Measurements of confined alphas and tritons in the MHD quiescent core of TFTR plasmas using the pellet charge exchange diagnostic

Technical Report · Wed May 01 04:00:00 EDT 1996

DOI:https://doi.org/10.2172/238594· OSTI ID:238594

Medley, S S; Budny, R V; Mansfield, D K ^[1]

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1. and others

The energy distributions and radial density profiles of the fast confined trapped alpha particles in DT experiments on TFTR are being measured in the energy range 0.5--3.5 MeV using a Pellet Charge eXchange (PCX) diagnostic. A brief description of the measurement technique which involves active neutral particle analysis using the ablation cloud surrounding an injected impurity pellet as the neutralizer is presented. This paper focuses on alpha and triton measurements in the core of MHD quiescent TFTR discharges where the expected classical slowing down and pitch angle scattering effects are not complicated by stochastic ripple diffusion and sawtooth activity. In particular, the first measurement of the alpha slowing down distribution up to the birth energy, obtained using boron pellet injection, is presented. The measurements are compared with predictions using either the TRANSP Monte-Carlo code and/or a Fokker-Planck Post-TRANSP processor code, which assumes that the alphas and tritons are well confined and slow down classically. Both the shape of the measured alpha and triton energy distributions and their density ratios are in good agreement with the code calculations. The authors conclude that the PCX measurements are consistent with classical thermalization of the fusion-generated alphas and tritons.

• Research Organization: Princeton Univ., NJ (United States). Plasma Physics Lab.; General Atomics, San Diego, CA (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC02-76CH03073; FG03-92ER54150
• OSTI ID: 238594
• Report Number(s): PPPL--3175; ON: DE96010508
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ALPHA PARTICLES
CHARGE EXCHANGE
COMPARATIVE EVALUATIONS
CONFINEMENT
ENERGY SPECTRA
EXPERIMENTAL DATA
ION DENSITY
PELLET INJECTION
PLASMA DIAGNOSTICS
SLOWING-DOWN
TFTR TOKAMAK
TRITONS