PFPO plasma scenarios for exploration of long pulse operation in ITER

Long Pulse Scenarios (LPSs) in ITER at Pre-Fusion Power Operation (PFPO), foreseen in the ITER Research Plan (IRP) [1], are assessed using 1.5D transport simulations within the ASTRA framework [2]. Such assessment is required to predict the operational space for LPS operation in PFPO, as well as to estimate which physics processes for LPS operation at Fusion Power Operation (FPO) could be validated at PFPO. An important issue is to minimize lifetime consumption of the Central Solenoid (CS). The maximum pulse length achievable in PFPO with no consumption of CS lifetime (ICS ≤ 30 kA) has been assessed for different heating schemes and confinement regimes in He and hydrogen plasmas (figure 1b). The operational space of LPS is explored through density scans (figures 2, 4) to determine the operational space with H&CD mix suggested for steady state phase of ITER operation [3] with acceptable NBI and ECH shine through loss (with the ECH calculated by OGRAY code [4]). Similarity of LPS PFPO and low density operation is studied including the MHD stability analysis with KINX [5] and TAE stability with high-n kinetic ballooning code HINST [6].