An examination of the Neutral Penetration Model1/ne,pedscaling for its validity of spatially varying neutral sources

• DOI: 10.1016/j.nme.2021.101037
• Publication Date: 2021-07-06T15:40:04Z
• Authors: J. Simpson; D. Moulton; C. Giroud; F. Casson; M. Groth; A. Chankin; L. Horvath; D.S. Gahle; L. Garzotti; G. Corrigan; F. Kochl
• Keywords: Pedestal

The core transport code, JETTO, coupled to the neutral Monte Carlo EIRENE, has been used examine sensitivity of JET H-mode pedestal flux crossing separatrix. Neutral Penetration Model (NPM) [Groebner et. al., Physics Plasmas 9, 2134 (2002)] predicts width density along path scale with inverse its height: 1/ne,ped. By keeping same physics assumptions in NPM, and setting deuterium atoms cross separatrix at location as synthetic diagnostic line sight (i.e. outer mid-plane, OMP), we were able reproduce this scaling JETTO-EIRENE. However, when set X-point (more consistent EDGE2D-EIRENE simulations H-modes), OMP was found be much more sensitive height (approximately proportional 1/ne,ped2). This is attributed a radial variation poloidal expansion from X-point, over range ionisation mean free lengths explored scan. Accounting for allowed expected recovered. Implications are discussed experimental comparisons NPM application prediction models.