Investigating the occurrence and predictability of pitch angle scattering events at ADITYA-Upgrade tokamak with the electron cyclotron emission radiometer  

作　　者：Varsha SIJU Santosh P.PANDYA S.K.PATHAK Ansh PATEL Umesh NAGORA Shishir PUROHIT Sameer JHA M.K.GUPTA K.TAHILIANI R.KUMAR R.L.TANNA J.GHOSH 

机构地区：[1]Institute for Plasma Research,Gandhinagar 382428,India [2]Homi Bhabha National Institute(HBNI),Anushaktinagar,Mumbai 400094,India [3]Eindhoven University of Technology,Eindhoven 5600 AZ,Netherlands [4]Institute of Science,Nirma University,Gujarat 382481,India

出　　处：《Plasma Science and Technology》2024年第11期45-57,共13页等离子体科学和技术（英文版）

摘　　要：This paper describes the experimental analysis and preliminary investigation of the predictability of pitch angle scattering(PAS) events through the electron cyclotron emission(ECE)radiometer signals at the ADITYA-Upgrade(ADITYA-U) tokamak. For low-density discharges at ADITYA-U, a sudden abnormal rise is observed in the ECE signature while other plasma parameters are unchanged. Investigations are done to understand this abrupt rise that is expected to occur due to PAS. The rise time is as fast as 100 μs with a single step and/or multiple step rise in ECE radiometer measurements. This event is known to limit the on-axis energy of runaway electrons. Being a repetitive event, the conditions of its repetitive occurrence can be investigated, thereby exploring the possibility of it being triggered and surveyed as an alternate runaway electron mitigation plan. Functional parameterization of such events with other discharge parameters is obtained and the possibility to trigger these events is discussed.PREDICT code is used to investigate the possible interpretations for the PAS occurrence through modeling and supporting the ECE observations. The trigger values so obtained experimentally are set as input criteria for PAS occurrence. Preliminary modeling investigations provide reliable consistency with the findings.

关 键 词：pitch angle scattering anomalous Doppler resonance electron cyclotron emission radiometer diagnostic runaway electrons wave-particle interaction 

分 类 号：TL631.24[核科学技术—核技术及应用]