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UKAEA-CCFE-PR(21)692021
The ASCOT orbit-following code has been equipped with a model for simulating charge exchange (CX) of fast ions with background atoms in magnetically confined fusion plasmas. The model was successfully verified by comparing simulated reaction mean free paths to analytical values across a range of fusion-relevant parameters. ASCOT was used to simulat…
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UKAEA-CCFE-PR(21)212021
In this work, we use reduced and perturbative models to examine the stability of TAEs during the ITB afterglow in JET experiments designed for the observation of alpha driven TAEs. We demonstrate that in JET-like conditions, it is sufficient to use an incompressible cold plasma model for the TAE to reproduce the experimental adiabatic features…
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UKAEA-CCFE-CP(23)112020
Dimensionless experiments test the invariance of plasma physics to changes in the dimensional plasma parameters, when the canonical dimensionless parameters are conserved [1], [2]. Isotope identity experiments exploit the change in isotope ion mass A = mi/mp to obtain plasmas with identical dimensionless profiles in the same tokamak. However, condi…
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UKAEA-CCFE-CP(20)712020
The fast-ion transport has been investigated in low-collisionality discharges at ASDEX Upgrade and TCV using offaxis neutral beams. In both devices Alfven eigenmode activity was observed which does, however, not strongly affect the global fast-ion confinement. In contrast, charge exchange losses have been identified to have a strong effect. At TCV …
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UKAEA-CCFE-PR(20)1142020
Achieving high neutron yields in today’s fusion research relies on high power auxiliary heating in order to attain required core temperatures. This is usually achieved by means of high Neutral Beam (NB) and Radio Frequency (RF) power. Application of NB power is accompanied by production of fast beam ions and associated Beam-Target (BT) reactio…
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UKAEA-CCFE-PR(20)932020
Parametric dependencies of the linear stability of toroidal Alfven eigenmode (TAE) in the presence of neutral beam injection (NBI) are investigated to understand the beam drive and damping effect of TAEs in JET and KSTAR. It is found that the results depend on the drift orbit width of the beam-ions normalized to the characteristic mode widths. I…
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UKAEA-CCFE-PR(20)192019
A study of mixed hydrogen-deuterium H-mode plasmas has been carried out in JET-ILW to strengthen the physics basis for extrapolations to JET D-T operation and to support the development of strategies for isotope ratio control in future experiments. Variations of input power, gas fuelling and isotopic mixture were performed in H-mode plasmas of the…
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UKAEA-CCFE-PR(20)1242018
NBI-heated L-mode plasmas have been obtained in JET with the Be/W ITER-like wall (JET-ILW) in H and D, with matched profiles of the dimensionless plasma parameters in the plasma core confinement region and same Ti/Te and Zeff. The achieved isotope identity indicates that the confinement scale invariance principle is satisfied in the core confine…
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UKAEA-CCFE-CP(20)922018
Dimensionless identity experiments test the invariance of plasma physics to changes in the dimensional plasma parameters, e.g. ne and Te, when the dimensionless parameters are conserved [1] [2]. However, conditions at the plasma boundary, such as influx of neutral particles, may introduce additional physics. An isotope identit…
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UKAEA-CCFE-PR(20)082019
The initial current ramp phase of JET hybrid plasmas is used to optimise the target q-profile for main heating to allow access to high beta and avoid MHD instabilities. Mixed protium-deuterium experiments, carried out at JET since the installation of the beryllium-tungsten wall, have shown that the q-profile evolution during this Ohmic phase varies…
Showing 31 - 40 of 61 UKAEA Paper Results