Electron and ion heating characteristics during magnetic reconnection in MAST

Electron and ion heating characteristics during magnetic reconnection in MAST

Electron and ion heating characteristics during magnetic reconnection in MAST 150 150 Mathew

Electron and ion heating characteristics during merging reconnection startup on the MAST spherical tokamak have been revealed in detail using 130 channel YAG- and 300 channel Ruby-Thomson scattering system and a new 32 chord ion Doppler tomography diagnostic. Detailed 2D profile measurements of electron and ion temperature together with electron density have been achieved for the first time and it is found that electron temperature forms a highly localized hot spot at the X point and ion temperature globally increases downstream. For the push merging experiment when the guide field is more than three times the reconnecting field, a thick layer of closed flux surface formed by reconnected field sustains the temperature profile for longer than electron and ion energy relaxation time 4??10ms, both characteristic profiles finally forming a triple peak structure at the X point and downstream. An increase in the toroidal guide field results in a more peaked electron temperature profile at the X-point, and also produces higher ion temperatures at this point, but the ion temperature profile in the downstream region is unaffected.

Collection:
Journals
Journal:
Physical Review Letters
Publisher:
APS
Published date:
11/01/2015