chaturvedi
Abstract
Abstract The ADITYA upgrade (ADITYA-U), a medium-sized <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mrow> <mml:mo>(</mml:mo> <mml:mrow> <mml:mrow> <mml:msub> <mml:mi>R</mml:mi> <mml:mn>0</mml:mn> </mml:msub> </mml:mrow> <mml:mo>=</mml:mo> <mml:mn>75</mml:mn> <mml:mrow> <mml:mtext> cm</mml:mtext> </mml:mrow> <mml:mo>,</mml:mo> <mml:mstyle scriptlevel="0"/> <mml:mstyle scriptlevel="0"/> <mml:mi>a</mml:mi> <mml:mo>=</mml:mo> <mml:mn>25</mml:mn> <mml:mrow> <mml:mtext> cm</mml:mtext> </mml:mrow> </mml:mrow> <mml:mo>)</mml:mo> </mml:mrow> </mml:mrow> </mml:math> 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 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mrow> <mml:msub> <mml:mi>D</mml:mi> <mml:mn>2</mml:mn> </mml:msub> </mml:mrow> </mml:mrow> </mml:math> 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.