{"title":"The optimal values of Greenwald density limit and plasma safety factor in inductive and non-inductive operation modes","authors":"F Sharifi, S M Motevalli, F Fadaei","doi":"10.1007/s12043-024-02751-0","DOIUrl":null,"url":null,"abstract":"<div><p>The spherical tokamak (ST) operates in a steady state with a high fusion gain. The 0-dimensional power balance model, including radiation losses to determine <i>Q</i> value as an inductive fusion gain, and the current balance model for determining <span>\\(Q_{\\textrm{CD}}\\)</span> as a non-inductive fusion gain, is used to investigate the viability of D–<span>\\(^{3}\\)</span>He fuel for a steady-state operation. The spherical tokamak’s geometry, including the magnetic field <span>\\(B_{t}\\)</span> and <span>\\(\\beta _{\\textrm{th}}\\)</span> as a ratio of its kinetic pressure to the magnetic pressure, is used to analyse the impact of the confinement enhancement factor <span>\\(H_{y2}\\)</span> and the impurity density fraction <span>\\(f_{\\textrm{I}}\\)</span> on <span>\\(Q_{\\textrm{CD}}\\)</span>. By comparing the obtained values with the device data, plasma characteristics, such as the safety factor <span>\\(q_{\\textrm{I}}\\)</span> and Greenwald density limit <span>\\(N_{\\textrm{G}}\\)</span> are examined to determine the optimum density limit and safety factor for an assurance about <span>\\(Q\\approx Q_{\\textrm{CD}}\\)</span> as the aim of steady-state operation. A comparison with ARIES-III performance is also made. The overall plant power balance equation is included. Furthermore, the desirable plant thermal efficiency value <span>\\(\\eta _{\\textrm{th}}\\)</span> and normalised beta value <span>\\(\\beta _{N}\\)</span> for producing net electric power <span>\\(P_{\\textrm{NET}}>\\)</span> 1 GW for the ST are achieved. Therefore, ST’s capability of having a lower aspect ratio <i>A</i> and higher elongation <span>\\(\\kappa _{s}\\)</span> than ARIES-III in generating more significant fusion power with lower <span>\\(H_{y2}\\)</span> and higher energy confinement time <span>\\(\\tau _{E}\\)</span> is approved.</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"98 2","pages":""},"PeriodicalIF":1.9000,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Pramana","FirstCategoryId":"4","ListUrlMain":"https://link.springer.com/article/10.1007/s12043-024-02751-0","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"PHYSICS, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
The spherical tokamak (ST) operates in a steady state with a high fusion gain. The 0-dimensional power balance model, including radiation losses to determine Q value as an inductive fusion gain, and the current balance model for determining \(Q_{\textrm{CD}}\) as a non-inductive fusion gain, is used to investigate the viability of D–\(^{3}\)He fuel for a steady-state operation. The spherical tokamak’s geometry, including the magnetic field \(B_{t}\) and \(\beta _{\textrm{th}}\) as a ratio of its kinetic pressure to the magnetic pressure, is used to analyse the impact of the confinement enhancement factor \(H_{y2}\) and the impurity density fraction \(f_{\textrm{I}}\) on \(Q_{\textrm{CD}}\). By comparing the obtained values with the device data, plasma characteristics, such as the safety factor \(q_{\textrm{I}}\) and Greenwald density limit \(N_{\textrm{G}}\) are examined to determine the optimum density limit and safety factor for an assurance about \(Q\approx Q_{\textrm{CD}}\) as the aim of steady-state operation. A comparison with ARIES-III performance is also made. The overall plant power balance equation is included. Furthermore, the desirable plant thermal efficiency value \(\eta _{\textrm{th}}\) and normalised beta value \(\beta _{N}\) for producing net electric power \(P_{\textrm{NET}}>\) 1 GW for the ST are achieved. Therefore, ST’s capability of having a lower aspect ratio A and higher elongation \(\kappa _{s}\) than ARIES-III in generating more significant fusion power with lower \(H_{y2}\) and higher energy confinement time \(\tau _{E}\) is approved.
期刊介绍:
Pramana - Journal of Physics is a monthly research journal in English published by the Indian Academy of Sciences in collaboration with Indian National Science Academy and Indian Physics Association. The journal publishes refereed papers covering current research in Physics, both original contributions - research papers, brief reports or rapid communications - and invited reviews. Pramana also publishes special issues devoted to advances in specific areas of Physics and proceedings of select high quality conferences.