Beam-Ion Profile Diagnostic Using 3 MeV Protons
Abstract
Calculations based on classical beam-ion confinement often overestimate the measured pressure profile and neutron rate, particularly in DIII-D Advanced Tokamak plasmas with beam-driven Alfvén activity. In these discharges with plasma currents of ~1 MA, a significant fraction of the charged d-d fusion reaction products are unconfined, affording the opportunity to infer the d-d reaction profile from measurements of 3-MeV protons that are lost on their first orbit. In contrast to earlier studies,(W.W. Heidbrink and J.D. Strachan, Rev. Sci. Instrum. 56) (1985) 501. the advent of accurate poloidal field reconstructions based on Motional Stark Effect measurements simplifies the design requirements for a useful diagnostic. Sensitivity studies and a preliminary design are presented.
- Publication:
-
APS Division of Plasma Physics Meeting Abstracts
- Pub Date:
- October 2001
- Bibcode:
- 2001APS..DPPRP1028C