Experimental investigation of the confinement of d(³He,p)αand d(d,p)t fusion reaction products in JET

Abstract

In ITER, magnetic fusion will explore the burning plasma regime. Because such burning plasma is sustained by its own fusion reactions, alpha particles need to be confined (Hazeltine 2010 Fusion Eng. Des. 7–9 85). New experiments using d(3He,p)α and d(d,p)t fusion reaction products were performed in JET. Fusion product loss was measured from MHD-quiescent plasmas with a charged particle activation probe installed at a position opposite to the magnetic field ion gradient drift (see figure )—1.77 m above mid-plane—in the ceiling of JET tokamak. This new kind of escaping ion detector (Bonheure et al 2008 Fusion Sci. Technol. 53 806) provides for absolutely calibrated measurements. Both the mechanism and the magnitude of the loss are dealt with by this research. Careful analysis shows measured loss is in quantitative agreement with predictions from the classical orbit loss model. However, the comparison with simulated loss radial profile, although improved compared with previous studies in TFTR, Princeton, US (Zweben et al 2000 Nucl. Fusion 40 91), is not fully satisfactory and potential explanations for this discrepancy are examined.

First fusion proton measurements in TEXTOR plasmas using activation technique

“…1) was placed at a more suitable poloidal position in TEXTOR than in JET. 12,13 The total number of emitted 2.45 MeV D-D neutrons inferred from the induced activation product in tantalum foils is (1) and (2) have similar cross sections, this yields (7.8 ± 0.4) × 10 9 for the calculated number of protons which agrees within uncertainty with the above measured value of (8.6 ± 1.0) × 10 9 .…”

“…This number is ∼6 times larger compared to previous measurements obtained in JET. 12,13 While in JET only a small fraction of fusion products is first orbit lost, in these TEXTOR plasma (B t = 1.9T, I p = 300 kA) experiments, all the DD 3 MeV protons are first orbit lost. Furthermore, the ion detector (see in Fig.…”

On a class of nonlinear Schrödinger–Poisson systems involving a nonradial charge density

“…E. Sufficient conditions for point concentration. Following a personal communication of Denis Bonheure [13] setting…”

Adjoint Monte Carlo simulation of fusion product activation probe experiment in ASDEX Upgrade tokamak

“…The presented numerical analysis provides, for the first time, absolutely calibrated flux of fusion products to the probe. This is an improvement compared to the previous analysis [5] performed on JET measurements, that only provided relative profiles of the flux as a function of major radius and thus required external calibration. Furthermore, the analysis was performed for an alternative probe geometry, as suggested by a previous study [8].…”

“…The fusion product flux at the midplane manipulator in ASDEX Upgrade (AUG) was measured for the first time [4] using an activation probe [5]. This contribution presents numerical analysis of these experiments using the ASCOT code [6].…”