27 August 2017 to 1 September 2017
RAI Congress Center, Amsterdam, The Netherlands
Europe/Amsterdam timezone

Role of electrostatic charges in the calculation and measurement of AC losses in superconducting coils.

29 Aug 2017, 16:15
15m
G102-103 Room

G102-103 Room

Regular 15 minutes Oral Presentation G4 - Losses in Conductors and Coils Tue-Af-Or18

Speaker

Dr Fedor Gömöry (Slovak Academy of Sciences)

Description

Dissipation of energy in a superconducting coil generating magnetic field that varies in time could be evaluated locally as the product of electrical field and current density. The effect of electric field exerting force and accelerating the electric charge carriers that transport the current is commonly incorporated into AC loss calculation by inserting a realistic current-voltage dependence e.g. in form of a power law. A direct experimental confirmation of this computation approach would require the placement of a suitable sensor inside the conductor forming the coil winding. Therefore such approach to AC loss analysis is ruled out for real superconducting coils. On the other hand one can measure the total voltage appearing at the coil winding. We prove that this voltage is in fact the electrostatic field produced by the electric charges accumulated at the conductor non-uniformities like the coil terminations. Practical aspects of this approach are demonstrated analysing a series of thought experiments on objects with increasing complexity.

Submitters Country Slovakia

Primary author

Dr Fedor Gömöry (Slovak Academy of Sciences)

Presentation Materials