| Title: |
High beta experiments on JET in preparation of JT60SA |
| Authors: |
F P Orsitto; L Garzotti; G Pucella; S Gabriellini; F Auriemma; M Baruzzo; A Burckhart; J Bernardo; C Challis; R Dumont; N Hawkes; D Keeling; D King; J Mailloux; A Patel; C Piron; C Sozzi; V. K. Zotta; L Senni |
| Contributors: |
P Orsitto, F; Garzotti, L; Pucella, G; Gabriellini, S; Auriemma, F; Baruzzo, M; Burckhart, A; Bernardo, J; Challis, C; Dumont, R; Hawkes, N; Keeling, D; King, D; Mailloux, J; Patel, A; Piron, C; Sozzi, C; Zotta, V. K.; Senni, L |
| Publisher Information: |
European Physical Society |
| Publication Year: |
2024 |
| Collection: |
Sapienza Università di Roma: CINECA IRIS |
| Subject Terms: |
Nuclear fusion; magnetic confinement; tokamak; JT60SA; JET |
| Description: |
High beta discharges with dimensionless parameters collisionality (ν*) and normalized Larmor radius (ρ*), and also normalized beta (βN) relatively close to the JT-60SA scenarios hybrid and advanced were realized on JET. In particular the JET poloidal Larmor radius ρP*=0.036 and bootstrap fraction fBS=0.6 were close to JT60-SA values. So the discharges realized on JET are expected having similar confinement properties as in JT60SA[1]. Since the maximum normalized beta βNMAX≈ A-1/2, is dependent on the aspect ratio A, the equilibrium properties at high beta on JET (A=3.2) would be similar as in JT-60SA(A=2.7). Strategy of the experiments was to explore high normalized beta (βN) values, MHD effects at different BT ( Toroidal Magnetic field on axis) and find an optimal set of parameters for discharges with mild MHD. Deuterium plasmas were realized in a variant of the hybrid-advanced scenario at BT = 1.7, 2, 2.4 T, Ip = 1.4 MA, elongation k = 1.6, and high triangularity δ ≈ 0.4, q95=4-6, and central safety factor q0>1.2 at NBI ( Neutral Beam Injection) start, with NBI power PNBI = 16-25 MW, no ICRH ( Ion Cyclotron Resonant Heating). Shots at BT=2.4T were realized in third Deuterium-Tritium (DTE3) campaign. The deuterium dataset is new: the pulses at BT=1.7/Ip=1.4MA have the same characteristics of 2014 Hybrid power scan at high δ[2], but there is an extension in the range of NBI power to PNBI =25MW. While pulses at BT=2.4T are executed at higher q95 (q95>5) with respect to the yr 2014 advanced pulses[3]. Two scans were carried out : i) a NBI power scan, affecting 50th EPS Conference on Contr. Fusion and Plasma Phys, 8-12 July 2024 F. P. Orsitto et al. : P1.051 (2024) 2 βN and ii) a NBI start time scan, affecting the central safety factor q0 at the time of NBI onset, which is a key ingredient for MHD stability of the high beta phase. Main results of the experiments are: i) Good confinement properties and relatively high βN values; the normalized beta achievable increases with input power, βN≈3.7-4 for ... |
| Document Type: |
conference object |
| Language: |
English |
| Relation: |
ispartofbook:50th EPS Conference on Plasma Physics Salamanca, 8th - 12th July 2024; 50thEPS Conference on Controlled Fusion and Plasma Physics; volume:48A; firstpage:1; lastpage:4; numberofpages:4; https://hdl.handle.net/11573/1719890 |
| Availability: |
https://hdl.handle.net/11573/1719890 |
| Rights: |
info:eu-repo/semantics/openAccess |
| Accession Number: |
edsbas.40307F53 |
| Database: |
BASE |