Conference Papers

Showing 11 - 20 of 23 Conference Paper Results
2018
UKAEA-CCFE-CP(20)92
45th European Physical Society Conference on Plasma Physics (EPS), Prague, 2-6 July 2018

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…

Preprint Published
2018
UKAEA-CCFE-CP(20)81
30th Symposium on Fusion Technology (SOFT), Giardini Naxos, Messina, Sicily, 16-21 September 2018

The Alfvén Eigenmode Active Diagnostic system (AEAD) has undergone a major upgrade and redesign to provide a state of the art excitation and real-time detection system for JET. The new system consists of individual 4kW amplifiers for each of the six antennas, allowing for increased current, separate excitation and real time control of relative …

Preprint Published
2019
UKAEA-CCFE-CP(19)48
46th European Physical Society Conference on Plasma Physics (EPS), Milan, 8-12 July 2019

An understanding of the plasma edge and divertor is essential for predicting the performance of next-step machines such as ITER. Transport codes used to study the divertor behaviour [1] employ atomic physics data in two applications. The first is to predict the power radiated by the fuel and impurity atoms, which is carried out as a post-processing…

Preprint Published
2019
UKAEA-CCFE-CP(19)43
46th European Physical Society Conference on Plasma Physics (EPS), Milan, 8-12 July 2019

The resonant detection and measurement of the damping rates of Alfvén Eigenmodes (AEs) is of critical importance to the design of experiments and development of models of AE stability [1]. With the Alfvén Eigenmodes Active Diagnostic (AEAD) on JET, weakly-damped Toroidal AEs (TAEs) have been probed. Theoretical modeling using the Gyrokinetic Toro…

Preprint Published
2019
UKAEA-CCFE-CP(19)41
46th European Physical Society Conference on Plasma Physics (EPS), Milan, 8-12 July 2019

An n = 1 locked, or slowly rotating, mode has been observed in most pulses prior to JET disruptions. However, a small fraction of non-disruptive pulses has a locked mode which eventually vanishes without disruption. Hence, on JET the locked mode amplitude is routinely used as an indicator of unhealthy plasma. There are two threshold levels…

Preprint Published
2019
UKAEA-CCFE-CP(19)35
46th European Physical Society Conference on Plasma Physics (EPS), Milan, 8-12 July 2019

In high-performance, ITER baseline-scenario pulses (3MA/2.7T) in JET-ILW with high levels (~ 32 MW) of heating power, typically ~ 20-40% of the input power is radiated, predominantly by W impurities, which are sputtered from the divertor targets and reach the confined plasma. Sustained ELMy H-mode operation at such high heating power in JET-ILW req…

Preprint Published
2019
UKAEA-CCFE-CP(19)33
46th European Physical Society Conference on Plasma Physics (EPS), Milan, 8-12 July 2019

The initial Ohmic current ramp phase of JET hybrid plasmas, including a current ‘overshoot’ before the main heating, is used to optimise the q-profile shape to allow access to high β and avoid MHD instabilities [1]. Such hybrid plasmas have never been operated using tritium (T) or mixed deuterium-tritium (D-T) fuel. However, experiments with i…

Preprint Published
2019
UKAEA-CCFE-CP(19)20
23rd International Conference on Plasma Surface Interactions in Controlled Fusion Devices (PSI), Princeton, NJ, USA, 17-22 June 2018

Reducing the plasma power exhaust impacting on plasma facing components during steady state operation is one of the major design issues in future tokamaks such as ITER. Impurity seeding, e.g. with N, is one method of achieving this and has been used for a long time in tokamak research [1]. In this work we exploit a recently developed spectroscopic …

Preprint Published
2019
UKAEA-CCFE-CP(19)13
45th European Physical Society Conference on Plasma Physics (EPS), Prague, 2-6 July 2018

Empirically-based power-balance calculations of the inter-ELM separatrix loss power are presented for JET pulses with both the carbon- (JET-C) and ITER-like (JET-ILW) walls, to facilitate comparisons with results of on-going, non-linear gyro-kinetic calculations of pedestal heat transport, e.g. as reported in [1]. These might be able to explain the…

Preprint